Intended for healthcare professionals


Zika virus is a global public health emergency, declares WHO

BMJ 2016; 352 doi: (Published 02 February 2016) Cite this as: BMJ 2016;352:i657
  1. Anne Gulland
  1. 1London

The Zika virus, and its suspected link to an increase in the number of babies born with microcephaly and a spike in neurological conditions is a global public health emergency, the World Health Organization has declared.1 2 3 4 5 6

WHO’s public health emergency committee, which met on Monday 1 February, declared that the spread of the virus was an emergency of public health concern, triggering funding into research, vector control, and efforts to stop pregnant women becoming infected.

WHO’s director general, Margaret Chan, told a press conference that the virus was an “extraordinary event and a public health threat to other parts of the world.” She said that evidence for a link between the virus and the increase in cases of microcephaly in babies and a spike in cases of Guillain-Barré syndrome was growing.

David Heymann, chair of the emergency committee, told the press conference that it was hard to say how long it would take to definitively prove the link. “It’s a complicated issue. Microcephaly is a rare event, and you have to find the cases and compare them with cases that don’t have microcephaly and then look at mosquito exposure,” he said.

Brazil has been the country hardest hit by the Zika complications, with about 4000 babies born with microcephaly since October last year. In 2014 French Polynesia also reported a spike in the number of babies born with the condition. The virus, which in most people causes only mild symptoms such as fever, rash, and conjunctivitis, has been reported in 25 countries in the Americas.1

Chan warned that countries such as India that have outbreaks of dengue, yellow fever, and chikungunya, all carried by the same mosquito vector (Aedes aegypti) that carries the Zika virus, needed to be alert to cases. “The mosquito that spreads the Zika virus is ubiquitous in so many countries that it’s incumbent on us to work with these countries,” she said.

WHO is not urging any restrictions on trade or travel, nor has it advised women in countries where the virus is present to avoid getting pregnant.

Chan said that microcephaly posed a heavy burden on women in particular and urged pregnant women and women who may become pregnant to take measures to avoid being bitten, such as covering their arms and legs, wearing mosquito repellent, and sleeping under a bed net.

The emergency committee called for the “aggressive” promotion of vector control and personal protective measures and said that special attention should be given to ensuring that women of childbearing age and, in particular, pregnant women had the right information and materials to reduce their risk of exposure. Pregnant women who have been exposed to the virus should be counselled, the committee added.

Bruce Aylward, WHO’s executive director for outbreaks and emergencies, told the press conference that he was not worried about sounding a false alarm, given the lack of firm evidence. “These are the right measures to be taking at this time, based on the information available,” he said.

Jeremy Farrar, director of the UK medical research charity the Wellcome Trust, said that WHO should be congratulated for its quick reaction to the Zika virus, given its slow response to the outbreak of Ebola virus disease. He added, “Alongside the emergency response that Zika necessitates, we must put in place the permanent reforms, health system strengthening, and proactive research agenda that are needed to make the global health system more resilient to the threat of future pandemics.”

Public Health England has said that, despite the limited evidence of sexual transmission of the virus, men returning from a country where the virus is endemic should use a condom for 28 days if their female partner is pregnant or at risk of getting pregnant. Men who suspect that they have been exposed to the virus should use a condom for six months after recovery.


Cite this as: BMJ 2016;352:i657


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