The contagion curve in Brazil appears to have plateaued and is set to remain at the current level until at least the end of 2020. Investing in the identification and isolation of infected people and their close contacts, keeping schools closed and improving the quality of the information offered to the public are measures governments should take to make sure the situation does not become even worse (image: FGV/FM-USP)
Published on 03/19/2021
By Karina Toledo | Agência FAPESP – Investing heavily in health surveillance strategies that facilitate the identification and rapid isolation of people with symptoms of COVID-19 and their close contacts. Keeping schools closed at least until the end of this year. Holding campaigns to raise awareness of the importance of face covering and social distancing, among other precautionary measures, until an effective vaccine is available. Not claiming that the pandemic is unimportant or that the worst is over. According to experts, all this needs to be done by government at all levels to enable Brazilians to weather the second half of 2020 with a minimum of security, given the decline in social isolation rates throughout the country and the lack of political will to implement lockdowns or similarly strict measures to contain transmission of the virus.
The experts were participants in the July 14 webinar “Four months of COVID-19 in Brazil: balance sheet and prospects” organized by Agência FAPESP and Canal Butantan.
“Many people have the false impression that the contagion curve has turned down in the state of São Paulo. The truth is that the number of new cases will continue to rise at least until October given that the current social isolation rate is between 45% and 50%. The curve will actually turn down only in November, and even so provided all other factors stay the same,” said Dimas Tadeu Covas, Director of Butantan Institute.
The death curve appears to have stabilized in the state of São Paulo, Covas added, albeit at a high level – around 300 per day – and this trend is set to persist until the start of 2021.
Brazilian Health Ministry statistics show that nationwide the rapid rise in cases and deaths has also been interrupted at an alarmingly high level, with some 40,000 new cases and about 1,000 deaths notified each day, no sign of a sustained reversal, and notorious undernotification.
“Some politicians have used the plateau as an argument to ease restrictions on mobility and shopping. In reality, however, the plateau evidences the failure of containment policies. Every epidemic curve worthy of the name must peak and start to fall. However, the data shows a decline in social isolation and the contagion curve will probably remain high as a result. In the state of São Paulo, for example, it’s expected to stabilize in the range of 17,000 new infections per day, possibly until November,” said Eduardo Massad, a professor and researcher in the School of Applied Mathematics at Getúlio Vargas Foundation (FGV).
According to Paulo Inácio Prado, a professor in the University of São Paulo’s Bioscience Institute (IB-USP), the contagion curve in the city of São Paulo trended down between mid-May and end-June. The same pattern is not clear, however, from an analysis of severe acute respiratory syndrome (SARS) cases in the city. These are classed as suspected COVID-19 cases, he explained, and may or may not be confirmed by lab tests.
“The number of suspected cases appears to have rebounded recently. This may or may not be reflected shortly in a rise in the number of confirmed critical COVID-19 cases. The signs we see in the graphs are still highly uncertain. They don’t clearly show whether the downtrend in severe cases will be maintained in the city of São Paulo or whether the curve will turn up again,” said Prado, who is affiliated with Observatório COVID-19, an online platform that produces analyses of official data on the transmission of SARS-CoV-2 in Brazil and is the result of collaboration among scientists affiliated with São Paulo State University (UNESP), the University of São Paulo (USP) and the Federal University of the ABC (UFABC).
Outside the state capital, the situation is even more uncomfortable, noted Otavio Ranzani, a researcher affiliated with the University of São Paulo’s Medical School (FM-USP) and the Barcelona Institute for Global Health (ISGlobal) in Spain. “In the interior of the state the contagion curve is clearly rising,” he said.
Moreover, as Covas stressed, intensive care unit occupancy is close to the limit in major cities across the state of São Paulo, such as Ribeirão Preto, Campinas and São José do Rio Preto.
Reopening of schools and herd immunity
When the epidemic finally peaks, which will happen at a different time in each region of the country, cases and deaths will be twice the current levels. “At least this has been the history of viral epidemics, which don’t end suddenly and typically have a long tail,” Ranzani said in his presentation.
“I firmly believe the number of deaths will hit 100,000 within a month, and we’ll unquestionably reach 200,000 in Brazil,” told Massad. He added that deaths among under-fives, currently on the order of 300, could rise in an alarming pace if schools reopen next in August.
According to Ranzani, children were not allowed back into schools in Europe until the effective reproductive number (Rt) fell to less than 1, meaning that each infected person transmitted the virus to less than one other person on average. Rt is estimated to be close to 1 in the state of São Paulo, and if the trend continues it will not fall to a safe level until December or thereabouts. He also stressed that Brazil has historically had a deficit in pediatric intensive care beds.
For the participants in the webinar, betting on herd immunity as a solution to the public health crisis is not a sensible idea, although São Paulo appears to be approaching this threshold.
“Today we have about 50% of the population sheltering at home and 50% circulating,” Massad said. “For the half that’s exposed, herd immunity is reached if 25% are infected. However, when social isolation and lockdowns are relaxed, more people circulate and the threshold rises rapidly. This is a Zeno’s paradox, something you’re running towards but never reach.”
For Prado, waiting until herd immunity is reached (whatever the percentage may be) would be a “declaration of failure”.
“It would be tantamount to letting nature deal with something civilization has addressed throughout history. Epidemiology was born as a science from the need to find better solutions, and we have the conditions to produce better solutions,” he said.
Possible avenues
Lockdowns have become a steadily less feasible option in Massad’s opinion, so the level of social isolation should ideally be kept at 50% or more until a vaccine arrives.
“It’s costly and hard. People are fed up. But at least they should be told we’ll reopen gradually and the worst isn’t over, neither is the epidemic,” he said. “We’ve been swamped by a wave of optimism, and there are people saying we should reopen schools, malls, and gyms. At the end of the day, it’s all lies.”
The participants in the webinar agreed that in the absence of a vaccine the least costly and most effective way to slow or stop the spread of the disease in Brazil is to identify infected individuals and their close contacts as quickly as possible and to provide the wherewithal for them to self-isolate completely for at least 14 days.
“Now that the great wildfire has been damped down by social isolation we need to fight the local hotspots and prevent their becoming another major fire,” Prado said. In his view, Brazil is privileged to have teams of community health agents who can take effective action to track infected people and make sure they self-isolate.
“It’s an outstandingly comprehensive network that covers even the smaller towns. However, there’s no federal coordination as there’s supposed to be under the 2006 Health Pact governing the SUS [Sistema Único de Saúde, Brazil’s national health service]. The funds that could be spent to equip and train agents are sitting unused in the Health Ministry,” he said.
Covas advocated the use of technology and alternative strategies to identify suspected cases. “We’re trying to implement a health surveillance strategy that’s deficient mainly in small and medium towns,” he said. “We’ve tried to enhance its effectiveness with the available instruments, including smartphone apps that help people identify symptoms of the disease and encourage those with symptoms to self-isolate even if tests aren’t available.”
Beatriz Kira, a researcher at Oxford University’s Blavatnik School of Government in the UK, told the webinar about a survey conducted by her group showing that most Brazilians are able to recognize the symptoms of COVID-19 and are aware that the disease is more severe than a bout of flu. However, only 44% of the respondents know how to behave if they have to self-isolate.
“Many people don’t realize that self-isolation means not having any contact with the outside world for as long as they’re contagious. They think they can go out to do shopping, buy medications and so on. So in addition to testing more, it seems to me we need to improve the quality of the public information given to people,” Kira said.
The survey also showed that Brazilians have responded well to the public policies implemented to combat the epidemic, above all by state governors and city mayors, and that a change in societal behavior indeed occurred in March.
“This highlights the crucial role of policymakers, and the need for policies to evolve in step with the epidemiological data, always focusing on the most vulnerable social groups,” Kira said. “It’s easier to design policies for those who can work from home or wash their hands frequently. It’s much more complex to formulate policy for the poor. Above all, governments must go out front to promote the policies they design.”
Source: https://agencia.fapesp.br/33738
