BY PATIENCE IVIE IHEJIRIKA |
Test to diagnose viral infection like the SARS-CoV-2 is key to controlling the pandemic, but achieving testing target has not been feasible in Nigeria.
This is partly due to delay in getting test results and lack of adequate equipment and reagents needed to carry out the PCR test.
In a bid to improve its testing capacity, the federal government had welcomed the use of test kits, including developing a molecular test kit namely SARS-COV2 Isothermal Molecular Assay (SIMA).
The test kit, developed by the Nigeria Institute of Medical Research (NIMR) can produce results in less than 40 minutes.
This is faster as compared to the Reverse Transcription- Polymerase Chain Reaction (RT-PCR) which is currently the main source of testing in the country, said the minister of state for Health, Dr Momora Adeleke.
However, the minister of Health, Dr. Osagie Ehanire, recently disclosed that four antibody-based test kits evaluated by the Medical Laboratory Science Council of Nigeria for testing COVID- 19 failed validation, saying results from them were false and misleading.
According to the minister, the Polymerase Chain Reaction testing method was the only testing technique approved by the Nigeria Centre for Disease Control for COVID-19 testing.
Also, the Medical Laboratory Science Council of Nigeria (MLSCN) has urged local and foreign manufacturers of COVID–19 test kits to take urgent steps to improve on the standardisation of their products to meet the minimum validation requirements.
This, the Council said will help guarantee reliable, accurate, and timely test results.
The call was made by the Registrar/CEO, MLSCN, Dr. Tosan Erhabor, during a press briefing on the outcome of the second batch of Pre-market Validation of COVID-19 test kits recently carried out by the agency, recently in Abuja.
Erhabor, while noting that MLSCN regulates the production, importation, sales and stocking of diagnostic reagents, equipment and chemicals (Act 11 of 2003), added that, following the outbreak of the COVID–19 pandemic, the agency commenced the process of validating test kits in the country for detecting SARS-CoV-2 infection.
According to the Registrar, MLSCN received a total of 43 brands of test kits for validation. The goal was to determine the laboratory performance characteristics of Rapid/PCR Test Kits.
Erhabor noted that a total of 33 test kits and systems were validated, but expressed regret that all the antigen and antibody test kits, rapid or otherwise, failed to meet the minimum acceptable criteria.
“For a rapid test kit to be deployed for disease surveillance and diagnosis, it must be able to detect a disease-causing agent when it is present and to return a negative result if the causative agent is absent.
“Therefore, for a kit to be consiadered reliable for laboratory diagnosis and disease surveillance, the kit should have a high sensitivity and specificity. A kit performing very well in one of these characteristics without the other renders it unsuitable for diagnostic testing,” he said.
He, therefore, noted that the 22 rapid Test kits being reported had not met the expected performance characteristics of sensitivity and specificity to qualify them for deployment for the purposes of testing in disease surveillance and routine diagnosis.
Similarly, he noted that non-rapid antibody detection test kits had sensitivities and specificities below the acceptable minimum of 95 per cent and are, therefore, unsuitable for use as IVDs in the country, while explaining that the PCR test kits evaluated had a relatively better performance than the antigen and antibody detection test kits.
Erhabor regretted that from the standardised validation done by MLSCN, “The manufacturers’ claims as contained in the product insert about Sensitivity, Specificity and Accuracy are not always correct. In this case, a significant standard deviation was observed- an indication that Rapid Test kits that are not validated pose higher risks of providing false positive and negative results.”
Consequently, he said that, for diagnosis, none of the antigen or antibody detection test kits is recommended for SARS-CoV-2 infection testing in the country. “For the purpose of PCR testing, Viasure PCR kit is recommended as a first line test while Standard M may be used as second line test,” he said.
However, the Registrar reiterated that no SARS-CoV-2 Rapid Test kit is currently approved for use in the country. He therefore cautioned against the use of any non-validated Rapid / PCR Test Kits for COVID-19 testing, saying this will attract sanctions in accordance with the law.
“None of the antigen or antibody detection test kits is recommended for SARS-CoV-2 infection testing in Nigeria.
“For purposes of diagnosis, Viasure PCR kit is recommended as a first line test while Standard M may be used as second line test.
“For surveillance purposes, Standard MnCoV Real Time Detection kit is recommended.
“No SARS-CoV-2 Rapid Test kit is currently approved for use in Nigeria.”
Meanwhile, the MLSCN, according to Erhabor, has recommended that all indigenously-developed test kits for COVID-19 testing in the country should be submitted for validation to support standardization and promote reliable and accurate test results.
In view of these findings, it is pertinent to recommend the establishment and institutional participation in External Quality Assessment programme for COVID-19 testing in the country,” he said.
The Registrar added that MLSCN was working closely with NCDC to ensure that the two (2) WHO pre-qualified Antigen Rapid Test Kits will go through validation as soon as they arrive the country.
He also used the medium to call on the Nigeria Institute for Pharmaceutical Research and Development (NIPRD) and the Nigeria Institute of Medical Research (NIMR) to submit their kits for validation.
“You cannot produce your kit and validate it your self and you say it should be used in our country, that is not the process. We are calling on them. We are waiting”, he said.