As of Thursday morning, there have been 31 laboratory-confirmed
cases of the mosquito-borne Zika virus in the United States, all travel-related, according to Lyle
Peterson of the Centers for Disease Control and Prevention (CDC).
“This number is increasing rapidly,” Peterson said during
a World Health Organization (WHO) information session on Zika virus held at WHO
headquarters in Geneva on Thursday.
There are also 20 laboratory-confirmed cases in U.S.
territories, mostly due to local transmission, Peterson said — 19 in Puerto
Rico and one in the U.S. Virgin Islands.
Zika is primarily transmitted through the bite of infected Aedes
mosquitoes. It can be transmitted from a pregnant mother to her baby
during pregnancy or around the time of birth, the CDC said.
The CDC has a travel alert in place that recommends
pregnant women postpone travel to areas where the virus has been reported, as
it has been associated with an increase of babies born with microcephaly, a congenital
condition associated with incomplete brain development. In some cases, it is
also associated with Guillain-Barré syndrome, in which the immune system
attacks the nervous system, sometimes resulting in paralysis.
The CDC travel alert includes Puerto Rico, Brazil,
Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique,
Mexico, Panama, Paraguay, Suriname, Venezuela, Barbados, Bolivia, Ecuador,
Guadeloupe, St. Martin, Guyana, Cape Verde, Samoa, and most recently, the U.S.
Virgin Islands and Dominican Republic.
WHO said this week it expects Zika virus to expand into
all of the Americas, with the exception of Canada and Chile.
Also during the information session, WHO's director general, Dr.
Margaret Chan, announced she will convene an International Health Regulations
Emergency Committee on Zika virus to meet in Geneva on Monday, Feb. 1.
“The level of concern is high, as is the level of
uncertainty,” Chan said. “Questions abound. We need to get some answers
quickly.”
She will seek some of those answers from the committee.
“I am asking the committee for advice on the appropriate
level of international concern and for recommended measures that should be
undertaken in affected countries and elsewhere,” she said. “I will also ask the
committee to prioritize areas where research is most urgently needed.”