Which statement is true about eastern equine encephalitis vectors in Maryland?

Which statement is true about eastern equine encephalitis vectors in Maryland?

• A. Culiseta melanura is the primary bird-to-bird vector for EEE
• B. Aedes aegypti is the primary vector for EEE
• C. Anopheles gambiae is the primary vector for EEE
• D. Ochlerotatus sollicitans is the primary vector for EEE

Answer: (A)

Eastern equine encephalitis virus is kept in nature mainly through a bird–mosquito cycle in swampy woodlands. The key transmitter within birds is Culiseta melanura, which feeds mostly on birds and passes the virus from one bird to another, keeping the virus circulating in the avian population. Humans and horses get infected only occasionally when a different mosquito species, acting as a bridge vector, bites an infected bird and then bites a human or horse. In Maryland, this primary bird-to-bird transmission is driven by Culiseta melanura, making it the best answer. The other species listed are not the main bird-to-bird transmitters for EEE; some are involved in spillover to humans in certain contexts, but they do not sustain the enzootic cycle the way Cs. melanura does.

Eastern equine encephalitis virus is kept in nature mainly through a bird–mosquito cycle in swampy woodlands. The key transmitter within birds is Culiseta melanura, which feeds mostly on birds and passes the virus from one bird to another, keeping the virus circulating in the avian population. Humans and horses get infected only occasionally when a different mosquito species, acting as a bridge vector, bites an infected bird and then bites a human or horse. In Maryland, this primary bird-to-bird transmission is driven by Culiseta melanura, making it the best answer. The other species listed are not the main bird-to-bird transmitters for EEE; some are involved in spillover to humans in certain contexts, but they do not sustain the enzootic cycle the way Cs. melanura does.