Ministry of Health acting Director-General Patrick Amoth has revealed that some of the testing kits used in the country may be faulty.
Speaking during the daily Covid-19 brief from Afya House on Wednesday, May 20, explained that the country had adopted a testing method based on the variation of the approved gold standard - Realtime Polymerous Chain Reaction (PCR) - that involves collecting a specimen from the junction of your nose and your throat.
Based on this, the actual viral particle is extracted, after which it goes into the laboratory where health practitioners plot curves to see whether one has the virus or not.
Amoth stated that the realtime PCR method had been approved by the World Health Organisation (WHO) and is the one being used in the 20 laboratories set up by the government across the country.
The DG further revealed that the Ministry of Health had received rapid testing kits from vendors, and a validation of the kits established that some were faulty.
"For a particular kit we did validation on, where the realtime PCR was showing positive tests in all the 8 cases, this particular kit was showing a negative in all the cases," Amoth revealed.
Antibodies
The DG went further to explain that the cause of the disparity in the test results was that the said rapid testing kit was based on antibodies. WHO describes an antibody as a blood protein produced by the body in response to antigens such as viruses and in this case Covid-19.
Amoth stated that in this scenario, the tests by the kit may have come out as negative because in some people the proteins may be produced much later after 14 days of infection.
Therefore, if the kit is used in testing someone, he or she may test negative because the specific protein the kit is looking for has not been produced. The test may show one as negative while the samples are positive. This, the DG described as a false negative.
False Positive
Amoth went further to add that rapid kits were not specific and therefore a false result is expected.
"There is a large group of Coronaviruses including one that causes the common cold. So you could just be having a common cold caused by the Coronaviruses but this particular test could label you as Covid-19 positive. So that is a False Positive," Amoth stated.
He further revealed that the kit faced a third limitation in the sense that not every person produces sufficient quantities of antibodies that can be measured in samples from blood/plasma. These may include members of the public with serious illnesses, infections like HIV/AIDS or TB, and those suffering from malnutrition.
They may not produce significant quantities of antibodies and therefore one may be tested and the result comes out as negative because the particular antibody has not been released.
Amoth pronounced that those using the kits and those using the realtime PCR may experience the variance.
{"preview_thumbnail":"/files/styles/video_embed_wysiwyg_preview/public/video_thumbnails/mY-fX9jwAN4.jpg?itok=hjju13s6","video_url":"","settings":{"responsive":1,"width":"854","height":"480","autoplay":0},"settings_summary":["Embedded Video (Responsive)."]}
