Zika virus explained: Should India be worried?

The world might have forgotten Zika virus, but the virus has not forgotten us. The number of Zika virus cases in Kanpur, Uttar Pradesh, has breached the 100 mark since the infection was first detected on October 23, as of November 11, 2021. 

What is Zika? Where was it first detected? How worrisome is it in India? Down to Earth explains:  

• Zika was first isolated from the rhesus monkey in Uganda’s Zika forest in 1947 and in humans in 1952. Over the next five decades, only 15 cases were reported from Africa and Southeast Asia. 
• There was a massive spread of this zoonotic disease (infections that emerge in animals and jump to humans) in Yap, an island group in the Western Pacific, in 2007. The virus then spread to other Pacific Islands before reaching Brazil. It then spread rapidly to other parts of South America, central America, Mexico and the Caribbean. 
• On February 1, 2016, the huge number of cases forced the World Health Organization to declare it a Public Health Emergency of International Concern.
• The virus usually causes mild fever, aches, rashes and conjunctivitis. But in 2016, it was linked with microcephaly (a condition of underdeveloped heads and brain defects) in children born to women who suffered from the infection during pregnancy. The virus also seems to have a link with Guillain-Barré Syndrome, a progressive neurological disease that causes paralysis. 
• In Brazil, a total of 2,639 cases of microcephaly were reported during the epidemic in 2015-2017. The different strain was circulating in Brazil and was the reason microcephaly was being reported only from this country. 
• Prevalence studies on the Zika virus carried out as early as in 1952-53 by the National Institute of Virology, Pune, showed presence of antibodies in humans in several parts of central and western India.
• The Zika virus is spread by Aedes aegypti and Aedes albopictus mosquitoes. It can also be transmitted through blood transfusions, sexual contact and via exposure to urine.
• A nationwide vector surveillance published in 2021 carried out by the Indian Council of Medical Research showed that mosquitoes in 3 of the 6,492 pools assessed were positive for Zika virus. Aedes aegypti sampled during the 2018 Zika outbreak in Jaipur, Rajasthan, showed the presence of Asian lineage of the virus and not the American lineage that is linked to the pandemic.