Professor Cheryl Cohen, co-head of the Centre for Respiratory Disease and Meningitis at the National Institute for Communicable Diseases (NICD) told the Mail & Guardian on Friday that there is no need for South Africans to be concerned yet about the country’s first case of Covid-19.
Cohen said the case “has been isolated in hospital [and] all the contacts are being followed up. They will be monitored and isolated and the situation is being contained at this time”.
“There is no evidence there’s any risk of its spreading within the community in South Africa. The fact that there is one case that has been contained does not mean that there is any suggestion that the virus is spreading widely in the community.”
But Cohen said that concern about the global spread of Covid-19 relates to the fact that, despite strategies of containment by a number of countries, the virus has continued to spread.
“So certainly the consensus among experts is increasing that it is unlikely we will be able to totally contain this virus,” she said. “In other words, all countries in the world should prepare for and expect that at some time the virus may come to their shores, and that there will be widespread community transmission.
“Accepting that, the next important consideration is to think about the potential impact of widespread community transmission. The reassuring information is that the vast majority of cases are mild. However, there are cases that are severe and people do die,” Cohen added. “But, that being said, I think all countries in the world do need to take the threat seriously, including South Africa. And we need to start preparing ourselves for a possible and community outbreak within South Africa and that is what is actively being done.”
She said the purpose of the containment in South Africa and globally “is to buy a little time to allow countries to prepare better”.
“So we should be concerned and we should be monitoring the situation. We need to review the evidence out there but we need to make sure that our responses are proportionate to the current status, and that’s what we really are doing.”
When asked about how Covid-19 stacks up compared to other outbreaks, Cohen said: “What has been difficult up until now is to get good, reliable scientific evidence about how serious the disease is.”
Cohen said the information usually used to determine an outbreak’s seriousness is called the case-fatality ratio — the proportion of cases that result in death to those that do not.
“This number is actually really hard to get because you are much more likely to diagnose people who die than people who have mild illness. So an illness like this that has a lot of mild cases, if you don’t count the mild cases, you would think it is more severe than it is,” she noted.
The current available evidence suggests that the case fatality ratio of Covid-19 is between 1% and 2%. This is higher than the seasonal flu, which is less than 1%, Cohen said. “But what is not clear is how reliable that evidence is. It could be lower.”
“I think that is why the global community is taking this virus very seriously. Because it is possible that it will be, to some extent, more severe than the common flu.”
But, Cohen added, “What we do know is that it is definitely much less severe than other coronaviruses”.
The severe acute respiratory syndrome coronavirus 2, commonly known as SARS, had a 10% fatality ratio.