WASHINGTON – There is no indication yet that the deadly West Nile virus has infected humans in Maryland, after the discovery of an infected bird in Baltimore, state health officials said.
A case of encephalitis reported Friday morning was being reviewed, along with other encephalitis cases reported in the state since mid-October. But the possibility that any of these were linked to the West Nile virus was very low, officials said.
“We are not aware of anyone who is sick from this virus now. The risk to Maryland citizens is very low,” said Georges C. Benjamin, secretary of health and mental hygiene.
He said the onset of cold weather “is the best thing to have happened,” because it kills mosquitoes that can spread the disease to humans.
Benjamin said it has not been determined if the infected crow found in Baltimore had migrated from New York, where West Nile virus has killed six people since August. Connecticut is the only other state outside New York where the virus has been found in dead birds.
The West Nile virus, which can be transmitted from birds to humans only by mosquitoes, can cause encephalitis, a potentially fatal disease. No mosquitoes from Maryland have been tested for the virus yet.
The state is continuing to collect bird samples and is encouraging people who find large numbers of dead birds to call a 24-hour hotline, 1-888-584-3110. The hotline had received 70 calls since it was set up in mid-September, but it got several Friday after news of the infected bird was reported, a Department of Natural Resources spokesman said.
Maryland sent 34 crows to be tested for the virus, including samples from a group of 15 crows found dead in Howard County two weeks ago. Except for the Baltimore bird, the virus has not been confirmed in any of the other crows, a state health department spokesman said.
Health officials have asked hospitals all over the state to keep an eye out for people with symptoms of the West Nile virus or encephalitis.
Jeffrey Roche, chief of clinical epidemiology in the state health department, said the encephalitis cases reported recently in Maryland were not geographically clustered, as would have been the case with a West Nile virus infection. But chances of a West Nile infection have not been ruled out totally in some cases pending test results, he added.
Apart from encephalitis, a West Nile virus infection can cause symptoms that include headache, fever and body aches, often with skin rash and swollen lymph glands. More severe infection is marked by high fever, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions, and paralysis.
Currently, there is no vaccine against the virus, nor any specific therapy for its treatment. Persons most at risk from the virus are those with weak immune systems and the elderly.
The federal Centers for Disease Control and Prevention is working with “states up and down the eastern seaboard. They’ve been regularly sending us samples,” said spokesman Tom Skinner.
Testing is also being carried out on blood samples taken from 32 ducks in Maryland, after ducks in New York were found to be carrying the virus.