Travel health update

This month’s travel update focuses solely on the Zika virus, which is dominating the news and global public health agenda, pointing travel nurses in the right direction for accurate and up-to-date information

Zika virus features in almost every news bulletin just now, and quite rightly so, as the impact of the epidemic is so significant that the World Health Organization has announced a Public Health Emergency of International Concern earlier this month, the first since the Ebola virus epidemic in 2014-15. With so much information now available it can become overwhelming to know where to look for advice. I thought I would therefore write this entire column to address queries about the disease that I feel I would want to know for my day-to-day practice. Please remember this is a changing picture and you would be well advised always to look at the latest advice published on NaTHNaC and TRAVAX in the days and weeks to come.

WHAT IS Zika AND HOW IS IT SPREAD?

Zika is a viral infection transmitted by the Aedes mosquitoes which are daytime biting – very similar to transmission of dengue infection. The disease was first identified in Uganda in 1947 in rhesus monkeys and subsequently in humans in 1952 in Uganda and the United Republic of Tanzania. There have been outbreaks of Zika virus disease recorded in Africa, the Americas, Asia and the Pacific. There have also been two cases of Zika virus through sexual intercourse, and transmission to the baby via the placenta.

WHAT IS THE IMPACT OF THE ILLNESS?

This disease is usually mild with a fever, skin rash and conjunctivitis lasting between 2 and 7 days. However, during large outbreaks in French Polynesia (2013) and in Brazil (2015) there was found to be a rise in cases of congenital malformations and neurological complications. An increasing body of evidence is pointing towards a link between Zika virus and microcephaly although this has not been scientifically proven yet. At present the WHO Emergency Committee has found no public health justification for restrictions on travel or trade to prevent the spread of Zika virus.

PREVENTION, DIAGNOSIS AND TREATMENT

There is currently no vaccine available so the most important protective measures are controlling the numbers of mosquitoes and preventing mosquito bites in infected regions, especially in pregnant women. Diagnosis is based on blood samples but this can be difficult as the virus can cross-react with other flaviviruses such as dengue, West Nile and yellow fever.

WHAT SHOULD WE BE ADVISING OUR TRAVELLERS

Women who are pregnant or considering becoming pregnant are advised not to travel to countries affected by Zika virus if at all possible. Women who have already travelled to such areas should have an antenatal check as soon as possible on return home. An interim testing algorithm and clinical guidelines have been developed and are published on the Royal College of Obstetricians and Gynaecologists website, available at https://www.rcog.org.uk/en/news/interim-clinical-guidelines-on-Zika-virus-infection-and-pregnancy/

NHS choices advises that if a female traveller has experienced Zika symptoms either during or within two weeks of returning home, she should wait at least six months after full recovery before trying to conceive. Even if no symptoms were experienced, conception should be avoided for at least 28 days after returning home, by using condoms. For anyone travelling to infected areas, stringent bite avoidance measures are required with particular attention mid-morning and late afternoon to dusk when the Aedes is particularly active. More detailed information is available from NaTHNaC, TRAVAX and NHS Choices.

WHAT ABOUT PEOPLE WHO DONATE BLOOD, SEMEN OR TISSUE?

If the traveller experienced symptoms of Zika virus then blood, semen or tissue should not be donated for a minimum of 6 months and those without symptoms who travelled to an area with infection, should wait for 28 days.

WHERE TO GO FOR MORE INFORMATION

Excellent information is available at:

• RCPG, RCM, PHE, HPS clinical guidelines. Zika virus infection and pregnancy; updated 2019. https://www.rcog.org.uk/globalassets/documents/guidelines/zika-virus-rcog-feb-2019.pdf
• Public Health England. Zika virus (ZIKV): clinical and travel guidance; updated 2019. https://www.gov.uk/government/collections/zika-virus-zikv-clinical-and-travel-guidance
• Travel Health Pro. Zika virus (ZIKV) update to guidance; 2019. https://travelhealthpro.org.uk/news/394/zika-virus-zikv-update-to-guidance

Other resources are available from the World Health Organization. http://www.who.int/mediacentre/factsheets/Zika/en/