VIDALIA — Adams County had its first reported case of West Nile virus of 2018 confirmed Aug. 6 by the Mississippi State Department of Health.

West Nile virus can cause fever, headache, nausea, vomiting, a rash, muscle weakness and swollen lymph nodes in people who are infected. In the worst cases, the disease can cause encephalitis or meningitis, which can lead to paralysis, coma and possibly death.

However, Ricky Smith, a biologist and owner of Bug Busters Pest Control service in Vidalia, said WNV is rarely fatal and can be avoided with a few simple precautions.

How WNV is transmitted

“(WNV) is mainly carried by mosquitoes,” Smith said. “They carry the disease, they don’t cause it. … The disease is mainly associated with birds during their nesting season.”

Smith said birds are the main carriers of WNV, and some birds die because of it. Still, Smith said some breeds of birds develop immunity to the West Nile virus once they’re exposed — not unlike humans with WNV, chicken pox or other illnesses that can only affect a person once in a lifetime.

Therefore, Smith said WNV is more likely to be transmitted during the summer months of the year, which have both an abundance of newly hatched birds and mosquitoes.

Some species of birds — such as robins — and other animals can carry the virus for a lifetime without ever showing any symptoms, Smith said.

The Mississippi State Department of Health reported that the peak season for the virus is July through September.

As of Thursday, Aug. 9, the state has confirmed 17 known human cases of the West Nile virus this year in 11 counties throughout the state, including two cases in Adams County.

“One thing about West Nile is that it can’t be transmitted from person to person,” Smith said, “not through contact or even mosquito bites. If you have West Nile and a mosquito feeds on you and then feeds on your neighbor, it’s not going to transmit the disease.”

Smith said humans are referred to as “dead-end” hosts for WNV because infected individuals cannot cause another animal to become infected.

“In viral diseases, you have hosts and you have dead-end hosts,” Smith said. “A host is an animal that can get the virus and a mosquito can feed on them and transmit it to other animals. … The ones who can get the disease but do not have a high enough viral load in their blood to transmit it to another are a dead-end host.”

Smith said two common species of mosquitoes in the South carry WNV, the Aedes albopictus — Asian Tiger mosquito — and the Culex quinquefasciatus — Southern House mosquito.

Smith said the Asian Tiger mosquito, which can be identified by distinct white stripes on its abdomen and appendages, is the most common outdoor mosquito and feeds aggressively on humans throughout the day while the Southern House mosquito, which is brown, feeds mostly at night and prefers to live in dark spaces such as closets or cabinets.

The symptoms

Smith said WNV could be particularly difficult to trace unless a medical provider has a specific reason to be looking for it.

“Approximately 80 percent of the people who get WNV will never know they had it,” Smith said. “It won’t hurt them at all. They’ll get it and be immune to it for life with no symptoms, while 19 percent feel like they have the flu. They’ll be achy and fatigued and may have vomiting or diarrhea. … It could be mild or severe. Fatigue could last for months.”

Smith said only 1 percent of those who have WNV experience fatal symptoms that affect the central nervous system, and 0.2 percent that have severe symptoms could die from WNV while 0.8 percent could experience permanent neurological damage.

Smith said older victims and children with weaker immune systems are the most affected by the disease, while most of the population can live without ever knowing they’ve had WNV.

The only way to know for sure is to have a blood test for WNV antibodies, Smith said.

How to prevent WNV

The most common methods used to prevent mosquito bites, and ultimately WNV, malaria or other mosquito-borne illnesses are wearing loose fitting, long and light clothing when going outdoors, Smith said. Also cover exposed skin with mosquito or insect repellant with diethyltoluamide, or DEET, listed as the active ingredient.

Smith said buckets, tires, pools or any kind of standing water in the yard should be drained and cleaned regularly and grass and shrubs should be cut short to reduce mosquito breeding grounds and habitats.

Mosquito-eating fish or mosquito dunks — a type of water pellet — can be added to fountains or ponds that cannot be drained, Smith said, and he highly recommends hiring a commercial pest control contractor for severe infestations of mosquitoes.

“Get a commercial contractor to do mosquito control in your yard,” Smith said. “It will reduce the mosquito population by at least 90 percent. … (City sprays) don’t really help a lot. When cities do mosquito control, they use an adulticide that is only active for one or two hours. … There is no residual effect.”

Smith said the pesticides that Bug Busters and most other commercial pest control services use will last more than a month and will not be harmful to plants, pets or other animals.