While the key marker of the pandemic — increasing number of daily positive cases — continues to be unrelenting, small comforts can be derived from other parameters that show some improvements. Among them, in T.N., is the falling rate of active cases, calculated as a percentage of total number of cases.
While the active case rate saw two peaks, one in April and the other in May, after the COVID-19 epidemic began its march in the State, the rate has since been steadily on the decline. On July 25, it dropped to its lowest, at 25%. In sheer numbers, of a total of 2,06,737 cases, 52,273 were active.
Active cases are the “currently infected cases” we get after removing deaths and recoveries/discharge from the total cases. These include people in hospitals, home quarantine, and those in COVID care centres. In the first month, March, it hovered between 100% and 50%, while in the next month, April, the peak hit 97%, and it also recorded 40% the same month. May’s high point was an active case rate of 75%, and the lowest was 42%. June stayed in the 40% region right through, while in July it dropped to 25% towards the end of the month.
“This is an indication of employing a good clinical protocol, that people who tested positive are making a quick turn around,” says Health Secretary J. Radhakrishnan. He claims that active testing and isolation of persons who test positive has a role to play in this. “Early testing is basically catching the patients early and treating them early, so that they do not lapse into complications,” he adds.
Testing average
Tamil Nadu does an average of 60,000 tests per day, with Chennai alone accounting for 12,000-13,000, the highest anywhere in the country. This plays a role in early tracking of cases, and ensuring that people get the health care they might require early enough, Dr. Radhakrishnan adds.
Former Director of Public Health K. Kolandaisamy says the data is dynamic, and will tend to have highs and lows. The denominator — the total number of cases — continues to increase on a daily basis, and it needs to be accounted for. When there is a decline in the total number of positive cases, daily positive cases, the positivity rate, there can be an indication of a declining epidemic, he says.
The admission (into hospitals)-discharge rate is also a statistic that would yield information on how the epidemic is progressing, in addition to the mortality rate. Keeping an eye on the gender ratio of new infections (it started out infecting more men than women) and the 60-plus positivity rate will indicate the transmission to the vulnerable populations. In addition, Dr. Kulandaisamy says, the positivity rate among pregnant women admitted for delivery should be regularly calculated.
