Antibodies to Aedes aegypti D7L salivary proteins as a new serological tool to estimate human exposure to Aedes mosquitoes

IntroductionAedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes. MethodsWe tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG. ResultsWe found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue. DiscussionThe IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion

Cambodia (2005): MAP Study Evaluating Coverage and Quality of Coverage of Hormonal Contraceptives and Condoms in Urban and Rural Areas First Round

Project Measuring Access and Performance (MAP) aims to assess or gauge the coverage, quality, equity of access and efficiency of product social marketing and service delivery systems. Project MAP was undertaken to determine the coverage and quality of coverage of PSI/Cambodia's HIV and birth spacing (BS) products (Number One Condom, Number One-Plus Condom, OK Condom, OK Pill and OK Injection) in rural, urban, and Phnom Penh areas. Lot Quality Assurance Sampling (LQAS) was used to draw a sample of 19 areas within each geographic category. Geographic categories in which data were collected are: Rural areas (nineteen villages), an urban area (Kampong Cham provincial town; selected randomly from among all provincial capitals, and divided into nineteen zones) and a hyper urban area, Phnom Penh (nineteen Sangkats)

Serologic Evidence of Human Exposure to Bat-Borne Zoonotic Paramyxoviruses, Cambodia

Fruit bats in the genus Pteropus are the natural reservoirs for zoonotic paramyxoviruses, notably henipaviruses and pararubulaviruses, which are found across Southeast Asia and Oceania. The genetic and antigenic diversity of viruses in both genera, and region specificity, are ill-defined, limiting health security measures aimed at minimizing spillover. For example, Nipah virus has been isolated from bats in the Battambang province of western Cambodia, and surveys suggest bat foraging behaviors occur in close proximity to human settlements. However, there have been no historical cases of Nipah virus in Cambodia. Here, we use a multiplex microsphere immunoassay to identify cryptic human exposure to selected henipaviruses and pararubulaviruses in Cambodia. Convalescent human sera from persons presenting with acute respiratory illness were screened to detect the presence or absence of antibodies reactive with attachment glycoprotein antigens from Nipah virus, Hendra virus, Cedar virus, and Ghana virus, and a hemagglutinin-neuraminidase antigen from Menangle virus. In this sero-survey, we detected antibodies that were specifically reactive with Cedar virus and Menangle virus, including one serum sample that neutralized a recombinant Cedar virus. Additionally, we detected a pattern of cross-reactivity with Hendra virus, Cedar virus, and Ghana virus, suggesting previous infection by an antigenically-related henipavirus. We did not detect high antibody reactivity with the NiV glycoprotein. Future studies should expand serological surveillance for these transboundary pathogens, including genetic surveillance to aid in henipavirus discovery, and focused biosurveillance where interfaces with livestock and humans occur

Table_1_Antibodies to Aedes aegypti D7L salivary proteins as a new serological tool to estimate human exposure to Aedes mosquitoes.docx

IntroductionAedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes. MethodsWe tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG. ResultsWe found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue. DiscussionThe IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion. </p

DataSheet_1_Antibodies to Aedes aegypti D7L salivary proteins as a new serological tool to estimate human exposure to Aedes mosquitoes.docx

IntroductionAedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes. MethodsWe tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG. ResultsWe found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue. DiscussionThe IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion. </p