- The World Health Organization on Monday declared the Zika virus outbreak to be a public health emergency of international concern," days after warning the virus was "spreading explosively" in the Americas.
- The Director-General of the WHO, Margaret Chan, called for a "coordinated international response" to bolster transmission surveillance and hasten the development of diagnostic testing and a vaccine for the virus.
- Borne by mosquitos, Zika has spread to 22 countries and territories in the Americas and has been linked by Brazilian health officials to microcephaly, or abnormally small heads and underdeveloped brains, in newborns.
In making its declaration, the WHO indicated it strongly suspects, but cannot scientifically prove, a connection between the spread of the Zika virus and the sharp rise in the number of reported cases of microcephaly, particularly in Brazil. Since transmission of the virus was confirmed in May 2015, Brazil has seen nearly 4,000 reported cases of microcephaly, compared to less than 150 in 2014.
The WHO's declaration functions more as a call to action, and as a warning, although it does boost international communication and research collaboration. Under Chan's watch, the 2009 H1N1 outbreak, the possible resurgence of polio in 2014, and the West African Ebola epidemic have previously been designated a "public health emergency of international concern."
The emergency committee convened Monday recommended standardized surveillance for microcephaly along with increased research to determine "causative links." Zika has also been associated to a rare neurological condition known as Guillain-Barré Syndrome, which has been observed in some of the same pockets as Zika transmission.
The lack of population immunity, coupled with the absence of any vaccine of treatment underpinned the WHO's concern.
No travel or trade restrictions were announced, but the WHO pushed for greater dissemination of up-to-date information to travelers. Separately, the U.S. Centers for Disease Control has recommended pregnant women reconsider travel to areas where Zika transmission is occurring. The agency has issued Zika-related level 2 travel alerts ("practice enhanced precautions") for 24 countries and territories.
Pregnant women are consider at greatest risk due to the potential ramifications for the health of the fetus. In a press conference following the announcement, Chan said pregnant woman could delay travel to affected regions, and should protect themselves from mosquito bites.
Adults infected by the Zika virus typically experience a mild fever, skin rash, or conjunctivitis for 2 days to a week. The mild symptoms in adults, coupled with the low prominence of previous outbreaks, have contributed to the relative obscurity of the virus prior to its spread throughout the Americas. There are no current treatments or vaccines.