Omicron Study in South Africa Points to End of Acute Pandemic Phase

(Bloomberg) -- A South African study from the epicenter of the world’s omicron surge offers a tantalizing hint that the acute phase of the Covid-19 pandemic may be ending.

The infection wave moved with “unprecedented speed” and caused much milder illness than earlier strains, a study of patients infected with Covid-19 at a large hospital in the South African city where the first outbreak of the omicron variant was recorded showed. 

“If this pattern continues and is repeated globally, we are likely to see a complete decoupling of case and death rates,” the researchers said. That suggests “omicron may be a harbinger of the end of the epidemic phase of the Covid pandemic, ushering in its endemic phase.”

The study at the Steve Biko Academic Hospital Complex analyzed records of 466 patients from the current wave and 3,976 from previous bouts of infection. Researchers that worked on it included Fareed Abdullah, a director at the council and an infectious disease doctor at the hospital.

South Africa, the first country to have a major omicron outbreak, is being closely watched to see how infections from the variant may pan out globally. The comparatively young age of the country’s population and those hospitalized in the latest wave could also mask the severity of disease caused by the variant, the researchers said.

Still, the data add to hope among researchers that concern over omicron’s high transmission rates is being tempered by the mildness of the disease it appears to cause and the limited number of deaths that result from its infections.

Less Death

South African hospitalizations have crested at half of their record in previous waves. Weekly excess deaths, a measure of the number of deaths compared with a historical average, peaked at less than a fifth of their record during the pandemic.

If other countries have similar experiences, that may help move the pandemic to an endemic phase, where widespread exposure gives more people immunity resulting in less serious disease. Still, the virus could mutate further into a strain that causes more severe disease and more easily evades antibodies produced from prior infections or vaccinations.

The study showed that just 4.5% of patients with Covid-19 died during their hospital stay in the current wave compared with an average of 21% in earlier waves, according to the South African Medical Research Council’s website. Fewer people were admitted to intensive-care units, and hospital stays were “significantly shorter.”

Asymptomatic Disease

The rate of admissions climbed rapidly but began to decline within 33 days of the first analyzed, the study said. A snapshot of patients in the hospital on Dec. 14 and 15 showed that almost two-thirds of those infected with Covid-19 had been admitted for other reasons.

“This phenomenon has not been observed to this extent before in the Steve Biko Academic Hospital Complex or anywhere in South Africa,” the study said. It “most likely reflects high levels of asymptomatic disease in the community with omicron infection,” it said. 

It also found: 

• Hospital stays averaged 4 days compared with 8.8 in previous waves
• The mean age of those admitted was 39 compared with almost 50 in earlier waves
• Admissions to intensive-care units dropped to 1% of patients from 4.3%
• Admissions peaked at 108 compared with 213 during the delta wave

The findings “were comparable to city-wide trends when cases and admissions from all public and private hospitals reported,” the researchers said. There was “a lower admission per case ratio, lower death rate and lower rates of admission to the ICU compared to previous waves.”

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