Excessive rainfall means an increase in standing water, which creates the perfect breeding ground for mosquitoes, said Nikki Laska, a representative for the Maryland Department of Health, in an email Tuesday.
So far this year, 38 Marylanders have been infected with West Nile, which mosquitoes get from birds and pass on to humans or animals after biting them. That’s seven times higher than in 2017, which saw five cases. There were six cases in 2016, but Maryland saw another high number, 46 cases, in 2015.
The state health department does not release details about victims because of privacy laws.
Most people with the disease show no symptoms, but in severe cases West Nile can attack the central nervous system. About 1 in 150 people who are infected with the virus develop disorders such as encephalitis, or inflammation of the brain, and meningitis, or inflammation of the membranes that surround the brain and spinal cord, according to the Centers for Disease Control and Prevention. People older than age 50 are more likely to come down with more serious symptoms.
Symptoms can appear in two to 14 days and include fever, headache, body aches, skin rash and swollen lymph glands. Fewer than 1 percent of those exposed develop more severe infections, such as headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.
There is no vaccine to treat West Nile. Pain killers can help with some symptoms, but some people may need to be hospitalized and given intravenous fluids.
West Nile cases commonly rise and fall as climate and other factors vary from one year to the next, Laska said.