Savannah mosquitoes tested positive for West Nile Virus. Is this a common occurrence?
A sample of the mosquito population in Savannah collected on July 7 by Chatham County Mosquito Control tested positive for West Nile Virus on Monday.
West Nile Virus is a disease that comes from birds and spreads to humans through mosquitoes. Eight in 10 people who contract the virus won’t even know they had it, said Dr. Taras Nebeluk, an infectious disease specialist with Novant Health. Two out of 10 may experience fever, joint aches or body rash.
More rare is the instance of a severe outcome where one in 125 to 150 could develop meningitis which is a condition of brain inflammation. There is also a similar risk of encephalitis, which is inflammation of the surfaces that cover the brain and spinal cord.
People over the age of 50 are at higher risk of developing more severe symptoms according to Nebeluk.
Even with a positive test of the mosquitoes in Savannah, there have been no confirmed cases of human infection this year, according to Will Peebles, Chatham Public Information Officer.
Are the positive tests more common in the summer?
Following the positive test, Carlson said Chatham County is stepping up its catching operations and applying pesticides.
“With West Nile virus being detected, or actually, if there was any mosquito-borne disease detected, it changes those thresholds so we can react faster, potentially, to the virus,” Carlson said.
West Nile Virus in Savannah is common this time of year, Carlson said.
“Unfortunately, it seems like, I think we’re about eight years in a row now where we’ve detected West Nile, about the start of July is pretty common for it,” he said. “Last year, it was about a month earlier we got our first positive, I think on like June 10, and then we had probably our most active West Nile year in 2024, so it being a month later than last year is a little bit better news.”
South Carolina’s Department of Public Health has a surveillance system that includes testing mosquitoes, dead birds, animals and people. If any humans are positive, they will take action to make public health officials aware. If any animals or mosquitoes are positive, they notify local county officials, such as a county administrator, said Dr. Chris Evans. Evans is the state’s entomologist.
How West Nile Virus is treated
There is no vaccine or treatment for West Nile Virus. but the results of contracting the resulting illnesses can be serious. Experts also admit that the likelihood of humans contracting a severe case is small.
“It’s essentially supportive care, fluids and pain management,” Nebeluk said.
The virus does not spread from person to person. Mosquitoes pick up the virus almost always from birds, Carlson said.
The more severe cases, such as the ones that develop meningitis and encephalitis, are the ones that have threat of severe, long-term effects such as a polio-like paralysis.
For cases showing symptoms, long-term effects can also be fatigue, similar to other viral diseases.
“It can cause this sort of post-viral that has been reported with other viruses like COVID or the flu, where people, even when they recover, they just feel very tired for an extended period,” Nebeluk said.
How to avoid exposure
Individuals are advised to avoid being outside during dusk and dawn as those times of day are the most active for virus-carrying mosquitoes, Carlson said. Additionally, he said to wear long sleeves, to apply mosquito repellent and reapply as directed on the label.
Residents are also encouraged to clean up stagnant water in their yards by draining and wiping down surfaces that collect water, like bird baths, according to Carlson.
Carlson said the county is doing what they can to keep people from getting bites.
“Late June and early July, there’s a lot of mosquito to bird to mosquito to bird, that whole cycle is just feeding itself right now,” Carlson said. “We’re trying to interrupt that part of the cycle right now and prevent people from getting mosquito bites.”
This story was originally published July 16, 2025 at 12:13 PM.