World Health Organization (WHO) Director-General Dr Margaret Chan yesterday declared that the recent cluster of microcephaly cases and other neurologic disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes a Public Health Emergency of International Concern.
It is strongly suspected that Zika virus disease during pregnancy may cause microcephaly, though this is not yet scientifically proven.
A Public Health Emergency of International Concern, as defined by the International Health Regulations (IHR), is “an extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response”.
A Public Health Emergency of International Concern means that there is the need for increased international collaboration to respond to the health event or outbreak – in this case, to reduce the impact of Zika virus in those countries currently experiencing outbreaks, and to limit transmission to new countries. The IHR Emergency Committee which met yesterday to advise the WHO Director-General recommended a range of short and medium term measures to respond to the current situation in Brazil, including enhancing and standardizing surveillance for microcephaly and Guillain-Barré syndrome, and conducting further research into the new clusters to ascertain whether there is a causative link to Zika virus.
People can catch Zika virus by being bitten by an infected Aedes mosquito – the same type of mosquito that spreads dengue, chikungunya and yellow fever.
In general, the symptoms known to be caused by Zika virus tend to be mild. They include fever, rash, joint pain and conjunctivitis (pinkeye). They typically occur 2 to 7 days after infection and are usually self-limiting. Many people infected with Zika virus don’t show any symptoms at all. Those who do can be treated with common pain and fever medicines, rest and drinking plenty of water.
More concerning is the suspected link between Zika virus and an increased number of reports of babies born with unusually small heads (microcephaly). Zika virus is also suspected to be linked with rare cases of Guillain-Barré syndrome (GBS), a neurological disorder that can result in paralysis.
Zika virus has not been reported in mainland China to date. However, an ‘imported’ or travel-related cases may occur, as has been the case in other countries. Major outbreaks of Zika virus can occur in cities and towns where environments for the Aedes mosquito to breed and thrive are ideal, mainly in southern coastal areas where dengue transmission occurs on a seasonal basis, such as in Guangdong province. However, the risk of transmission is low during the current winter season in China, because the climatic conditions are not suitable for the activity of the Aedes mosquito.
“WHO is working closely with the Chinese health authorities to discuss the implications of this Public Health Emergency of International Concern. However, the risk of a widespread outbreak of Zika virus disease in China appears to be low at this point in time. We will of course continue to closely monitor the situation,” said Dr Bernhard Schwartländer, WHO Representative in China.
In areas where the Aedes mosquito exists, the key measures for reducing transmission of Zika virus include protection against mosquito bites, for instance by using insect repellent, wearing clothes (preferably light-coloured) that cover as much of the body as possible, and using physical barriers such as screens, closed doors and windows. In addition, any containers that can hold even small amounts of clear water such as buckets and flower pots should be emptied, cleaned or covered so that mosquitoes cannot use them to breed.
Note to editors: What is microcephaly and Guillain-Barré syndrome?
Microcephaly is a rare condition where a baby has an abnormally small head, due to abnormal brain development in the womb or during infancy. Babies and children with microcephaly often have challenges with their brain development as they grow older.
Guillain-Barré syndrome is a condition in which the body’s immune system attacks part of the nervous system. It can be caused by a number of viruses and can affect people of any age. Exactly what triggers the syndrome is not known. The main symptoms include muscular weakness and tingling in the arms and legs. Severe complications can occur if the respiratory muscles are affected, requiring hospitalization.
About the World Health Organization
WHO is the directing and coordinating authority for health within the United Nations system. It is responsible for providing leadership on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence-based policy options, providing technical support to countries and monitoring and assessing health trends.
For more information please contact:
Ms WU Linlin
WHO China Office
E-mail: wul@who.int
Office Tel: +86 10 6532 7191