SNOW HILL – The first West Nile Virus case in Maryland this year may have sprung up in Worcester County last week, say local and state health officials, but the diagnosis has not yet been proven correct.
Tests confirming the illness should be back in early September, according to Karen Black of Maryland’s Department of Health and Mental Hygiene (DHMH). “The test is still pending,” she said.
The results could be back as soon as the first week of September, said Becky Shockley, director of Community Health Nursing and Emergency Preparedness at the Worcester County Health Department.
Health officials would not reveal age or sex of the patient, citing confidentiality, but Shockley did say that the patient is an adult.
If confirmed, this would be the first West Nile Virus case in Worcester County in two years. West Nile Virus is a mosquito borne disease that first appeared in the U. S. in 1999.
West Nile Virus patients can exhibit a variety of systems, which range in severity, beginning three to 15 days after the infecting bite. According to DHMH, less than one percent of those infected will develop severe symptoms, such as high fever, coma, convulsions and paralysis. Most experience mild fevers, headaches, and body aches and sometimes swollen lymph glands and a rash.
“It is not recommended that tests be done for mild symptoms of West Nile Virus,” said Shockley. “There’s no one symptom that indicates that it’s West Nile Virus. The serious symptoms are a very high fever. Anytime somebody has a very high fever, that may be a symptom of many diseases. You should contact your doctor.”
The risk of contracting the disease correlates with mosquito numbers.
“Mosquito population had been very low in Worcester County up until the last week. The population is now higher than normal in many coastal areas of the Lower Eastern Shore counties, which is expected to continue until mid-September,” said Cy Lesser, head of mosquito control for the Maryland Department of Agriculture.
The Worcester County mosquito population has been low for the last two years.
“We’re running about a third of what we were last year,” Lesser said.
The recently increased adult mosquito population stems not from recent torrential rains, but from a very high tide during the new moon in mid-August, said Lesser, which flooded dry marshes and hatched out mosquito larvae.
“Right after the mosquito hatch in mid-August we started larvaciding quite heavily,” said Lesser.
The MDA mosquito control program has also been spraying for adult mosquitoes recently.
“We’ve also stepped up the surveillance of the adult mosquito population, taking samples from more areas than we typically do,” said Lesser.
The adult mosquitoes are trapped and sent to a Maryland DHMH lab in Baltimore for testing for West Nile Virus.
There has been little West Nile Virus detected in Maryland the last four years, peaking in 2003 with 73 people testing positive and eight fatalities. Only six human cases appeared statewide in 2006.
“We’ve not seen any evidence of any transmission at all this year,” said Lesser, until this possible case in Worcester County.
DHMH records indicate that there has been only one other case in Worcester County since the disease entered the U.S. in 1999, and no fatalities.
“We’ve been fortunate in Worcester County,” said Lesser. “We’re not really sure why that is.”
Surprisingly, the virus has never had a strong presence on the Eastern Shore, despite the high local mosquito population.
“On the Eastern Shore in general West Nile has not been as pervasive as in the metropolitan and suburban counties,” Lesser said. “It is a puzzle.”
Eastern Equine Encephalitis (EEE), another mosquito-borne disease with some similar effects on humans, has historically been present on the Eastern Shore, thriving in a mosquito common to the Pocomoke River basin. EEE has not been seen recently, however, despite being found in several horses a few years ago.
Lesser urged people to take precautions to prevent mosquito bites and to vaccinate horses and dogs against mosquito carried diseases like West Nile Virus, EEE, and in the case of dogs, heartworms. There is no West Nile Virus vaccine for humans.
Shockley said that people should be concerned over mosquito-borne diseases and should take steps to prevent contact with mosquitoes.
People need to stay inside when mosquitoes are busiest at dawn and dusk, and use mosquito-repellant on exposed skin when outside. Long sleeved shirts and pants will protect better than T-shirts and shorts. Screens on windows, doors, and porches need to be hole-free.
Standing water in flower pots, old tires and other containers that hold water should be dumped out or removed. Wading pools, wheelbarrows and the like should be turned over when not in use.
Water can also accumulate on pool and boat covers, garbage can lids, and poorly drained areas. Boat bilges should be pumped out, and canoes and other small boats turned over. Pet water bowls and birdbaths should be refreshed with new water regularly. Mosquitoes need just one-quarter inch of water to lay eggs in.