Four months in, Brazil’s coronavirus data still doesn’t explain the outbreak

Since the beginning of the pandemic, we at The Brazilian Report have warned readers that official data on the coronavirus outbreak in the country must be taken with a grain of salt. Doubts around the reliability of testing data have persisted — and the more we know about them, the more reason we have to be skeptical.

The case of Brazil’s highest-profile coronavirus patient helps us understand why.

On July 6, President Jair Bolsonaro took a Covid-19 test after feeling ill for a couple of days — he announced on the following day that he had contracted the virus. This was Mr. Bolsonaro’s fourth test, with the first three were taken under aliases in March, after dozens of his aides caught the coronavirus after a trip to meet U.S. President Donald Trump in Florida.

According to the Health Ministry’s latest coronavirus update, the country ran 1,147,408 RT-PCR tests — molecular tests that diagnose active infections — until July 4. But the numbers don’t reveal exactly how many individuals took these tests. There is no way of knowing how many overzealous patients took multiple exams, as Mr. Bolsonaro did. While they could be in the small minority,...