All You Need To Know About The Virus, The Risks And Treatment

Zika virus: On Monday, December 12, a five-year-old girl from Raichur, Karnataka, became the first confirmed case of Zika virus in the state. Karnataka Health Minister K Sudhakar said there is no need to worry or concern, because the state government is taking all the necessary measures, according to media reports. 

Quoting Sudhakar, a PTI report said a lab report about the confirmed case of Zika was obtained from Pune. The sample was processed on December 5, and the results reported on December 8. He added that three specimens were sent to the lab, two of which turned out to be negative, and one came positive. The sample of the five-year-old girl from Raichur was the one that came positive. 

Here is everything you need to know about Zika virus disease. 

What is Zika virus disease?

Zika virus spreads mostly by the bite of infected Aedes mosquito species such as Aedes aegypti and Aedes albopictus. The virus can be transmitted from a pregnant woman to her foetus, and may result in birth defects. It may also be transmitted sexually. 

First discovered in 1947, Zika virus is named after the Zika Forest in Uganda. The virus was detected in a Rhesus macaque monkey. The first human cases of Zika were detected in 1952. In the 1950s, cases of Zika virus disease were reported in African countries. 

Since then, outbreaks of Zika virus disease have been reported in tropical Africa, Southeast Asia, and the Pacific Islands, according to the Centers for Disease Control and Prevention. 

Sporadic human infections were detected across Africa and Asia, from the 1960s to 1980s. 

The symptoms of Zika are similar to those of many other diseases, and hence, many cases may not have been documented. 

The Zika virus infection outbreaks that occurred over the last decade were found to be associated with increased incidence of Guillain-Barré syndrome, according to the World Health Organization (WHO). Guillain-Barré syndrome is a condition in which the immune system attacks the nerves, and is triggered by an acute bacterial or viral infection. Symptoms of this disease include weakness and tingling in the feet and legs that may spread to the upper body. 

Zika virus disease was found to be associated with microcephaly, when the virus emerged in the Americas. Microcephaly is a condition in which a baby’s head is significantly smaller than expected, often due to abnormal brain development, and occurs because of infections, malnutrition or exposure to toxins. In 2015, a large epidemic of Zika virus disease occurred in Brazil. 

The WHO declared a Public Health Emergency of International Concern (PHIEC) regarding microcephaly, other neurological disorders and Zika virus, from February to November 2016. Soon, the causal link between Zika virus and congenital malformations was confirmed.

Aedes aegypti mosquitoes were responsible for Zika virus disease outbreaks throughout most of the Americas and in other regions. The same mosquito transmits diseases like dengue, chikungunya and yellow fever. 

Travellers from active transmission areas are often found to be infected with the Zika virus disease. 

From 2017 onwards, cases of Zika virus disease globally declined. In the Americas and other endemic regions, Zika virus transmission persists at low levels. In 2019, the first local mosquito-transmitted Zika virus disease cases were reported in Europe. 

In 2021, Zika virus outbreak activity was detected in India. A total of 89 countries and territories have reported evidence of mosquito-transmitted Zika virus infection so far.

What are the symptoms of Zika virus disease?

While most people infected with Zika virus do not develop symptoms, the ones who do start experiencing the symptoms three to 14 days after infection. The symptoms mostly include rash, fever, muscle and joint pain, conjunctivitis, malaise and headache. These symptoms usually last for two to seven days.

Since these symptoms are common to other arboviral and non-arboviral diseases, laboratory confirmation is necessary to confirm Zika virus infection. Arboviral diseases are the infections which are caused by a group of viruses spread to people by the bite of infected arthropods such as mosquitoes and ticks. 

How deadly is Zika virus disease?

People often do not realise that they have been infected with Zika virus disease because they usually do not get sick enough to go to the hospital, and very rarely die of the illness.

Also, Zika virus usually remains in the blood of an infected person for about a week, and hence, people must visit their doctor if they develop symptoms or if they have travelled in an area with the risk of Zika. 

What complications does Zika virus lead to?

If a pregnant woman is infected with Zika virus, her child may have microcephaly or other congenital malformations. These include high muscle tone, hearing loss, limb contractures and eye abnormalities. Collectively, the clinical features are referred to as congenital Zika syndrome. 

According to the WHO, an estimated five to 15 per cent of babies born to women infected with Zika virus during pregnancy have faced Zika-related complications. Some complications which occur due to Zika virus infection during pregnancy include foetal loss, preterm birth and stillbirth.

Adults and older children can also suffer from neuropathy and myelitis due to Zika virus infection. Neuropathy refers to weakness, numbness and pain from peripheral nerve damage. Peripheral nerves are those located outside the brain and spinal cord. Myelitis refers to the inflammation of the spinal cord. 

Why only some people require Zika testing

Very few people require Zika testing because the number of Zika cases reported from most parts of the world has declined since 2017, and is now very low. People who experience the symptoms of Zika virus disease must get tested as soon as possible. Also, a pregnant woman experiencing the symptoms of this disease should get tested immediately. 

A pregnant woman who has travelled to an area with the risk of Zika must get tested for the virus. 

How is Zika virus disease diagnosed?

Zika virus disease can be diagnosed through laboratory tests of blood or other body fluids, and must be differentiated from related flaviviruses such as dengue virus and yellow fever virus, to which the patient may have been exposed recently or vaccinated against. 

Serological testing which looks for antibodies in the body can be conducted to detect Zika virus infection. A molecular test which looks for the presence of the Zika virus in the body can also be conducted. For pregnant women, serological testing is not recommended. 

In order to determine if one has contracted Zika virus disease through sexual transmission, they should undergo a blood or urine test.

How can Zika virus disease be prevented?

People can prevent Zika virus disease by avoiding mosquito bites and using reproductive barrier methods such as condoms during sexual intercourse. 

At home, people can wear long-sleeved shorts and long pants, if there is an outbreak in their area. They should wear preferably light-coloured clothes to prevent attracting mosquitoes. Also, people living in such areas must treat their personal belongings with permethrin, an insecticide. 

People can use insect repellents registered under the Environmental Protection Agency. These repellents must contain one of the following ingredients: picaridin, oil of lemon eucalyptus or para-menthane-diol, among others. 

Pregnant and breastfeeding women should use insect repellents which are proven safe. Children younger than three years of age must not use products containing oil of lemon eucalyptus or para-menthane-diol, according to the CDC.

People should cover their babies younger than two months in mosquito netting at home. Pregnant women should also sleep inside mosquito nets.

Those living in affected areas and travellers must take the same steps.

Since Aedes mosquitoes breed in small collections of water, people should eliminate these mosquito breeding sites by covering water storage containers, cleaning up trash and removing standing water in flower pots. 

Larvicides and insecticides must be used in localities to reduce mosquito populations. 

How is Zika virus disease treated?

While no specific treatment or vaccine is available for Zika virus disease, people experiencing the symptoms of this illness must consume antipyretics and analgesics. Antipyretics reduce fever, and analgesics relieve pain. 

People infected with the disease must get plenty of rest, drink fluids to prevent dehydration, and consume medicines such as acetaminophen to reduce fever and pain. 

If the symptoms are severe, people should immediately seek medical help.