Monitoring on vector-borne virus lays foundation for control of vector-borne disease, and a scientific and highly-efficient surveil ance method is of great signifi-cance for prevention and control ing of vector-borne ...Monitoring on vector-borne virus lays foundation for control of vector-borne disease, and a scientific and highly-efficient surveil ance method is of great signifi-cance for prevention and control ing of vector-borne diseases. The research sum-marized mosquito and mosquito-borne disease monitoring methods and proposed problems in the monitoring system, as wel as introducing new monitoring methods at home and abroad, providing references for improvements of integrated surveil-lance of mosquito or mosquito-borne viruses.展开更多
Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainsta...Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainstay of effective control.But,indiscriminate and rampant use of the chemical insecticides in controlling mosquito vectors,in order to prevent diseases vectored by them,has resulted problems related to the adverse environmental effects for their(insecticides)potential toxicity,high operational cost,community acceptance,and the development of insecticide resistance among the vectors.The factors mentioned above prompted the search for new means of control strategies.Currently,the botanicals(viz.,plant extracts,essential oils and phytochemicals)with mosquitocidal potential展开更多
Objective: To evaluate the ovicidal, larvicidal and adulticidal potential of neem cake fractions of different polarity against the rural malaria vector Anopheles culicifacies(An.culicifacies).Methods: Neem cake fracti...Objective: To evaluate the ovicidal, larvicidal and adulticidal potential of neem cake fractions of different polarity against the rural malaria vector Anopheles culicifacies(An.culicifacies).Methods: Neem cake fractions' total methanol extract(NTMeOH), total ethyl acetate extract(NTAc OEt), ethyl acetate fraction after repartition with NTMe OH(NRAc OEt),butanol fraction after repartition with NTMeOH(NRBuOH), and aqueous fraction after repartition of NTMeOH(NRH2O) were tested against An. culicifacies eggs, fourth instar larvae and adults.Results: In larvicidal experiments, NTMeOH, NTAcOEt, NRAcOEt, NRBuOH and NRH2O achieved LC50 values of 1.32, 1.50, 1.81, 1.95 and 2.54 mg/L, respectively. All fractions tested at 150 mg/L were able to reduce egg hatchability of more than 50%, with the exception of NTAc OEt and NRAc OEt. In adulticidal assays, NTMeOH, NTAcOEt,NRAcOEt, NRBuOH and NRH2O achieved LC50 values of 3.01, 2.95, 3.23, 3.63 and3.00 mg/L, respectively.Conclusions: Overall, this study suggests that the methanolic fractions of neem cake may be considered as a new and cheap source of highly effective compounds against the rural malaria vector An. culicifacies.展开更多
Mosquito-borne diseases(MBDs),like malaria and mosquito-borne viruses(MBVs),have caused the deaths of millions of people.Their threat resides in the variety of transmission modes that they possess,along with the wide ...Mosquito-borne diseases(MBDs),like malaria and mosquito-borne viruses(MBVs),have caused the deaths of millions of people.Their threat resides in the variety of transmission modes that they possess,along with the wide selection of favorable hosts,such as humans,cattle,and rodents.MBDs are increasingly gaining a reputation as one of the most dangerous threats to public health in recent years.Mosquito numbers have been increasing in recent years as a result of multiple factors such as climate change and deforestation.This situation highlights the urgent need for actions to mitigate mosquito and MBD pathogen distributions.In the Middle East,many outbreaks of MBDs have been reported in the region.However,there are no reports of any endemic episodes of MBDs.The Middle East has faced many challenges over the years;however,the Syrian refugee crisis may be strongly related to the spread of infectious diseases.As mass gatherings and high-density populations are common features in the region,it is possible to understand why MBDs can spread easily.This review summarizes the state of MBDs in the Middle East,highlighting the different types of MBDs that have been reported in the region and discussing how to move forward with controlling their spread and limiting the risks they pose.According to the data reported by the electronic State Parties Self-Assessment Annual Reporting Tool(e-SPAR),the capacity to anticipate MBVs varies among Middle East countries.Therefore,the Middle East is on the frontline in the challenge to control a potential public health crisis.Consequently,the countries of the Middle East should be encouraged to improve their health and research capacities to mitigate the threat posed by MBDs.展开更多
Mosquito-borne viruses(MBVs)are a large class of viruses transmitted mainly through mosquito bites,including dengue virus,Zika virus,Japanese encephalitis virus,West Nile virus,and chikungunya virus,which pose a major...Mosquito-borne viruses(MBVs)are a large class of viruses transmitted mainly through mosquito bites,including dengue virus,Zika virus,Japanese encephalitis virus,West Nile virus,and chikungunya virus,which pose a major threat to the health of people around the world.With global warming and extended human activities,the incidence of many MBVs has increased significantly.Mosquito saliva contains a variety of bioactive protein components.These not only enable blood feeding but also play a crucial role in regulating local infection at the bite site and the remote dissemination of MBVs as well as in remodeling the innate and adaptive immune responses of host vertebrates.Here,we review the physiological functions of mosquito salivary proteins(MSPs)in detail,the influence and the underlying mechanism of MSPs on the transmission of MBVs,and the current progress and issues that urgently need to be addressed in the research and development of MSP-based MBV transmission blocking vaccines.展开更多
Mosquito-borne diseases present a significant threat to human health,with the possibility of outbreaks of new mosquito-borne diseases always looming.Unfortunately,current measures to combat these diseases such as vacc...Mosquito-borne diseases present a significant threat to human health,with the possibility of outbreaks of new mosquito-borne diseases always looming.Unfortunately,current measures to combat these diseases such as vaccines and drugs are often either unavailable or ineffective.However,recent studies on microbiomes may reveal promising strategies to fight these diseases.In this review,we examine recent advances in our understanding of the effects of both the mosquito and vertebrate microbiomes on mosquito-borne diseases.We argue that the mosquito microbiome can have direct and indirect impacts on the transmission of these diseases,with mosquito symbiotic microorganisms,particularly Wolbachia bacteria,showing potential for controlling mosquito-borne diseases.Moreover,the skin microbiome of vertebrates plays a significant role in mosquito preferences,while the gut microbiome has an impact on the progression of mosquito-borne diseases in humans.As researchers continue to explore the role of microbiomes in mosquito-borne diseases,we highlight some promising future directions for this field.Ultimately,a better understanding of the interplay between mosquitoes,their hosts,pathogens,and the microbiomes of mosquitoes and hosts may hold the key to preventing and controlling mosquito-borne diseases.展开更多
Dear Editor,The genus Orbivirus,within the family Reoviridae,includes 22 virus species(King et al.,2011).They are distributed globally,but are particularly prevalent in Europe,Asia,and Africa.In addition,they can be t...Dear Editor,The genus Orbivirus,within the family Reoviridae,includes 22 virus species(King et al.,2011).They are distributed globally,but are particularly prevalent in Europe,Asia,and Africa.In addition,they can be transmitted by ticks or other hematophagous insect vectors,including Culicoides,mosquitoes,and sandflies(Belaga-展开更多
Background:Mosquito-based arbovirus surveillance can serve as an early warning in evaluating the status of mosquito-borne virus prevalence and thus prevent local outbreaks.Although Tengchong County in Yunnan Province-...Background:Mosquito-based arbovirus surveillance can serve as an early warning in evaluating the status of mosquito-borne virus prevalence and thus prevent local outbreaks.Although Tengchong County in Yunnan Province-which borders Myanmar-is abundant and diverse in mosquitoes,very few mosquito-based arbovirus investigations have been conducted in the recent decade.Herein,this study aims to evaluate the presence and the diffusion of mosquito-borne pathogens,currently prevalent in this region.展开更多
Most of the vector-borne diseases show a clear dependence on seasonal variation,including climate change.In this paper,we proposed a nonautonomous mathematical model consisting of a periodic system of nonlinear differ...Most of the vector-borne diseases show a clear dependence on seasonal variation,including climate change.In this paper,we proposed a nonautonomous mathematical model consisting of a periodic system of nonlinear differential equations.In the proposed model,the realistic functional forms for the different temperature-dependent parameters are considered.The autonomous system of the proposed model is also analyzed.The nontrivial solution of the autonomous model is locally asymptotically stable if R0<1.It is shown that a unique endemic equilibrium point of the autonomous model exists when R0>1 and proved that endemic solution is linearly stable when R0>1.The nonautonomous model is shown to have a nontrivial disease-free periodic state,which is globally asymptotically stable whenever temperature-dependent reproduction number is less than unity.It is observed that a unique positive endemic periodic solution of the nonautonomous system exists only when a temperature-dependent reproduction number greater than unity,which makes for the persistence of the disease.Numerical simulation has been carried out to support the analytical results and shows the effects of temperature variability in the life span of mosquitoes as well as the persistence of the disease.展开更多
BACKGROUND:The Chikungunya(CHIK)virus was recently reported by the CDC to have spread to the United States.We report an early documented case of CHIK from the state of Pennsylvania after a patient recently returned fr...BACKGROUND:The Chikungunya(CHIK)virus was recently reported by the CDC to have spread to the United States.We report an early documented case of CHIK from the state of Pennsylvania after a patient recently returned from Haiti in June of 2014.METHODS:A 39-year-old man presented to the emergency department complaining of fever,fatigue,polyarthralgias and a diffuse rash for two days.Four days before,he returned from a mission trip to Haiti and reported that four of his accompanying friends had also become ill.A CHIK antibody titer was obtained and it was found to be positive.During his hospital stay,he responded well to supportive care,including anti-inflammatories,intravenous hydration and anti-emetics.RESULTS:His condition improved within two days and he was ultimately discharged home.CONCLUSIONS:Manifestations of CHIK can be similar to Dengue fever,which is transmitted by the same species of mosquito,and occasionally as a co-infection.Clinicians should include Chikungunya virus in their differential diagnosis of patients who present with fever,polyarthralgia and rash with a recent history of travel to endemic areas,including those within the United States.展开更多
Infectious diseases caused by arboviruses are a public health concern in Pakistan.However,studies on data prevalence and threats posed by arboviruses are limited.This study investigated the seroprevalence of arbovirus...Infectious diseases caused by arboviruses are a public health concern in Pakistan.However,studies on data prevalence and threats posed by arboviruses are limited.This study investigated the seroprevalence of arboviruses in a healthy population in Pakistan,including severe fever with thrombocytopenia syndrome virus(SFTSV),Crimean-Congo hemorrhagic fever virus(CCHFV),Tamdy virus(TAMV),and Karshi virus(KSIV)based on a newly established luciferase immunoprecipitation system(LIPS)assays,and Zika virus(ZIKV)by enzyme-linked immunosorbent assays(ELISA).Neutralizing activities against these arboviruses were further examined from the antibody positive samples.The results showed that the seroprevalence of SFTSV,CCHFV,TAMV,KSIV,and ZIKV was 17.37%,7.58%,4.41%,1.10%,and 6.48%,respectively,and neutralizing to SFTSV(1.79%),CCHFV(2.62%),and ZIKV(0.69%)were identified,as well as to the SFTSV-related Guertu virus(GTV,0.83%).Risk factors associated with the incidence of exposure and levels of antibody response were analyzed.Moreover,co-exposure to different arboviruses was demonstrated,as thirty-seven individuals were having antibodies against multiple viruses and thirteen showed neutralizing activity.Males,individuals aged40 years,and outdoor workers had a high risk of exposure to arboviruses.All these results reveal the substantial risks of infection with arboviruses in Pakistan,and indicate the threat from co-exposure to multiple arboviruses.The findings raise the need for further epidemiologic investigation in expanded regions and populations and the necessity to improve health surveillance in Pakistan.展开更多
In Canada,the periodic circulation of West Nile Virus(WNV)is difficult to predict and,beyond climatic factors,appears to be related to the migratory movements of infected birds from the southern United States.This hyp...In Canada,the periodic circulation of West Nile Virus(WNV)is difficult to predict and,beyond climatic factors,appears to be related to the migratory movements of infected birds from the southern United States.This hypothesis has not yet been explored in a spatially distributed model.The main objective of this work was to develop a spatially explicit dynamic model for the transmission of WNV in Canada,that allows us to explore non-climate related hypotheses associated with WNV transmission.A Cellular Automata(CA)approach for multiple hosts(birds and humans)is used for a test region in eastern Ontario,Canada.The tool is designed to explore the role of host and vector spatial heterogeneity,host migration,and vector feeding preferences.We developed a spatialized compartmental SEIRDS-SEI model for WNV transmission with a study region divided into 4 rectangular cells.We used 2010–2021 bird data from the eBird project and 2010–2019 mosquito data collected by Ontario Public Health to mimic bird and mosquito seasonal variation.We considered heterogeneous bird densities(high and low suitability areas)and homogeneous mosquito and human densities.In high suitability areas for birds,we identified 5 entry points for WNV-infected birds.We compared our simulations with pools of WNV-infected field collected mosquitoes.Simulations and sensitivity analyses were performed using MATLAB software.The results showed good correspondence between simulated and observed epidemics,supporting the validity of our model assumptions and calibration.Sensitivity analysis showed that a 5%increase or decrease in each parameter of our model except for the biting rate of bird by mosquito(c^(B,M)and mosquito natural mortality rate(d^(M)),had a very limited effect on the total number of cases(newly infected birds and humans),prevalence peak,or date of occurrence.We demonstrate the utility of the CA approach for studying WNV transmission in a heterogeneous landscape with multiple hosts.展开更多
A field investigation of arboviruses was conducted in Dejiang, Guizhou Province in the summer of 2016. A total of 8,795 mosquitoes, belonging to four species of three genera, and 1,300 midges were collected. The mosqu...A field investigation of arboviruses was conducted in Dejiang, Guizhou Province in the summer of 2016. A total of 8,795 mosquitoes, belonging to four species of three genera, and 1,300 midges were collected. The mosquito samples were identified on site according to their morphology, and the pooled samples were ground and centrifuged in the laboratory. The supernatant was incubated with mosquito tissue culture cells(C6/36) and mammalian cells(BHK-21) for virus isolation. The results indicated that 40%(3,540/8,795) were Anopheles sinensis, 30%(2,700/8,795) were Culex pipiens quinquefasciatus, and 29%(2,530/8,795)were Armigeres subbalbeatus. Furthermore, a total of eight virus isolates were obtained, and genome sequencing revealed two Zika viruses(ZIKVs) isolated from Culex pipiens quinquefasciatus and Armigeres subbalbeatus, respectively; three Japanese encephalitis viruses(JEVs) isolated from Culex pipiens quinquefasciatus; two Banna viruses(BAVs) isolated from Culex pipiens quinquefasciatus and Anopheles sinensis, respectively; and one densovirus(DNV) isolated from Culex pipiens quinquefasciatus.The ZIKVs isolated from the Culex pipiens quinquefasciatus and Armigeres subbalbeatus mosquitoes represent the first ZIKV isolates in China's Mainland. This discovery presents new challenges for the prevention and control of ZIKV in China, and prompts international cooperation on this global issue.展开更多
Background:The increasing trend of adult cases of Japanese encephalitis(JE)in China,particularly in northern China,has become an important public health issue.We conducted an epidemiological investigation in the south...Background:The increasing trend of adult cases of Japanese encephalitis(JE)in China,particularly in northern China,has become an important public health issue.We conducted an epidemiological investigation in the south of Shanxi Province to examine the relationships between mosquitoes,Japanese encephalitis virus(JEV),and adult JE cases.Methods:Mosquito specimens were collected from the courtyards of farmers’households and pig farms in Shanxi Province.Mosquitoes were pooled,homogenized,and centrifuged.Reverse transcription-polymerase chain reaction(RT-PCR)was used to detect mosquito-borne arbovirus genes in homogenates.Specimens positive for these genes were inoculated into the baby hamster kidney cell line(BHK-21)to isolate virus.Minimum infection rate was calculated and phylogenetic analyses were performed.Results:A total of 7943 mosquitoes belonging to six species in four genera were collected;Culex tritaeniorhynchus accounted for 73.08%(5805/7943),C.pipiens pallens for 24.75%(1966/7943),and the remaining 3%(104/7943)consisted of Anopheles sinensis,Aedes vexans,Ae.dorsalis,and Armigeres subalbatus.Sixteen pools were positive for JEV based on RT-PCR using JEV pre-membrane gene nested primers.Phylogenetic analyses showed that all JEVs belonged to genotype I;two pools were positive using Getah Virus(GETV)gene primers.In addition,one JEV strain(SXYC1523)was isolated from C.pipiens pallens specimens.These results indicate that the minimum infection rate of JEV in mosquito specimens collected from the courtyards of farmers’households with pigsties was 7.39/1000;the rate for pig farms was 2.68/1000;and the rate for farmers’courtyards without pigsties was zero.Conclusions:The high-prevalence regions of adult JE investigated in this study are still the natural epidemic focus of JEV.Having pigsties near dwellings is a potential risk factor contributing to the prevalence of adult JE.To prevent the occurrence of local adult JE cases,a recommendation was raised that,besides continuing to implement the Expanded Program on Immunization for children,the government should urge local farmers to cease raising pigs in their own courtyards to reduce the probability of infection with JEV.展开更多
Background Chongming Island in China serves as a breeding and shelter point on the East Asian–Australasian Flyway.The resting frequency of migratory birds,abundance of mosquito populations,and the popular domestic po...Background Chongming Island in China serves as a breeding and shelter point on the East Asian–Australasian Flyway.The resting frequency of migratory birds,abundance of mosquito populations,and the popular domestic poultry industry pose a potential risk of mosquito-borne zoonotic diseases.The aim of this study is to explore the role of migratory birds in the spread of mosquito-borne pathogens and their prevalent status on the island.Methods We conducted a mosquito-borne pathogen surveillance in 2021,in Chongming,Shanghai,China.Approxi‑mately 67,800 adult mosquitoes belonging to ten species were collected to investigate the presence of faviviruses,alphaviruses,and orthobunyaviruses by RT-PCR.Genetic and phylogenetic analyses were conducted to explore the virus genotype and potential nature source.Serological survey was performed by ELISA to characterize Tembusu virus(TMUV)infection among domestic poultry.Results Two strains of TMUV and Chaoyang virus(CHAOV)and 47 strains of Quang Binh virus(QBV)were detected in 412 mosquito pools,with the infection rate of 0.16,0.16,and 3.92 per 1000 Culex tritaeniorhynchus,respectively.Fur‑thermore,TMUVs viral RNA was found in serum samples of domestic chickens and faecal samples of migratory birds.Antibodies against TMUV were detected in domestic avian serum samples,generally ranging from 44.07%in pigeons to 55.71%in ducks.Phylogenetic analyses indicated that the TMUV detected in Chongming belonged to Cluster 3,Southeast Asia origin,and most closely related to the CTLN strain,which caused a TMUV outbreak in chickens in Guangdong Province in 2020,but distant from strains obtained previously in Shanghai,which were involved in the 2010 TMUV outbreak in China.Conclusions We speculate that the TMUV was imported to Chongming Island through long-distance spreading by migratory birds from Southeast Asia,followed by spill over and transmission in mosquitoes and domestic avian species,threatening the local domestic poultry.In addition,the expansion and prevalence of insect-specifc favivi‑ruses and its simultaneous circulation with mosquito-borne virus are worthy of close attention and further study.展开更多
The amount and distribution of precipitation can determine dengue risk by affecting mosquito breeding;however,previous studies failed to incorporate this bivariate characteristic to examine dengue fever transmission.I...The amount and distribution of precipitation can determine dengue risk by affecting mosquito breeding;however,previous studies failed to incorporate this bivariate characteristic to examine dengue fever transmission.In the present research,nationwide data on daily dengue cases in China between January 2005 and December 2020 were obtained,and the top 12 cities accounting for 78%of total cases were selected for analysis.Precipitation patterns were quantified by weekly precipitation and precipitation concentration degree(PCD).On the basis of the combinations of both parameters,the exposure-response relationships of precipitation with dengue risk were established using generalised additive models,and the high-dengue-risk thresholds of precipitation patterns were further identified.Dengue burden was assessed by calculating attributable dengue cases.For the same amount of precipitation,the dispersed precipitation in the pre-summer rainy season leads to a higher dengue risk in autumn.The weekly precipitation of 100-150 mm and PCD of 0.2-0.4 constitute the highest risk scenario,and the average frequency of precipitation associated with dengue risk in 2013-2020 is 1.6 times higher than that in 2005-2012.A total of 3093 attributable dengue cases are identified.From 2005 to 2020,the amount of dispersed precipitation increased in southern and southwestern China and posed high dengue risks in central China.This study has improved the understanding of the health impacts of irregular rainfall under climate change.Our approach to identifying thresholds provides information for early warning systems and helps reduce the risk of dengue transmission in the long run.展开更多
Background Mosquito research in Europe has a long history,primarily focused on malaria vectors.In recent years,invasive mosquito species like the Asian tiger mosquito(Aedes albopictus)and the spread of arboviruses lik...Background Mosquito research in Europe has a long history,primarily focused on malaria vectors.In recent years,invasive mosquito species like the Asian tiger mosquito(Aedes albopictus)and the spread of arboviruses like dengue virus,chikungunya virus or bluetongue virus have led to an intensifcation of research and monitoring in Europe.The risk of further dissemination of exotic species and mosquito-borne pathogens is expected to increase with ongoing globalization,human mobility,transport geography,and climate warming.Researchers have conducted various studies to understand the ecology,biology,and efective control strategies of mosquitoes and associated pathogens.Main body Three invasive mosquito species are established in Europe:Asian tiger mosquito(Aedes albopictus),Japanese bush mosquito(Ae.japonicus),and Korean bush mosquito(Aedes koreicus).Ae.albopictus is the most invasive species and has been established in Europe since 1990.Over the past two decades,there has been an increasing number of outbreaks of infections by mosquito-borne viruses in particular chikungunya virus,dengue virus or Zika virus in Europe primary driven by Ae.albopictus.At the same time,climate change with rising temperatures results in increasing threat of invasive mosquito-borne viruses,in particular Usutu virus and West Nile virus transmitted by native Culex mosquito species.Efective mosquito control programs require a high level of community participation,going along with comprehensive information campaigns,to ensure source reduction and successful control.Control strategies for container breeding mosquitoes like Ae.albopictus or Culex species involve community participation,door-to-door control activities in private areas.Further measures can involve integration of sterile insect techniques,applying indigenous copepods,Wolbachia sp.bacteria,or genetically modifed mosquitoes,which is very unlike to be practiced as standard method in the near future.Conclusions Climate change and globalization resulting in the increased establishment of invasive mosquitoes in particular of the Asian tiger mosquito Ae.albopictus in Europe within the last 30 years and increasing outbreaks of infections by mosquito-borne viruses warrants intensifcation of research and monitoring.Further,efective future mosquito control programs require increase in intense community and private participation,applying physical,chemical,biological,and genetical control activities.展开更多
Introduction:Yellow fever(YF)is primarily transmitted by Haemagogus species of mosquitoes.Under climate change,mosquitoes and the pathogens that they carry are expected to develop faster,potentially impacting the case...Introduction:Yellow fever(YF)is primarily transmitted by Haemagogus species of mosquitoes.Under climate change,mosquitoes and the pathogens that they carry are expected to develop faster,potentially impacting the case count and duration of YF outbreaks.The aim of this study was to determine how YF virus outbreaks in Brazil may change under future climate,using ensemble simulations from regional climate models under RCP4.5 and RCP8.5 scenarios for three time periods:2011-2040(short-term),2041-2070(mid-term),and 2071-2100(long-term).Methods:A compartmental model was developed to fit the 2017/18 YF outbreak data in Brazil using least squares optimization.To explore the impact of climate change,temperature-sensitive mosquito parameters were set to change over projected time periods using polynomial equations fitted to their relationship with temperature according to the average temperature for years 2011-2040,2041-2070,and 2071-2100 for climate change scenarios using RCP4.5 and RCP8.5,where RCP4.5/RCP8.5 corresponds to intermediate/high radiative forcing values and to moderate/higher warming trends.A sensitivity analysis was conducted to determine how the temperature-sensitive parameters impacted model results,and to determine how vaccination could play a role in reducing YF in Brazil.Results:Yellow fever case projections for Brazil from the models varied when climate change scenarios were applied,including the peak clinical case incidence,cumulative clinical case incidence,time to peak incidence,and the outbreak duration.Overall,a decrease in YF cases and outbreak duration was observed.Comparing the observed incidence in 2017/18 to the projected incidence in 2070-2100,for RCP4.5,the cumulative case incidence decreased from 184 to 161,and the outbreak duration decreased from 21 to 20 weeks.For RCP8.5,the peak case incidence decreased from 184 to 147,and the outbreak duration decreased from 21 to 17 weeks.The observed decrease was primarily due to temperature increasing beyond that suitable for Haemagogus mosquito survival.Conclusions:Climate change is anticipated to have an impact on mosquito-borne diseases.We found outbreaks of YF may reduce in intensity as temperatures increase in Brazil;however,temperature is not the only factor involved with disease transmission.Other factors must be explored to determine the attributable impact of climate change on mosquito-borne diseases.展开更多
In this paper,a delayed mosquito population suppression model,where the number of sexually active sterile mosquitoes released is regarded as a given nonnegative function,and the birth process is density dependent by c...In this paper,a delayed mosquito population suppression model,where the number of sexually active sterile mosquitoes released is regarded as a given nonnegative function,and the birth process is density dependent by considering larvae progression and the intra-specific competition within the larvae,is developed and studied.A threshold value r^(*)for the releases of sterile mosquitoes is determined,and it is proved that the origin is globally asymptotically stable if the number of sterile mosquitoes released is above the threshold value r^(*).Besides,the case when the number of sterile mosquitoes released stays at a constant level r is also considered.In the special case,it is also proved that the origin is globally asymptotically stable if and only if r>r^(*)and that the model exhibits other complicated dynamics such as bi-stability and semi-stability when r≤r^(*).Numerical examples are also provided to illustrate our main theoretical results.展开更多
Climate change is an emerging global problem.It has hazardous effects that vary across different geographic regions and populations.It is anticipated to have significant effects in Saudi Arabia.The present work review...Climate change is an emerging global problem.It has hazardous effects that vary across different geographic regions and populations.It is anticipated to have significant effects in Saudi Arabia.The present work reviews the future of human parasitoses in Saudi Arabia in response to the expected climate change.The key projections are increased precipitations,flash floods,unstable temperatures,sea-level rise and shoreline retreat.Such environmental changes could strongly influence the epidemiology of fly-borne,mosquito-borne,snail-borne and water-borne human parasitoses in the country.展开更多
基金Supported by Nanchang Center for Disease Control and Prevention~~
文摘Monitoring on vector-borne virus lays foundation for control of vector-borne disease, and a scientific and highly-efficient surveil ance method is of great signifi-cance for prevention and control ing of vector-borne diseases. The research sum-marized mosquito and mosquito-borne disease monitoring methods and proposed problems in the monitoring system, as wel as introducing new monitoring methods at home and abroad, providing references for improvements of integrated surveil-lance of mosquito or mosquito-borne viruses.
文摘Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainstay of effective control.But,indiscriminate and rampant use of the chemical insecticides in controlling mosquito vectors,in order to prevent diseases vectored by them,has resulted problems related to the adverse environmental effects for their(insecticides)potential toxicity,high operational cost,community acceptance,and the development of insecticide resistance among the vectors.The factors mentioned above prompted the search for new means of control strategies.Currently,the botanicals(viz.,plant extracts,essential oils and phytochemicals)with mosquitocidal potential
基金Supported by UGC-MRP,New Delhi,India[No.F.No.36-250/2008(SR)24/03/2009]King Saud University,Saudi Arabia,Vice Deanship of Research Chairs:Research Chairs
文摘Objective: To evaluate the ovicidal, larvicidal and adulticidal potential of neem cake fractions of different polarity against the rural malaria vector Anopheles culicifacies(An.culicifacies).Methods: Neem cake fractions' total methanol extract(NTMeOH), total ethyl acetate extract(NTAc OEt), ethyl acetate fraction after repartition with NTMe OH(NRAc OEt),butanol fraction after repartition with NTMeOH(NRBuOH), and aqueous fraction after repartition of NTMeOH(NRH2O) were tested against An. culicifacies eggs, fourth instar larvae and adults.Results: In larvicidal experiments, NTMeOH, NTAcOEt, NRAcOEt, NRBuOH and NRH2O achieved LC50 values of 1.32, 1.50, 1.81, 1.95 and 2.54 mg/L, respectively. All fractions tested at 150 mg/L were able to reduce egg hatchability of more than 50%, with the exception of NTAc OEt and NRAc OEt. In adulticidal assays, NTMeOH, NTAcOEt,NRAcOEt, NRBuOH and NRH2O achieved LC50 values of 3.01, 2.95, 3.23, 3.63 and3.00 mg/L, respectively.Conclusions: Overall, this study suggests that the methanolic fractions of neem cake may be considered as a new and cheap source of highly effective compounds against the rural malaria vector An. culicifacies.
文摘Mosquito-borne diseases(MBDs),like malaria and mosquito-borne viruses(MBVs),have caused the deaths of millions of people.Their threat resides in the variety of transmission modes that they possess,along with the wide selection of favorable hosts,such as humans,cattle,and rodents.MBDs are increasingly gaining a reputation as one of the most dangerous threats to public health in recent years.Mosquito numbers have been increasing in recent years as a result of multiple factors such as climate change and deforestation.This situation highlights the urgent need for actions to mitigate mosquito and MBD pathogen distributions.In the Middle East,many outbreaks of MBDs have been reported in the region.However,there are no reports of any endemic episodes of MBDs.The Middle East has faced many challenges over the years;however,the Syrian refugee crisis may be strongly related to the spread of infectious diseases.As mass gatherings and high-density populations are common features in the region,it is possible to understand why MBDs can spread easily.This review summarizes the state of MBDs in the Middle East,highlighting the different types of MBDs that have been reported in the region and discussing how to move forward with controlling their spread and limiting the risks they pose.According to the data reported by the electronic State Parties Self-Assessment Annual Reporting Tool(e-SPAR),the capacity to anticipate MBVs varies among Middle East countries.Therefore,the Middle East is on the frontline in the challenge to control a potential public health crisis.Consequently,the countries of the Middle East should be encouraged to improve their health and research capacities to mitigate the threat posed by MBDs.
基金supported by the grants from the National Key Research and Development Plan of China(2021YFC2300200,2020YFC1200104,and 2018YFA0507202)The National Natural Science Foundation of China(32188101,31825001,81730063,81961160737,and 82102389)+5 种基金Tsinghua University Spring Breeze Fund(2020Z99CFG017)Shenzhen San-Ming Project for prevention and research on vector-borne diseases(SZSM201611064)the Yunnan Cheng gong expert workstation(202005AF150034)Innovation Team Project of Yunnan Science and Technology Department(202105AE160020)Tsinghua-Foshan Innovation Special Fund(2022THFS6124)Young Elite Scientists Sponsorship Program(2021QNRC001).
文摘Mosquito-borne viruses(MBVs)are a large class of viruses transmitted mainly through mosquito bites,including dengue virus,Zika virus,Japanese encephalitis virus,West Nile virus,and chikungunya virus,which pose a major threat to the health of people around the world.With global warming and extended human activities,the incidence of many MBVs has increased significantly.Mosquito saliva contains a variety of bioactive protein components.These not only enable blood feeding but also play a crucial role in regulating local infection at the bite site and the remote dissemination of MBVs as well as in remodeling the innate and adaptive immune responses of host vertebrates.Here,we review the physiological functions of mosquito salivary proteins(MSPs)in detail,the influence and the underlying mechanism of MSPs on the transmission of MBVs,and the current progress and issues that urgently need to be addressed in the research and development of MSP-based MBV transmission blocking vaccines.
基金This work was funded by the grants from the National Key R&D Program of China(Nos.2021YFC2300200,2018YFA0507202,2020YFC1200104,2021YFC2302405,2022YFC2303200,and 2022YFC2303400)National Natural Science Foundation of China(Nos.32188101,31825001,and 81961160737),Yunnan Chenggong expert workstation(Nos.202005AF150034)+2 种基金Innovation Team Project of Yunnan Science and Technology Department(Nos.202105AE160020)Tsinghua-Foshan Innovation Special Fund(TFISF)(Nos.2022THFS6124)Shenzhen San-Ming Project for prevention and research on vector-borne diseases.
文摘Mosquito-borne diseases present a significant threat to human health,with the possibility of outbreaks of new mosquito-borne diseases always looming.Unfortunately,current measures to combat these diseases such as vaccines and drugs are often either unavailable or ineffective.However,recent studies on microbiomes may reveal promising strategies to fight these diseases.In this review,we examine recent advances in our understanding of the effects of both the mosquito and vertebrate microbiomes on mosquito-borne diseases.We argue that the mosquito microbiome can have direct and indirect impacts on the transmission of these diseases,with mosquito symbiotic microorganisms,particularly Wolbachia bacteria,showing potential for controlling mosquito-borne diseases.Moreover,the skin microbiome of vertebrates plays a significant role in mosquito preferences,while the gut microbiome has an impact on the progression of mosquito-borne diseases in humans.As researchers continue to explore the role of microbiomes in mosquito-borne diseases,we highlight some promising future directions for this field.Ultimately,a better understanding of the interplay between mosquitoes,their hosts,pathogens,and the microbiomes of mosquitoes and hosts may hold the key to preventing and controlling mosquito-borne diseases.
基金supported by a grant from the China MegaProject on Infectious Disease Prevention(grant numbers 2013ZX10004-605,2013ZX10004-607,2013ZX10004-217,and 2011ZX10004-001)the National Hi-Tech Research and Development(863)Program of China(grant numbers 2014AA020108,2012AA022-003)the National Natural Science Foundation of China(grant numbers 81273138,81572045)
文摘Dear Editor,The genus Orbivirus,within the family Reoviridae,includes 22 virus species(King et al.,2011).They are distributed globally,but are particularly prevalent in Europe,Asia,and Africa.In addition,they can be transmitted by ticks or other hematophagous insect vectors,including Culicoides,mosquitoes,and sandflies(Belaga-
文摘Background:Mosquito-based arbovirus surveillance can serve as an early warning in evaluating the status of mosquito-borne virus prevalence and thus prevent local outbreaks.Although Tengchong County in Yunnan Province-which borders Myanmar-is abundant and diverse in mosquitoes,very few mosquito-based arbovirus investigations have been conducted in the recent decade.Herein,this study aims to evaluate the presence and the diffusion of mosquito-borne pathogens,currently prevalent in this region.
文摘Most of the vector-borne diseases show a clear dependence on seasonal variation,including climate change.In this paper,we proposed a nonautonomous mathematical model consisting of a periodic system of nonlinear differential equations.In the proposed model,the realistic functional forms for the different temperature-dependent parameters are considered.The autonomous system of the proposed model is also analyzed.The nontrivial solution of the autonomous model is locally asymptotically stable if R0<1.It is shown that a unique endemic equilibrium point of the autonomous model exists when R0>1 and proved that endemic solution is linearly stable when R0>1.The nonautonomous model is shown to have a nontrivial disease-free periodic state,which is globally asymptotically stable whenever temperature-dependent reproduction number is less than unity.It is observed that a unique positive endemic periodic solution of the nonautonomous system exists only when a temperature-dependent reproduction number greater than unity,which makes for the persistence of the disease.Numerical simulation has been carried out to support the analytical results and shows the effects of temperature variability in the life span of mosquitoes as well as the persistence of the disease.
文摘BACKGROUND:The Chikungunya(CHIK)virus was recently reported by the CDC to have spread to the United States.We report an early documented case of CHIK from the state of Pennsylvania after a patient recently returned from Haiti in June of 2014.METHODS:A 39-year-old man presented to the emergency department complaining of fever,fatigue,polyarthralgias and a diffuse rash for two days.Four days before,he returned from a mission trip to Haiti and reported that four of his accompanying friends had also become ill.A CHIK antibody titer was obtained and it was found to be positive.During his hospital stay,he responded well to supportive care,including anti-inflammatories,intravenous hydration and anti-emetics.RESULTS:His condition improved within two days and he was ultimately discharged home.CONCLUSIONS:Manifestations of CHIK can be similar to Dengue fever,which is transmitted by the same species of mosquito,and occasionally as a co-infection.Clinicians should include Chikungunya virus in their differential diagnosis of patients who present with fever,polyarthralgia and rash with a recent history of travel to endemic areas,including those within the United States.
基金supported by the National Key Research and Development Programme of China[Grant Number 2021YFC2300900,2022YFC2302700]International Partnership Programme of the Bureau of International Cooperation,Chinese Academy of Sciences[Grant Number 153B42KYSB20200013]+1 种基金National Natural Science Foundation of China[Grant Number U22A20363]Biological Resources Programme,Chinese Academy of Sciences[Grant Number KFJ-BRP-017-74].
文摘Infectious diseases caused by arboviruses are a public health concern in Pakistan.However,studies on data prevalence and threats posed by arboviruses are limited.This study investigated the seroprevalence of arboviruses in a healthy population in Pakistan,including severe fever with thrombocytopenia syndrome virus(SFTSV),Crimean-Congo hemorrhagic fever virus(CCHFV),Tamdy virus(TAMV),and Karshi virus(KSIV)based on a newly established luciferase immunoprecipitation system(LIPS)assays,and Zika virus(ZIKV)by enzyme-linked immunosorbent assays(ELISA).Neutralizing activities against these arboviruses were further examined from the antibody positive samples.The results showed that the seroprevalence of SFTSV,CCHFV,TAMV,KSIV,and ZIKV was 17.37%,7.58%,4.41%,1.10%,and 6.48%,respectively,and neutralizing to SFTSV(1.79%),CCHFV(2.62%),and ZIKV(0.69%)were identified,as well as to the SFTSV-related Guertu virus(GTV,0.83%).Risk factors associated with the incidence of exposure and levels of antibody response were analyzed.Moreover,co-exposure to different arboviruses was demonstrated,as thirty-seven individuals were having antibodies against multiple viruses and thirteen showed neutralizing activity.Males,individuals aged40 years,and outdoor workers had a high risk of exposure to arboviruses.All these results reveal the substantial risks of infection with arboviruses in Pakistan,and indicate the threat from co-exposure to multiple arboviruses.The findings raise the need for further epidemiologic investigation in expanded regions and populations and the necessity to improve health surveillance in Pakistan.
文摘In Canada,the periodic circulation of West Nile Virus(WNV)is difficult to predict and,beyond climatic factors,appears to be related to the migratory movements of infected birds from the southern United States.This hypothesis has not yet been explored in a spatially distributed model.The main objective of this work was to develop a spatially explicit dynamic model for the transmission of WNV in Canada,that allows us to explore non-climate related hypotheses associated with WNV transmission.A Cellular Automata(CA)approach for multiple hosts(birds and humans)is used for a test region in eastern Ontario,Canada.The tool is designed to explore the role of host and vector spatial heterogeneity,host migration,and vector feeding preferences.We developed a spatialized compartmental SEIRDS-SEI model for WNV transmission with a study region divided into 4 rectangular cells.We used 2010–2021 bird data from the eBird project and 2010–2019 mosquito data collected by Ontario Public Health to mimic bird and mosquito seasonal variation.We considered heterogeneous bird densities(high and low suitability areas)and homogeneous mosquito and human densities.In high suitability areas for birds,we identified 5 entry points for WNV-infected birds.We compared our simulations with pools of WNV-infected field collected mosquitoes.Simulations and sensitivity analyses were performed using MATLAB software.The results showed good correspondence between simulated and observed epidemics,supporting the validity of our model assumptions and calibration.Sensitivity analysis showed that a 5%increase or decrease in each parameter of our model except for the biting rate of bird by mosquito(c^(B,M)and mosquito natural mortality rate(d^(M)),had a very limited effect on the total number of cases(newly infected birds and humans),prevalence peak,or date of occurrence.We demonstrate the utility of the CA approach for studying WNV transmission in a heterogeneous landscape with multiple hosts.
基金supported by the National Natural Science Foundation of China(81290342,81501757)the Special National Project on Research and Development of Key Biosafety Technologies(2016YFC1201904)+3 种基金the National Key Plan for Scientific Research and Development of China(2016YFD0500300)the Development Grants of State Key Laboratory of Infectious Disease Prevention and Control(2014SKLID103,2015SKLID505)the National Key Research and Development Program of China(2017YFC1200202)the Open Research Fund Program of Wuhan National Bio-Safety Level 4 Lab of CAS(2017SPCAS003)
文摘A field investigation of arboviruses was conducted in Dejiang, Guizhou Province in the summer of 2016. A total of 8,795 mosquitoes, belonging to four species of three genera, and 1,300 midges were collected. The mosquito samples were identified on site according to their morphology, and the pooled samples were ground and centrifuged in the laboratory. The supernatant was incubated with mosquito tissue culture cells(C6/36) and mammalian cells(BHK-21) for virus isolation. The results indicated that 40%(3,540/8,795) were Anopheles sinensis, 30%(2,700/8,795) were Culex pipiens quinquefasciatus, and 29%(2,530/8,795)were Armigeres subbalbeatus. Furthermore, a total of eight virus isolates were obtained, and genome sequencing revealed two Zika viruses(ZIKVs) isolated from Culex pipiens quinquefasciatus and Armigeres subbalbeatus, respectively; three Japanese encephalitis viruses(JEVs) isolated from Culex pipiens quinquefasciatus; two Banna viruses(BAVs) isolated from Culex pipiens quinquefasciatus and Anopheles sinensis, respectively; and one densovirus(DNV) isolated from Culex pipiens quinquefasciatus.The ZIKVs isolated from the Culex pipiens quinquefasciatus and Armigeres subbalbeatus mosquitoes represent the first ZIKV isolates in China's Mainland. This discovery presents new challenges for the prevention and control of ZIKV in China, and prompts international cooperation on this global issue.
基金This work was supported by grants from National Natural Science Foundation of China(81290342 and 81501757)Development Grant of State Key Laboratory of Infectious Disease Prevention and Control(2014SKLID103).
文摘Background:The increasing trend of adult cases of Japanese encephalitis(JE)in China,particularly in northern China,has become an important public health issue.We conducted an epidemiological investigation in the south of Shanxi Province to examine the relationships between mosquitoes,Japanese encephalitis virus(JEV),and adult JE cases.Methods:Mosquito specimens were collected from the courtyards of farmers’households and pig farms in Shanxi Province.Mosquitoes were pooled,homogenized,and centrifuged.Reverse transcription-polymerase chain reaction(RT-PCR)was used to detect mosquito-borne arbovirus genes in homogenates.Specimens positive for these genes were inoculated into the baby hamster kidney cell line(BHK-21)to isolate virus.Minimum infection rate was calculated and phylogenetic analyses were performed.Results:A total of 7943 mosquitoes belonging to six species in four genera were collected;Culex tritaeniorhynchus accounted for 73.08%(5805/7943),C.pipiens pallens for 24.75%(1966/7943),and the remaining 3%(104/7943)consisted of Anopheles sinensis,Aedes vexans,Ae.dorsalis,and Armigeres subalbatus.Sixteen pools were positive for JEV based on RT-PCR using JEV pre-membrane gene nested primers.Phylogenetic analyses showed that all JEVs belonged to genotype I;two pools were positive using Getah Virus(GETV)gene primers.In addition,one JEV strain(SXYC1523)was isolated from C.pipiens pallens specimens.These results indicate that the minimum infection rate of JEV in mosquito specimens collected from the courtyards of farmers’households with pigsties was 7.39/1000;the rate for pig farms was 2.68/1000;and the rate for farmers’courtyards without pigsties was zero.Conclusions:The high-prevalence regions of adult JE investigated in this study are still the natural epidemic focus of JEV.Having pigsties near dwellings is a potential risk factor contributing to the prevalence of adult JE.To prevent the occurrence of local adult JE cases,a recommendation was raised that,besides continuing to implement the Expanded Program on Immunization for children,the government should urge local farmers to cease raising pigs in their own courtyards to reduce the probability of infection with JEV.
文摘Background Chongming Island in China serves as a breeding and shelter point on the East Asian–Australasian Flyway.The resting frequency of migratory birds,abundance of mosquito populations,and the popular domestic poultry industry pose a potential risk of mosquito-borne zoonotic diseases.The aim of this study is to explore the role of migratory birds in the spread of mosquito-borne pathogens and their prevalent status on the island.Methods We conducted a mosquito-borne pathogen surveillance in 2021,in Chongming,Shanghai,China.Approxi‑mately 67,800 adult mosquitoes belonging to ten species were collected to investigate the presence of faviviruses,alphaviruses,and orthobunyaviruses by RT-PCR.Genetic and phylogenetic analyses were conducted to explore the virus genotype and potential nature source.Serological survey was performed by ELISA to characterize Tembusu virus(TMUV)infection among domestic poultry.Results Two strains of TMUV and Chaoyang virus(CHAOV)and 47 strains of Quang Binh virus(QBV)were detected in 412 mosquito pools,with the infection rate of 0.16,0.16,and 3.92 per 1000 Culex tritaeniorhynchus,respectively.Fur‑thermore,TMUVs viral RNA was found in serum samples of domestic chickens and faecal samples of migratory birds.Antibodies against TMUV were detected in domestic avian serum samples,generally ranging from 44.07%in pigeons to 55.71%in ducks.Phylogenetic analyses indicated that the TMUV detected in Chongming belonged to Cluster 3,Southeast Asia origin,and most closely related to the CTLN strain,which caused a TMUV outbreak in chickens in Guangdong Province in 2020,but distant from strains obtained previously in Shanghai,which were involved in the 2010 TMUV outbreak in China.Conclusions We speculate that the TMUV was imported to Chongming Island through long-distance spreading by migratory birds from Southeast Asia,followed by spill over and transmission in mosquitoes and domestic avian species,threatening the local domestic poultry.In addition,the expansion and prevalence of insect-specifc favivi‑ruses and its simultaneous circulation with mosquito-borne virus are worthy of close attention and further study.
基金supported by the National Key R&D Program of China(2018YFA0606200)the Sanming Project of Medicine in Shenzhen,China(SZSM202111001).
文摘The amount and distribution of precipitation can determine dengue risk by affecting mosquito breeding;however,previous studies failed to incorporate this bivariate characteristic to examine dengue fever transmission.In the present research,nationwide data on daily dengue cases in China between January 2005 and December 2020 were obtained,and the top 12 cities accounting for 78%of total cases were selected for analysis.Precipitation patterns were quantified by weekly precipitation and precipitation concentration degree(PCD).On the basis of the combinations of both parameters,the exposure-response relationships of precipitation with dengue risk were established using generalised additive models,and the high-dengue-risk thresholds of precipitation patterns were further identified.Dengue burden was assessed by calculating attributable dengue cases.For the same amount of precipitation,the dispersed precipitation in the pre-summer rainy season leads to a higher dengue risk in autumn.The weekly precipitation of 100-150 mm and PCD of 0.2-0.4 constitute the highest risk scenario,and the average frequency of precipitation associated with dengue risk in 2013-2020 is 1.6 times higher than that in 2005-2012.A total of 3093 attributable dengue cases are identified.From 2005 to 2020,the amount of dispersed precipitation increased in southern and southwestern China and posed high dengue risks in central China.This study has improved the understanding of the health impacts of irregular rainfall under climate change.Our approach to identifying thresholds provides information for early warning systems and helps reduce the risk of dengue transmission in the long run.
基金funded by the Federal Ministry of Education and Research of Germany(BMBF)under the project NEED(Grant no.01Kl2022).
文摘Background Mosquito research in Europe has a long history,primarily focused on malaria vectors.In recent years,invasive mosquito species like the Asian tiger mosquito(Aedes albopictus)and the spread of arboviruses like dengue virus,chikungunya virus or bluetongue virus have led to an intensifcation of research and monitoring in Europe.The risk of further dissemination of exotic species and mosquito-borne pathogens is expected to increase with ongoing globalization,human mobility,transport geography,and climate warming.Researchers have conducted various studies to understand the ecology,biology,and efective control strategies of mosquitoes and associated pathogens.Main body Three invasive mosquito species are established in Europe:Asian tiger mosquito(Aedes albopictus),Japanese bush mosquito(Ae.japonicus),and Korean bush mosquito(Aedes koreicus).Ae.albopictus is the most invasive species and has been established in Europe since 1990.Over the past two decades,there has been an increasing number of outbreaks of infections by mosquito-borne viruses in particular chikungunya virus,dengue virus or Zika virus in Europe primary driven by Ae.albopictus.At the same time,climate change with rising temperatures results in increasing threat of invasive mosquito-borne viruses,in particular Usutu virus and West Nile virus transmitted by native Culex mosquito species.Efective mosquito control programs require a high level of community participation,going along with comprehensive information campaigns,to ensure source reduction and successful control.Control strategies for container breeding mosquitoes like Ae.albopictus or Culex species involve community participation,door-to-door control activities in private areas.Further measures can involve integration of sterile insect techniques,applying indigenous copepods,Wolbachia sp.bacteria,or genetically modifed mosquitoes,which is very unlike to be practiced as standard method in the near future.Conclusions Climate change and globalization resulting in the increased establishment of invasive mosquitoes in particular of the Asian tiger mosquito Ae.albopictus in Europe within the last 30 years and increasing outbreaks of infections by mosquito-borne viruses warrants intensifcation of research and monitoring.Further,efective future mosquito control programs require increase in intense community and private participation,applying physical,chemical,biological,and genetical control activities.
文摘Introduction:Yellow fever(YF)is primarily transmitted by Haemagogus species of mosquitoes.Under climate change,mosquitoes and the pathogens that they carry are expected to develop faster,potentially impacting the case count and duration of YF outbreaks.The aim of this study was to determine how YF virus outbreaks in Brazil may change under future climate,using ensemble simulations from regional climate models under RCP4.5 and RCP8.5 scenarios for three time periods:2011-2040(short-term),2041-2070(mid-term),and 2071-2100(long-term).Methods:A compartmental model was developed to fit the 2017/18 YF outbreak data in Brazil using least squares optimization.To explore the impact of climate change,temperature-sensitive mosquito parameters were set to change over projected time periods using polynomial equations fitted to their relationship with temperature according to the average temperature for years 2011-2040,2041-2070,and 2071-2100 for climate change scenarios using RCP4.5 and RCP8.5,where RCP4.5/RCP8.5 corresponds to intermediate/high radiative forcing values and to moderate/higher warming trends.A sensitivity analysis was conducted to determine how the temperature-sensitive parameters impacted model results,and to determine how vaccination could play a role in reducing YF in Brazil.Results:Yellow fever case projections for Brazil from the models varied when climate change scenarios were applied,including the peak clinical case incidence,cumulative clinical case incidence,time to peak incidence,and the outbreak duration.Overall,a decrease in YF cases and outbreak duration was observed.Comparing the observed incidence in 2017/18 to the projected incidence in 2070-2100,for RCP4.5,the cumulative case incidence decreased from 184 to 161,and the outbreak duration decreased from 21 to 20 weeks.For RCP8.5,the peak case incidence decreased from 184 to 147,and the outbreak duration decreased from 21 to 17 weeks.The observed decrease was primarily due to temperature increasing beyond that suitable for Haemagogus mosquito survival.Conclusions:Climate change is anticipated to have an impact on mosquito-borne diseases.We found outbreaks of YF may reduce in intensity as temperatures increase in Brazil;however,temperature is not the only factor involved with disease transmission.Other factors must be explored to determine the attributable impact of climate change on mosquito-borne diseases.
基金supported by the National Natural Science Foundation of China (No.12171193)the Science and Technology Key Project of Henan Province of China (No.222102110028)the Key scientific research projects of colleges and universities in Henan Province of China (Nos.22B110006,22A110012 and 20B110008).
文摘In this paper,a delayed mosquito population suppression model,where the number of sexually active sterile mosquitoes released is regarded as a given nonnegative function,and the birth process is density dependent by considering larvae progression and the intra-specific competition within the larvae,is developed and studied.A threshold value r^(*)for the releases of sterile mosquitoes is determined,and it is proved that the origin is globally asymptotically stable if the number of sterile mosquitoes released is above the threshold value r^(*).Besides,the case when the number of sterile mosquitoes released stays at a constant level r is also considered.In the special case,it is also proved that the origin is globally asymptotically stable if and only if r>r^(*)and that the model exhibits other complicated dynamics such as bi-stability and semi-stability when r≤r^(*).Numerical examples are also provided to illustrate our main theoretical results.
文摘Climate change is an emerging global problem.It has hazardous effects that vary across different geographic regions and populations.It is anticipated to have significant effects in Saudi Arabia.The present work reviews the future of human parasitoses in Saudi Arabia in response to the expected climate change.The key projections are increased precipitations,flash floods,unstable temperatures,sea-level rise and shoreline retreat.Such environmental changes could strongly influence the epidemiology of fly-borne,mosquito-borne,snail-borne and water-borne human parasitoses in the country.
