While nearby Chatham County, Ga., is discovering West Nile virus in a record number of mosquitoes -- and possibly one human -- Beaufort County has yet to record a single positive test.
In fact, tests in mosquitoes, birds, horses and humans haven't detected the virus throughout the state, said entomologist Chris Evans of the S.C. Department of Health and Environmental Control's Bureau of Laboratories.
Meanwhile, Chatham County Mosquito Control has collected 78 positive samples at six testing sites throughout Savannah's urban area, department director Henry Lewandowski said.
That's more than the record of 67 set in 2003 during the entire season, which runs from late June to October. Nine people in Chatham County had the virus that year, and one died of it.
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Lewandowski said several factors are fueling the resurgence. The drought hasn't flushed out stormwater catch basins where mosquitoes breed. Also, birds that are immune to the disease have died out. That means this year's robins, blue jays and crows could be susceptible as carriers.
Evans said the virus is fairly new to American shores, so it's not clear yet why it occurs more in some years than in others.
Beaufort County has the same mosquitoes, the same birds and the same breeding habitats, but lacks the large urban area and aging stormwater infrastructure that may be causing the Chatham County infestation, Beaufort County Mosquito Control director Gregg Hunt said.
"Downtown Savannah is an old city with old sewer systems and lots of standing water in old storm drains," Evans said.
Evans said positive samples are usually collected beginning in July, with 60 percent of the cases recorded in August and September.
DHEC spokesman Nick Davidson said South Carolina residents should still be vigilant because "mosquitoes don't pay much attention to a state border."
That vigilance includes wearing protective clothing, using mosquito repellent and clearing property of standing water.
Symptoms of West Nile virus range from mild cases with flu-like symptoms to rare cases that include high fever, headache, neck stiffness, muscle weakness and disorientation or paralysis.
A Savannah woman's case hasn't been confirmed, and she is scheduled for follow-up testing this week, Lewandowski said.
Hunt said that while the threat of West Nile virus in Beaufort County so far is nil, the number of mosquitoes buzzing around certainly isn't.
Mosquito Control has received 300 requests for service since April, double the amount it received during the same period last year, Hunt said.
"With recent rains and high tides, it's a serious task right now," Hunt said.
Follow staff writer Allison Stice at twitter.com/BlufftonBlogIP.