100 COVID-19 positive cases in 24 hours:-
From 284 samples obtained, and 270 analysed, we announced 86 positive cases at our 11am press update today. Shortly afterwards, we had cause to announce 14 more positive cases based on the remaining 14 samples analysed (total of 100 positive cases). 67 of those are attributed to the Kuwait repatriation, and 19 (WU), 5 (WR), 1 (Tonkolili), 1 (Kambia), 6 (Bo), 1 (Kono).
Indeed our fellow citizens were repatriated from Kuwait, and we have received them wholeheartedly. Upon their arrival, the mandatory quarantine was activated, and all necessary protocols matching their situation shall apply. Testing them on the first day of quarantine was a smart decision.
Perhaps for the first time since Sierra Leone recorded its index on March 30, I see questions being raised about Sierra Leone’s COVID-19 testing regime.
Well, healthcare systems all over the world have adopted two dominant testing paths -PCR and serologic tests. The first is what we are doing (collecting swabs from nose/throat and analysing samples in our laboratories). This is used to establish whether or not someone has the coronavirus. And if you do, we isolate and treat. This is the viral test for a current infection. By the way, Sierra Leone’s testing is gold standard and used to detect nuclear materials. We are not yet doing the serologic (antibody tests) that some others are doing. This antibody test merely determines whether someone had the virus and has recovered (as opposed to our brand of test which tells us that you do have the virus or not). So, antibody test may tell us whether a lot of us may have had the virus and recovered without even knowing it.
Sierra Leone’s testing path (the RT-PCR) is gold standard and we are using WHO recommended test kit. Close attention is paid to national quality assurance broadly. Our virologists and lab technicians are highly acclaimed, and have a dedicated team they work with. If a sample is analysed and result shows positive, they seek to ensure the positive predictive value (that is, a high probability that a person who has a positive screening test, is indeed positive). If someone’s screening test shows negative, they will similarly establish the threshold of that predictive value. If tests are run and they show ‘indeterminate’, there will be a re-run to establish specificity. That’s the kind of team we have at the National Covid-19 Emergency Response Center (NACOVERC). They seek diagnostic accuracy -not the most perfect of systems, and that is the case the world over. For a positive case to be declared, your RNA (turned into DNA) has to match the genetic code of SARS Coronavirus 2.
Of course, it may be the case that testing standards, more so regarding cycle threshold (CT) value, may be set slightly differently from country to country. We see the testing menu expanding, and several recipes developed by different countries to address the evolving coronavirus genetic profile. Whatever testing brand a country adopts, there are sensitivities. It is possible for test kits from different countries or brand to show different sensitivities, and we have seen several countries express concerns over test kits and results based on several factors.
With the 100 positive cases recorded in Sierra Leone in 24 hours (67 attributed to the Kuwait repatriation), it’s too early to cast aspersions due to any variance in results. There is need for deeper technical examination of the issue, which would warrant sharing our testing models and experiences with others, and learning from theirs as well (including what thresholds and kits are being used); and this is the position of NACOVERC. We believe that our experts working at the Labs and those collecting samples are some of the most dedicated and professional people who are giving their best to address infections and break the chain of transmission. And we also continue to use what is the recommended standard. With respect to the Kuwaiti repatriation positive cases, let me say again, our experts are at work, and they have always had the culture of ascertaining veracity -and the 100 cases shall never escape that compelling necessity. With a disease that keeps evolving, and testing recipes expanding (different models seemingly applying in different places), we need time to unravel the puzzle. I choose to trust our lab professionals and testing systems.
Solomon Jamiru Esq
National Covid-19 Emergency Response Center (NACOVERC)