Cape Town doctor tests positive for Covid-19 twice: 'We are not safe from the claws of SARS-CoV-2'

• A Cape Town doctor has tested positive for Covid-19 twice in three months.
• She is urging South Africans to help stave off an anticipated second Covid-19 wave.
• More than 300 deaths have been recorded among healthcare workers in the public and private sectors.

"We are not safe from the claws of SARS-CoV-2," said Dr Davinia Masimila who tested positive twice - once in June and a second time, after she recovered, in September.

However, whether she had a true reinfection had not been confirmed, even though she had a positive test result and was experiencing Covid-19 symptoms.

Masimila told News24 she was admitted to hospital for Covid-19 treatment in June after she had severe chest pains and shortness of breath. She recovered, but in September, she started showing symptoms again.

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"More than three months after my initial infection, I experienced this unusual tiredness and severe headaches. I then had a scratchy feeling in my throat and later became dizzy and developed diarrhoea."

She double-checked if the symptoms she experienced the second time around could be Covid-19 related.

"I also contacted an infectious diseases colleague regarding my symptoms and whether it warranted a second swab. My colleague suggested a retest for SARS-CoV-2 as I had symptoms suggestive of Covid-19 and more than 90 days had lapsed since my initial infection, but we were also aware that other common viral infections should also be considered."

Masimila said the concern was that the immunity against SARS-CoV-2 was still unknown, and although you might have antibodies, it was not entirely sure whether you're completely protected from a second infection.

Professor Wolfgang Preiser, a virologist at Stellenbosch University, told News24 there were unsubstantiated reports of people testing positive repeatedly, early in the pandemic.

"However, we soon learnt that it is quite common for viral genome (RNA) to remain detectable for several weeks after the onset of symptoms, which explained these early reports."

This phenomenon, he said, did not signify reinfection, nor did it mean that the patient remained infectious.

"It is referred to as 'residual shedding' of viral RNA which is picked up by PCR (the polymerase-chain-reaction test - which is the gold standard test used) because they are so highly sensitive, which means it is able to detect even small amounts of viral genome. It can cause confusion though, as people need to figure out what it means in a particular case."

Studying genetic material

Professor Burtram Fielding, a molecular biologist from the University of the Western Cape, explained to News24 what a so-called true reinfection is.

"Typically, reinfection would indicate that a person was infected, the virus was cleared from the body by the person's immune system, and then at a later stage the person becomes infected with another SARS-Cov-2 again."

These two SARS-CoV-2 viruses will be genetically slightly different, he said.

"Since they are different, the immune system is not that effective in preventing the new infection, or in clearing the virus, and the person can develop Covid-19 again."

Verifying reinfection

South Africa was also guided by international discussions to assist in standardising investigations to confirm if someone had indeed been infected twice, according to Dr Anne von Gottberg, a clinical microbiologist, who's the head of the Centre for Respiratory Diseases and Meningitis at the National Institute For Communicable Diseases and an associate professor at the School of Pathology at Wits University.

"In short, consent is obtained from the affected individual, careful descriptions of both episodes [are] recorded, and then all the details and specimens from the first and second episode are retrieved from the relevant laboratories.

"In addition, new specimens may be requested. These can then be tested and retested, but can also be processed with less routine tests, like whole genome sequencing, culture from respiratory specimens or serology from blood specimens," she explained.

A plea to continue to flatten the curve

Meanwhile, Masimila said it saddened her that the public had become complacent about the deadly virus.

The 38-year-old worked as a general specialist and assisted with the care of pregnant women who had high-risk obstetric conditions, as well as the training of junior staff at Tygerberg Hospital.

"As healthcare workers, we are always in contact with patients and we continuously try to not only protect ourselves, but also our patients to limit the spread of the virus."

Masimila said she had always been aware that she could either contract the virus at work or be a carrier and spread it to her loved ones.

Healthcare worker at risk of infection

She said she made a conscious decision to change her habits, in the best way she could, at work and at home to try to avoid contracting Covid-19.

However, she added: "There is always a loophole no matter how cautious you are, but we all should still play our part to try and contain the spread of the virus."

Masimila, who usually started working at 07:30 and finished at 16:00, was, also at times, on call or on night duty. This meant she worked a 24-hour shift in the emergency section of the obstetrics department where she oversaw or assisted with any complicated cases in the labour ward or theatre.

As of 26 September 2020, more than 73 000 healthcare workers in the public and private sectors were admitted to hospital because of Covid-19, with 308 deaths reported, according to the National Institute for Occupational Health.

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