The state of Florida has identified 10 more cases of Zika virus caused by local mosquitoes and has asked the US Centers for Disease Control and Prevention to send in experts to help with its investigation of the outbreak.
The state now has 14 cases of Zika caused by locally transmitted mosquitoes, according to a statement issued on Monday by Florida Governor Rick Scott.
Scott said the state has called on the CDC to activate a CDC Emergency Response Team (CERT) to assist the Florida Department of Health and other partners in their investigation, sample collection and mosquito control efforts.
The team will consist of public health experts who will augment Florida's response efforts, Scott said.
Reuters was first to report that as of last Friday, Florida had not activated a CERT team to help with its investigation, raising concerns from infectious disease experts that the state was not taking every step it could to contain the spread of Zika in the continental United States.
CERT teams are a key part of the CDC's national Zika plan and are intended to help local officials track and contain the virus. A similar team was sent to Utah earlier this month to investigate how a person may have become infected while caring for a Zika-infected patient, before local officials went public with the case.
The state said it began investigating its first suspected case of locally transmitted Zika on July 7. According to CDC spokeswoman Kathy Harben, the CDC first became aware of the investigation on July 18, a day before the state announced its investigation into possible local transmission.
Florida on Friday said the first four cases of Zika in the state likely were caused by mosquitoes, the first sign that the virus is circulating locally, although it has yet to identify mosquitoes carrying the disease.
Scott said in a statement the 10 new cases of Zika also were likely caused by the bite of a local mosquito.
The Florida Department of Health said six of the 10 new cases are asymptomatic and were identified through the door-to-door community survey and testing that it is conducting.
The health department said it believes active transmission of Zika is restricted to 1 square-mile (2.6 square km) area in Miami-Dade County, just north of downtown Miami.
The state health department has been testing individuals in three locations in Miami-Dade and Broward counties for possible local transmissions through mosquito bites. Based on its investigations, two locations have been ruled out for possible local transmission of Zika.
The current Zika outbreak was first detected last year in Brazil, where it has been linked to more than 1,700 cases of the birth defect microcephaly, and has since spread rapidly through the Americas.
Scott said women who live within the impacted area and are either pregnant or thinking of becoming pregnant should contact their doctor for guidance and to receive a Zika prevention kit.