DNA Explainer: Know about origin and spread of mosquito-borne Zika virus and how harmful it is to humans

One of the worst COVID-affected states in India, Kerala has now reported its first case of Zika virus infection on Thursday. These new and re-emerging pathogens with epidemic potential have threatened health security. Just like dengue and malaria, Zika is a kind of virus that spreads from the bite of a mosquito. 

Zika, a flavivirus transmitted mainly by mosquitos in the genus Aedes, was discovered in 1947 in Uganda. First identified in Uganda in 1947 in monkeys, Zika was later identified in humans in 1952.

The first large outbreak of disease caused by Zika infection was reported from the Island of Yap in 2007. There are currently several countries experiencing Zika virus outbreaks.

Zika is caused by a virus transmitted primarily by Aedes mosquitoes, which bite during the day. The same mosquito is responsible for spreading dengue and chikungunya as well.

How Zika virus spread

From the 1960s to 1980s, human infections were found across Africa and Asia, typically accompanied by mild illness.

The first major outbreak of disease caused by Zika infection was reported from the Island of Yap in 2007, as the virus moved from Southeast Asia across the Pacific.

During a 2013-14 outbreak in French Polynesia, the neurological disorder Guillain-Barré syndrome was linked to Zika infection.

In South America, the first reports of locally transmitted infection came from Brazil in May 2015.

In July 2015 Brazil reported an association between Zika virus infection and Guillain-Barré syndrome (GBS).

In October 2015 Brazil reported an association between Zika virus infection and microcephaly. For neither event was a causal link proven.

In February 2016, WHO declared Zika infection associated with microcephaly and other neurological disorders, a Public Health Emergency of International Concern.

By the start of February 2016, local transmission of Zika infection had been reported from more than 20 countries and territories in the Americas.

Beyond the range of mosquito vectors, Zika virus infections are expected to be carried worldwide by international travel.

Symptoms of Zika virus

Symptoms are generally mild and include fever, rash, conjunctivitis, muscle and joint pain, malaise, or headache.

Symptoms typically last for 2-7 days. Most people with Zika virus infection do not develop symptoms.

Side effects of Zika virus

Zika virus infection during pregnancy can cause infants to be born with microcephaly and other congenital malformations, known as congenital Zika syndrome.

Infection with Zika virus is also associated with other complications of pregnancy including preterm birth and miscarriage.

An increased risk of neurologic complications is associated with Zika virus infection in adults and children, including Guillain-Barré syndrome, neuropathy, and myelitis.

(Inputs from World Health Organization website)