(WOMENSENEWS)—The fast approaching 2016 Summer Olympics in Brazil have been surrounded since last year by concerns over the Zika virus outbreak.
This particular Olympic hurdle might actually be lower than feared, however, since Brazil, in the Southern Hemisphere, is cooler in August, at its lowest rainfall and entering its lower risk time of year.
Kacey Ernst, an associate professor in the epidemiology and biostatistics department at the University of Arizona says something else also bodes well: the possibility of rising resistance in the Brazilian population.
“The transmission has occurred in relatively high levels,” Ernst said during a recent phone interview. “We don’t exactly know what percentage of the population has to be infected and recovered to create what we call herd or community immunity. But once a large percentage of the population has previously been infected, we think with Zika the immunity is complete. Once you’ve had it once, you don’t get it again. That’s the current working knowledge.”
However, that means the opposite is true in the U.S., where temperatures continue to rise as the summer wears on and where the first case of female-to-male sexual transmission was recently reported.
To help with the fight against Zika, Ernst created a model of Zika risk in the U.S. Using meteorological data from the past 10 years to track the abundance of Aedes mosquitoes in 50 U.S. cities within the mosquitoes’ livable range, along with travel data and socioeconomic factors, she assessed the potential for transmission.
“All cities studied were able to support some sort of Aedes aegypti population in the summer months,” says Ernst. Her model, however, finds that only the most southern states, such as Texas and Florida, sustained the mosquitoes into the winter.
Currently, Ernst is working with the Atlanta-based Centers for Disease Control and Prevention (CDC) and the Skoll Global Threats Fund to develop an app that will allow people to report symptoms.
“If you can identify when these diseases are first introduced, then you can exert some serious control and pressure around those first cases to minimize potential further spread,” Ernst says.
The app will also help educate people on the mosquitoes and the viruses they transmit.
On the Periphery
“Most of us in the U.S. are lucky to be in the periphery,” says Ernst. “But of course with sexual transmission it doesn’t matter where you live.”
As of July 13, the CDC had confirmed 1,306 cases of Zika within the 50 U.S. states, all of which were caused by travel outside of the U.S. But last week, the Florida Department of Health reported they were investigating two potential cases of mosquito-transmitted Zika contraction, which, if confirmed, would be the first such cases in the continental U.S.
Though the current outbreak has been widely covered, it’s certainly not the first. The virus, named after a forest in Uganda, was first found in humans in 1952 and known outbreaks have occurred in Africa, Southeast Asia and the Pacific Islands.
“It wasn’t until Brazil and the associations with microcephaly [a birth defect] were speculated that it kind of leapt to the forefront of people’s awareness and interest,” says Ernst.
Symptoms of the virus include fever, rash, joint pain, conjunctivitis and sometimes muscle pain or headache, according to the CDC.
Typically, Zika virus is spread through mosquito bites, specifically from the Aedes species, but it can also be transmitted through sexual intercourse, from a pregnant woman to her fetus and potentially through blood transfusions, though that has yet to be confirmed.
The virus is believed to remain in the blood for less than two weeks, but has been found in semen up to two months after infection. Because of the link between Zika virus and birth defects, pregnant women are of the most concern. As reported in USA Today, as of the end of June seven babies have been born in in the U.S. with birth defects and the virus has been connected to six pregnancy losses, which includes both miscarriages and abortions.
Abortion rights have already been targeted by a number of lawmakers all over the country and this could make it harder for Zika-infected pregnant women to obtain abortions. Abortion restrictions could also, as Politico reports, hinder Zika research that would greatly benefit from fetal tissue. Florida, one of the states most at risk of seeing local Zika transmission, has instituted anti-abortion legislation that blocks the donation of aborted tissue altogether.
In Brazil, where, as of July 14, 1,687 cases of Zika-associated microcephaly have been reported, abortion is only legal in three circumstances: when it threatens the pregnant woman’s life, in the case of rape and when the fetus is diagnosed with anencephaly, a disorder where the fetus begins to develop without major portions of the brain and head.
Women’s groups in Brazil are currently working to challenge current abortion laws and make abortion a legal option for women infected with Zika.
For now, the protocol is to monitor a woman and her fetus closely if a pregnant woman has been diagnosed with Zika because, unfortunately, there aren’t any treatments against Zika infection as of now.
As Science Friday reported, several vaccines are in the works, but after Congress failed to approve funding for Zika research in July, progress towards vaccine development may falter. Congress is now in recess until September, meaning any chance of government funding will have to wait until then.
Zika itself isn’t new, but the reports of microcephaly caused by the virus are. Microcephaly is a birth defect featuring smaller than average head size in babies that’s likely caused by an underdeveloped brain.
The link to microcephaly may have existed in other parts of the world, but Ernst says the large population in Brazil and the massive number of cases aided detection. “Because microcephaly is relatively rare, when you have such a large population, that’s when you start to see these events more clearly,” she says.
Best Plan of Action
While Zika can cause microcephaly, it doesn’t cause it in every infected pregnant woman; a variation in the disease that is not yet understood.
For now, the best plan of action is to prevent Zika. If you’re pregnant, that means not traveling to known high-risk Zika regions and not engaging in unprotected sexual intercourse with those who have. Also, preventing mosquito bites is key.
“I think the issue with Zika that makes it so scary is because we don’t have a lot of answers,” Maguire said during a recent phone interview, “and for now we’re kind of just waiting to see what the summer brings.”
Meanwhile she offers this advice if you’re living in an area that might start having local transmission, like Florida. “We’re recommending mosquito repellent, long sleeves, pants and to avoid walking at dusk or dawn when mosquitoes are prevalent,” says Maguire.
She also suggests using a condom or avoiding intercourse altogether if your partner has traveled to an area with Zika virus. For more information on mosquito repellents, search these Environmental Protection Agency and Consumer Reports websites.
Ernst also suggests those in areas with a Zika risk should make sure screens in windows and doors are intact, and after each rainfall empty any containers with standing water, which is where mosquitoes lay their eggs. For standing water that can’t be removed, such as small water features or even bromeliad flowers that hold enough water for mosquitoes to breed in, she suggests using Bti pellets, which can be purchased from hardware stores. Bti, a type of bacteria that kills mosquito larvae, is safe for humans and pets.