Mexico Acute Lung Infections Up 50%, Imply Covid Undercount

(Bloomberg) --

Severe acute respiratory infections in Mexico spiked 50% this season compared with a year ago, almost certainly all due to coronavirus, suggesting that government figures on Covid-19 cases are far too low.

In the most recent week, health ministry data show, Mexico registered 12,000 new cases of such respiratory infections, versus 671 in the same period a year ago.

“Of course that jump in cases is Covid-19, because influenza is on its way out this time of year,” said Alejandro Macías, the former national commissioner for influenza in Mexico during the H1N1 outbreak. “There’s no doubt.”

A top government official agreed that was likely. “Flu monitoring continues as in every year, and there’s evidence that Covid-19 has taken the place of the flu,” said Dr. Jose Luis Alomia, director general of epidemiology at the health ministry.

Mexico is monitoring the spread of the coronavirus through a sentinel model, meaning it tests selectively and with narrow criteria. The strategy has been questioned by experts who say the country is walking “blindly through the woods” and that the number of unaccounted cases will make containment harder.

Multiplying Factor

The government said on Friday that Mexico had 12,872 confirmed coronavirus cases and 1,221 deaths. Deputy Health Minister Hugo Lopez Gatell has said this model may require the number of confirmed cases to be multiplied by eight to get the full picture.

Some experts say the real multiplier could be as high as 30, which would bring the total number of cases to around 386,000, second only to the U.S.

The gap in multipliers and the separate data sets for severe respiratory infections and coronavirus aren’t the only concerns that have been raised about Mexico’s handling of the pandemic. President Andres Manuel Lopez Obrador spent much of March insisting that markets and shops should remain open, even as much of the world went into lockdown.

As for severe acute respiratory infections, the growth in cases had been mirroring past years until the week of April 5, when they jumped 17.4% to 59,440 and the week after that, when cases jumped 30% to 67,397.

“It’s very possible that those so-called cases of influenza are in reality Covid-19,” said Carlos del Rio, an epidemiologist at Emory University in Atlanta.

Hospital Capacity

Mexico’s public health system was in a precarious state before coronavirus. A change by Lopez Obrador’s administration in how it buys medicines and from whom had caused shortages for months.

As the new virus spread, the percentage of confirmed cases needing hospitalization has grown to 37% from around 10% when the country started providing the data in early March. Macias said the high rate could be a reflection of the limitations of the sentinel model, where tests are only administered to those with severe symptoms.

As of Thursday, 4,420 patients had required hospitalization and 530 were in intensive care, according to health ministry data.

Some public hospitals in Mexico City have reached capacity. Four out of 52 have no beds available, the city said. Seven others have limited capacity.

The same information is not yet available for the rest of the country but will be soon, deputy health minister Lopez Gatell said on Tuesday.

©2020 Bloomberg L.P.