South African doctors and researchers battling a second wave of Covid-19 cases are rushing to understand what role a new variant of the coronavirus may play in the new outbreak of infections.
The total confirmed cases of Covid-19 in South Africa exceeded one million this week. On Wednesday, the 60 million country registered 17,710 new infections, more than any daily case load seen during its first wave of infections, which peaked in July.
Doctors say they need to ration oxygen and have no manpower to do the best care, like turning patients on their stomachs. One third of coronavirus tests are positive, suggesting that the true number of infections is likely to be much higher.
In November, South African researchers first discovered the new coronavirus variant – which shows similarities to a variant found in December in the United Kingdom – and quickly became dominant in the country’s coronavirus outbreaks. The researchers say the South African variant has the same mutation as UK scientists say it may have made the variant significantly more contagious than other versions of the virus.
South African researchers say they have also found changes in the structure of the virus that, in previous laboratory tests, have increased the antibody resistance of people who have recovered from Covid-19.
However, the researchers said that human behavior is still the main reason for the further increase in cases of Covid-19. Millions of South Africans have traveled in recent weeks to see their family across the country, while tens of thousands have flocked to restaurants, bars and beaches during the festive season that coincides with the country’s main summer holidays.
Covid-19 cases confirmed daily in South Africa, seven-day moving average
Source: Johns Hopkins CSSE
“It is likely that the variant is playing a very small role” in the recent rise in infections in South Africa, said Jinal Bhiman, the chief medical scientist at the National Institute of Communicable Diseases in Johannesburg, who studies the new variant. But, said Bhiman, “it can also be a perfect storm”.
Several countries have banned travel to and from South Africa due to concerns about the spread of the new variant. Last week, laboratories in Finland, the United Kingdom, Japan, Australia and Switzerland found the South African variant in coronavirus tests conducted there. Researchers in neighboring Zambia said on Wednesday that the South African variant also appears to be the dominant virus there.
It is not clear whether the mutations can affect the effectiveness of Covid-19 vaccines.
Richard Lessells, an infectious disease specialist at the KwaZulu-Natal Research Innovation and Sequencing Platform, or KRISP – the group of scientists who sequenced the South Africa variant – said his discovery coincided with another worrying development: doctors are reporting more patients, including healthcare workers, who are testing positive for Covid-19 for the second time after having had it in the first wave.
“We are genuinely concerned and that is why we need to do research to understand this variant as quickly as possible,” said Dr. Lessells.
Lessells and doctors treating Covid-19 patients in South Africa said they have not been able to prove whether these repeated positive tests are genuine reinfections – which many scientists believe to be extremely rare – or the resurgence of a previous disease. South Africa’s public health system generally tests only people with symptoms of Covid-19.
To complicate matters, most South African laboratories do not store test samples of coronavirus for more than a few weeks, which means that it is almost impossible to verify whether a new infection comes from a different variant of the virus.
Overworked healthcare professionals are at high risk of catching Covid-19 a second time, due to exposure to sick patients and because stress can weaken their immune systems.
A liquor store in Johannesburg was closed on Tuesday in a week when South Africa registered its millionth Covid-19 case.
Photograph:
phill magakoe / Agence France-Presse / Getty Images
“What we’re seeing is a very dark box here, where no one understands what’s in it,” said John Black, who heads the infectious disease division at Livingstone Hospital in Port Elizabeth, the city hardest hit by South Africa’s second wave. . Dr. Black said he saw a small number of his patients tested positive again, more than three months after the first positive test.
At Tygerberg Hospital, the main public hospital that treats patients with coronaviruses in Cape Town, doctors are seeing patients and health professionals tested positive again three months after a previous infection, a spokeswoman said. What doctors do not know, she said, is whether these repeated positives are due to true reinfections or to some people who have been carrying the virus for longer. Health officials are checking whether they can isolate the new variant from the new test samples, the spokeswoman said.
A medical intern at another public hospital in Cape Town interviewed by The Wall Street Journal said that four of her fellow interns recently tested positive for the second time after contracting Covid-19 at the start of the first wave. Another doctor at a maternity hospital in another hot spot in South Africa said she tested positive again this week, after suffering Covid-19 symptoms for the second time since August.
A document setting out a new coronavirus testing strategy released Tuesday by the government of the Western Cape province of South Africa – one of the regions where the new variant is now considered dominant – warned of the risk of people catching Covid-19 for the second time. turn .
“Concerns about its greater likelihood of transmissibility and its possible resistance to neutralizing antibodies, suggest that a second infection with Covid-19 may be more likely than previously predicted,” says the document, which was seen by the Journal.
Doctors in South Africa do not know whether the repeated positive test results are due to reinfection or to people with the virus for longer periods; a mobile test unit at OR Tambo International Airport on Wednesday.
Photograph:
luca sola / Agence France-Presse / Getty Images
The document says that people who experience symptoms of Covid-19 a second time after recovering from a previous infection should be tested again after 30 days, instead of waiting for the 90 days previously recommended. He says that people who test positive again should also receive an antibody test to confirm that they have a second true infection, because an antibody test can indicate whether a patient is acutely infected or whether the antibodies are derived from an older disease .
Meanwhile, South African researchers are cultivating a live version of the new virus, which will be used to test how the new variant responds to blood collected from people who have recovered from a Covid-19 infection and people who have received a Covid vaccine. -19. “We should know more in a week or more,” said Bhiman.
Like the UK variant, the South African variant has an unusually high number of mutations, including eight in the spike protein, through which the virus binds and infects human cells. One such mutation, dubbed 501Y, is the same mutation that UK scientists have said may be making the variant more contagious.
Another, dubbed E484K, has shown in laboratory tests to increase resistance to laboratory-produced antibodies and blood serum from patients recovered from Covid-19, Lessells said.
“The mutation is probably changing the formation of the protein so that antibodies cannot control it well,” said Lessells. But even if more advanced tests with the live virus confirm antibody resistance, he added, Covid-19 vaccines are likely to trigger a broader immune response that goes beyond antibodies.
Lessells and other researchers also emphasized that measures such as wearing masks and social distance will still prevent the spread of the new variant.
South African researchers believe the new variant probably originated in the coastal city of Port Elizabeth, which was hit hard by the first and second wave of infections. One theory is that the unusually large number of mutations may have been triggered by a long-term infection suffered by an immunocompromised person, such as a patient undergoing chemotherapy.
“There is strong evidence that this new variant has emerged due to immune pressure,” said Dr. Bhiman.
Port Elizabeth and other regions where the new variant is believed to be dominant had a high number of people with antibodies as a result of previous coronavirus infections during the first wave. This, said Bhiman, may have contributed to making the new variant dominant over variants of the virus that do not have these mutations.
Write to Gabriele Steinhauser at [email protected] and Benjamin Katz at [email protected]
Copyright © 2020 Dow Jones & Company, Inc. All rights reserved. 87990cbe856818d5eddac44c7b1cdeb8