Zika might be declining in Brazil, but that doesn't mean it's going away.
Officials from Brazil announced last week that the crisis over the Zika virus had ended in the country: The number of cases of Zika in Brazil this year dropped by 95 percent between January and April compared to the same period in 2016, and no deaths were reported, compared to eight deaths last year.
But while Zika is declining in Brazil, that doesn't mean it's going away, particularly as we head into summer, according to the Centers for Disease Control (CDC).
Transmission from Latin America
Brazil was at the epicenter of this latest epidemic that began in 2015, and last week's announcement was seen as a major victory. This upcoming summer will be a crucial moment in fighting Zika's spread, however, as the damp, muggy climates — particularly along the Gulf Coast of the U.S. — offer the right environment for the Aedes aegypti mosquito.
“This summer will depend on what’s going on in countries like Brazil because Zika is not endemic here,” Janet McAllister, an entomology researcher with the CDC, told Travel + Leisure. "We’re going to see it brought into the country again, and we are already seeing travelers returning with Zika.”
The virus is relatively harmless to most people, and only about 1 in 5 who contract it experience flu-like symptoms. However, Zika can be extremely dangerous for pregnant women, symptoms or not, and it has been linked to microcephaly in the unborn child, a condition in which the infant's head is abnormally small and the brain is underdeveloped.
Zika quickly spread across Latin America and into the Caribbean islands in 2015 and 2016 before making its way up to parts of the southern U.S., where populations of the Aedes aegypti mosquito have started to rebound, according to McAllister.
Multiple factors for viral spread
If people travel to or from Zika-prone countries in South America and return with the virus to cities like New Orleans where Aedes aegypti are present, the local mosquitos can begin to carry it. If high rates of transmission are then coupled with heavy rainfall, the spread of the disease could be rapid, McAllister said.
“You have to have that combination,” she noted.
Zika is present in Florida and Texas, and some public health officials have already begun bracing for the spread of the virus. The Gulf coast is particularly susceptible to the virus and should be more closely monitored, according to researchers.
“Our analyses indicate that the health and economic burden of even low attack rates of Zika in the continental U.S. would be both substantial and enduring,” wrote researchers from Baylor College of Medicine in the journal PLOS Neglected Tropical Diseases.
The number of confirmed cases in the U.S. may go up this summer, but that does not necessarily mean that the virus is spreading more rapidly: The CDC issued new guidelines for doctors, recommending tests for Zika for a greater number of people, as well as more frequent testing of pregnant women, meaning older cases could also be identified.
How to protect yourself
Travelers to regions affected by Zika can take precautions to prevent contracting the disease by protecting themselves against mosquitos. The CDC recommends visitors to areas with Zika wear long-sleeved clothing, apply mosquito repellant, and use a mosquito net at night.
They can also avoid places with standing water where mosquitos often breed. The disease is sexually transmitted, and public health officials recommend not having sex with people who might be infected, or using protection.