As the number of Zika cases in the country ticks upward, and the calendar approaches prime-mosquito season, experts in Beaufort County are remaining cautiously optimistic.
Gregg Hunt, director of Beaufort County Mosquito Control, says odds are low that this area will see local mosquito-borne Zika virus transmission, as is the case in one small Miami neighborhood and three U.S. territories - American Samoa, Puerto Rico and the U.S. Virgin Islands.
But, Hunt says, he could be wrong, and Mosquito Control isn’t waiting to find out.
The county has stepped up its surveillance and testing, has sent samples to the S.C. Department of Health and Environmental Control and is ready to treat any areas at risk for Zika transmission.
“I can’t predict the summer,” Hunt said. “I can’t predict what's going to happen with Zika virus in the Lowcountry. … This is a new disease for the United States and it’s going to be a learning experience.”
7 things to know about Zika in Beaufort County
How does it spread?
Of the 57 varieties of mosquitoes found in Beaufort County, only two types of mosquitoes carry the Zika virus, and one has not been seen in Beaufort County since 1992 — Aedes aegypti, the yellow fever mosquito.
The other species —Aedes albopictus, the Asian tiger mosquito — was first discovered in Beaufort County the same year, and has also been known to carry dengue and chikungunya.
It can be identified by its black body and white stripes. And they’re short-distance fliers, usually sticking to an area of 100 feet or less.
To date, there have been no reports of local mosquitoes infecting people in South Carolina. But there are 33 recorded cases of travel-associated Zika in the state, including one person who contracted Zika through sexual transmission.
How does the county monitor mosquitoes?
Mosquito Control has 69 traps strategically placed across the county to collect samples, which the county then identifies in its own lab.
Of the traps:
- 26 are set up underground in storm water systems.
- 16 are gravid traps, which are designed to catch carriers of West Nile virus.
- 12 are ovitraps, black-colored glass jars partially submerged in water, which are designed to catch carriers of Zika.
- Six are BG-Sentinel traps, which are designed to chemically attract and catch carriers of Zika.
- The remaining nine are general traps designed by the Centers for Disease Control and Prevention. They are suspended from tree limbs, about four to six feet above the ground, and attract mosquitoes with a small light bulb and a container of dry ice, which simulates the carbon dioxide in mammals’ breath.
The county also has collaborates with Naval Hospital Beaufort, Marine Corps Recruit Depot Parris Island, Marine Corps Air Station Beaufort, and Laurel Bay base housing. Those entities send mosquitoes to the county for testing, and allow Mosquito Control to respond and treat areas as needed.
In a typical year, the county may collect 20,000 mosquitoes and identify 12,000 to 15,000 of them.
“They’re really well-engineered, well-designed and they work,” Hunt said.
Do our mosquitoes have Zika?
Testing is still underway to determine whether any of the county’s Ae. albopictus mosquitoes carry the virus.
On its own, Mosquito Control has identified about 830 Ae. albopictus to date, far more than in past years because of the county’s extra steps to collect samples of the species. But the county doesn’t have the capabilities to test for Zika.
So, since early July, the county has also frozen another 950 to 1,200 Ae. albopictus with dry ice to ship overnight to DHEC’s lab in Columbia.
Hunt says he’s still waiting on the results from Beaufort County’s samples.
What if they test positive?
If state test results show areas of Beaufort County are active with Zika, Mosquito Control can respond within 24 hours.
The county’s mosquito abatement program has three phases.
To treat a small area, like a neighborhood, the county can spray what’s called thermal fog insecticide, which produces a visible cloud. That product is dispersed by hand-held equipment, or by attaching the canisters to a golf-cart sized vehicle that slowly drives through a neighborhood.
To cover multiple areas in a short period of time, the county can spray a similar product, ultra low-level insecticide, from a spray truck or from the sky.
The county employs an OV-10 D Bronco plane to spray for adult mosquitoes and an MD-500 D helicopter to spray for larvae.
What about no-spray zones?
There are about 130 designated no-spray zones in the county, 87 of them for beekeepers, and the rest for organic farmers and people allergic to the pesticide.
But in the event of a Zika public health crisis, those zones would disappear. The county has the authority to spray wherever necessary to contain and eliminate the spread of the virus.
Residents would have plenty of advance warning, though, Hunt says. Anyone in a no-spray zone would get a phone call, email or both with ample time to cover their beehives, leave town or take other precautions to protect themselves, their bees or their crops.
What is the government doing?
South Carolina was awarded $4.5 million from the federal government last month to help combat the Zika virus.
The money is targeted at public health, particularly among pregnant women, and will be used to support the U.S. Zika Pregnancy Registry to monitor mothers-to-be and, eventually, their infants.
Some of the funds are also available to improve mosquito control and monitoring. Nationwide, the government has awarded nearly $60 million to respond to Zika.
What can you do to help?
Residents can play a big part in controlling the spread of mosquitoes, from the disease-carrying variety to everyday pests.
- Use bug spray to ward off biters.
- Wear long sleeves and pants for extra protection.
- Keep windows closed, or make sure they’re screened.
- Empty any containers of standing water. Birdbaths, buckets, plant saucers — all should be emptied if possible, or dumped and refilled every day or two to prevent mosquito breeding.
- Call the county if your area is experiencing far worse mosquitoes than usual.
- Don’t disturb the county’s traps.
For more information, visit the Beaufort County Mosquito Control website or call 843-255-5800.
A to Z: Answers to key questions about Zika virus, Aug. 2, 2016