The warm temperatures this spring may usher in an earlier mosquito season, causing health officials to devise plans to fight the mosquito-borne Zika virus in the unlikely event it reaches Ohio and Toledo.
Zika is a virus that is spread to people primarily through the bite of an infected mosquito, which can cause a mild illness or very serious complications in newborn children if their mother is infected.
The Centers for Disease Control and Prevention has created a map estimating where in the United States the Zika-carrying mosquitoes will likely be found yet this year.
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The map shows the insects are expected to reach most of Ohio, including much of northwest Ohio, but the numbers and exact locations were not included in the estimate.
But based on past mosquito migration patterns, there is only a small chance one of the two mosquito species that carry the virus will move into northwest Ohio in great numbers, said Paul Bauman, biologist for the Toledo Area Sanitary District.
The primary Zika-carrying mosquito, Aedes aegypti, is found in the tropics and southern United States, but it is not established in Ohio.
A “cousin,” Aedes albopictus, also known as the Asian tiger mosquito, is found in parts of Ohio and may potentially transmit the Zika virus.
State health officials say the Asian tiger mosquito has been spotted in several northwest Ohio counties, including Lucas, Hancock, and Huron in the past.
Mr. Bauman, though, who has been monitoring Lucas County mosquito traps for the past two years looking for the Asian tiger mosquito, said he has not “found a single one,” despite his attempts.
The larger area threat is for people traveling to places where the virus is present and bringing it back to northwest Ohio, said Travis Taylor, assistant professor and researcher of microbiology at the University of Toledo medical school, the former Medical College of Ohio.
The country of Brazil is experiencing a wide-scale outbreak of the virus and is the center of the Zika epidemic, but other South and Central American countries, as well as the Caribbean and Pacific Island countries, are also trouble spots, according to the CDC.
There are currently 10 travel-related Zika cases in Ohio, but none is in Lucas County, according to the Toledo-Lucas County Health Department.
About the virus
The colder climate in the Toledo area will make it more difficult for the Zika-carrying mosquitoes to build up a large enough population to become a threat, predicts Mr. Taylor, who studies many of the diseases carried by the same mosquitoes that host the Zika virus. West Nile virus, which can cause encephalitis or meningitis, and dengue fever, a painful, debilitating mosquito-borne disease, are in the same family with Zika, he said. West Nile is a much bigger threat in our area, Mr. Taylor said.
The Zika virus, however, is very concerning, he said.
“All of the scare around Zika is justified” because it is changing and mutating in unique ways researchers have not seen before, he said.
The Zika virus behaves differently in people than do some other mosquito-borne viruses, such as West Nile. If a person gets West Nile from a mosquito, that person is a “dead-end host,” which means they don’t build up enough virus in their blood to transfer it back to a new clean mosquito, Mr. Bauman said.
All it would take with Zika is the right kind of mosquito biting a returning traveler who’s infected, and then biting someone else nearby. That would start the cycle of mosquito-to-person transmission and perhaps the beginnings of a localized outbreak.
“That is the big concern,” he said.
Mr. Taylor noted the virus is usually only in a person’s blood for about a week after they have symptoms of the disease, and a mosquito would have to strike at the right time.
“Yes, a mosquito could bite someone who traveled from Florida if they still have it in their blood. We are talking about such a low probability event that it’s not going to establish an outbreak,” he said.
Those who are most at risk are people who are planning travel to places where the virus is rampant. The Zika virus can be contracted from mosquitoes, sexual contact, or through blood transfusion.
“I’m not concerned about getting Zika [in Toledo] at all but I would not take anybody pregnant down to a Zika-virus area. If I had to travel there, I would abstain from having sex for a while,” he said.
Zika virus infection during pregnancy can cause a serious birth defect called microcephaly, as well as other severe fetal brain defects, he said.
Most people, or 80 percent, who are infected with Zika virus do not have any symptoms. Of those who do experience symptoms, they are usually mild and include fever, rash, joint pain, or red eyes.
So a person can be a carrier even if they don’t display symptoms. “The virus can stick around in semen for awhile, so men should be wearing condoms if they have traveled in those areas,” he said.
Health officials are seemingly learning new information every day about the Zika virus, but there is now a consensus among scientists that it is linked to microcephaly, where babies are born with severe brain abnormalities, Mr. Taylor said.
“We are starting to pay attention [to Zika] only because of the effect on the babies,” Mr. Taylor said.
The number of cases of microcephaly in Brazil, associated with Zika, has reached nearly 5,000 babies, he said.
Another rare disease being connected to Zika virus is Guillain-Barre syndrome, which is a neurological disorder. According to the CDC, Guillain-Barre syndrome is sickness of the nervous system in which a person’s own immune system damages the nerve cells, causing muscle weakness, and sometimes, paralysis. Most people fully recover but some people have permanent damage, and in 1 out of 20 cases people have died.
Mr. Taylor said there is still much to learn about the virus and both the National Institutes of Health and the World Health Organization are focusing resources on research and on developing a vaccine for it. Currently, there is no cure and no vaccine.
Local preparations
His lab at UT’s medical school will be getting some samples of the Zika virus in a few weeks. He will conduct experiments to understand how it interacts with human cells, how it replicates, and how it compares with other viruses such as West Nile and dengue.
Local health departments are also getting prepared in the unlikely event of a local Zika infection outbreak. The Ohio Department of Health hosted a Zika “tabletop” at the beginning of March, during which officials went over different scenarios of the mosquito coming to Ohio and developed plans on what to do if there is a local transmission of the virus, said spokesman Melanie Amato.
The state health department also is holding a workshop this week for county health departments, in Columbus, to discuss local control of mosquito populations, she said.
Lucas County’s mosquito control department and the health department will be working together to monitor the situation. If there is a report of a Toledo-area person with Zika virus, there will be a concentrated effort to eradicate all the mosquitoes in the area near their home, Mr. Bauman said. This is same process the department currently uses if a local case of West Nile virus is detected, he said.
Contact Marlene Harris-Taylor at: mtaylor@theblade.com, 419-724-6091, or on Twitter @marlenetaylor48.
First Published April 24, 2016, 4:00 a.m.
