Mosquito study could help fight Rift Valley fever
Scientists have identified the average levels of water areas and air temperature that can lead to the permanent removal of mosquito populations and Rift Valley fever.
Fresh insights into mosquito populations in Kenya could help to mitigate the rising threat of the deadly Rift Valley fever, scientists say.
Rift Valley fever presents a growing threat and was recently added to the World Health Organisation’s priority list. Endemic to Africa, it is spread by biting mosquitos and infects both animals and humans.
The spread of disease increases if there are large numbers of infected mosquitos, which is largely controlled by water levels and temperature. A consortium of scientists have identified the average levels of water areas and air temperature that can lead to the permanent removal of mosquito populations and Rift Valley fever.
According to findings published in the journal PNAS, in a region of around 250 acres, the Culex mosquito population will fade out when the surface area of water is under 1000m2, or if the temperature falls below 14ºC.
Meanwhile, if the annual surface of the water is 2000m2, Culex mosquitos will disappear if the mean temperature is below 18ºC or above 31ºC.
Scientists say understanding how mosquito ecology is controlled by water areas and temperature is crucial to estimating the abundance of mosquitos and exploring how the disease spreads. This can help to inform policy makers on the risk of disease in particular areas, when deciding to build a new dam or change irrigation patterns.
Dr Gianni Lo Iacono, from the University of Surrey’s School of Veterinary Science, said: “With increasing temperatures due to climate change, the patterns of vector borne diseases such as Rift Valley Fever will change and potentially become more of a threat to the general population.
“Temporary methods such as using insecticides are useful to remove the short term threats such diseases pose; however, the danger still remains as the mosquito populations will re cultivate and once again spread the disease.
“Learning more about the populations, and implementing methods such as carefully designing the patterns of irrigation, could help to reduce mosquitos and Rift Valley fever infection.”
Defra has published guidance for the vet sector ahead of a proposed UK-EU Sanitary and Phytosanitary agreement.
