South African doctors and researchers battling a second wave of Covid-19 cases are vying to understand what role a new variant of coronavirus could play in the new wave of infections.
The total number of confirmed cases of Covid-19 in South Africa has exceeded one million this week. On Wednesday, the 60 million country recorded 17,710 new infections, higher than any daily load of cases observed during its first wave of infections, which peaked in July.
Doctors say they need to ration oxygen and do not have the manpower to care for best practices, such as turning patients on their stomachs. One-third of coronavirus tests return positive, suggesting that the actual number of infections is probably much higher.
South African researchers first discovered the new coronavirus variant in November – which bears resemblance to a variant found in December in the UK – and quickly became dominant in the country’s hot spots of coronavirus. Researchers say the South African version has the same mutation that scientists in the UK say could have made the version there much more contagious than other versions of the virus.
South African researchers say they have also discovered changes in the structure of the virus that, in previous laboratory tests, have led to increased antibody resistance in people who have recovered from Covid-19.
However, the researchers said that human behavior is still the main reason for the new increase in Covid-19 cases. Millions of South Africans have traveled in recent weeks to see family across the country, while tens of thousands have flocked to restaurants, bars and beaches during a festive season that overlaps with the country’s main summer holidays.
The South African daily confirmed the Covid-19 cases, an average of seven days
Source: Johns Hopkins CSSE
“The variant is likely to play a very small role” in the recent rise in infections in South Africa, said Jinal Bhiman, chief medical scientist at the National Institute of Communicable Diseases in Johannesburg, who studied the new variant. But, said Dr. Bhiman, “it could be a perfect storm.”
Several countries have banned travel to and from South Africa due to concerns about the spread of the new variant. In the last week, laboratories in Finland, the United Kingdom, Japan, Australia and Switzerland found the South African version in coronavirus tests performed there. Researchers in neighboring Zambia said on Wednesday that the South African version now appears to be the dominant virus there.
It is unclear whether the mutations could affect the effectiveness of Covid-19 vaccines.
Richard Lessells, a specialist in infectious diseases at the KwaZulu-Natal Research Innovation and Sequencing Platform, or KRISP – the group of scientists who sequenced the South African version – said his discovery coincided with another worrying development: doctors report more patients, including health care workers, who test positive for Covid-19 a second time after having it in the first wave.
“We are really concerned, and that is why we need to do research to understand this variant as quickly as we can,” said Dr. Lessells.
Dr. Lessells and doctors treating Covid-19 patients in South Africa said they had failed to prove whether these positive repetitive tests were genuine reinfections – which many scientists thought were extremely rare – or the recurrence of a previous diseases. The public healthcare system in South Africa generally tests only people who have symptoms of Covid-19.
Complicating matters, most laboratories in South Africa do not store coronavirus test samples for more than a few weeks, which means that it is almost impossible to see if a new infection comes from another variant of the virus.
Overworked health workers are at increased risk of taking Covid-19 a second time because of their exposure to sick patients and because stress can weaken their immune systems.
A liquor store in Johannesburg was closed in a week on Tuesday when South Africa registered one million cases of Covid-19.
Photo:
phill magakoe / Agence France-Presse / Getty Images
“What we’re looking at is a very dark box here, where no one understands what’s in it,” said John Black, who heads the infectious diseases division at Livingstone Hospital in Port Elizabeth, the city hardest hit by Africa’s second wave. South . Dr. Black said he saw again a small number of patients who tested positive again, more than three months after their first positive test.
At Tygerberg Hospital, the main public hospital that treats coronavirus patients in Cape Town, doctors see both patients and health care workers testing positive again within three months of a previous infection, a spokeswoman said. What doctors don’t know, she said, is whether these repeated positives are due to real reinfections or people carrying the virus for a longer period of time. Health officials are currently checking to see if they can isolate the new variant from the new test samples, the spokesman said.
An intern at another public hospital in Cape Town, interviewed by The Wall Street Journal, said four of her fellow trainees recently tested positive for the second time after receiving Covid-19 at the start of the first wave. Another doctor at a maternity hospital in another hot spot in South Africa said she herself tested positive this week after suffering Covid-19 symptoms for the second time in August.
A document setting out a new coronavirus testing strategy circulated on Tuesday by the Western Cape government in 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. .
“Concerns about its higher likelihood of transmissibility and its possible resistance to antibody neutralization suggest that a second Covid-19 infection may be more likely than previously predicted,” said the document, which was consulted by the Journal.
Doctors in South Africa do not know if the results of repeated positive tests are due to reinfection or people who have the virus for longer periods; a mobile test unit at OR Tambo International Airport on Wednesday.
Photo:
luca sola / Agence France-Presse / Getty Images
The document says that people who have symptoms of Covid-19 for the second time after recovery from a previous infection should be tested again after 30 days, rather than waiting for the 90 days previously recommended. It is said that people who test positive again should also receive an antibody test to confirm if they have a second true infection, because an antibody test can indicate if a patient is acutely infected or if the antibodies come from a more serious disease. old.
Meanwhile, South African researchers are developing a live version of the new virus, which will be used to test how the new variant responds to blood taken from people who have recovered from a Covid-19 infection and from people who received a Covid-19 vaccine. “We should know more in a week or so,” said Dr. Bhiman.
Like the British version, the South African version has an unusually large number of mutations, including eight on the spike protein through which the virus attaches and infects human cells. One of these mutations, called 501Y, is the same mutation that scientists in the UK have said could make the variant more contagious.
Another, called E484K, has been shown in laboratory tests to increase resistance to antibodies and laboratory serum in the blood of patients with recovered Covid-19, Dr. Lessells said.
The mutation is likely to change the formation of proteins so that antibodies cannot get good adhesion on it, said Dr. Lessells. But even if more advanced live virus tests confirm antibody resistance, he added, Covid-19 vaccines should trigger a broader immune response that goes beyond antibodies.
Dr. Lessells and other researchers also pointed out that measures such as wearing masks and social distancing will continue to stop the spread of the new variant.
Researchers in South Africa believe that the new variant probably appeared in the coastal city of Port Elizabeth, which was hit hard by both the first and second wave of infections. One theory is that an unusually large number of mutations could 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 now considered to be dominant had a large number of people with antibodies due to previous coronavirus infections during the first wave. This, said Dr. Bhiman, could have helped turn the new variant into a dominant one over the virus variants that do not have these mutations.
Write to Gabriele Steinhauser at [email protected] and Benjamin Katz at [email protected]
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