The worst of COVID-19 should be over for one hard-hit Brazilian city. But it’s not

In the Brazilian jungle metropolis of Manaus, nurse Francinete Simões thought she saw the latest death of COVID-19 at the emergency care center where she works in July. Hospitals finally had room to re-admit critical patients after a violent initial wave of the virus left many of the city’s dead in mass graves.

But in recent weeks, Simões says, “hospitals are filling up and I see people dying again.” The state government has now ordered the closure of insignificant businesses between December 26th and January 10th as a virus-suppression measure for the city of 2.2 million.

The recent revival of the port city should sound an international alarm about how much the virus can spread when it is poorly controlled, researchers say. One study, which tested blood donation over a number of months to count COVID cases, estimates that the virus could have attacked as many as 76% of Manaus residents by October.

“Some people think the virus will go away as soon as the infections reach the immunity level of the herd,” said immunologist Esther Sabino of the University of Sao Paulo, a lead researcher in the study. Science Magazine. “But for a while it just moves slower, still killing people.”

Although much of the world is still waiting for the vaccine, Sabino says, if the virus is not checked, “slower or faster, what happens in Manaus can happen anywhere.” For its part, the Brazilian government has not yet announced a clear timeline for vaccination.

Petri dish of inequality

The key factor behind the Manaus explosion is inequality – both in access to adequate housing and in access to health care – says epidemiologist Jesem Orellana of the Oswaldo Cruz Foundation (Fiocruz), Brazil’s national health research institute. More than 53% of households are in overcrowded slums. At the start of the pandemic, Manaus was the only city in its state of 4 million that had intensive care beds and suffered from a lack of doctors. Most people seeking care in the city could only get it in tightly packed boats that “quickly spread the virus up and down [Amazon] river, ”says Fiocruz microbiologist Felipe Naveca, who has sequenced virus strains across the country.

Naveca also believes a large number of strains of the virus were introduced into Manaus via its international airport; the city is a free trade zone with frequent business traffic from Europe and Asia. He sequenced four strains of SARS-CoV-2 in a country not identified elsewhere in Brazil, but matching strains identified in Colombia, Denmark, and the United Kingdom.

Manaus first identified the case of the virus on March 13. City officials responded with physical removal measures, such as moving unimportant city jobs to telecommuting and revoking permits for major events. They have also increased access to health services, including the opening of a Polish hospital, says health department spokesman Renildo Rodrigues. Public schools were closed on March 17, unimportant services were ordered to close on March 23, and non-resident foreigners were banned from flying into the country on March 30. Face masks were not needed until May 11.

Orellana describes the authorities’ overall response to the virus as “slow and deadly”. By the end of May, according to government censuses, over 2,000 people had died from COVID-19.

Mobile phone data shows that only about half of Manaus residents practiced physical distancing in April and May. “A lot of people didn’t believe the pandemic was real,” says Simões, a nurse. Manaus is a stronghold of voters for Brazilian President Jair Bolsonar, who has repeatedly dismissed COVID-19 as a “small flu”.

On June 1, the state allowed companies to reopen. By the end of the month, mortality from COVID-19 had dropped to about five a day from a maximum of 50 a day in late April.

Sabino and her fellow researchers, a group from Brazilian, British and American institutions, attribute the reduced mortality in part to the growing immunity of the population.

In June, “the population was more aware, mostly because of the high number of deaths in April and May 2020, which led them to better adhere to protective measures,” says Rosemary Costa Pinto, director of the state health department. He says deaths could also have fallen due to an increase in the number of hospital beds available and an improved understanding by healthcare professionals about how to deal with the virus.

Costa Pinto said a well-known study published in Science they report much higher numbers than the government, but do not want to comment on it. The state’s official count of confirmed cases of the virus is 3.5% of the population.

Testing the data collection method

Although the Manaus scientific community widely believes that the state is insufficient, some have criticized it Science reliance of the study on blood donors in drawing conclusions about the wider population, even after the authors have mathematically adjusted to take into account the limited age range of donors (16 to 69) and the fact that most are men.

In June, a household survey conducted by the Federal University of Pelotas found that the population rate with COVID antibodies was significantly lower than a blood donation study over the same time period. The Science the authors mention a household survey in their article, writing that it was not conducted throughout the city and that they used a less sensitive test. Their own assessment also includes additional calculations that reflect the decline of antibodies over time.

Others, including microbiologist Natália Pasternak, say the study was a “very well done job” that acknowledges its limitations and must now be “well interpreted”. Pasternak directs the scientific literacy NGO Instituto Questão da Ciência. “It’s not always possible to make a good population sample,” she says. “This kind of study is another scientific tool.”

A study of blood donors is currently underway around the world to better understand the pandemic, including in the United States. The Centers for Disease Control and Prevention is conducting a national blood donor survey on antibodies to SARS-CoV-2, conducted by one of Sabin’s co-authors, Michael Busch of the Vitalant Research Institute. Busch and Sabino are part of a 20-year partnership between American and Brazilian blood researchers, the REDS Brazil program, which is supported by the National Institutes of Health.

There is a scientific consensus in Manaus about one thing: the outbreak is not over yet.

“Everyone has to stay alert,” says Quezia Monteiro, an infectologist at the public health system. “People are relaxing, even saying that the pandemic in Manaus is over, which will cost more lives.”

Catherine Osborn is a Brazilian journalist and frequent contribution to NPR.

Copyright 2020 NPR. To see more, visit