Did TN Botch up on COVID-19 Testing two weeks ago?

TN has seen a massive upsurge in cases over the last one week.

3086 cases were added in the last one week taking the Tally from 2300 on 30th April to 5400 on 7th May

It is remarkable because TN appeared to be doing a fabulous job over the last two weeks. It took 15 days to go from nearly 1300 to 2300 on 30th. Which means an addition of about 60 to 70 a day.

How did an average of 60 to 70 a day suddenly jump to an average of 400 a day?

Exploring Testing Data

We are comparing TN with Rajasthan in the Chart below because these two States have been cross-crossing each other for quite sometime

10th April, TN was 911, Rajasthan was 561

17th April, TN was 1323, Rajasthan was 1229

24th April, TN was 1755, Rajasthan was 2034

1st May, TN was 2526, Rajasthan was 2666

7th May, TN was 5409, Rajasthan was 3427

In just one week, the gap between TN and Rajasthan has dramatically changed. Let us look at the Test data.

The % you see above is how many COVID positive cases are being found when Tests are being done. So 4.1% for India in the last one week means, out of every 100 tests done, 4 cases are coming out as COVID Positive.

In the week of 10th to 16th April, Rajasthan was at 3.1%, TN was 2.6%.Over the next 2 weeks, TN kept increasing tests but the incidence of cases fell to around 1%. Rajasthan too kept increasing Tests but incidence first stayed at 2.9% and then fell 1.8% and has remained at 2%. If you look at the range for Rajasthan, it is 1.3% (Max=3.1%, Min=1.8%). In case of TN it is double at 2.7% (Max=3.7%, Min=1%). India Range in the same chart is just 1.3%

This huge volatility in TN testing data can be better seen in the chart below

In the 3rd week of April, Tests went up a massive 139% over previous week, but total cases found fell by 4% compared to previous week. In the 4th week, a 35% jump in tests also led to a 54% jump in Cases. In the first week of May, a 54% jump in Tests has led to a massive 382% jump in cases.

Ordinarily, a massive jump in Cases found could be attributed to more efficiency in Testing or changing Test Criteria. But in Case of TN, the incidence was reasonably high at 2.6% early last month. The dramatic fall in the 3rd and 4th week in incidence and then a massive jump indicates something went wrong during that two week period.

Hypothesis: Most of the initial cases in TN were Tablighi Jamaat cases. Many of them were difficult to trace and a lot of the State’s resources were focussed on finding them and testing all their contacts. In the meanwhile it is likely that resources deployed towards managing the rest of the population were not adequate. All of which is visible in the massive jump in cases.

TN has an excellent healthcare system which will eventually sort this. However, it is a lesson to all States to be more vigilant and not end up just tracking testing numbers but also see how volatile that data is and take adequate counter measures.