More and better testing: On viral disease outbreaks and State responses
States must develop capacity to conduct testing and sequencing of viruses
Since the Zika outbreak began on June 20, when the first case was reported from Pune, confirmed cases have been slowly but steadily rising. As of August first week, Maharashtra has reported 88 confirmed cases. Pune city, the epicentre, alone accounts for 73 cases, while six are from Pune rural. Of the total number reported so far, at 37, pregnant women alone account for half the number of confirmed infections. Though rare, people with Zika virus infection run a risk of suffering from Guillain-Barré syndrome, a neurological disorder in which the immune system mistakenly attacks part of the peripheral nervous system. But a more harmful effect is seen in pregnant women who run a risk of giving birth to babies with a smaller than average head size, called microcephaly, and other neurological impairments. As in a January 2023 paper in The Lancet Regional Health – Americas, a meta-analysis of babies born to 1,548 pregnant women infected with the Zika virus, from 13 studies in Brazil between 2015 and 2017, found the absolute risk of microcephaly to be 6.6% either at birth or during follow-up. Babies also had 18.7% absolute risk of suffering from functional neurological abnormalities, and a relatively smaller risk of neuroimaging, ophthalmic and auditory abnormalities. There was also a significant risk of premature birth (10.5%), low birth weight and small for gestational age (16.2%). Less known is the risk of sexual transmission of the virus by infected men due to the presence of potentially infectious virus in their semen for at least two months. It is hence important for infected men, especially those planning a family, to be made aware of the risk as well as recommend measures to prevent viral transmission to women for at least three months, as in the U.S. CDC guidelines.
Given the harmful effects of the virus, it is shocking that the Pune-based ICMR lab ramped up testing only after the publication of news about the Pune Municipal Corporation planning to send samples to a government medical college instead to cut the delay in testing. As Kerala just demonstrated in the latest outbreak of the Nipah virus, and as Gujarat learnt it the hard way in the ongoing Chandipura virus outbreak and acute encephalitis syndrome cases, it is becoming increasingly important and necessary that States develop the capacity to conduct high-quality testing and sequencing of viruses that cause frequent and deadly outbreaks. From the time that the first suspected case is observed, the reduction in the lead time to test results is the key to instituting timely public health responses that can limit the virus spread and stop an outbreak. The COVID-19 pandemic demonstrated the advantages of decentralised testing and sequencing, and this should be replicated for every pathogen that causes deadly outbreaks.