Zika situation report

29 September 2016

Zika virus, Microcephaly and Guillain-Barré syndrome

Key updates

  • Countries and territories reporting mosquito-borne Zika virus infections for the first time in the past week:
    • None
  • Mosquito-borne Zika infections acquired by travelers returning from the Maldives were reported by Germany and Spain in the past week. Prior Zika cases were reported in January 2016.
  • Countries in the Western Pacific Region continue to report new cases as seen in Singapore, Philippines, Malaysia and Viet Nam. Thailand, in the South-East Asia Region, has also recently reported Zika cases. Key areas of the response as identified by members of the Association of Southeast Asian Nations (ASEAN) are disease surveillance and risk assessment, relevant and timely sharing of data, regional surveillance and response, vector control, diagnostic testing, laboratory networks and risk communication, and sharing knowledge and best practices. The Ministry of Public Health of Thailand is investigating cases of microcephaly to determine if they may be linked to Zika infection.
  • Countries and territories reporting microcephaly and other central nervous system (CNS) malformations potentially associated with Zika virus infection for the first time in the past week:
    • None
  • Countries and territories reporting Guillain-Barré syndrome (GBS) cases associated with Zika virus infection for the first time in the past week:
    • None


  • Overall, the global risk assessment has not changed.
  • The investigation of microcephaly cases in Thailand is important to determine whether these cases are linked to Zika infection – if found to be linked, these would be the first identified cases of Zika-associated microcephaly in Southeast Asia. If Zika is identified, viral sequencing would be necessary to determine the strain of the virus to determine whether it is a local or imported strain.
  • The sequencing results from 5 Zika virus cases reported in Malaysia indicate that all are from the “Asian” lineage. Two of the cases, including the imported case, are similar to the virus that was circulating in French Polynesia in 2013, i.e., a post-2007 “Asian” strain. The other 3 locally acquired cases are reported to be a similar to a previously circulating Southeast Asian strain of the “Asian” lineage.

This page links all WHO information to its response on the Public Health Emergency of International Concern.