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Hepatitis B seroepidemiology and booster vaccination in pre-clinical medical students in a Malaysian university

Othman SN, Zainol Rashid Z, Abdul Wahab A, Abdul Samat MN, Ding CH, Ali UK

Malays J Pathol, 2018 Dec;40(3):295-302.
PMID: 30580360

INTRODUCTION: Infant hepatitis B vaccination was introduced into the Expanded Programme on Immunisation (EPI) in Malaysia in 1989. This study aimed to investigate seroprevalence of hepatitis B among UKM pre-clinical medical students, born between 1991 and 1995, and had their infant vaccination more than 20 years ago.
MATERIALS AND METHODS: A prospective, cross-sectional study involving 352 students, comprising 109 (31.0%) males and 243 (69.0%) females. Blood specimens were tested for anti-HBs, where levels of ≥10 mIU/mL was considered reactive and protective. Students with non-reactive levels were given a 20 μg HBV vaccine booster. Anti-HBs levels were tested six weeks after the first booster dose. Those with anti-HBs <10 mIU/mL were then given another two booster doses, at least one month apart. Anti-HBs levels were tested six weeks after the third dose.
RESULTS: Ninety-seven students (27.6%) had anti-HBs ranging from 10 to >1000 mIU/mL while 255 (72.4%) had anti-HBs <10 mIU/mL. After one booster dose, 208 (59.1%) mounted anti-HBs ≥10 mIU/mL. Among the remaining 47 (13.3%), all except two students (0.6%) responded following completion of three vaccination doses. They were negative for HBsAg and anti-HBcore antibody, thus regarded as non-responders.
CONCLUSIONS: Anti-HBs levels waned after 20 years post-vaccination, where more than 70% were within non-reactive levels. For healthcare workers, a booster dose followed by documenting anti-HBs levels of ≥10 mIU/mL may be recommended, to guide the management of post-exposure prophylaxis. Pre-booster anti-HBs testing may not be indicated. Serological surveillance is important in long-term assessment of HBV vaccination programs. No HBV carrier was detected.
Diagnostic performance of COVID-19 serology assays

Zainol Rashid Z, Othman SN, Abdul Samat MN, Ali UK, Wong KK

Malays J Pathol, 2020 Apr;42(1):13-21.
PMID: 32342927

INTRODUCTION: The World Health Organization (WHO) declared COVID-19 outbreak as a world pandemic on 12th March 2020. Diagnosis of suspected cases is confirmed by nucleic acid assays with real-time PCR, using respiratory samples. Serology tests are comparatively easier to perform, but their utility may be limited by the performance and the fact that antibodies appear later during the disease course. We aimed to describe the performance data on serological assays for COVID-19.
MATERIALS AND METHODS: A review of multiple reports and kit inserts on the diagnostic performance of rapid tests from various manufacturers that are commercially available were performed. Only preliminary data are available currently.
RESULTS: From a total of nine rapid detection test (RDT) kits, three kits offer total antibody detection, while six kits offer combination SARS-CoV-2 IgM and IgG detection in two separate test lines. All kits are based on colloidal gold-labeled immunochromatography principle and one-step method with results obtained within 15 minutes, using whole blood, serum or plasma samples. The sensitivity for both IgM and IgG tests ranges between 72.7% and 100%, while specificity ranges between 98.7% to 100%. Two immunochromatography using nasopharyngeal or throat swab for detection of COVID-19 specific antigen are also reviewed.
CONCLUSIONS: There is much to determine regarding the value of serological testing in COVID-19 diagnosis and monitoring. More comprehensive evaluations of their performance are rapidly underway. The use of serology methods requires appropriate interpretations of the results and understanding the strengths and limitations of such tests.
Fulltext Draft Genome Sequences of Four Methicillin-Resistant Staphylococcus aureus Strains (M080_2017, M106_2017, M181_2017, and M191_2017), Isolated from a Malaysian Teaching Hospital

Ang MY, Binti Mohamad Farook NA, Kamarudin N, Lam SD, Di Gregorio S, Tengku Jamaluddin TZM, et al.

Microbiol Resour Announc, 2022 Dec 15;11(12):e0086722.
PMID: 36413024 DOI: 10.1128/mra.00867-22

Draft genome sequences were obtained for four methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from various wards of the Hospital Canselor Tuanku Muhriz (HCTM), Kuala Lumpur, Malaysia, in 2017. Using different bioinformatics tools, we annotated the draft genomes and identified multiple antimicrobial resistance genes.
Fulltext Unravelling the link between SARS-CoV-2 mutation frequencies, patient comorbidities, and structural dynamics

Azzeri A, Mohamed NA, Wan Rosli SH, Abdul Samat MN, Rashid ZZ, Mohamad Jamali MA, et al.

PLoS One, 2024;19(3):e0291892.
PMID: 38483913 DOI: 10.1371/journal.pone.0291892

Genomic surveillance is crucial for tracking emergence and spread of novel variants of pathogens, such as SARS-CoV-2, to inform public health interventions and to enforce control measures. However, in some settings especially in low- and middle- income counties, where sequencing platforms are limited, only certain patients get to be selected for sequencing surveillance. Here, we show that patients with multiple comorbidities potentially harbour SARS-CoV-2 with higher mutation rates and thus deserve more attention for genomic surveillance. The relationship between the patient comorbidities, and type of amino acid mutations was assessed. Correlation analysis showed that there was a significant tendency for mutations to occur within the ORF1a region for patients with higher number of comorbidities. Frequency analysis of the amino acid substitution within ORF1a showed that nsp3 P822L of the PLpro protease was one of the highest occurring mutations. Using molecular dynamics, we simulated that the P822L mutation in PLpro represents a system with lower Root Mean Square Deviation (RMSD) fluctuations, and consistent Radius of gyration (Rg), Solvent Accessible Surface Area (SASA) values-indicate a much stabler protein than the wildtype. The outcome of this study will help determine the relationship between the clinical status of a patient and the mutations of the infecting SARS-CoV-2 virus.