Zika hasn’t been in the news as much these days, but that doesn’t mean that the virus has gone away.
Like other mosquito-borne diseases, Zika — which can cause babies to be born with neurological damage and microcephaly (a particularly small head and underdeveloped brain) if a pregnant woman is infected — became less of a concern as weather cooled. Serious virus control and mosquito eradication efforts played a role too.
But really, the Zika threat never went away completely. The CDC still says that pregnant women should consider postponing travel to large parts of the Caribbean and Latin America and small sections of the US.
“People are just going to have to accept that as part of the new reality,” Dr. Martin Cetron, director of the CDC’s global migration and quarantine division, told STAT.
And as summer heats up and mosquito season begins again, the risk for Zika and other mosquito-borne diseases like dengue, chikungunya, and West Nile will rise also.
It’s still unclear just how high the Zika risk will be this summer. Some researchers have predicted that the number of cases could explode, while others point to past success controlling the virus in the US at least as an indication that risk is not high.
But researchers do think that funding cuts could make it impossible to conduct the necessary surveillance for the mosquito-borne illness.
“Without active surveillance — I’m worried we missed [many cases of] Zika last year and we’ll miss Zika this year,” Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, in Houston, told Kaiser Health News. “If you’re a woman of reproductive age, living on the Gulf Coast of the United States, or Arizona or Southern California, and you’re pregnant or might be pregnant — you don’t really know if Zika’s in your area or not.”
But even if most of the US outside those regions is unlikely to see active transmission, officials still want people to be aware that for pregnant women, a Zika infection is just as serious as it has ever been. That means people need to be conscious of the risk of travel to certain places and of the risk of sex with a person that has been in those regions, since Zika can be sexually transmitted. We’re just beginning to understand the consequences of the virus on brain development and it may be years before we know just how long-lasting and severe the effects are.
Zika is not the only concern. The same mosquitoes that spread Zika also spread dengue and chikungunya. Recent studies have found that these mosquitoes are more common than we thought and that the optimal temperature for them to spread disease is 84 degrees Fahrenheit.
Other mosquitoes that carry West Nile virus also thrive in summer. While West Nile is rare, it can be devastating. Most people have no symptoms if infected, but a tiny fraction can experience a potentially fatal neurological condition.
Mosquito-borne disease in general is expected to become a bigger problem in a warming world, Durland Fish, professor emeritus of epidemiology at the Yale School of Public Health, told Business Insider.
There are studies showing that in warmer temperatures, mosquitoes have enough time to go through an extra life cycle in northern latitudes, Fish said.
“If they go through an extra life cycle, there’s going to be more mosquitoes,” he said. “If they’re transmitting a disease, the incidence of the disease is going to be higher.”
In addition to that, Fish says that six or seven new species of mosquito have recently been introduced to Florida, two within the past year. More and different types of mosquitoes increase the chances that a new disease could appear.
It’s not just climate, either. Environmental change and globalization have also made it easier for diseases to spread, something that is seen with mosquitoes and with creatures like ticks, too. In general, says Fish, diseases seem to be emerging at an increasing rate.
“The trend is pretty frightening,” he says. “We didn’t seem to have these scares 30 or 40 years ago.”