The concern: The government this week asked the Indian Council of Medical Research (ICMR) to evaluate the accuracy of rapid antigen tests (RAT) and analyse if the proportion of false negatives is substantially high. The Delhi High Court has also asked the state government why it was going with these tests which have a high rate of false negative results as the primary test of Covid-19.
The protocol: According to ICMR’s protocol, any sample testing negative through RAT will have to be mandatorily retested with RT-PCR, which is considered the gold standard for detection of Sars-Cov2 virus, if the person demonstrates symptoms. Those testing negative with no symptoms are to be monitored for a few days. If they develop symptoms, then they are to undergo RT-PCR testing too.
The reality: Barely 1% of people who tested negative in rapid antigen tests in Maharashtra have undergone an RT-PCR test. Roughly 1.9 lakh rapid antigen tests have been carried out in the state, of which 31,227 (16.5%) have tested positive. But of the about 1.6 lakh who came negative, only 1,817 were re-tested. Similar concerns have been made in Telangana too, where the administration has ramped up testing by relying almost exclusively on rapid antigen tests.
The risk: Experts say such low numbers of re-tests could amount to missing cases and the possibility of infection spread in the community. That coupled with the falling levels of contact tracing (in Karnataka it has dropped from 47 per patient to 6 now) puts a much bigger population at risk. Even for those undergoing the RT-PCR test, the delay in arrival of test results (the turnaround time can be anywhere between a couple of hours and week) is a worry and it delays diagnosis and in several cases treatment as well. The delay has also led to a surge in demand for chest CT scans for knowing a patient’s Covid status. The ground glass appearance of lungs is regarded as indicative of the viral infection, but these tests can cost Rs 5,000 and more.
Reactogenicity refers to inflammatory responses to vaccination; they are often mild to moderate such as injection-site pain, redness, swelling or fever and headache. The term is back in focus as many of the Covid-19 vaccine candidates in advance stages of trials have caused some reactogenicity.
Massachusetts-based Moderna and China’s CanSino Biologics have both stopped testing higher doses of their vaccine candidates following some adverse reactions in volunteers. The keenly-followed “Oxford vaccine”, the ChAdOx1 nCoV-19 developed by Oxford University, too, had caused fever and headache in nearly 60% of the volunteers in phase I/II trials.
Health experts say such reactogenicity is not to be worried about. They say as long as the side effects are mild to moderate, the reactogenicity is just a sign of the immune system cranking up. Note: Vaccines mostly trigger an immune response by duping the body to believe it is infected, by introducing a virus-specific characteristic — spike proteins in the case of coronavirus.
There is, however, another worry to reactogenicity: It may stop people from getting inoculated. It’s a challenge health workers are already facing during vaccinations programmes in certain countries and communities, and they worry about a similar response to the Covid-19 vaccine — whenever we have one. Hence, they say, communication and awareness is key. “As with many vaccines, we have found that if we let people know what to expect, then they have fewer concerns if side effects happen,” Kathleen Neuzil, director of the Center for Vaccine Development at the University of Maryland School of Medicine, told StatNews.
Having witnessed a spurt in Covid-19 cases since July 1, Andhra Pradesh reported 10,093 fresh cases on Wednesday — the highest for any state in the country. Not only was it the first time that AP reported 10,000+ cases in a day, it also became the only state after Maharashtra where more than 10,000 patients tested positive in a single day. (Maharashtra had seen a record 10,576 new cases on July 22).
On the day, the caseload gap between AP and the state nearest its tally on Wednesday was 2,376. Maharashtra, which has been topping the Covid daily chart, reported 7,717 against AP’s 10,093.
At this rate, AP, currently No. 4 with 120,390 cases, could go past Delhi’s caseload of 133,310 in the next few days to emerge as the third-worst affected state. With 65 fresh deaths, the state’s toll reached 1,213, making it the eighth worst-affected.
That said, AP tested 70,584 samples, the highest one-day test total, to find the 10,093 cases. So far, the state has conducted 1.82 million tests with a case positivity rate of 6.61%. The mortality rate stood at 1%. About 2,780 Covid patients were declared cured on Wednesday. There are currently 63,771 active cases with 55,406 recoveries and 1,213 deaths.
The state’s performance graph on positivity and recovery rate has nosedived. The virus seems to have an upper hand in the state putting the official machinery on tenterhooks if the high number of Covid cases reported in the last 30 days is any indication. Of the 120,000 Covid cases detected so far in the state, about 105,000 infections were found in July alone.
The list of helpline numbers in your state or union territory is here
Live updates here
Follow news that matters to you in real-time.
Join 3 crore news enthusiasts.
Be First to Comment