With science, a more complete picture is emerging
When it comes to managing and predicting disease outbreaks, science is working at prevention by studying paths and rates of infection. These efforts, though, are often done well after the fact.
In the case of Zika in the United States, though, a more complete picture has emerged within a year of the 2016 outbreak. By studying and comparing the DNA of infected mosquitoes and infected humans, researchers have established a more complete picture of Zika in Florida.
DNA determined the country of Zika’s origin
Using genetic information collected from infected mosquitos and people, scientists believe the Zika that arrived in Florida most likely came from the Caribbean. Miami, in particular, was a perfect storm for infection.
The South Florida region, thanks to its warm and humid sub-tropical climate, already had a large and active population of Aedes aegypti, the mosquito responsible for transmission. In addition, large numbers of people arrive daily, by air and sea, from the Caribbean at a time when mosquitos are most active. During the first half of 2016, nearly 3 million travelers arrived in Miami from the Caribbean.
Zika’s symptoms made it especially difficult to track
For most people, the Zika infection is mild. Most people don’t even get sick. If they do, symptoms are usually a slight fever, a rash, and joint paint – nothing powerful enough to bring people to a doctor. The greatest danger is to women who are infected during pregnancy. Infected travellers, therefore, had no idea they carried Zika with them into the United States.
Based on scientific evidence, Zika was introduced to Florida on at least four occasions – but each introduction failed to sustain a permanent hold, which is defined as at least one secondary infection per primary infection. A secondary infection is one that occurs via an infected mosquito or directly with an infected person. As a comparison, Brazil experienced three secondary infections per each primary infection.
Time was on Zika’s side
It’s estimated that Zika arrived in Florida in March 2016, months before the outbreak alarm was sounded in July of that year. During that time, infected female mosquitos did what all female mosquitos do – they fed on the blood of unsuspecting people, and with each bite, the Zika virus was transmitted. Then, as other mosquitos fed on people who had no idea they were infected, they picked up the virus and spread it to others.
Scientists estimate mosquitos had to bite 30-40 infected people to produce the outbreak. By July 2016, it was the lead story on both local and national news.
Preventing future outbreaks
Science is a step-by-step process. While it’s important to note that the Zika research helped produce a clearer picture, the answers also came after the fact. At some point, researchers hope to use the knowledge gained in this research to gather data that prevents future outbreaks from occurring.
In the meantime, there’s a lot you can do on a personal level. The first is to take care of any areas on your property that contain standing water. Another option is to install an automatic misting system that targets mosquitos and other pests.