Microcephaly/Zika virus disease talking points

1 December 2018

WHO has announced that the recent cluster of microcephaly and other neurological abnormalities reported in the Americas region constitutes a Public Health Emergency of International Concern (PHEIC).

  • The announcement followed an Expert Committee meeting called under the International Health Regulations (IHR). The group agreed that a causal relationship between this cluster and Zika virus disease is strongly suspected.

The experts agree on the urgent need to coordinate international efforts to investigate and understand the relationship better through:

-Improved surveillance;

-Detection and tracking of infections, congenital malformations and neurological complications

-Intensification of efforts to reduce mosquito populations;

-Expedited research and development into diagnostic tests and vaccines to protect people at risk, especially during pregnancy.

The committee found no justification for restrictions on travel or trade. However, travelers to areas where Zika virus cases have been found are urged to protect themselves from mosquito bites including personal and household prevention steps (see below for list).

Zika alone would not constitute a PHEIC

  • The symptoms known to be caused by Zika infection tend to be mild. They include fever, rash, joint pain and conjunctivitis (pinkeye), typically occur 2 to 7 days after infection and are usually self-limiting.
  • Many people infected with Zika virus don’t show symptoms. Those who do can be treated with common pain and fever medicines, rest and drinking plenty of water. The virus is not easily passed from person to person.

More concerning is the unproven link between Zika and an increased number of reports of babies born with unusually small heads.

  • Microcephalyresults in delayed development and mental retardation in some babies.Since last May, more than 4,000 suspect cases of microcephaly have been reported in Brazil. Brazil’s total in previous years was only about 160 cases.

Zika is also suspected of causing Guillain-Barré syndrome (GBS), a neurological disorder that can result in paralysis.

WHO recommends:

  • Reducing populations of mosquitoesthat transmit Zika virus.The same Aedes mosquitoesthat transmitZika virus also transmit dengue,chikungunya and Yellow Fever.Mosquito-control programmes include use of larvicide (insecticide that kills the mosquito in its larval stage) to treat standing-water sites that cannot be treated in other ways (cleaning, emptying, covering).
  • Personal and household protection. WHO recommends people protect themselves from mosquito bitesby

using insect repellent;

wearing clothes (preferably light-coloured) that cover as much of the body as possible;

using physical barriers such as screens, closed doors and windows;

sleeping under mosquito nets, especially during the day, when Aedes mosquitoes are most active; and

emptying or covering containers that can hold water, such as buckets, flower pots and tyres, so that mosquitoes cannot use them to breed.

  • Pregnant women and women planning to become pregnant.Pregnant women who feelthey may have been exposed to Zika virusmay wish to consult with their health-care providers for close monitoring of her pregnancy.
  • Travel recommendations. WHO is not recommending travel restrictions related to Zika virus disease.Pregnant women living in or considering travel to affected areas may wish to consult with health authorities. They should also practice personal and household steps to prevent mosquito bites (see above).
  • Blood safety. Zika can be transmitted through blood, but this occurs infrequently. WHO recommends that precautions already in place for ensuring safe blood donations and transfusions be followed.
  • Disinsection in aircrafts. Disease vectors, particularly mosquitoes, have long been imported into countries on aircraft and transmitted disease. WHO recommends that airlines dis-insect planes flying into or out of areas where Zika virus is circulating.
  • National policy. WHO advises Member States to base their recommendations on their assessment of evidence in their own countries and to consider local risk factors and consequences as they relate to their own populations.

WHO response

  • WHO has activated its new incident management system, established under the Organization’s emergency reform programme. It is also using its new Contingency Fund to help finance the response.
  • WHO’s Regional Office for the Americas (PAHO) has been working closely with affected countries since May 2015, when the first reports of Zika virus disease emerged from northeastern Brazil. PAHO has mobilized WHO’sGlobal Outbreak and Response Network to help ministries of health strengthen their abilities to detect the virus through laboratory testing and rapid reporting. The aim is to ensure accurate diagnosis and treatment, to track the spread of the virus and the mosquito that carries it, and to promote prevention, especially by reducing the Aedes mosquito populations.
  • WHOhas been working with countries to enhance surveillance ofZikavirus and of the conditions that may be associated with it, including microcephaly.
  • In December 2015, WHO called together experts to assess the potential link between microcephaly and Zika.It plans another meeting in March. A number of studies are ongoing, including case-control studies.
  • WHO is working to assess the knowledge and toolsthat already exist and to prioritize research in the areas of vaccines, drugs, diagnostics and mosquito control.
  • WHO supports Member States in their efforts to strengthen their capacity in risk communication to help them meet their commitments under the International Health Regulations.
  • WHO offices (headquarters, regional offices, country offices) are responding to the outbreak.

Further information:

  • WHO statement on the first meeting of the IHR Emergency Committee on Zika virus and observed increase in neurological disordrs and neonatal malformations
  • Statement of the WHO Director-General Margaret Chan, 28 January 2016:
  • Speech of the WHO Director-General Margaret Chan, 28 January 2016:
  • Fact sheet on Zika virus:
  • Q&A on Zika virus disease:
  • More about Zika virus disease:
  • More information from PAHO:
  • Link to audio file from the Virtual Press briefing on Zika virus, 28 January 2016:

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