The chikungunya epidemic in the Caribbean is continuing to spill over into the United States, with federal and state officials reporting at least 74 cases in 23 states yesterday.
The Centers for Disease Control and Prevention (CDC) yesterday reported 73 cases in 22 states, up from 57 cases in 13 states on Jun 17. In addition, the Kentucky Department for Public Health (KDPH) reported the state's first case—which was not included in the CDC update—with test results awaited in nine more suspected cases.
The CDC also said Puerto Rico has identified 14 locally transmitted cases, and the US Virgin Islands has one such case. The number for Puerto Rico has been revised downward; the CDC had mentioned 23 locally transmitted cases there in its Jun 17 update.
All but one of the cases in the continental United States were linked to travel to the Caribbean, and the other case involved travel to Asia, the CDC said. No local transmission has been discovered.
Florida has most cases by far
Florida has by far the most cases, at 34, followed by Virginia with 6, while Connecticut and New Jersey have 4 each, according to the CDC.
The case in Kentucky involves an Anderson County resident who recently traveled to Haiti, the KDPH reported. "Results for nine possible cases in other individuals who recently traveled to the same region are still pending, but are expected to be positive," the agency said.
It went on to warn, "Kentucky does have both species of mosquitoes that can become infected with CHIKV [chikungunya virus] and then transmit the virus to humans, so it is possible that the illness will become more common in the state and the country in coming years."
Similarly, the CDC said imported cases are likely to increase and may lead to local transmission of the virus in the United States. The virus does not spread from person to person, but it can spread when a mosquito bites an infected person and then bites someone else.
From 2006 to 2013, studies identified an average of 28 chikungunya cases per year in the United States, all of them in travelers who visited affected countries, the CDC noted.
Jun 24 CDC chikungunya update
Jun 24 KDPH statement
Jun 20 PAHO update
Related Jun 19 CIDRAP News item