Mosquito-borne Disease Outbreaks Research Articles

Seasonal species composition, abundance and public health importance of mosquito vectors (Diptera: Culicidae) in Huai Tha Khoei Reservoir, Ratchaburi, Thailand

Abstract. Chaiphongpachara T, Laojuna S. 2024. Seasonal species composition, abundance and public health importance of mosquito vectors (Diptera: Culicidae) in Huai Tha Khoei Reservoir, Ratchaburi, Thailand. Biodiversitas 25: 1264-1275. Mosquitoes are vectors for pathogens that cause life-threatening diseases in humans and animals. Significant mosquito-borne diseases include malaria, dengue, chikungunya, Zika, Japanese encephalitis, and filariasis. Anthropogenic environmental changes can significantly impact the dynamics of disease vector populations, which can lead to outbreaks of mosquito-borne diseases. This study investigated the seasonal variation in species composition and abundance of mosquito vectors around the Huai Tha Khoei Reservoir in Ratchaburi Province, Thailand, across cool, hot, and rainy seasons. A total of 1363 mosquitoes, representing 30 species from five genera, were collected. In particular, 25 of these species, accounting for 83.33% of the total, were identified as vectors of human pathogens. The most dominant species across all seasons was Culex tritaeniorhynchus Giles 1901, representing 39.47% (n=538) of the total, followed by Anopheles barbirostris Wulp 1884 s.l. (14.38%, n = 196) and Culex vishnui Theobald 1901 (9.02%, n=123). The Shannon diversity index was highest during the rainy season (H’= 2.144) and lowest in the hot season (H’=1.788). This is consistent with the results of the UPGMA tree based on beta diversity, indicating that mosquito diversity in the rainy season differs significantly from that in the cool and hot seasons. The findings enhance our understanding of the impact of seasonality on mosquito vectors in this region, which is crucial for developing effective disease control strategies. Additionally, this study serves as a valuable reference for understanding the diversity of mosquito vectors in other areas.

Landscape level associations between birds, mosquitoes and microclimates: possible consequences for disease transmission?

BackgroundMosquito-borne diseases are on the rise. While climatic factors have been linked to disease occurrences, they do not explain the non-random spatial distribution in disease outbreaks. Landscape-related factors, such as vegetation structure, likely play a crucial but hitherto unquantified role.MethodsWe explored how three critically important factors that are associated with mosquito-borne disease outbreaks: microclimate, mosquito abundance and bird communities, vary at the landscape scale. We compared the co-occurrence of these three factors in two contrasting habitat types (forest versus grassland) across five rural locations in the central part of the Netherlands between June and September 2021.ResultsOur results show that forest patches provide a more sheltered microclimate, and a higher overall abundance of birds. When accounting for differences in landscape characteristics, we also observed that the number of mosquitoes was higher in isolated forest patches.ConclusionsOur findings indicate that, at the landscape scale, variation in tree cover coincides with suitable microclimate and high Culex pipiens and bird abundance. Overall, these factors can help understand the non-random spatial distribution of mosquito-borne disease outbreaks.Graphical

Vector competence of Swedish Culex pipiens mosquitoes for Usutu virus

Usutu virus (USUV) is an emerging mosquito-borne flavivirus with increasing prevalence in Europe. Understanding the role of mosquito species in USUV transmission is crucial for predicting and controlling potential outbreaks. This study aimed to assess the vector competence of Swedish Culex pipiens for USUV. The mosquitoes were orally infected with an Italian strain of USUV (Bologna 2009) and infection rates (IR), dissemination rates (DR), and transmission rates (TR) were evaluated over 7 to 28 days post-infection. The study revealed that Swedish Cx. pipiens are susceptible to USUV infection, with a gradual decrease in IR over time. However, the percentage of mosquitoes with the ability to transmit the virus remained consistent across all time points, indicating a relatively short extrinsic incubation period. Overall, this research highlights the potential of Swedish Cx. pipiens as vectors for USUV and emphasizes the importance of surveillance and monitoring to prevent future outbreaks of mosquito-borne diseases.

Applications of nanomaterials in mosquito vector control: A review

The periodic outbreak of mosquito-borne diseases like dengue fever, zika fever, and yellow fever all over the world highlights the need for effective mosquito control methods targeting the biological system. Due to the lack of therapeutic measures, preventive treatments or vaccines against pathogens, insecticide resistance eventually lead the research focus towards novel technological applications in mosquito management. Nanomaterials with ovicidal, larvicidal, adulticidal, and repellent properties for controlling mosquito vectors are under research. A literature search was carried out for advancements in nanomaterials, insecticides, and mosquito control in PubMed/MEDLINE, Scopus, Google Scholar, ScienceDirect, and Web of Science. This paper aims to provide insights into various nanomaterials relevant to mosquito-borne diseases, in vivo and in vitro toxicity evaluation against mosquito species, mode of action, effect on non-target organisms, and ecological risks. Organic and inorganic materials that provide controlled release, target delivery, less dosage, prolonged efficacy, a reduction in the use of organic solvents and emulsifiers, and minimum pollution to the environment have already been explored. Indeed, further research on the ecological risk and economic feasibility of nanomaterials in mosquitocidal applications should be done prior to commercialization.

Interactive effects of climate, land use and soil type on Culex pipiens/torrentium abundance

The incidence and risk of mosquito-borne disease outbreaks in Northwestern Europe has increased over the last few decades. Understanding the underlying environmental drivers of mosquito population dynamics helps to adequately assess mosquito-borne disease risk. While previous studies have focussed primarily on the effects of climatic conditions (i.e., temperature and precipitation) and/or local environmental conditions individually, it remains unclear how climatic conditions interact with local environmental factors such as land use and soil type, and how these subsequently affect mosquito abundance.Here, we set out to study the interactive effects of land use, soil type and climatic conditions on the abundance of Culex pipiens/torrentium, highly abundant vectors of West Nile virus and Usutu virus. Mosquitoes were sampled at 14 sites throughout the Netherlands. At each site, weekly mosquito collections were carried out between early July and mid-October 2020 and 2021. To assess the effect of the aforementioned environmental factors, we performed a series of generalized linear mixed models and non-parametric statistical tests.Our results show that mosquito abundance and species richness consistently differ among land use- and soil types, with peri-urban areas with peat/clay soils having the highest Cx. pipiens/torrentium abundance and sandy rural areas having the lowest. Furthermore, we observed differences in precipitation-mediated effects on Cx. pipiens/torrentium abundance between (peri-)urban and other land uses and soil types. In contrast, effects of temperature on Cx. pipiens/torrentium abundance remain similar between different land use and soil types.Our study highlights the importance of both land use and soil type in conjunction with climatic conditions for understanding mosquito abundances. Particularly in relation to rainfall events, land use and soil type has a marked effect on mosquito abundance. These findings underscore the importance of local environmental parameters for studies focusing on predicting or mitigating disease risk.

Temperature preference of sugar- or blood-fed Aedes japonicus mosquitoes under semi-natural conditions

Mosquito-borne diseases pose a major burden on humans and animals. Temperature strongly influences the physiology and life cycle of mosquitoes and also the pathogens they transmit. Thermoregulatory behaviour of mosquitoes has been addressed in a few laboratory studies. Here, we expand such studies by investigating the thermal preference when resting of Aedes japonicus, an invasive and putative vector species of many pathogens, in a semi-field setup during summers in a temperate climate. Blood-fed or sugar-fed Ae. japonicus females were released in the late afternoon in a large outdoor cage containing three resting boxes. The next morning, temperature treatments were applied to the boxes, creating a “cool” (over all experiments around 18 °C), and a “warm” (around 35 °C) microhabitat in addition to an untreated “ambient” (around 26 °C) one. The mosquitoes resting within the three boxes were counted five times, every 2 h between 9h and 17h. The highest proportions of mosquitoes (e.g. up to 21% of blood-fed ones) were found in the cool box while both blood-fed and sugar-fed mosquitoes avoided the warm box. The mean resting temperatures of Ae. japonicus were below the ambient temperatures measured by a nearby meteorological station, and this was more pronounced at higher outdoor temperatures and in blood-fed as compared to sugar-fed mosquitoes. Thus, over all experiments with blood-fed mosquitoes, the calculated average resting temperature was 4 °C below the outdoor temperature. As mosquitoes prefer cooler resting places than temperatures measured by weather stations in summer, models to predict mosquito-borne disease outbreaks need to account for the thermoregulatory behaviour of mosquitoes, especially in the wake of climate change.

SURVEILLANCE OF AEDES DIVERSITY, SEASONAL PREVALENCE AND HABITAT CHARACTERIZATION IN BULANDSHAHR, UTTER PRADESH, INDIA

Mosquitoes have the ability to spread several parasites and pathogens that cause serious diseases in both humans and animals. In order to effectively control disease and mosquito populations, analysis of mosquito diversity, prevalence and habitat characterization in any location is frequently necessary. In order to compile comprehensive first-hand data on mosquitoes, the current study was carried out in the Khurja area of the Bulandshahar district in Utter Pradesh, India. The study was carried out over a period of one year. Ladle and dipping methods were used to collect the larvae of the Aedes mosquito. 48 human habitations were selected randomly from the Bulandshahar region. The accumulated data were used to compute the monthly and seasonal Relative Abundance (RA), Per Man Hour Density (PMHD), House Index (HI) and Container Index (CI) of Aedes species. Three species from the genus Aedes including Aedes aegypti, Aedes albopictus, and Aedes vittatus identified in the Bulandshahr region. The most prevalent species was Aedes aegypti. The RA, PMHD, HI and CI were highest for Aedes aegypti (53.33%, 36.67, 44.08) followed by Aedes albopictus (28.33%, 19.49, 32.98), and Aedes vittatus (18.33%, 12.62, 15.10) and CI=12.53%. In seasonal population dynamics of Aedes species in relation to meteorological factors, only temperature and rainfall are significant variables (P>0.05) of climate that affect the density of mosquitoes in the study area, with no correlation with the relative humidity. According to the findings, there is a substantial probability of mosquito-borne disease outbreaks. There must be precautions taken because dengue fever outbreaks are frequent in the region. Interventions for prevention are necessary since the region is vulnerable to dengue fever outbreaks and other diseases spread by mosquitoes. Keywords : Aedes aegypti, Aedes albopictus, Aedes vittatus, Bulandshahr, Mosquito diversity. Seasonal prevalence.

SURVEILLANCE OF AEDES DIVERSITY, SEASONAL PREVALENCE AND HABITAT CHARACTERIZATION IN BULANDSHAHR, UTTER PRADESH, INDIA

Mosquitoes have the ability to spread several parasites and pathogens that cause serious diseases in both humans and animals. In order to effectively control disease and mosquito populations, analysis of mosquito diversity, prevalence and habitat characterization in any location is frequently necessary. In order to compile comprehensive first-hand data on mosquitoes, the current study was carried out in the Khurja area of the Bulandshahar district in Utter Pradesh, India. The study was carried out over a period of one year. Ladle and dipping methods were used to collect the larvae of the Aedes mosquito. 48 human habitations were selected randomly from the Bulandshahar region. The accumulated data were used to compute the monthly and seasonal Relative Abundance (RA), Per Man Hour Density (PMHD), House Index (HI) and Container Index (CI) of Aedes species. Three species from the genus Aedes including Aedes aegypti, Aedes albopictus, and Aedes vittatus identified in the Bulandshahr region. The most prevalent species was Aedes aegypti. The RA, PMHD, HI and CI were highest for Aedes aegypti (53.33%, 36.67, 44.08) followed by Aedes albopictus (28.33%, 19.49, 32.98), and Aedes vittatus (18.33%, 12.62, 15.10) and CI=12.53%. In seasonal population dynamics of Aedes species in relation to meteorological factors, only temperature and rainfall are significant variables (P<0.05) of climate that affect the density of mosquitoes in the study area, with no correlation with the relative humidity. According to the findings, there is a substantial probability of mosquito-borne disease outbreaks. There must be precautions taken because dengue fever outbreaks are frequent in the region. Interventions for prevention are necessary since the region is vulnerable to dengue fever outbreaks and other diseases spread by mosquitoes. Keywords : Aedes aegypti, Aedes albopictus, Aedes vittatus, Bulandshahr, Mosquito diversity. Seasonal prevalence.

Arboviral disease outbreaks, Aedes mosquitoes, and vector control efforts in the Pacific

Recurring outbreaks of mosquito-borne diseases, like dengue, in the Pacific region represent a major biosecurity risk to neighboring continents through potential introductions of disease-causing pathogens. Aedes mosquitoes, highly prevalent in this region, are extremely invasive and the predominant vectors of multiple viruses including causing dengue, chikungunya, and Zika. Due to the absence of vaccines for most of these diseases, Aedes control remains a high priority for public health. Currently, international organizations put their efforts into improving mosquito surveillance programs in the Pacific region. Also, a novel biocontrol method using Wolbachia has been tried in the Pacific region to control Aedes mosquito populations. A comprehensive understanding of mosquito biology is needed to assess the risk that mosquitoes might be introduced to neighboring islands in the region and how this might impact arboviral virus transmission. As such, we present a comprehensive review of arboviral disease outbreak records as well as Aedes mosquito biology research findings relevant to the Pacific region collected from both non-scientific and scientific sources.

Questionnaire-Based Analysis of Adverse Events and Compliance with Malaria Chemoprophylaxis in Taiwan

Malaria was eradicated in Taiwan in 1952; however, imported malaria cases are reported every year. The subtropical climate in Taiwan permits mosquito propagation and possible outbreaks of mosquito-borne diseases. The aim of this study was to investigate travelers' compliance and side effects of malaria prophylaxis to prevent a malaria outbreak in Taiwan. In this prospective study, we enrolled travelers who visited our travel clinic before going to malarious areas. A total of 161 questionnaires were collected and analyzed. Associations between the occurrence of side effects and compliance with antimalarial drugs were analyzed. Adjusted odds ratios were calculated after adjusting for potential risk factors in multiple logistic regression analysis. Of the 161 enrolled travelers, 58 (36.0%) reported side effects. Insomnia, somnolence, irritability, nausea, and anorexia were associated with poor compliance. Mefloquine was not associated with more neuropsychological side effects than doxycycline. Multiple logistic regression analysis showed that chemoprophylaxis compliance was affected by a younger age, visiting friends and relatives, visiting the travel clinic more than 1 week before the trip, and preferring to use the same antimalarial regimen on the next trip. Our findings could provide information to travelers besides labeled side effects to improve compliance with malaria prophylaxis and consequently help to prevent malaria outbreaks in Taiwan.

Culex Y Virus: A Native Virus of Culex Species Characterized In Vivo.

Mosquitoes are vectors of various pathogens that cause diseases in humans and animals. To prevent the outbreak of mosquito-borne diseases, it is essential to control vector populations, as treatment or vaccination for mosquito-borne diseases are often unavailable. Insect-specific viruses (ISVs) have previously been described as being potentially helpful against arboviral disease outbreaks. In this study, we present the first in vivo characterization of the ISV Culex Y virus (CYV). CYV was first isolated from free-living Culex pipiens mosquitoes in 2010; then, it was found in several mosquito cell lines in a further study in 2018. For mammalian cells, we were able to confirm that CYV does not replicate as it was previously described. Additionally, we found that CYV does not replicate in honey bees or locusts. However, we detected replication in the Culex pipiens biotype molestus, Aedes albopictus, and Drosophila melanogaster, thus indicating dipteran specificity. We detected significantly higher mortality in Culex pipiens biotype molestus males and Drosophila melanogaster, but not in Aedes albopictus and female Culex pipiens biotype molestus. CYV could not be transmitted transovarially to offspring, but we detected venereal transmission as well as CYV in mosquitos' saliva, indicating that an oral route of infection would also be possible. CYV's dipteran specificity, transmission routes, and killing effect with respect to Culex males may be used as powerful tools with which to destabilize arbovirus vector populations in the future.

Facebook and mosquito-borne disease outbreaks: An analysis of public responses to federal health agencies' posts about dengue and Zika in 2016.

Responses of Facebook users to four United States federal health agencies' social media posts about dengue and Zika (mosquito-borne diseases), surveillance, and control during the Zika outbreak in 2016 were tracked. Official Facebook pages of health agencies were analyzed, and a qualitative analysis program was used to perform a thematic analysis of the data on public responses to health agency posts. Public sentiment analysis showed that Facebook users had a negative sentiment towards health information observed in this study. Themes were identified in the studied posts, giving insight into the nature of public discussions and responses to federal health agencies. Themes were assessed based on the way the agencies' mosquito-borne disease information was received by the public through the social media platform, Facebook. Results indicate that public perception/understanding of mosquito-borne disease outbreaks can be assessed by analyzing public interactions with health agencies on Facebook. The importance of maximizing effectiveness by addressing issues in sharing health education information, risk communication, and monitoring of public responses by health agencies through social media platforms is discussed.

A Study on Mosquito Density and Trend of Larval Indices from a Hospital Campus of Rural Area, Thrissur District Kerala

Introduction: Dengue is one of the most important arboviral disease in Kerala. Development of the control measures mainly depends upon the knowledge regarding the bionomics of mosquito. The larval indices are one of the methods of entomological surveillance, which can predict the outbreak of mosquito borne diseases. The hospital premises need to be mosquito free and need to be safe place for staff and patients. Hence, the present study was done to calculate the standardized larval indices, trends and to determine major breeding source in hospital campus of, Thrissur district, Kerala.

LARVICIDAL ACTIVITY OF THE METHANOLIC EXTRACT OF Warbugia ugadensis SEED OIL ON Aedes aegypti

Mosquito is a vector implicated with Vector-borne diseases such as malaria (Anopheles’ species) dengue (Aedes species) and west Nile fever (Culex species). Kenya experiences mosquito-borne disease outbreaks with the recent ones being the dengue virus and chikungunya disease outbreak that occurred along the coast of Kenya. Medicinal plants such as Warburgia ugandensis that possess larvicidal activity, have major importance in the control of mosquitoes. This study investigated the larvicidal activity and phytochemical screening of the methanolic extract from the seed’s oil of Warburgia ugandensis. Quasi-experimental research design was used as the study design. The plant was identified and authenticated by a taxonomist. Mature fruits of Warburgia ugandensis were obtained from the school of pharmacy’s botanical garden and seeds were separated and washed. Seeds were air-dried, and crushed. Half of the GSP was used to extract seed oil while the other half was subjected to various phytochemical screening. The larvicidal activity of the plant extracts was evaluated according to the World Health Organization guidelines for laboratory and field testing of mosquito larvicides. The activity of the methanol plant extract was evaluated at 25, 50, 100, and 125 ppm to determine the LC50 value. Permethrin was used as a positive control. About 8.06% of the seed oil was extracted. The seed oil and the leaves had a characteristic odour, a bitter taste, and pale yellow in color. Alkaloids, fixed oils, tannins, and phytosterols were abundantly present in the seed. Proteins and carbohydrates were moderately present while saponins were slightly present. Bioassays on mosquito larvae indicated larvicidal activity of methanolic seed oil extract of Warburgia ugandensis against Aedes aegypti at concentrations of 25, 50, 100, and 200 ppm. Seed oil of Warbugia ugandensis contains phytochemicals that possess larvicidal activity against Aedes aegypti mosquito species. Keywords: Larvicidal Activity, Lethal Concentration, Lethal Dose, Warburgia Ugandensis

Mosquito (Diptera: Culicidae) diversity and medical importance in Koh Kong mangrove forests, Cambodia.

Mangroves are an ecosystem interface between land and sea, forming distinctive shallow-water marine communities in tropical and subtropical waters. The mangrove forest surface in Cambodia is being reduced due to deforestation. Because the mangrove type of ecosystem generally hosts a great diversity of mosquitoes, the urbanization of these ecosystems will increase interactions between humans and wild mosquitoes, and might thus serve as a potential source of new infectious diseases. Understanding mosquito diversity and analyzing their virome is critical to estimate the risk of emergence or future outbreaks of mosquito-borne diseases. To understand the mosquito diversity of mangrove forests of Koh Kong province (Cambodia). In 2019, the mosquito fauna was sampled for 3 consecutive days using BG-Sentinel and light traps, in 3 locations in the mangrove forests of Koh Kong province (Cambodia) during both dry and rainy seasons. A total of 3107 samples were collected, belonging to 10 genera for 34 species. The Culex genus was the most diverse, accounting for 10 species. One species, Culex sitiens, represented over 60% of all collected mosquitoes. A total of 12 medically important species were recorded, 2 species, Aedes (Stegomyia) albopictus and Culex vishnui, were collected in all sites and during both the dry and rainy seasons, highlighting a potential risk of these species acting as bridge vectors. If new arboviruses were to be recorded in this peculiar area, it would indicate that the mosquito species found have the potential to act as a bridge between sylvatic and anthropogenic arboviruses.

Mapping the Distributions of Mosquitoes and Mosquito-Borne Arboviruses in China.

The geographic expansion of mosquitos is associated with a rising frequency of outbreaks of mosquito-borne diseases (MBD) worldwide. We collected occurrence locations and times of mosquito species, mosquito-borne arboviruses, and MBDs in the mainland of China in 1954−2020. We mapped the spatial distributions of mosquitoes and arboviruses at the county level, and we used machine learning algorithms to assess contributions of ecoclimatic, socioenvironmental, and biological factors to the spatial distributions of 26 predominant mosquito species and two MBDs associated with high disease burden. Altogether, 339 mosquito species and 35 arboviruses were mapped at the county level. Culex tritaeniorhynchus is found to harbor the highest variety of arboviruses (19 species), followed by Anopheles sinensis (11) and Culex pipiens quinquefasciatus (9). Temperature seasonality, annual precipitation, and mammalian richness were the three most important contributors to the spatial distributions of most of the 26 predominant mosquito species. The model-predicted suitable habitats are 60–664% larger in size than what have been observed, indicating the possibility of severe under-detection. The spatial distribution of major mosquito species in China is likely to be under-estimated by current field observations. More active surveillance is needed to investigate the mosquito species in specific areas where investigation is missing but model-predicted probability is high.

Vector control strategies in Brazil: a qualitative investigation into community knowledge, attitudes and perceptions following the 2015–2016 Zika virus epidemic

ObjectiveThe World Health Organization declared a Public Health Emergency of International Concern following the rapid emergence of neonatal microcephaly in Brazil during the 2015–2016 Zika virus (ZIKV) epidemic. In response,...

Erratum: "The Complex Epidemiologic Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping Review".

Vol. 129, No. 12 ErratumOpen AccessErratum: “The Complex Epidemiologic Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping Review”is correction ofThe Complex Epidemiological Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping Review Jenna E. Coalson, Elizabeth J. Anderson, Ellen M. Santos, Valerie Madera Garcia, James K. Romine, Joy K. Luzingu, Brian Dominguez, Danielle M. Richard, Ashley C. Little, Mary H. Hayden, and Kacey C. Ernst Jenna E. Coalson https://orcid.org/0000-0002-8591-5642 Search for more papers by this author , Elizabeth J. Anderson Search for more papers by this author , Ellen M. Santos Search for more papers by this author , Valerie Madera Garcia Search for more papers by this author , James K. Romine Search for more papers by this author , Joy K. Luzingu Search for more papers by this author , Brian Dominguez Search for more papers by this author , Danielle M. Richard Search for more papers by this author , Ashley C. Little Search for more papers by this author , Mary H. Hayden Search for more papers by this author , and Kacey C. Ernst Search for more papers by this author Published:28 December 2021CID: 129001https://doi.org/10.1289/EHP10706AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail A coauthor was inadvertently excluded from the author list of this manuscript. The author list should read: Jenna E. Coalson, Elizabeth J. Anderson, Ellen M. Santos, Valerie Madera Garcia, James K. Romine, Joy K. Luzingu, Brian Dominguez, Danielle M. Richard, Ashley C. Little, Mary H. Hayden, Kacey C. ErnstThe authors regret the error.FiguresReferencesRelatedDetailsRelated articlesThe Complex Epidemiological Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping ReviewSep 28, 2021, 12:00:00 AMEnvironmental Health Perspectives Vol. 129, No. 12 December 2021Metrics Downloaded 268 times About Article Metrics Publication History Manuscript received1 December 2021Manuscript accepted3 December 2021Originally published28 December 2021 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Seasonal Prevalence and Host Preference of Some Medically Important Aedes Species of Doon Valley, India

In the recent past, several outbreaks of mosquito-borne diseases in Dehradun city make it necessary for a comprehensive understanding of man-vector contacts, disease transmission and determination of appropriate resting sites for adult mosquitoes. The study was conducted within the periphery of Dehradun city in Doon valley, Uttarakhand state, India consisting of eight (08) locations namely Sahaspur, Premnagar, Raipur, Karanpur, Sahastradhara, Dudhli, Doiwala and Rani Pokhri with the objective to analyze and assess the seasonal prevalence and host choice of the mosquitoes with special reference to Aedes species. Among the eight locations of the current study, Raipur registered the highest mosquito abundance (17%) trailed by Sahaspur (16%) and Karanpur (15%). A low abundance of mosquitoes was registered conjointly from Doiwala and Rani Pokhri areas (9% from each area). In these areas, the profile plots of the 2-way ANOVA displayed the highest variation for the data collected from human habitations followed by bovine sheds, whereas the lowest recorded variation was from the poultry. With regards to seasonal prevalence, the highest mosquito abundance was registered during the monsoon followed by the post-monsoon. In provender analysis, a total of 1912 blood meals were collected for antibody test among which 1851 were found positive, with the highest reaction with human antisera (57.75%), followed by bovine antisera (21.34%) and pigs antisera (4.97%). Ae. aegyptihad the highest Anthropophilic Index (A.I.) with 68.78%, followed by Ae. albopictus (64.89%) and Ae. vittatus (55.55%). However, Human Blood Predominance (H.B.P.) and Pure Human Blood Pervasiveness (P.H.B.P.) were found highest for Ae. albopictus with values 0.43 and 0.44 respectively. The results also show the seasonal prevalence and feeding habits of these vectors. This study would be helpful in formulating season-wise strategies for the control of Aedes vector mosquitoes in different eco-epidemiological situations.

The Complex Epidemiological Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping Review.

Background:Climate change is expected to increase the frequency of flooding events. Although rainfall is highly correlated with mosquito-borne diseases (MBD) in humans, less research focuses on understanding the impact of flooding events on disease incidence. This lack of research presents a significant gap in climate change–driven disease forecasting.Objectives:We conducted a scoping review to assess the strength of evidence regarding the potential relationship between flooding and MBD and to determine knowledge gaps.Methods:PubMed, Embase, and Web of Science were searched through 31 December 2020 and supplemented with review of citations in relevant publications. Studies on rainfall were included only if the operationalization allowed for distinction of unusually heavy rainfall events. Data were abstracted by disease (dengue, malaria, or other) and stratified by post-event timing of disease assessment. Studies that conducted statistical testing were summarized in detail.Results:From 3,008 initial results, we included 131 relevant studies (dengue , malaria , other MBD ). Dengue studies indicated short-term () decreases and subsequent (1–4 month) increases in incidence. Malaria studies indicated post-event incidence increases, but the results were mixed, and the temporal pattern was less clear. Statistical evidence was limited for other MBD, though findings suggest that human outbreaks of Murray Valley encephalitis, Ross River virus, Barmah Forest virus, Rift Valley fever, and Japanese encephalitis may follow flooding.Discussion:Flooding is generally associated with increased incidence of MBD, potentially following a brief decrease in incidence for some diseases. Methodological inconsistencies significantly limit direct comparison and generalizability of study results. Regions with established MBD and weather surveillance should be leveraged to conduct multisite research to a) standardize the quantification of relevant flooding, b) study nonlinear relationships between rainfall and disease, c) report outcomes at multiple lag periods, and d) investigate interacting factors that modify the likelihood and severity of outbreaks across different settings. https://doi.org/10.1289/EHP8887