Ever since the Zika virus arrived in South and Central America in late 2015, it was felt that it could reach the US. This seems to be the case since it is believed that at least 40,000 people in the USA may already have the Zika virus mainly because of traveling to destinations where the virus is endemic. This number has been acquired by extrapolating the number of pregnant women who have been confirmed to be carrying the virus after visiting countries in South America like Colombia and Brazil.
Zika virus does not cause any symptoms in most people. It may sometimes cause a mild flu like illness. But infants born to women who acquire the virus during pregnancy may develop varying degrees of skull deformation, which is often associated with brain damage.
Pregnant women who travel and get infected are the first to be diagnosed in the USA mainly because they visit their healthcare provider more regularly during pregnancy.
Researchers from Boston looked at the epidemic data and airline transit numbers of visitors going to South America and estimated that pregnant women accounted for about 1% of the total number of travelers infected with the Zika virus in the US. The latest data released from the US Centers for Disease Control and Prevention indicate that so far the number of infected pregnant women who have returned to the US amount to 433 cases. If this represents only 1% of cases, then the total number of infected cases in the US is probably 43,300.
Other infectious disease experts also support such predictions made by the Boston researchers but warn that the extrapolation is only a rough figure. The numbers may be slightly overstated. It should be remembered that many visitors to South America also stay away from virus areas by staying in air-conditioned hotels and by using preventive measures such as insect repellants and mosquito nets.
The first cases of locally spread Zika virus in the US were just confirmed last week by the CDC. Researchers reported that there have been 14 local cases and thus a travel advisory warning has been put out for pregnant women who plan to go to Florida, especially Miami.