WASHINGTON — Nine months after the Zika virus was first discovered in South America, international health organizations are still struggling with how to confront what appears to be the largest global public health crisis since Ebola decimated eastern Africa in 2014.
U.S. researchers have blasted the World Health Organization for what they say has been a slow response, and some pressed the international organization to declare a public health emergency before the mosquito-borne virus becomes an “explosive pandemic.”
“It’s the same challenge with Ebola — the slow response of the international governing bodies,” said professor Oscar Cabrera, executive director of the O’Neill Institute for National and Global Health Law at Georgetown University.
Officials from the World Health Organization acknowledged Thursday that the Zika virus was “spreading explosively” in the Americas and set an emergency meeting for Monday to decide whether to declare a public health emergency.
“The level of alarm is extremely high,” said Margaret Chan, WHO’s director-general.
The international response to controlling the spread of the virus is crucial to much of the United States, where mosquitoes are pests, especially South Florida, where Zika could become a year-round threat if it were to spread to the mosquito population.
Florida is among the U.S. locations where mosquitoes are active 12 months of the year, and it is also a destination for travelers from the Latin American and Caribbean nations where the virus has spread so quickly.
The World Health Organization was widely criticized for delays in its response to the West Africa Ebola epidemic, which killed more than 11,000 people. On Monday, Chan acknowledged some of the missteps and promised that the organization would make “profound transformational changes in the way we respond to outbreaks and emergencies.”
She is already being tested.
Zika has been confirmed in two dozen countries and territories in the Western Hemisphere. In Brazil, the epicenter of the problem, Zika has affected as many as 1.3 million people. More than 220,000 soldiers have been mobilized to pass out leaflets and help spray for mosquitoes. In El Salvador, health officials have advised women to delay getting pregnant until 2018.
There have been 31 cases in the United States in 11 states. At least three are in Florida, according to the Centers for Disease Control and Prevention. Two are Miami-Dade County residents who traveled to Colombia in December, and the third is a Hillsborough County resident who traveled to Venezuela in December, according to the Florida Department of Health.
Walter Tabachnick, former director of the Florida Medical Entomology Laboratory, pressed residents to help with the effort by cleaning up their properties and eliminating standing water, where mosquitoes breed.
“Just walk around your own house and look for any container holding water for any length of time. If you have a pail outside; your gutters could be clogged,” said Tabachnick, who is a professor at the University of Florida at Vero Beach.
The speed of the U.S. response is also in question. While all the U.S. cases are travel-related, the CDC has yet to impose any additional screening of passengers arriving from areas where Zika has become common. Officials said the CDC and Customs and Border Protection were assessing the situation to determine what, if any, measures should be taken.
Migdalia Arteaga, a CBP spokeswoman in Miami, confirmed that agents in the airport were not conducting any special screening but noted existing standards to alert health officials of anyone possibly infected with a contagious disease.
It’s tourist season in the U.S. Virgin Islands, where 26 million people visited last year, according to the Caribbean Tourism Organization.
Zika was discovered last week on the islands, raising concerns that it may lead to vacation cancellations.
Esther Ellis, territorial epidemiologist at the U.S. Virgin Islands Department of Health, said the government was following CDC guidelines and advising travelers not to visit the island if they were pregnant.
She said it was an overabundance of caution but that it was better to be safe because officials didn’t yet know all the risks. They’re conducting training. On Thursday Ellis joined a meeting of obstetrics and gynecological doctors about Zika risks.
She noted that the last case of chikungunya, a related virus carried by the same mosquito, was six months ago.
“So if a patient comes in with fever, joint pain or rash, it is suspected to be Zika at this point, because we do know we have Zika here,” Ellis said.
The Zika virus is not transmitted through human contact but by the same Aedes mosquitoes that have spread dengue, yellow fever and West Nile virus.
It took only three years for West Nile to spread across 44 states and the District of Columbia after it was identified in New York City in 1999, the first time it was discovered outside the Eastern Hemisphere.
One of the challenges of identifying the Zika virus is that the symptoms are so mild. They include a fever, headache and possible red eyes. But most people don’t ever realize they have the disease.
The bigger risk, however, is to unborn children. Zika is suspected to be linked to a huge increase in the incidence of a birth defect, microcephaly, that results in a smaller-than-normal head and an underdeveloped brain. Brazil has reported more than 4,000 incidents of the defect in the months since Zika was first detected there.
Writing in the Journal of the American Medical Association, Daniel Lucey and Lawrence Gostin say the WHO’s failure to act decisively cost thousands of lives. They warn of a similar catastrophe.
“Despite internal reforms, however, WHO is still not taking a leadership role in the Zika pandemic,” they wrote.
