Two months after Haiti confirmed it was having an outbreak of the painful mosquito-borne virus chikungunya in 2014, Haitians began complaining about a new fever epidemic and wondered whether it was Zik or Zika, the other virus carried by the same mosquito.
Haiti health officials and experts from the U.S. Centers for Disease Control and Prevention quickly dismissed the Zika rumors, regarding the fever symptoms as another bout of fast-spreading chikungunya.
Now, infectious-disease specialists at the University of Florida believe that diagnosis was wrong. Zika, according to new research, was not only present in the Western Hemisphere before it was confirmed in Brazil in March 2015 — it was in Haiti.
“What seems to have happened is that the chikungunya outbreak was followed by [dengue] and Zika,” Dr. J. Glenn Morris, Jr., a professor of medicine and the director of the University of Florida’s Emerging Pathogens Institute, which runs a lab in Haiti, said about the June 2014 rumors sweeping Haiti.
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Moris said the UF study, while focused on samples taken in December 2014, suggest that it’s not “an unreasonable possibility that” the dengue-like symptoms that Haitians were reporting in June of 2014 were Zika cases.
Following Haiti’s April 2014 chikungunya outbreak, UF’s laboratory began monitoring the virus and collecting blood samples from schoolchildren in the Gressier/Leogane region, southwest of Port-au-Prince, where the laboratory is located.
Soon, the center’s nurses began noticing that some of the children started coming down with a fever.
“The nurses said, ‘Everybody is getting it again,’” Morris said, recalling how almost everyone dismissed the illness as a second wave of chikungunya.
Everyone except for one curious virologist: John Lednicky, who would become the lead author of UF’s study on the findings. The study was published Monday in PLOS Neglected Tropical Diseases.
The scientists from UF’s environmental and global health department and the Emerging Pathogens Institute specialists began doing additional lab studies. Sick schoolchildren had blood sampled and were screened for dengue, chikungunya and malaria. After the samples came back negative for all three, they were classified as “mystery” viruses.
Using a more sophisticated testing method, researchers subsequently sequenced and identified the Zika virus. The plasma samples that yielded Zika virus were taken in December 2015, three months before Brazilian scientists confirmed that Zika was present in the South American country.
The Haitian strain, while genetically similar to the Brazilian, is more similar to the strain from the French Polynesian islands, said Dr. Jacques Boncy, director of Haiti’s National Public Health Laboratory.
In June 2014, Boncy was asked about whether Zika was present in Haiti. He told the Miami Herald that Zika had been confirmed in Yap Island and in French Polynesia, islands in the Pacific, but it was “not in the Caribbean region.”
Now, after speaking with Morris, Boncy says he may have been wrong.
“They did sequencing, and that is where they saw three children who came back positive for Zika,” he said.
Boncy said that before Zika was confirmed in Brazil, it was reported on Easter Island, a Chilean territory, where an annual festival is believed to be the source of transmission. On March 3, 2014, Chile notified the Pan-American Health Organization/World Health Organization of Zika’s existence on the island.
Haiti has United Nations troops from Chile stationed in the country, and a number of Haitians are employed in Brazil’s construction industry — factors that could have led to Zika’s transmission in the country.
“We will never know where the current Zika outbreak in the Americas started,” said Daniel Impoinvil, CDC research epidemiologist involved in helping Haiti monitor the spread of the virus. “Most likely it was imported into Haiti and once it is imported, you can expect additional cases.”
Impoinvil noted that during the time period of the UF study, Haiti was 20 weeks into a major chikungunya outbreak.
“The symptoms of chikungunya, dengue and Zika are remarkably similar,” he said. “Given the similar symptoms and the lack of history of Zika in the Americas and around the world at that time, Zika would not necessarily have been considered as a source of infection.”
As of April 2, there have been 2,024 suspected reported cases of Zika in Haiti since the virus’ Jan. 15 confirmation, the CDC said. A dozen of the cases involve pregnant women.
CDC director Dr. Tom Frieden recently confirmed that a study looking at brain scans of babies born with suspected Zika-related microcephaly in Brazil confirms that the virus causes the birth defect. Babies with the birth defect have been born with smaller than usual heads to mothers infected with Zika in Brazil and several other countries, according to the WHO.
“We haven’t yet found any cases of microcephaly, but we have found about three cases of Guillain-Barré Syndrome,” Boncy said. Guillain-Barré Syndrome, also linked to Zika, is a neurological syndrome in adults that leads to difficulty in walking.
Morris said the lack of money for Zika research is frustrating, and stifles scientists’ ability to find answers to so many unknowns. Funding for Zika research, preparation and treatment remains stalled in Congress.
“This was an unexpected pathogen; we didn’t think Zika would come in and do all of this,” he said. “Zika was an obscure disease that you learned for your medical boards. There is still an awful lot that we don’t know about it.’’
Zika is transmitted by the same mosquito, the Aedes aegypti, that transmits dengue and chikungunya.
To help Haiti better monitor Zika outbreaks, the CDC has trained staff at the National Public Health Laboratory on Zika testing. The lab now can independently conduct Zika tests.
“Our studies in Haiti have just scratched the surface,” he added. “Where it is coming from, where it is moving, how it is evolving? Our entire purpose is to try and answer these questions.”