The Zika virus has been a hot topic lately, however the concern is not virus-carrying mosquitoes invading Northwest Ohio. Though an infestation here is unlikely, the more pressing threat involves travelling residents bringing the virus back from areas— Central and South America— where the virus is a more immediate problem.
The disease is primarily spread through the bite of an infected Aedes aegypti mosquito – also known as the yellow fever mosquito – recognizable by white markings on its legs. Symptoms include fever, rash, joint pain, or red eyes, according to Shannon Lands, public information officer for the Toledo-Lucas County Health Department.
“There’s been no local transmission of Zika anywhere in the United States,” said Lands. “It’s only been travel-associated.” Among the 10 travel-related cases in Ohio, the closest originated from a resident in Summit County in Northeast Ohio.
Symptoms and pregnancy
Zika symptoms are similar to the flu, often mild, rarely resulting in death, many don’t even realize they have been infected. However, the real issue is with pregnant women who are traveling to those areas heavily affected right now. Zika can cause microcephaly, a birth defect causing a baby’s head to be smaller than expected and preventing the brain from developing properly.
“There’s testing that can be done at the state level and CDC, specifically for pregnant women,” Lands said. “But they are advising all pregnant women not to travel to these areas.”
The problem could even affect those couples trying to get pregnant, too. Although the CDC does not know how long the virus can stay in the semen of men who have had Zika, it is known that the virus can stay in semen longer than in blood. Abstaining from sex is the only way to be certain that one does not get Zika virus from sex, according to the CDC.
As for a remedy, the National Institute of Allergy and Infectious Diseases (NIAID), headquartered in Bethesda, Md., anticipates beginning phase 1 trials for several Zika virus vaccine candidates in the fall. Depending on the outcome of those trials, phase 2 trials could begin sometime in 2017, according to NIAID.
Travel with caution
As of late April 2016, CDC reported 388 travel-related cases nationwide, of which 33 involved pregnancy. As such, CDC recommends postponing trips to Central and South America, where the Aedes aegypti mosquito is a much larger threat – pregnant or not.
“The (CDC) guidance is to wear long sleeves and pants, treat clothing with permethrin, and stay in places with air conditioning, allowing for window and door screens to help keep mosquitoes outside,” Lands said. “And if you do travel, sleep under a mosquito bed net.”
While the cooler temperatures and first frost every fall generally signal the end of the mosquito season here in the continental United States, things are different in warmer climates.
“Throughout the tropics, the weather often doesn’t cool down,” said Candice Burns Hoffman, press officer for the Centers for Disease Control and Prevention in Atlanta. “The mosquito season then coincides with rainy season.”
Burns Hoffman indicates it is difficult to predict when this notice could be lifted.
“Local transmission means that mosquitoes in these areas have been infected with Zika virus and are spreading it to people,” she said. “The notices will remain in effect until the risk to travelers is decreased, based on rates of mosquito-borne transmission and other factors.”
Is Zika a real local concern?
While the Aedes aegypti mosquito has yet to be found in Ohio or Michigan, there is another related species – Aedes albopictus, also known as the Asian tiger mosquito – which is more common, and has been located in Central and Southern Ohio. Aegypti cannot survive in the colder temperatures here, but albopictus can, which leaves the local agency responsible for the abatement and control of mosquitoes ever vigilant.
“For the past 2-3 years, we’ve been doing intense surveillance,” said Paul Bauman, biologist for the Toledo Area Sanitary District (TASD). “The (albopictus) is of a secondary vector and not thought of to be the primary villain. Overall my concern is not overly high. I don’t want to downplay it, but we have a pretty good strategy in mind in terms of mosquito control and mosquito transmission.”
TASD especially looks for areas where mosquitoes breed, which include floodwaters, ditches, storm-sewer catch basins, tree holes, rain barrels, discarded automobile tires, and in nearly all types of artificial containers. It also has specific traps designed to check for mosquitoes, and so far neither species has been located.
“The larger concern is people who are traveling, for sure, into those areas with problems,” Bauman said.