The Zika virus is transmitted mostly by the bite of Aedes mosquitoes, especially the A.aegypti and the A.albopictus, which generally bite during the day. The infection caused by this virus is called Zika fever or Zika virus condition. These mosquitoes are seen mostly in tropical and subtropical regions and are responsible for spreading other illnesses like dengue, chikungunya, and yellow fever.
The earliest outbreaks of Zika virus infections were seen in Uganda and Tanzania more than 70 years ago, and it spread across Africa and Asia only in the past 15 years.
Incubation period – The time taken for the development of symptoms, from the time of exposure to the virus ranges from three days to two weeks.
Many people who are infected with the Zika virus show few or no symptoms. A few of them may exhibit some general symptoms which last up to a week. Their symptoms are similar to other mosquito-borne infections like dengue and chikungunya, and may include:
- Fever and headache
- Red, painful eyes
- Pain and swelling of the joints and muscles
- Generalised itching and rashes over the body
Zika virus and pregnancy
Zika virus can be transmitted from an infected pregnant woman to her foetus, and it has been found to cause miscarriage, stillbirth, and other birth defects like congenital Zika syndrome. This syndrome consists of babies born with severe microcephaly (smaller head than normal), hypertonia (muscles of the arms and legs become too stiff to move), and neurological manifestations.
Women planning to get pregnant should take necessary precautionary measures after returning from countries where there is a Zika virus outbreak.
In adults, the Zika virus has been known to trigger serious conditions that affect the nervous system, but this is very rare.
The Aedes species of mosquitoes are particularly active during early morning and late afternoon. Besides the bite of an infected mosquito, the Zika virus can be transmitted from a pregnant woman to her foetus.
There are possibilities that the virus can be transmitted during the incubation period, through sexual contact, and blood transfusion.
It is important to record the person’s travel history, especially any recent visit to West Africa, Asia, or any of several Pacific Islands, or Central and South America.
Zika virus infection can be confirmed by blood tests or urine tests. The virus can be detected in infected blood for about a week.
- Blood tests are usually done if the individual exhibits symptoms of Zika virus infection
- If the person is pregnant and has recently travelled to a Zika-affected country, an ultrasound scan is usually performed to examine the foetus
Once a person has recovered from Zika infection, they will generally develop immunity to a future infection.
There is no known treatment for Zika virus infection.
Those with symptoms can:
- Take plenty of fluids and rest
- Use simple painkillers as prescribed by the doctor
Currently, there is no vaccine to prevent Zika. The best way to prevent being bitten by such mosquitoes is to take protective measures such as:
- Wearing light-coloured clothing that covers the arms and legs
- Using clothes pre-treated with insect repellents
- Applying approved mosquito repellent sprays or creams on the skin
- Sleeping under mosquito nets that are treated with insecticides
- Eliminating stagnant water at homes and schools to prevent mosquitoes from breeding. All water storage containers should be covered, and there should be no standing water in flowerpots, tyres, and trash cans.