The World Health Organization (WHO) has called on countries to ‘test, test, test’ for COVID-19. We speak to Associate Prof. Dr. Chan Yoke Fun, a virologist from the Department of Medical Microbiology, Faculty of Medicine, University of Malaya to tell us how diagnostic test kits work and to share about potential treatments for COVID-19.
What is the diagnostic test kit being used now? How does it work?
“The Real-time RT-PCR (qRT-PCR) is based on the World Health Organization’s (WHO) protocol. It detects RNA, the genomic material of the virus. Small amount of coronavirus present in the COVID-19 patient will be amplified with repeating cycles of heating and million DNA copies will be detected by fluorescence emitted.”
For further reading of real-time PCR:
“We can buy as a commercial pre-packed kit or purchase each reagent separately. Anything close to WHO’s protocol and have FDA and CE-IVD marked are likely to be reliable.”
More info on reliable kits are available on these websites:
“If any test kits outside these lists, we should validate with existing assays. We should ask 3 questions:
- Is it approved by a regulatory body?
Step-by-step procedures are:
- Collection of nasopharyngeal swab
- Specimen transport to laboratory
- Sample processing and testing in laboratory
- Results and reporting
This is a good video of the test and current limitations.”
Limitations mentioned are:
- Inappropriate order of test- no clinical symptoms
- Poor specimen transport
- Poor sample swabbing
- Test kits have low sensitivity
Based on the most current guideline, we should screen asymptomatic contacts of confirmed cases. The change is due to new science that shows that even people who show no signs of being sick can spread the disease. This is highlighted in a study by Singapore (https://www.cdc.gov/mmwr/volumes/69/wr/mm6914e1.htm) which showed that an investigation of 243 cases of COVID-19 in Singapore during January 23–March 16 identified seven clusters of cases in which pre-symptomatic transmission is the most likely explanation for the occurrence of secondary cases.
Labs offering tests in Malaysia: http://www.moh.gov.my/moh/resources/user_35/Makmal.jpeg
Rapid antibody tests are also available in the market. Are these tests reliable?
“Specific antibodies only appear in the body about 5-8 days after infection. The test cannot detect viruses like real-time PCR, and therefore is not suitable for early detection of cases. This test is useful as an indication of who contracted the virus, and the patient develops immunity against the virus. Interestingly, Germany will issue coronavirus antibody certificates to allow quarantined people to re-enter society.”
MOH has also stressed not to use these kits for diagnosis. https://www.bharian.com.my/berita/nasional/2020/03/668832/covid-19-kkm-tidak-saran-guna-kit-ujian-pantas
The WHO has chosen Malaysia as one of the countries that will conduct joint research on the Remdesivir drug that is used to treat COVID-19 infection. What is the significance of this?
“Remdesivir is a novel antiviral drug used as a treatment for Ebola virus and Marburg virus infections, and the coronaviruses, including MERS and SARS viruses. It is a recognition that Malaysia has the ability to conduct trials and has a good healthcare system. It also means COVID-19 patients can have access to this novel drug.”
How do we do research on SARS-CoV-2 virus in Malaysia without a Biosafety Level 3 Lab?
“We can do research that will not requires growing the live virus. We have many researchers trained in handling this high-risk pathogen. Unfortunately, there are only a few BSL3 labs, and poorly maintained. Concerted efforts should be put to maintain a few regional labs and ensure all researchers have access.”
Health Director General, Datuk Seri Dr Noor Hisham Abdullah said chloroquine, hydroxychloroquine and a combination of lopinavir and ritonavir can be used to treat COVID-19. This includes imported Favipiravir dan Remdesivir. Which is the most effective and who should take them?
“I believe some of these drugs may be used as treatment or prophylaxis after exposure. I don’t think anyone has solid evidences as yet. That is why we are doing clinical trials.”
Chloroquine phosphate, an old drug for treatment of malaria, is shown to have apparent efficacy and acceptable safety against COVID-19. However, man in Arizona, US recently died after taking chloroquine phosphate, which is used in aquariums. What went wrong?
“He did it without a prescription and supervision of a healthcare provider. No one knows how much he took.”
Bionotes of expert
Associate Professor Dr Chan Yoke Fun is a virologist focused on the epidemiology and pathogenesis of enterovirus A71, an emerging virus that causes severe neurological disease. She leads a laboratory with research interests in epidemiology and pathogenesis of emerging viruses such as enterovirus A71, chikungunya, and respiratory viruses. With more than 20 years of research experience, she has over 80 publications, and has been involved in many research programs and grants at both national and international levels. Dr. Chan also served as an Associate Editor of BMC Infectious Diseases and guest editor in PLOS Neglected Tropical Diseases. She has multiple joint publications with collaborators from Asia, Europe, and the USA. Her studies have led to a better understanding of how viruses spread and infect humans.
**All previous posts about COVID-19 here: https://sciencemediacentremalaysia.com/tag/covid-19/
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