Maharashtra is the state, province, or region worst affected by Covid-19 in the world. The western Indian state, the most industrialised in the country, home to India’s commercial capital Mumbai, saw 943,772 cases of the coronavirus disease till Tuesday night, according to the HT dashboard. If it were a country, Maharashtra would be at No 5 in terms of the number of Covid-19 cases.

But it isn’t the sole Indian state in a listing of the top provinces by cases. Andhra Pradesh, with 517,094 comes in at #6; Tamil Nadu, with 474,940 cases at #7, and Karnataka, with 412,190 cases at #9. Uttar Pradesh, with 278,473 cases is just outside the top 10, at number 11.

India is now adding more cases a day (even when a seven-day average is taken) than any other country — more cases a day than China has seen in the entire run of the disease, although that country’s numbers are inexplicably low and the pandemic’s run there remarkably different from its trajectory in every other country in the world. Geographical area and population link the three countries worst affected by the coronavirus disease, the US, Brazil, and India. And it is inconceivable that China, which is third in terms of geographical area, and first in terms of the population, and where the viral infection began (in Wuhan), has seen only 85,000 cases. A previous edition of this column (Dispatch 119, published on July 31) looked at some possible answers to this mystery.

But we don’t need to go as far as China for a mystery. This writer, for instance, needs travel only around 30km for one — Uttar Pradesh, India’s most populous state with 225 million people. If it were a country, it would be either the fifth or the sixth most populous one in the world. It has conducted almost 30,000 tests per million — which means it has tested around 3% of its population, a proportion that is not insignificant. Yet, it has seen only 278,483 cases of Covid thus far (till Tuesday night). Its overall positivity rate is 4.11%. Its case fatality rate is 1.45%, lower than India’s. And this is a state with among the worst social indicators in the country.

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It isn’t that Uttar Pradesh’s positivity rate (number of people testing positive to number of tests) has reached this level after traversing the usual curve this metric does — it has pretty much stayed at the same level. The highest it ever reached on a seven-day average (since it started testing at least 1,000 samples a day) was 6.4%, and the lowest 2.1%.

Interestingly, the trend seen in Uttar Pradesh isn’t very different from that in many African countries (most have social indicators comparable to the Indian state). Africa’s relatively low number of cases and deaths, experts say, can only partly be explained by under-reporting of cases, or gaps in death registries. Scattered antibody tests that have been carried out around the continent show that there has been significant exposure to the Sars-CoV-2 virus in many African countries — with a test in Kenya highlighting a prevalence of around 20%.

Two theories are doing the rounds as possible explanations for Africa’s remarkable numbers. One revolves around the continent’s relatively younger population. The median age in many African countries is in the early 20s. The median age in Uttar Pradesh is also in the early 20s, among the lowest in India. The other is that populations in many African countries may have been exposed to other coronaviruses, even other infectious diseases, giving them greater immunity to Sars-CoV-2. The same can be said of Uttar Pradesh’s population.

There is, of course, a third theory. That Africa’s numbers are just a temporary aberration and that, eventually, countries in the continent will start seeing Covid-19 infection curves similar to those seen in Europe, the US, and Latin America. That could be true of Uttar Pradesh as well.