PARTNERSHIPS FOR ENHANCED ENGAGEMENT IN RESEARCH (PEER) HEALTH
Principal Investigator: Isra Wahid, Universitas Hasanuddin
NIH-Supported Collaborator: David Severson, University of Notre Dame
Title of NIH Award: Diapause in Culex mosquitoes
Project dates: October 2013 - April 2017
Arthropod-borne viruses are a concern in areas like Indonesia (an emerging pathogen ‘hotspot’) because of the ease with which vectors can transfer RNA viruses between wildlife, humans and livestock, and because of the large variety of pathogenic viruses already known to exist. However, there are no known records of these pathogenic viruses (such as West Nile, Sepik, Banna) in Indonesia though they are known to exist at similar latitudes. Dengue virus, present in Indonesia, is an emerging global health threat, and disease prevention depends completely on avoiding the mosquito host that transmits the virus from human to human. No other dengue disease prevention or treatment methods exist. Preliminary evidence suggests that there may be differences in allele frequencies related vector competence to transmit Dengue virus. This study seeks to understand the genetic composition of mosquito populations seasonally and among communities in order to predict levels of mosquito diversity and movement within and between communities, and to assess vector competence to transmit dengue viruses throughout a transmissions season. This study will make a survey of potentially pathogenic arboviruses from mosquitoes collected throughout Indonesia aimed at identifying viruses, their vectors, as well as temporal transmission characteristics towards discovery and informing intervention programs. The primary objective of this study is to survey for potentially pathogenic mosquito-borne arboviruses in their vectors to geographically map risk, estimate force of infection, and identify potential emerging pandemic threats. A secondary objective focusing on the dengue virus vector will investigate if there is a temporal change in the vector genotype with associated impacts on vector competence between the wet and dry seasons. This study will entail systematic collections of mosquitoes in all ecological zones prevalent on the island of Sulawesi. The study team will identify vectors to species to determine the diversity of mosquitoes and ID those known to harbor human pathogens. The researchers will also perform virus isolation in vertebrate cell cultures towards virus identification. Finally, the researchers will examine seasonal effects on Ae. aegypti population genetics and DENV susceptibility. It is expeced that the study team will collect circulating viruses that have never been recorded at these sites and the possibility exists of identifying novel viruses in the preliminary survey. Vector results will enable the characterization of geographic vector-virus transmission systems and will allow a better understanding of local dengue transmission and hence better intervention strategies.
|Mosquito capture nets placed between the village and the mosquito breeding site.||Mosquito collection efforts by Dr. Wahid and his team (photo courtesy Dr. Wahid)|| |Health Cycle 1 Recipients
Summary of Recent Activities:
As of March 2017, with the help of partners from other islands in the Eastern Indonesian regions the team collected Aedes eggs for the dengue vector competency study under PEER. Eggs collected were from the wet season, following the dry season collection from last year. The USG-partner at Notre Dame University has performed analysis of seasonal variation of dengue vector competence and the seasonal variation of allele frequency from the dry season egg collection and will perform analysis on the wet season eggs as well. Another main research output under this PEER project was the cataloging of mosquito samples from various regions of Indonesia. There have been more than 90K mosquito samples collected from 2014 and 2015. Of all the mosquito samples collected, 60,000 are stored in liquid nitrogen and the remaining samples were put in RNA later solution and stored at - 20 degree Celsius freezer. The research team started sample analysis for molecular identification of mosquito vectors and arboviruses harbored by the mosquitos collected. This required the preparation of several DNA virus controls, which occurring during the reporting period. To perform the identification, the team is using an anonymous archive serum with dengue positive to represent flavivirus and chikungunya positive as the representative for alphavirus. Control for bunyavirus was made by artificial DNA derived from bunyavirus sequences. However, this viral positive control is in the process of being sent from CDC-Colorado to the lab in Indonesia. Additional activities under PEER included the collecting of more mosquitoes from Papua, East Nusa Tenggara, and establishing a new research station at Arra village of Tompobulu, Maros-South Sulawesi to allow for longitudinal mosquito collecting.
The research lab, supported by USAID PEER funding, accepted a PhD student from Roma Tree University, Rome to conduct research on primate parasites. The PhD student will perform analysis of parasites in feces of Macaca maura (endemic monkey species in National Park in Sulawesi that located around human dwelling in Maros Regency) with the support of our lab facilities (especially parasite staining and microscopy) and the PI Isra Wahid will serve as his co-advisor. While conducting research in the lab, the PhD student will organize weekly English language class for lab staff and interested students. The lab also hosted researchers from Kitasato University, Japan focused on work related to soil parasites and leprosy. In 2017, the PEER PI’s lab will host 2 graduate students from the USAID Research and Innovation Fellowship program.
The research team had several knowledge translation activities. The PI was invited to the CDC Zika Summit held in Atlanta (February 2017) where he presented his findings of an innovative approach on low season vector control intervention. Due to the exposure of the presentation at CDC, the Ministry of Health is now in the process of modifying low season vector control interventions in other cities in Indonesia. The research team has been successful in obtaining two grants. The first is funded by UNICEF to study the dynamics of P. knowlesi transmission in Sabang-Aceh, Indonesia. The second will study Aedes aegypti in coastal areas and the risk of preserving dengue transmission by brackish water population of the larvae, funded by the Indonesian Science Fund (DIPI).