MEXICO CITY — Mexico says a clinical review of past deaths has led officials to raise the country’s confirmed COVID-19 death toll by 4,272, to a total of 227,840.

The adjustment announced Tuesday is largely one of record keeping, because even government officials acknowledge the true death toll is far higher.

Because the country of 126 million people does so little testing, many Mexicans have died at home or never got a test. So the government searches death certificates for mentions of symptoms related to COVID-19.

Those analyses of excess deaths related to COVID-19 now stand at over 348,750, which gives Mexico one of the highest per capita rates in the world.