Zika virus is a type of virus that is transmitted via the bite of Aedes mosquitoes leading to the development of Zika virus disease. The virus has been known to be in circulation in the Americas, Africa, the Pacific, and Asia.
Symptoms of Zika virus disease include a skin rash, mild fever, and conjunctivitis, etc., which typically prevail for 2 to 7 days. There is no vaccine for the disease and it does not have any kind of specific treatment options. The best option is to take preventive measures to avoid mosquito bites.
Zika virus and its global threat
Zika virus was first discovered in Africa. The first outbreak of the disease in the Pacific Yap in 2007 and in French Polynesia in 2013. It was first detected in Brazil in May 2015 and since then the country has been beset by the epidemic. It has now spread to over 22 countries in the region. In the US, Aedes aegypti mosquitoes are found in the southern region. However, Zika virus disease may not be as serious or as prevalent as it is in Latin America.
The main reason why health officials are worried about Zika virus disease is because studies indicate that the infection leads to microcephaly in infants as well as a neurological syndrome which may trigger paralysis. Microcephaly is a congenital condition wherein babies are born with damaged brains and unusually small heads.
There are several vaccine makers that are currently working towards developing a vaccine for the disease. But it may take some time before it can be used on humans.
Symptoms of Zika virus disease
The symptoms of Zika virus disease are the same as varied arboviral illnesses like dengue, etc. The incubation period, i.e., the time from contact with the virus and the occurrence of symptoms, is not clear, but doctors believe that it can be a 2 to 7 days. Some common signs and symptoms are listed below:
- About 20 percent of infected people may become ill and suffer from mild fever that lasts for many days to a week.
- Joint pain, skin rashes or exanthema, and pink eye may be evident.
- Some patients may also experience headache and muscle pain.
Zika outbreak investigations are pointing towards a possibility of an association between microcephaly and infection by Zika virus. Research is ongoing to prove and confirm this link.
Causes and transmission of Zika Virus
Zika virus disease is caused via the bite of infected Aedes genus mosquitoes, especially the Aedes aegypti type which is prevalent in tropical regions. This mosquito is the same that is responsible for transmission of pathogens that cause yellow fever, dengue, and chikungunya.
The Aedes mosquitoes live in urban areas and can breed in even small water containers like cans, flower pots, buckets, etc. with standing water. It usually bites humans and thus are very efficient in spreading diseases. It bites during the day, thereby rendering mosquito nets almost useless.
In rare cases, Zika virus may transmit from an infected mother to a baby at the time of childbirth; or from the mother to the fetus; or through sexual contact or infected blood exposure.
There is no evidence of the virus transmitting during or by breastfeeding.
Zika Virus – Pictures
Treatment and Prevention
Currently, there is no vaccine for Zika virus disease. Illness caused by Zika virus infection is generally mild and does not need any particular treatment. Patients must consult a doctor if the symptoms are moderate or serious.
A few treatment options include:
- It is important for patients to drink sufficient fluids to prevent dehydration.
- Get lots of rest.
- The associated symptoms, such as fever and pain, may be alleviated with common medications.
- Due to the under-investigation link of Zika virus with microcephaly, infected women are advised to avoid getting pregnant. Also, pregnant women should not visit areas with mosquito infestation.
Prevention of Zika virus infection is mainly concerned with measures to eradicate mosquito population, protection from mosquito bites, etc. as discussed below:
- Do not keep standing water in containers, etc. and thus prevent mosquito breeding.
- Sleeping under mosquito nets, covering almost all parts of the body, using screens and other physical barriers, and using insect repellants can help protect from mosquito bites.
- Use of WHO recommended insecticides can help destroy breeding sites.
- A British company called Oxitec has developed a genetically engineered type of Aedes aegypti mosquito to combat dengue. These genetically modified mosquitoes pass a lethal gene to its offspring, which die before becoming adults. It is said that this method can also be used to stop the spread of Zika virus. It may be noted that the genetically engineered mosquitoes are males; as only female mosquitoes are responsible for spreading the virus, these engineered mosquitoes do not contribute to spread of Zika.
- Infecting the mosquitoes with Wolbachia bacteria is another method to curb Zika virus. This bacteria restricts the ability of the mosquitoes to easily get and transmit varied viruses. Also, the bacteria passes via eggs to the next generation. Thus, the new generations need not be manually infected with the bacteria.