Based on observational, cohort and case-control studies there is strong scientific consensus that Zika virus is a cause of GBS, microcephaly and other neurological disorders.- WHO SitRep
Despite there still being significant gaps in our understanding of the Zika virus, and its impact on human health, today's 13-page WHO Zika SitRep contains the boldest language on causality of Microcephaly and GBS we've seen, citing `strong scientific consensus'.
Last week's report only referred to `mounting evidence' that Zika was `highly likely' to be a cause of microcephaly, GBS and other neurological disorders.
Apparently, based on the growing preponderance of evidence (which has been considerable), the level of confidence has increased. It will be interesting to see if we hear the same kind of scientific consensus expressed at tomorrow's Zika Summit being held by the CDC.
Perhaps the biggest news in this Sitrep are the long awaited details on the number of microcephalic births from Columbia, the second country in the Americas to report a significant spike in microcephaly after the arrival of Zika.
This from the PDF file:
On 30 March, Colombia reported 50 live births with microcephaly between 4 January 2016 and 20 March 2016. This number represents an increase compared to the historical annual average expected (140 per year).
Of the 50 cases registered, 16 were discarded for microcephaly with suspected association to Zika virus. Of the remaining 34 cases, two were ruled out for not meeting the national criteria for association with microcephaly by Zika virus.
The remaining cases (32) are under investigation, in order to establish the association with Zika virus infection. So far, eight of these 32 cases of microcephaly presented Zika virus positive results by real-time PCR. The investigation is ongoing and further information is expected.
This report also contains an expanded list of elevated GBS rates in the Americas, and their response plan. Follow the link to download and read the report in its entirety.
- From 1 January 2007 to 30 March 2016, Zika virus transmission was documented in a total of 61 countries and territories. Four of these (Cook Islands, French Polynesia, ISLA DE PASCUA – Chile, and New Caledonia) reported a Zika virus outbreak that is now over. Six countries have now reported locally acquired infection in the absence of any known mosquito vectors, probably through sexual transmission (Argentina, Chile, France, Italy, New Zealand and the United States of America).
- In the Region of the Americas, the geographical distribution of Zika virus has steadily widened since the presence of the virus was confirmed in 2015. Mosquito-borne Zika virus transmission has been reported in 33 countries and territories of this region.
- In the Western Pacific Region, mosquito-borne Zika virus cases have been reported in 16 countries and areas.
- Microcephaly and other fetal malformations have been reported in Brazil (944 cases), Cabo Verde (two cases), Colombia (32 cases), French Polynesia (eight cases), Martinique (one case) and Panama (one case). Two additional cases, linked to a stay in Brazil, were detected in the United States of America and Slovenia.
- In the context of Zika virus circulation, 13 countries or territories have reported an increased incidence of Guillain-Barré syndrome (GBS) and/or laboratory confirmation of a Zika virus infection among GBS cases.
- Based on observational, cohort and case-control studies there is strong scientific consensus that Zika virus is a cause of GBS, microcephaly and other neurological disorders.
- The global prevention and control strategy launched by the World Health Organization (WHO) as a Strategic Response Framework encompasses surveillance, response activities and research. This situation report is organized under those headings.