Covid- A look at some biases and some open questions: (Along with an analysis of Mumbai)

Covid is a very dangerous public health issue. Already, lakhs of deaths have been reported.

Gross Biases:


The ideological bias: The immediate, moronic and unfortunate stand of right-wingers like Trump, Bolsonaro etc , terming Covid a “little flu” and their seeming indifference to deaths and danger to life, caused people, and the entire academic and intellectual community to take an ideological stand against this. The likes of Philip Tetlock, has found, through rigorous studies, that ideological or entrenched positions of opinion, causes experts to fuck up phenomenally in their ability to understand and predict complex problems, and they perform worse than Chimpanzees throwing darts. It is the single largest cause of inaccurate assessments. This caused many, to overstate the danger grossly, and to advocate extreme measures.

Media bias : It is well known that the Media is fond of Drama, and Danger. The two ‘D’ s.


Overemphasis on Case Fatality Rate: It was very evident from the beginning, that only the most severe cases are being diagnosed, especially in the peak of the epidemic in an area. There were a very large proportion of asymptomatic and mild cases. So what we are interested in, is the Infection Mortality Rate. I will show by an analysis of cases in Mumbai that we have to divide CFR by thirty or fifty (at least) to get at the actual IFR.

Re- Infections: The idea that people get Covid again and again, was grossly overstated. Millions have got the disease, and only a handful of re-infections have been reported. This happens with influenza pandemics too, but the pandemic doesn’t rage on and on forever. Cross-resistance, lower proportion of susceptibles, and evolutionary attenuation of the virus ensures that this is so. More than that, the idea goes against most things that we know about viral epidemics.

Herd Immunity denial: Many completely denied that herd immunity exists! It is a well known epidemiological fact. This is possibly how the disease has slowed in Europe, Mumbai, Delhi, Chennai etc. Dharavi too.

Draconian Measures: Measures like complete lockdown with intense suffering to the population was touted as the main panacea for the disease. Indian government fell headlong into this trap. Now we know that it will only postpone the peak. Universal masking, Physical distancing, and avoidance of crowding, esp indoors are actually much more effective and practical over the long term. Even isolation, contact tracing and quarantine, probably doesn’t have a big effect. (See analysis of Mumbai, below)

Analysis of Mumbai:

Mumbai is a place where lockdowns, containment zones, isolation, quarantine, all were done as the epidemic was raging. Now, cases have started coming down.

By Early September, there are a total of 176000 cases reported in Mumbai, as of this writing. 8000 deaths have been reported.

The population of Mumbai is 1.84 crores.

Now, Antibody tests have shown that upto sixty percent of people in various areas of Mumbai are antibody positive. Some residential areas show around twenty percent. The test shows positivity rather reliably. And this reflects disease in July and August. So, even an overall 30 percent positivity would be a gross underestimate. But we will stick to 30.

30 percent of 1.84 crores come to 5500000 (55 lakhs).

A minimum of 55 lakhs were actually infected, and the number of detected cases are just 1.76 lakhs!

At the bare minimum, we are missing 30 (THIRTY) cases for every SINGLE case. Could be fifty. I had written previously, that in case of Dharavi, this is more than hundred. (More than 150, in fact).

The reported deaths are 8000. Now, an all-causes mortality rate of previous months in Mumbai, shows that this is possibly an underestimate by fifty percent. So, we will take it as 12000. Even then, dividing this by 55 lakhs, shows that the Infection Mortality Rate of Covid in Mumbai, is 0.2 percent. A similar analysis of Dharavi alone gave a figure of 0.05 percent.

Tentative Conclusions:

As per that data in Mumbai (which can be extrapolated to many places in India), we are missing thirty to fifty cases per one detected case. At least.

Infection Mortality Rate of Covid in Mumbai could be 0.05 to 0.2 percent.


  1. Since we are missing thirty to fifty cases, for every one detected case, aren’t measures targeting the whole population, like masking, distancing, and crowd control, much more effective than other measures?
  2. Containment zones, contact tracing, and quarantining are basic epidemiological measures that we aim to do. But as these are based on detected cases, and as we are missing the VAST MAJORITY of infections, how effective are they? Other than manufacturing stigma, what are they doing exactly? How much of an effect CAN they have?

Please feel free to offer criticism, as many of my friends are much more knowledgeable than me, in this area.

(Jimmy Mathew)

Dr Jimmy

I am a Doctor, Writer and Science Communicator. I am a member of Info- Clinic, and have written a few books. This site features my blog posts and stories. Thank you for visiting. ഞാൻ എഴുതാൻ ഇഷ്ടമുള്ള ഉള്ള ഒരു ഡോക്ടർ ആണ് . നിങ്ങളുടെ താത്പര്യത്തിന് നന്ദി .