Covid-19: What you need to know today

Photographs of crowded election rallies in Bihar (the last stage of polling is on Saturday) have caused concern in some quarters about a spike in coronavirus disease cases in the state.

Such concern is misplaced.

According to the HT dashboard, Bihar had a mere 7,001 active cases of Covid-19 on Tuesday night. On Tuesday, the state registered just 846 cases from the 143,642 tests it carried out. That translates to a positivity rate of 0.6%. The cumulative positivity rate of the state is 1.9% (it carried out 11.33 million tests till Tuesday evening and registered 218,964 cases). And it has a case fatality rate of 0.5%.

These are numbers of which Germany, a country widely acknowledged with managing the pandemic well — largely on the strength of aggressive testing and its legacy investments in hospital infrastructure — would be proud (Bihar’s numbers are a lot better than Germany’s, you see).

Bihar’s population, at 125 million, is around 50% higher than Germany’s 83 million. It is also 25 times New Zealand’s population. That island country’s cumulative positivity rate is 0.17%.

I’ve written previously about the mystery of Uttar Pradesh’s numbers, and how this is similar to the mystery of Africa’s (which has also seen disproportionately few cases and fewer deaths than most parts of the world).

It’s a mystery that’s led to some interesting hypotheses, such as this: “The mortality due to Covid-19 in different nations is associated with the demographic character of nations and the prevalence of autoimmunity.” That’s a paper by Bithika Chatterjee, Rajeeva Laxman Karandikar and Shekhar C Mande, published on the pre-print server medRxiv. The authors are from CSIR, National Centre for Cell Sciences, and Chennai Mathematical Institute. The paper, published in mid-October and not peer reviewed yet, suggests that the reason for this mystery could be the so-called “hygiene hypothesis”.

“The hypothesis postulates that exposure to pathogens early in life protects people from allergic diseases later in their lives. Moreover, improvement in hygiene practices such as better sanitation, availability of safe drinking water, hand washing facilities etc. reduces the impact of communicable diseases. On the contrary, such a reduction to the exposure to infectious agents might be related to higher prevalence of autoimmune disorders,” the authors write.

They picked “GDP, HDI, prevalence of various diseases, demographic parameters, various sanitation parameters”, demographic data, the administration of the BCG vaccine, and measured the correlation between these and the case fatality rate to prove their hypothesis. With the old caveat that correlation doesn’t mean causation, I believe this is an interesting study that merits further exploration, including field studies (the authors based their paper on secondary research using published data).

It is surprising that India’s federal health ministry or the Indian Council of Medical Research have not thought the achievements of Bihar and UP in managing the pandemic worthy of closer study. After all, why look to Germany or New Zealand as benchmarks when you have local ones (that you can be vocal about).

Both Bihar and Uttar Pradesh predominantly use rapid antigen tests, which are unreliable. A New York Times report said on November 2 that one popular rapid antigen test (Sofia, made by Quidel) identified only “32% of positive cases identified by the” more accurate reverse transcription polymerase chain reaction (RT-PCR test). Other studies have shown that rapid antigen tests miss around half the positive cases (although some companies, including Abbott Laboratories, have launched what they claim are accurate rapid antigen tests). But the numbers in these states are far too low, even if one were to account for the use of such tests.

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