The World Health Organization took the drastic step of declaring the Zika virus spreading through the Americas a public health emergency on Monday.
But the United Nations health agency did not call for travel restrictions to the most infected countries, which are primarily in Central and South America. Zika has spread to 25 countries, territories and areas including 10 states in the U.S.
The WHO said that it did not call for a public health emergency on the Zika virus itself, which is only transmitted by mosquito bites and can cause lesser health issues such as a fever or rash.
What concerns officials is the potential link between Zika and microcephaly, which causes babies to be born with abnormally small heads and can lead to brain damage.
“A causal relationship during pregnancy is strongly suspected, though not yet scientifically proven,” WHO Director General Margaret Chan said during a press conference in Geneva.
Brazil, hit hard by the virus, has seen a spike in microcephaly cases. El Salvador is calling for its women to not get pregnant for two years.
A public health emergency is the WHO’s highest level of alarm and reflects a public health risk that will require international coordination. A committee met on Monday to determine whether the Zika virus and its link to birth defects constitute such an emergency.
The committee took into account not just the spreading virus but also that there is no vaccine or treatment for Zika. It wants to further study and confirm a link between the virus and microcephaly, Chan said.
The Centers for Disease Control and Prevention has advised pregnant women and women of child-bearing age to not travel to countries where the disease is spreading. All of the cases in the U.S. have occurred from people who recently traveled to affected countries. The virus hasn’t spread locally yet, but CDC officials are expecting “limited” outbreaks.
Chan said the most important protective measures for women are “the control of mosquito populations and prevention of mosquito bites.”
She said the coordination among worldwide health agencies will be similar to that of the Ebola outbreak that raged for two years in West Africa.
She denied that the call for a public health emergency, which is swift for the outbreak that has been going on for weeks, had to do with criticism of the agency for a lax response to Ebola.
“When the evidence becomes first available that after such a period conditions like microcephaly and other abnormalities [occurred] we need to take action,” she said.
