Confusion over accuracy of Sierra Leone’s COVID-19 testing as infection rate doubles  

Sierra Leone Telegraph: 27 May 2020:

The accuracy of testing for the deadly COVID-19 virus by officials in Sierra Leone, has been in the spotlight since confirmation of the first group of cases two  months ago.

But last weekend, there were fresh allegations concerning the effectiveness of the testing kits used by officials, as well as their testing protocols which are now casting doubts over the accuracy of those tests.

These concerns come as the number of confirmed cases rises to almost 750, with over 400 suspected cases now in isolation. Over 40 people have so far died of the virus in Sierra Leone – most of them in the capital Freetown.

Almost 300 people have recovered from the illness, which also cast doubt on the accuracy of the testing as many believe that several cases of malaria and other underlying conditions have been misdiagnosed as COVID-19.

Last Saturday, Sierra Leone recorded its highest daily number of confirmed  COVID-19  cases, as 100 people were said to have tested positive.

But that number was quickly rejected by some officials – including the country’s Ambassador to Kuwait, after 67 out of the 85 Sierra Leoneans repatriated last Friday from Kuwait were tested positive in Freetown.

Spokesperson for the National Covid-19 Emergency Response Center (NACOVERC) – Mr Solomon Jamiru gave this statement in defence of the government’s testing protocol:

“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.”

But as the debate continues about the effectiveness of the testing done by officials in Sierra Leone, the head of the National Response Centre – Brigadier Kallie Conteh in response to calls for some cases to be retested, said: “Firstly, Sierra Leone uses only the WHO approved PCR test kits, unlike others who choose to use the rapid test kit which, by the way is not an approved test kit by WHO.

“Secondly, please be informed that Ghana is yet to carry out their own test of their returnees. This is authoritative information from our colleagues in Ghana. You see, we in Sierra Leone must learn to trust our own professionals. Even as we have our own challenges, like all other countries, we happen to be doing the right thing in the midst of difficult resources constraints. It is a shame that we cry down our own perpetually as long as we are not directly participating. Whether you hold an office or not in this fight against the virus, we are all in this, TOGETHER.

“Some others in the sub region have simply even stopped contact tracing, let alone carry out any test anymore. If they do, they go in for the cheaper, RDT which has already very high margin of error. Kuwait used the Rapid test kits at their airport just before throwing out our nationals. Have you asked yourselves how come every single one of them was negative?

“Please brothers and sisters, let us learn to respect our own professionals.  This pandemic is not a local or national issue; it is global; under the watchful eyes of the WHO. Sierra Leone uses the best test around (PCR test kits) ,that is approved by WHO. The Kuwaiti authorities used the RDT kits which is not approved by WHO.

“Also be informed that we are reliably informed by our counterparts in Ghana that they are yet to carry out any tests on their own returnees since their return.  We will follow up on the others. What you saw in social media as coming from Ghana,  is simply fake. Let us change our attitude which, for now, is not taking us anywhere,” Brigadier Conteh said on Monday.

But many Sierra Leoneans are still doubting the accuracy of the tests carried out by officials in Sierra Leone.

“Given BBC Umaru Fofana’s report, the only thing that will explain the discrepancy between the COVID-19 testing results of the returnees from Kuwait is either someone (i.e. in Kuwait or Sierra Leone) deliberately or in error concluded false positives or faulty testing kits. The latter will be a much bigger problem, and perhaps the most puzzling. If this is not handled right to restore reassurance, it will undermine the credibility of the entire COVID-19 intervention effort in Sierra Leone,” one commentator said.

Honourable Abdul Latif Sesay – Member of Parliament for Constituency 075 in the Port Loko district, told the Sierra Leone Telegraph:  “We are experiencing a lot of controversies regarding the Covid-19 test results. I am calling on government, the Ministry of Health, EOC and other relevant authorities to do proper testing of the different test kits available in our country to ascertain whether someone is positive or negative of Covid-19. I am suspecting that some kits are not giving the right results as opposed to the others.

“How can someone die of diabetes, high blood pressure, etc and when tested the result is Covid-19 positive? But after two or more weeks of quarantine or self-isolation of both primary and secondary contacts, their results proved to be negative?

“Yes we are in need of test kits but not those that can create more harm than good. We have to consider the psychological impact that a wrong result will have on an individual. Let’s test the test kits to ensure that tests that are carried out have no iota of doubt. Corona is real and let’s take the necessary precautions as stipulated by Government, health professionals and our International partners.”