Renewed vigilance over the biosecurity of the Galpagos Islands is needed, based on new research on the risk posed by West Nile virus.
Scientists from the Zoological Society of London (ZSL), the University of Leeds and the New York State Department of Health, together with the Galpagos National Park Service and University of Guayaquil, have been studying the disease threat posed by Islands' mosquito populations. They have discovered that a species of these biting insects is capable of transmitting West Nile virus, a potentially dangerous disease for the archipelago's unique wildlife.
West Nile virus (WNV) most commonly affects birds, but can infect mammals, including humans, and reptiles. Previous studies of West Nile virus impact in the USA have linked the virus to declines in several bird populations, demonstrating the high risk it poses to the Galpagos' endemic species. The virus recently invaded South America, but has yet to reach the Galpagos.
Recent studies on tourist boats and planes have shown that the mosquito species Culex quinquefasciatus (also known as the Southern house mosquito) is hitching a ride onto the Galpagos on airliners. Culex species are well-known vectors of WNV elsewhere in the world, so their presence on the Islands has caused concern amongst the scientific community.
The ability of mosquitoes to transmit particular disease agents effectively often varies between species, or between populations within species. Therefore to understand the risk posed by C. quinquefasciatus in Galpagos, the research team measured the ability of Galpagos C. quinquefasciatus to pick up and transmit WNV in the lab, under conditions that simulated those in the wild. They found that Galpagos C. quinquefasciatus were indeed effective vectors for the virus.
Prof Andrew Cunningham from ZSL says: "We now know that mosquitoes capable of carrying West Nile virus have a route onto the Galpagos, and once there, the virus could also spread into the
|Contact: Jo Kelly|
University of Leeds