Zika virus: the need to improve surveillance and vector control

Updated - July 16, 2024 03:14 pm IST

Published - July 11, 2024 09:37 pm IST

Mosquitoes can carry viruses including dengue, yellow fever, chikungunya and Zika.

Mosquitoes can carry viruses including dengue, yellow fever, chikungunya and Zika. | Photo Credit: AP

The Zika virus is making the news once again. At least 15 cases, including eight pregnant women, of Zika have been discovered so far in Pune, Maharashtra. In Karnataka, a 74-year-old who had Zika has died. State Health Department officials say the death was caused by other factors. Another suspected case in Karnataka is being investigated as well. 

The Pune Municipal Corporation has said it has stepped up surveillance; the Karnataka Health Department has released guidelines on the virus for the public, and both States have urged members of the public to ensure there are no mosquito-breeding sites at their homes.

Meanwhile, the Union Health Ministry has issued an advisory to States to be vigilant; screen pregnant women, and strengthen entomological surveillance and intensify vector-control activities. 

Read more: ‘Indian firm’s Zika virus vaccine 100% efficient in animal trials

The Indian Council of Medical Research (ICMR) has asked States not only to increase testing for Zika but also to test patients with chikungunya and dengue-like symptoms who test negative for these infections for Zika, as per a news report.

As the monsoon continues over large parts of the country, creating ideal breeding grounds for mosquitoes, and with cases of dengue spiking as well, State administrations and members of the public need to step up mosquito-control measures to prevent transmission of diseases. 

Here’s a quick FAQ on Zika:

What is the Zika virus?

As per the World Health Organization (WHO), Zika virus is a mosquito-borne virus first identified in Uganda in 1947 in a Rhesus macaque monkey, followed by evidence of infection and disease in humans in other African countries in the 1950s. Zika virus occurs through the bite of infected Aedes mosquitoes, mainly Aedes aegypti, which also transmits dengue and chikungunya. The Aedes mosquitoes usually bite during the day. Sexual transmission, transmission from mother to foetus and transfusions of blood and blood products are other routes of transmission.

What are the symptoms?

Most people infected with the Zika virus do not develop symptoms, the WHO says. Among those who do, they typically start 3–14 days after infection and are generally mild, including rash, fever, conjunctivitis, muscle and joint pain, and headache, which usually last for 2–7 days.

How is the Zika virus diagnosed?

Zika virus may be suspected based on symptoms or the fact that the person is living in or visiting areas where Zika transmission has occurred. A diagnosis can only be given after a laboratory test. A recent report in The Hindu pointed to gaps in the tracking and surveillance of the virus, highlighting the fact that in March 2023, the Central Drugs Standard Control Organisation (CDSCO), India’s apex agency for diagnostic approvals, confirmed that there was no approved diagnostic test for Zika. This limitation, the report said, hinders the country’s ability to diagnose Zika. At present, samples are generally sent to a few select labs, including the National Institute of Virology, for confirmation. The NIV, a media report indicates, is flooded with samples, leading to delays in the issuing of reports.

What are the complications caused by Zika?

Zika virus infection during pregnancy, the WHO says, can cause infants to be born with microcephaly and other congenital malformations and can also cause preterm births and miscarriage. Microcephaly is a condition in which an infant’s head is smaller than what is typical for their age and can be caused by the brain not developing properly. An estimated 5–15% of infants born to women infected with Zika virus during pregnancy have evidence of Zika-related complications, as per the WHO. Zika virus infection is also associated with Guillain-Barré syndrome, neuropathy, and myelitis in adults and children. Guillain-Barré syndrome is a rare condition that causes a person’s immune system attacks the peripheral nerves.

Is there a vaccine?

 No vaccine is as yet available for the prevention or treatment of Zika virus infection, the WHO says. The development of a Zika vaccine remains an active area of research. A few studies have shown promising results. In India for instance, several companies are attempting to make a vaccine. In a study published in 2017, Bharat Biotech’s “killed Zika virus vaccine” which uses an African strain showed 100% efficacy against mortality and disease in animal studies. Indian Immunologicals Limited, a wholly-owned subsidiary of the National Dairy Development Board said earlier this year that it was also working on developing a vaccine.

(zubeda.h@thehindu.co.in)

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.