By Daniella De Luca
Faculty partners with other universities to study mosquito-transmitted viruses
Most of us don’t give much thought to how mosquito-borne viruses move out of their animal hosts in Africa and infect humans. Yet, it wasn’t so long ago that an African virus, West Nile, arrived in New Mexico, where it continues to cause illness and death in both humans and horses.
Researchers at New Mexico State University are partnering with researchers from the University of Texas Medical Branch, Johns Hopkins University and Institut Pasteur in Senegal to research how mosquito-borne viruses like dengue, chikungunya and yellow fever emerge from non-human primates and infect humans in Senegal, West Africa. They will specifically investigate what ecological factors, like local habitat and mosquito behavior, predispose people to become infected with these viruses. Moreover, they will test whether newly emerged viruses tend to cause disease in humans by taking blood samples from both healthy people from local villages and sick people from local clinics to test whether they have been exposed to any of the viruses being studied.
Kathryn Hanley, NMSU assistant professor of biology, is representing the university over the four-year course of the project and hopes to assist in finding a treatment for mosquito-transmitted diseases. Chris Brown, associate professor of geography and director of the spatial applications research center, is also assisting in the project by analyzing the association between habitat types in Senegal and infection risk.
The group is researching in Kédougou in the southeastern part of Senegal and is helping to identify risk factors for infection. Once these risk factors have been identified the people should be empowered to lower their levels of exposure.
The research is part of the work being done for the National Institutes of Health and National Institute of Allergy and Infectious Diseases. Hanley said the institutes awarded a $2 million grant for this project, specifically to study the circulation of mosquito-transmitted viruses in non-human primate reservoir hosts and the emergence of these viruses into humans.
“Particularly in New Mexico, these viruses are at the gate. We want to understand the source,” Hanley said. She said the effects from the dengue virus were recently found near the Mexico/U.S. border. The symptoms of classic dengue fever are often a high fever, skin rash, pain behind the eyes, nausea and severe joint or muscle pain. Other more serious versions of dengue exist with conditions that could result in shock with a high risk of death.
The research group will retrieve necessary data by surveying monkeys, trapping the animals and taking blood samples. They will also survey mosquitoes by taking water samples from tree holes or catching them as they land on human volunteers.
“Outbreaks of mosquito-transmitted viral diseases like (these) have occurred regularly for centuries, taking a great toll in terms of loss of life and damage to local economies,” said Marvin Bernstein, NMSU biology department head.
Mosquito-transmitted viruses are not necessarily always obtained in tropical environments.
Hanley said Farmington, N.M., was the last area in which malaria was eradicated while West Nile virus is present throughout New Mexico. The West Nile virus is a “close cousin” of the dengue virus, although not the main area of focus for the research team. Chikungunya, the third virus the team is researching, gives infected individuals symptoms similar to dengue, in addition to cramped joints. While not always life-threatening, symptoms can last a few weeks or even months, according to the Center for Disease Control Emerging Infectious Diseases Web site. Although, chikungunya has been documented as the cause of death in recent outbreaks in India and Réunion Island. The vector for chikungunya occurs in New Mexico, Hanley said.
The team is also researching the frequency in which the viruses appear in West Africa. One of the motivations for this research is that the mosquito vectors for dengue and chikungunya occur in the southern U.S. including southern New Mexico. Risk of introduction to these viruses to the U.S. is, therefore, quite high, particularly because an infected person could board an airplane in West Africa and land at the El Paso airport in less than a day. In fact, the infection would not necessarily have to originate in West Africa because in 2007 chikungunya caused a major outbreak in northern Italy, Hanley said.
Collaborators from other universities include Scott Weaver, vice chair for research and professor of pathology at the University of Texas Medical Branch; Derek Cummings, assistant professor of epidemiology at Johns Hopkins University; and two faculty members from Institut Pasteur, Mawlouth Diallo and Amadou Alpha Sall.
“The results from this group’s collaboration will shed light on the mechanisms by which such viruses move from non-human primates to humans and suggest ways on how to prevent the transmission,” Bernstein said.
Editor’s Note: Dr. Kathryn Hanley, assistant professor of biology at NMSU’s College of Arts and Sciences, was a contributor to this article.