The Maryland Department of Agriculture (MDA) and the Maryland Department of Health and Mental Hygiene (DHMH) collaborate to conduct a surveillance program to detect mosquito-borne viruses of public health concern. The program monitors the occurrence of Zika Virus, eastern equine encephalitis (EEE) virus, West Nile virus (WNV), St. Louis encephalitis (SLE), and other viruses in mosquitoes, wild birds, domestic animals, and humans. These viruses are maintained in nature in mosquito cycles. Isolation of viral presence in the mosquito cycle provides an early warning of virus transmission and is cause for increasing public awareness campaigns to reduce the risk of disease and to take proactive steps for mosquito control to further reduce the risk to humans, domestic animals, and zoo animals.
West Nile virus has affected every region of Maryland and is now considered as being endemic throughout the state.