Four more cases of Zika infection that were likely spread through mosquito bites have been reported in the Miami area, bringing the total count of cases to 21, Florida Government The Florida Department of Health still believes these infections are only happening within one square mile in Miami-Dade County, in a neighbourhood known as Wynwood. Meanwhile, aerial spraying that began last week rapidly killed adult mosquitoes that ground-applied pesticides could not reach, Director of the U.S. Centres of Disease Control and Prevention.

Federal health officials have said repeatedly that they expect to see Zika infections in the United States this summer, particularly in hot, humid states like Florida, Louisiana and Texas. Most   Zika infections have occurred in Latin America and the Caribbean. Brazil has reported the vast majority of cases of a Zika-linked birth defect called microcephaly,…