Lack of Covid-19 testing has Mexico flying blind, experts say

Before travelling to Washington to meet Donald Trump earlier this month, the Mexican president took a coronavirus test.

Until then, Andrés Manuel López Obrador had never been tested, arguing that there was no need for it – even though several cabinet members had become infected with Covid-19.

The president, known as Amlo, took a second test on arriving in the US; both results were negative.

But testing has been rare in Mexico, even for people presenting Covid-19 symptoms at hospital and for the physicians, nurses and paramedics treating them.

“The WHO has said ‘test, test, test’ – but not even healthcare workers have access to tests,” said Rafael Soto, a nurse and spokesman for medical personnel protesting for healthcare improvements. “Many co-workers have died without ever having been tested.”

Mexico performs just three tests per 100,000 people, according to Johns Hopkins University’s dashboard; 66.9% of the results were positive on 15 July, the last day data was available, according to Our World In Data.

Such a high positivity rate means “a government is only testing the sickest patients who seek out medical attention and not casting a wide enough net”, according to Johns Hopkins.

By comparison, the United States performs 168 tests per 100,000 people

Exactly why Mexico refuses to test widely mystifies public health experts.

Some suspect the country’s thrifty president sees testing as a superfluous expense: Amlo has repeatedly predicted that the pandemic will end sooner rather than later, and has used the crisis to push through a package of deep cuts to government spending.

“It’s a strategy based on the idea of maximum savings – and it’s not producing results,” said Malaquías López-Cervantes, a public health professor at the National Autonomous University of Mexico (Unam).

Others believe Mexico’s government is attempting to copy the Swedish approach of minimizing lockdowns to limit the pandemic’s economic impact – something López Obrador has cited as important in a country where more than half the population work in the informal economy.

“The initial strategy of Mexico was definitely shooting for herd immunity,” said Laurie Ann Ximénez-Fyvie, head of the Unam molecular genetics laboratory. “Then they did everything possible to achieve that.”

<span class="element-image__caption">A woman rubs antibacterial gel into her hands as she waits in a distanced line to get tested for Covid-19 at a mobile diagnostic tent in San Gregorio Atlapulco in the Xochimilco district of Mexico City on Wednesday.</span> <span class="element-image__credit">Photograph: Rebecca Blackwell/AP</span>
A woman rubs antibacterial gel into her hands as she waits in a distanced line to get tested for Covid-19 at a mobile diagnostic tent in San Gregorio Atlapulco in the Xochimilco district of Mexico City on Wednesday. Photograph: Rebecca Blackwell/AP

As elsewhere, however, the strategy seems to have failed. The country has registered more than 360,000 Covid-19 cases and more than 41,000 fatalities. Its death toll recently passed those in Spain, France and Italy and it is fast approaching that of the United Kingdom.

After a short, non-obligatory quarantine, Mexico has already started to reopen its economy even though cases are still accumulating and the death toll racing to new records.

Mexico’s coronavirus tsar, Hugo López-Gatell, has steadfastly opposed widespread testing, calling it “a waste of time, effort and resources”. He also has acknowledged undercounting is occurring, but has said that was not unusual during a pandemic.

Public health experts say the strategy has left Mexico flying blind. Instead of testing, the country initially employed mathematical modeling, based on samples from 475 clinics around the country.

López-Cervantes said that system did not provide information that was granular enough to make decisions at a local level. In May, the government announced an ambitious plan under which 324 “municipalities of hope” – which supposedly lacked coronavirus cases – would be allowed to reopen.

But an analysis by the thinktank México ¿Cómo Vamos? found that two-thirds of the municipalities opened without performing a single test. Most of the municipalities subsequently suffered increased rates of infection.

López-Cervantes predicted that, with Mexico’s ongoing opening of its wider economy, “it’s going to get worse. The most important difference [with Europe] is they began to return to work when they had very few or no cases. Mexico started its reopening when it was in an ascending phase of the epidemic.”