Zika Virus
About Zika virus
The Zika virus is an infection, transmitted by mosquitoes, which resembles the Dengue, Yellow Fever and West Nile virus. Since it was discovered more than 50 years ago, the Zika virus has affected mainly the population of Africa and Asia, until it started spreading to the Western Hemisphere.
Zika is transmitted by the daytime bite of the Aedes mosquito; symptoms present similarly to other arbovirus infections with mild fever, rash, conjunctivitis, myalgia, arthralgia, malaise, and headache. Symptoms can last up to a week. A suspected complication seen in South America is microcephaly in new born children, and more recently Guillain – Barre syndrome, however until the link has been proven this is only circumstantial.
Where is Zika virus found?
Zika, a mosquito borne virus was first identified in Uganda in 1947 in the Rhesus monkey. Outbreaks have been reported throughout Africa, the Pacific, Americas, and Asia. In 2007, an outbreak in the Pacific Yap Islands resulted in 49 confirmed cases, the first outbreak of its kind, proving transmission of Zika outside Africa and Asia. Previously only 14 cases had been documented since 1947 (WHO, 2016).
In April 2015, reports of the virus emerged from North-east Brazil, by October 2015, 56,318 cases of suspected Zika virus was reported from one Northwest State alone. The Brazilian authorities estimate between 500,000 and 1,482,701 cases since the outbreak begun (WHO, 2016). The disease has now spread across 26 countries in the Americas and more recently Cape Verde off the coast of Africa, Thailand and islands in the Pacific have reported cases (HPS, 2016).
In response to this unprecedented outbreak, the World Health Organization convened an emergency committee to respond to the crisis. The spread of Zika virus is now a Public Health emergency of International concern, a global strategic response framework has been initiated to co-ordinate, manage and assist in the outbreak (WHO, 2016).
How Zika virus is spread?
The Zika virus is transmitted to people mainly through the bite of an infected species of mosquitoes, known as Aedes. The Aedes aegypti is particularly common in Hawaii, Florida and along the Gulf Coast, while the Aedes albopictus, or the Asian tiger mosquito, can be found closer to New York and Chicago.
The Aedes mosquitoеs usually lay their eggs in standing water in buckets, bowls, flower pots and animal dishes. They’re particularly active during the day, but many of them are also aggressive nighttime bitters.
In rare cases, the Zika virus can also be spread from a mother, already infected with the virus, to her child near the time of delivery. There are some reports of the spread of the virus through blood transfusion and sexual contact, as well.
Signs and symptoms
Around 1 in 5 infected with the Zika virus will develop Zika and display symptoms. These might range from fever, rash, joint pain to conjunctivitis, even though symptoms such as muscle pain and headache have also been reported. The incubation period is still unknown, but it’s likely to be between a few days to a week.
The symptoms of Zika usually lasts about a week, and morbidity rates are moderately low. Zika virus will usually remain in the blood of the patient around a week the following infection. Symptoms are similar to other mosquito borne diseases such as Dengue Fever.
Who is at risk?
Anyone, who was not previously exposed to the virus and lives in the affected area, where the mosquito is present, can be at risk for the Zika virus. Since the Zika virus has been found to cause microencephaly in newborns, pregnant women are advised to avoid countries, affected by the virus – including the Caribbean, Central America and South America.
Treatment
Currently, there is no vaccine that can prevent the Zika infection. The symptoms are treated with plenty of rest and fluids, as well as medicine such as Tylenol that can relieve the fever and the pain. Patients are usually advised against taking any aspiring or non-steroidal anti-inflammatory drugs. In most cases, the disease is mild and lasts between 2-7 days, and currently, there is no specific drug for the virus.
Minimising the risk of Zika virus
There is no vaccine for the Zika virus, even though efforts to make one have recently begun. CDC advises pregnant women to avoid travelling to regions, where they might be infected, because completely preventing mosquito bites is almost impossible. To minimize your risk, stay in screened or air-conditioned rooms, or use a mosquito net, when going to sleep. Wearing insect repellent at all times, as well as long sleeves, pants, shoes and hats might also protect you against infection with the Zika virus.
Advice for travellers
There is no vaccine available for Zika virus and no specific treatment. The vast majority of cases are mild and self-limiting. Travelers should be advised on bite avoidance.
- Deet 50% ( can be used for babies over 2 months)
- Loose covering clothing ( preferably light coloured)
- Insecticide impregnated bed nets and air conditioning in bedrooms.
- Physical barriers, windows screens, closed doors and windows.
- Treat clothing with permethrin.
- Cover children’s crib or pram with a protective net.
- Empty any containers used to store water to prevent mosquitoes breeding.
- Use condoms to prevent the risk of sexually transmitted infection of Zika (rare) (WHO,2016).
Zika and Pregnant travellers
Pregnant travellers are advised to seek specialist travel advice before travelling.
- Take bite avoidance measures
- Use Deet 50% (safe in pregnancy)
- Take travel insurance
- Consider consulting a health professional after travel.
(HPA, 2016, CDC, 2016)
The recent Zika Virus outbreak is now a Public health Emergency of International Concern, although the effects of the disease on our travellers is most likely mild and self limiting, the possible association between the Zika virus outbreak and a rise in Guillian-Barre syndrome and infant microcephaly cases being seen in the Americas adds to concern. Travellers need to take precautions both from a personal and global health perspective.
