Research and analysis

HPR volume 10 issue 5: news (5 February)

Updated 16 December 2016

1. Zika virus – epidemiological and guidance update

As of 5 February, 36 countries and territories worldwide have reported confirmed cases of locally-acquired Zika virus (ZIKV) infection in the last nine months (see PHE Zika webpage for latest information) [1].

The outbreak in the Americas continues to spread rapidly, with 27 countries within Central and South America and the Caribbean currently affected by active ZIKV transmission (see PHE Map).

Within continental Europe, no autochthonous ZIKV cases have been reported. However, active ZIKV transmission is ongoing in a number of the outermost European territories (French Guiana, Guadeloupe, Martinique, Saint Martin and Curacao) [2].

In the UK, the risk of autochthonous, vector-borne ZIKV virus transmission is deemed to be negligible due to climatic factors (that preclude the Aedes mosquito vector surviving). As at 4 February, five imported cases associated with the current outbreak have been reported in the UK (from Colombia, Guyana/Suriname and Mexico/Venezuela) [1].

Recent increases in congenital anomalies (particularly microcephaly), Guillain-Barré syndrome, and other neurological and autoimmune syndromes are being reported in areas where ZIKV outbreaks have occurred. The association of these illnesses with ZIKV is temporal and causality has yet to be proven, however evidence is accumulating. Further information about these findings is available from WHO [3].

On 1 February, the first meeting was convened of the WHO International Health Regulations Emergency Committee (EC) concerned with clusters of microcephaly cases and other neurological disorders in some areas affected by ZIKV. Following a review of the evidence currently available, the EC advised that the recent cluster of microcephaly cases and other neurological disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes an “extraordinary event” and a public health threat to other parts of the world, and therefore constitutes a Public Health Emergency of International Concern [4].

Declaring the PHEIC, the EC recommended a range of precautionary measures for affected countries and issued temporary recommendations which include: improved surveillance and control of Zika in at risk countries, and measures for travellers and pregnant women. They also found that there is currently no public health justification for restrictions on travel or trade to prevent the spread of ZIKV [4].

1.1 Current advice

The PHE Zika webpage [1] is a regularly updated resource for epidemiological information and guidance. Current guidance documents include:

• an interim algorithm for assessing pregnant women with a history of travel during pregnancy to areas with active (ZIKV) transmission

• guidance on ZIKV infection for primary care clinicians.

Also included on the webpage are links to current travel advice provided by NaTHNaC and a recent statement by NHS Blood and Transplant on blood donation deferral, in England and North Wales, affecting those who have travelled to countries where the Zika virus is endemic.

1.2 References

1. PHE website. Zika virus: health protection guidance collection.

2. ECDC (4 February). Epidemiological update: Outbreaks of Zika virus and complications potentially linked to the Zika virus infection.

3. WHO PAHO (17 January). Epidemiological Update – Neurological syndrome, congenital anomalies, and Zika virus infection.

4. WHO (1 February). WHO statement on the first meeting of the International Health Regulations Emergency Committee on Zika virus and observed increase in neurological disorders and neonatal malformations.