Teams selected to review current knowledge on Zika vectors

TDR news item
5 April 2017

Two scientific teams have been selected by TDR for a review of current knowledge on Zika mosquito vectors. The work to inform global research priorities for Zika virus disease is supported by an initiative led by the World Health Organization (WHO) to prevent and limit the impact of the disease and its complications.

Aedes mosquito
Aedes mosquito
Credit: WHO

To date, 84 countries and territories have reported evidence of Zika virus transmission. Zika virus is endemic in Africa, has been reported in South-East Asia and the Pacific islands and is becoming established in the Americas and the Caribbean.

Better characterization of the mosquito vector in different environments, and new vector control strategies for diverse settings, are at the top of the research agenda in Zika-affected areas, according to WHO.

“TDR is the only programme based at WHO that focuses on vector research to reduce vector-borne infectious diseases, so it was natural that we commission this review,” says Florence Fouque, head of TDR’s Vectors, Environment and Society unit.

Systematic review of existing literature and data is the primary method of each study. These reviews will identify gaps in current knowledge and recommend research priorities for next steps, she explained.

“These analyses should increase our understanding of the natural history of the Zika virus vectors in the wild in Africa, as well as how different vectors behave in new environments where the virus has recently moved,” she explains.

“We expect the investigations to result in a new hypothesis on transmission patterns and entomological indicators for the mosquito species of highest concern to human transmission,” she explains. “In other words, a new way to track the transmission force, or probability, of different mosquitos to infect people with Zika virus.”

In addition to formulating research questions about the Zika virus vectors, review groups will add to the discussion and definition of new vector control strategies for households and communities to reduce virus transmission to people.

“Research priorities drawn from this work should influence the global response to Zika virus disease and advance public health measures to prevent it,” says Fouque.

“This is critical public health work,” she says. “Avoiding bites from mosquitos through personal or community-level protective measures is the best prevention we have to protect pregnant women, their babies, and all other vulnerable people from Zika virus disease.”

Review topics and selected groups

The two selected teams, led by investigators from Zika-affected countries, will focus on separate topics.

Topic 1: The first group will review the natural history of the Zika virus transmission “in the wild” in endemic areas (in Africa). Scientists will also review published literature and data on vector competence, or the ability of these mosquito vectors to acquire, maintain and transmit the Zika virus.

This team will be led by researchers at the Pasteur Institute of Guadeloupe in the French West Indies, in collaboration with scientists from Instituto de Medicina Tropical “Pedro Kourí” in Cuba, University of Texas Medical Branch in the U.S., and Instituto Oswaldo Cruz (Fiocruz) in Brazil.

Topic 2: The second team will review the ecology and feeding patterns of mosquito vectors found positive for Zika virus in the current epidemic, and propose entomological indicators of mosquito species (data that is feasible to track and characterize the vector and its transmission force) in rural and urban settings.

Scientists at the Autonomous University of Yucatan in Mexico will lead this group, with researchers from the Institute of Public Health at University of Heidelberg in Germany and the Naval Medical Research Center Detachment (NMRCD) of University of California (UC Davis) in Iquitos, Peru.

The research consortiums were selected through a competitive process among 15 applications.

Findings from the commissioned reviews are expected in summer 2017. Results will be presented and discussed with vector-borne diseases specialists at the official launch of the TDR-supported Caribbean Network, to be held in Cuba in August, during the upcoming 15th International Dengue Course: “Challenges of Zika and Chikungunya transmission.”

For more information, please contact Jamie Guth