South African doctors and researchers battling a second wave of Covid-19 cases are stepping up to understand what role a new coronavirus variant might play in the new wave of infections.
The total number of confirmed cases of Covid-19 in South Africa exceeded one million this week. On Wednesday, the 60 million country recorded 17,710 new infections, higher than the daily load of cases observed during its first wave of infections, which peaked in July.
Doctors say they need to ration oxygen and don’t have the manpower to take care of best practices, such as putting patients in their wombs. One-third of coronavirus tests are positive again, suggesting that the actual 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 UK, and quickly became dominant in the country’s coronavirus hotspots. Researchers say the South African variant has the same mutation that British scientists say could have made the variant there 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 lab tests, led to increased antibody resistance in people who recovered from Covid-19.
However, the researchers said human behavior remains the main reason for the new wave of 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 newspaper confirmed the cases of Covid-19, 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, the chief medical scientist at the National Institute of Communicable Diseases in Johannesburg, who has been studying the new variant. But, Dr. Bhiman said, “it could 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. Investigators in neighboring Zambia said Wednesday that the South African variant also appears to be the dominant virus there.
It is unclear whether the mutations could 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 African variant, said his discovery coincided with another worrying development: Doctors report more patients, including health workers, testing positive for Covid-19 for the second time after having it in the first wave.
“We’re really concerned, and that’s why we need to do the research to understand this variant as quickly as possible,” Dr. Lessells said.
Dr. Lessells and doctors treating Covid-19 patients in South Africa said they could not prove whether these repeated positive tests are true reinfections (which many scientists have believed to be extremely rare) or the resurgence of a disease. previous. South Africa’s public health system usually tests only people who have symptoms of Covid-19.
As it is complicated, most South African laboratories do not store coronavirus test samples for more than a few weeks, which means that it is almost impossible to check if a new infection comes from a different variant of the virus.
Hard-working health workers have a high risk of contracting Covid-19 for the second time, due to its exposure to sick patients and because stress can weaken their immune system.
A liquor store in Johannesburg closed on Tuesday in a week when South Africa registered its million cases of Covid-19.
Photo:
phill magakoe / Agence France-Presse / Getty Images
“What we’re seeing is a very dark box here, where no one understands what’s there,” said John Black, who heads the infectious diseases division at Livingstone Hospital in Port Elizabeth, the city hardest hit by the second wave of South Africa. . Dr. Black said he has seen a small number of patients who have tested positive again, more than three months after his first positive test.
At Tygerberg Hospital, the leading public hospital that treats coronavirus patients in Cape Town, doctors see that both patients and health workers test positive in the three months following the previous infection, a spokeswoman said. What doctors don’t know, he said, is whether these positive repeats are due to real reinfections or to some people carrying the virus for longer. Health officials are currently checking to see if they can isolate the new variant from the new test samples, the spokeswoman said.
An intern at another public hospital in Cape Town, interviewed by The Wall Street Journal, said four of his fellow inmates had recently tested positive for the second time, after getting Covid-19 at the start of the first wave . Another maternity doctor in another hot spot in South Africa said she herself tested positive again this week after suffering symptoms of Covid-19 for the second time since August.
A document setting out a new coronavirus testing strategy released Tuesday by the government in the South African province of Western Cape (one of the regions where the new variant is now believed to be dominant) warned of the risk of people catching Covid-19 for the second time.
“Concern about its higher likelihood of transmissibility and possible resistance to neutralizing antibodies suggests that a second infection with Covid-19 may be more likely than previously anticipated,” says the paper, which has been seen by the journal.
South African doctors do not know whether the results of repeated positive tests are due to reinfection or to people who carry the virus for longer periods; a mobile testing unit at OR Tambo International Airport on Wednesday.
Photo:
luca sola / Agence France-Presse / Getty Images
The paper says people who have symptoms of Covid-19 for the second time after recovering from a previous infection should try again after 30 days, instead of waiting for the previous 90 days. It is said that those 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 ‘an older disease.
Meanwhile, South African researchers are growing a live version of the new virus, which will be used to test how the new variant responds to blood drawn from people who have recovered from a Covid-19 infection and people who received a vaccine against Covid-19. . “We should know more in a week or so,” Dr. Bhiman said.
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 to and infects human cells. One of these mutations, called 501Y, is the same mutation that scientists in the UK have said can make the variant more contagious.
Another, dubbed E484K, has been shown in laboratory tests to increase resistance to laboratory-made antibodies and serum from the blood of patients recovered from Covid-19, Dr. Lessells said.
“The mutation is probably changing the formation of the protein so that the antibodies can’t take it well,” Dr. Lessells said. But even if more advanced tests on the live virus confirm antibody resistance, he added, Covid-19 vaccines should trigger a broader immune response that goes beyond antibodies.
Dr. Lessells and other researchers also stressed that measures such as wearing masks and social distancing will still stop the spread of the new variant.
South African researchers believe the new variant probably originated in the coastal city of Port Elizabeth, which was hard hit 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 arose due to immune pressure,” Dr. Bhiman said.
Port Elizabeth and other regions where the new variant is now believed to be dominant had a high number of people with antibodies as a result of previous coronavirus infections during the first wave. That, said Dr. Bhiman, could have helped make the new variant dominant over virus variants that do not have these mutations.
Write to Gabriele Steinhauser to [email protected] and Benjamin Katz to [email protected]
Copyright © 2020 Dow Jones & Company, Inc. All rights reserved. 87990cbe856818d5eddac44c7b1cdeb8