What is the Zika virus?
The Zika virus is a mosquito borne illness similar to dengue fever. The first report of the infection was in 1947 in Africa. Outbreaks have been seen in Africa, the Pacific Islands and Southeast Asia prior to 2015, but recent outbreaks in the Americas (Central and South America) have been widespread as it is a new virus to these regions and therefore there is lower immunity within the community.
The most common symptoms of the Zika virus are joint pains, fever, rash and conjunctivitis. Only 1 in 5 people infected will exhibit symptoms of the illness. For most people the infection is mild and short-lived lasting from a few days to a week. It is rare to require admission to hospital. The symptoms are treated with rest, hydration and paracetamol for relief of pain and fever.
So what is the risk? Particularly to pregnant women?
In Brazil where the virus has been particularly prevalent there have been an increase in cases reported of microcephaly, where the baby’s brain does not form properly and results in a small head with intellectual impairment. To date there is not a clear causal link between the virus and the cases of microcephaly, but research is ongoing and there is a high suspicion of a relationship.
It is recommended that women who are pregnant defer travel to affected areas to avoid contact with the infection. If travel is essential, precautions against mosquito bites need to be taken as listed below. Mosquito repellents are safe to use in pregnancy and when breastfeeding. If you are pregnant and have had the symptoms of rash, fever and joint pains subsequent to travelling in areas with the Zika virus it is important that you speak to your doctor. Testing is available and may involve bloods tests, ultrasound and amniocentesis (sampling the baby’s amniotic fluid).
Are there any risks if I’m not pregnant?
There have also been an increase in reported cases of Guillain-Barre syndrome in areas affected by the Zika virus. This is a severe auto-immune condition where exposure to a viral illness triggers your immune system to attack the nervous system and in severe cases can result in paralysis. Again, a causal relationship has not been proven and more research is ongoing.
Is there a vaccine available? How can transmission of the virus be prevented?
There is no vaccine available for the Zika virus. The virus is transmitted by the Aedes mosquitos which typically bite in the early morning and late afternoon and evening. When travelling to countries where Zika is active, mosquito protection is the best way to avoid infection. This involves covering up with long sleeves and pants, and wearing mosquito repellent containing DEET or picaridin. Screens or mosquito netting should be used when sleeping.
Is there a risk of the virus coming to Australia?
The main risk for Australians is for those who are travelling to Zika affected areas and can catch the virus while overseas. There have been two cases of Zika reported in people returning to Australia. An outbreak in Australia is possible, but is likely to be limited to areas where the Aedes mosquito is found such as Far North Queensland. Authorities suggest that a large outbreak is unlikely and are monitoring the situation.