What does Zika virus mean for Loudoun?
“It’s still very early in knowing about Zika to make any predictions at this point,” said Loudoun County Health Department Director Dr. David Goodfriend in a briefing to county supervisors Tuesday.
Fortunately for Loudoun, there’s still a little time to figure it out.
Zika virus has spread very quickly around the Americas, Goodfriend said, mostly carried by the yellow fever mosquito. That mosquito doesn’t show up in Virginia—here, scientists are looking at the yellow fever mosquito’s near relative, the Asian tiger mosquito.
It’s not yet known how well the Asian tiger mosquito will host Zika, Goodfriend said, and right now there aren’t many of the white-and-black patterned mosquito around. During the summer months, it’s the most number one biter in Virginia.
Zika is a difficult virus to track. Goodfriend said there have been only three confirmed cases in Virginia, all related to travel abroad. But only one in five people infected with Zika will show symptoms, and for most people, it’s not a serious threat. The most common symptoms are fever, rash, joint pain, and red eyes—the same symptoms as diseases ranging from the relatively common enterovirus, to measles, to the relatively exotic Chikungunya.
In addition, only the CDC can currently test for Zika, although Goodfriend said the Virginia Department of Health will likely be approved to do its own testing in the next few weeks. The virus is hard to distinguish from other infections, causing a lot of false positives.
Goodfriend said many people who show these fairly common symptoms are not tested for Zika. If you’re not a woman who is or could be pregnant, he said, there’s not a good reason to get tested. By the time results come back, you’re past the time when you might pass the disease along. There is no treatment or vaccine, and patient care is the same as for many illnesses: plenty of rest, plenty of fluids, acetaminophen for fever and pain.
In most cases, it’s not a very dangerous disease—even among the 20 percent of people who will show symptoms, the disease usually runs its course naturally and is gone within about two weeks. Usually, people infected with Zika don’t pose a serious threat to the people around them.
The danger, as reported in national headlines, is to pregnant women. Zika is thought to be related to miscarriages and birth defects, especially microcephaly, although Goodfriend said the connection isn’t yet clear. The virus also persists for several weeks in semen, saliva, and urine, and Goodfriend reported there has been one case in the United States of sexual transmission. For that reason, male partners of women who are or may be pregnant should abstain from sexual contact or use protection for a few weeks.
It is also, in rare cases, linked to a paralyzing and potentially fatal condition called Guillain-Barré Syndrome, or GBS, which causes the immune system to attack nerve tissue.
“It’s scary, but it happens with a lot of different viral infections,” Goodfriend said. GBS, he said, is usually self-limiting, but can be fatal.
What To Do About Mosquitoes
“Fortunately, we’re in a time when our mosquito populations are pretty dormant,” Goodfriend said.
But with warmer weather will come the Asian tiger mosquito, which may be a vector for Zika.
Loudoun currently has no program for monitoring or controlling mosquito populations. And mosquito control programs of the past, focused on West Nile Virus, would have a hard time tackling the Asian tiger mosquito.
“It’s a pretty lazy mosquito,” Goodfriend said. “It doesn’t want to get very far from where it got its blood meal to lay its eggs.”
This means that fogging—which works best on mosquitos in flight—is less effective, and controlling mosquito breeding grounds means going onto private property, which few mosquito control programs have the authority to do.
While the common house mosquito, which is the major carrier for West Nile virus in the eastern U.S., breeds in open waters like ponds and storm sewers, Goodfriend said the Asian tiger mosquito prefers small, still bodies of water like stopped up roof gutters, planters, birdfeeders, and tire swings—all places found near the home.
In the meantime, the county has launched a public information campaign to educate Loudouners on how to protect themselves from Zika. For more information, visit loudoun.gov/zika.