WHO Zika Virus, Microcephaly and Guillain-Barré Syndrome Situation Report, 20 October 2016

from World Health Organization
Published on 20 Oct 2016


  • Countries and territories reporting mosquito-borne Zika virus infections for the first time in the past week: o None

  • 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: o Grenada

  • Countries and territories reporting Guillain-Barré syndrome (GBS) cases associated with Zika virus infection for the first time in the past week: o None

  • The Ministry of Health of Viet Nam has reported a case of microcephaly, for which testing is underway to determine the cause.


  • Overall, the global risk assessment has not changed.


  • 73 countries and territories (Fig. 1, Table 1) have reported evidence of mosquito-borne Zika virus transmission since 2007 (67 with reports from 2015 onwards), of which:

  • 56 with a reported outbreak from 2015 onwards (Fig. 2, Table 1).

  • Eight with having possible endemic transmission or evidence of local mosquitoborne Zika infections in 2016.

  • Solomon Islands was previously listed in category 3, however, a Zika virus infection in a returning traveller was reported by Australia. Solomon Islands has therefore been reclassified into category 2.

  • Nine with evidence of local mosquito-borne Zika infections in or before 2015, but without documentation of cases in 2016, or with the outbreak terminated.

  • Solomon Islands has been removed from this category.

  • Since February 2016, 12 countries have reported evidence of person-to-person transmission of Zika virus (Table 2).

  • 23 countries or territories have reported microcephaly and other CNS malformations potentially associated with Zika virus infection or suggestive of congenital infection . Grenada is the latest country to report Zika-associated microcephaly.

  • 19 countries and territories have reported an increased incidence of GBS and/or laboratory confirmation of a Zika virus infection among GBS cases (Table 4). Puerto Rico, which has previously reported GBS cases with confirmed Zika virus infections, has reported an increase in incidence of GBS cases in the last week.

  • On 17 October 2016, the Ministry of Health of Viet Nam reported a 4-month-old child with microcephaly. Blood specimens were collected and testing is being conducted to determine the potential cause of this microcephaly.

  • On 7 October 2016, the Grenada health authorities reported the first confirmed case of congenital syndrome associated with Zika virus infection. The case was laboratoryconfirmed by PCR.

  • In Guinea-Bissau, the investigation of five reported cases of microcephaly is ongoing.