It was a matter of when, not if. A handful of men and women living in Florida have been diagnosed with Zika, making them the first official cases of the virus contracted within the United States. The implication here is that the Zika-carrying Aedes aegypti mosquito, which can be found across many of the warmer southern states, is now able to spread the virus across parts of North America.
According to BBC News, more than 1,650 cases of Zika have been detected in the US, but none of them have been spread via mosquito within the nation’s borders. The majority of patients were infected abroad before traveling back home, whereas the remaining minority were infected with sexual activity, which is known to be able to transmit the virus from person to person.
At present, fourteen people have contracted the virus within Florida, most likely through bites from a local Ae. aegypti mosquito. However, as in most cases of Zika infection, they are not in any danger, nor have they been hospitalized. The problem here is that they have now become reservoirs for the virus, and Ae. aegypti could inadvertently use them to spread the disease to the wider population.
In fact, now that Zika exists within the blood of several people in the two most densely populated counties in Florida – Miami-Dade and Broward – it’s a near certainty that the virus will spread, particularly as the summer heat spreads further northwards and the mosquitos proliferate along with it.
Several studies over the last few months predicted that Zika was most likely going to first spread in Florida, with Georgia, Texas, South Carolina, Louisiana, and Alabama most likely to register cases next as the summer goes on. Metropolises as far north as New York City are also seen to be at risk, thanks to rising temperatures and the presence of the Ae. aegypti mosquito.
Where Zika is likely to spread, based on the prevalence of the Ae. aegypti mosqutio. PLOS Currents Outbreaks