Deadly Mosquito Sighted For First Time Since 1940’s Thursday 9th February 2012 | Osh The sighting of a mosquito carrying a deadly virus has been spotted for the first time since the 1940’s in England. The mosquito bears the West Nile virus which causes flu- like symptoms and inflammation of the brain and spinal cord. It has been discovered breeding in the south marshes of Kent and South Essex. Experts are now trying to figure out how wide spread the mosquito’s are but so far there haven’t been any victims.