Browsing by Author "Zhuo Lin Chong"
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- PublicationDengue Seroprevalence and Factors Associated with Dengue Seropositivity in Petaling District, Malaysia(2022)
;Rui Jie Ng ;Zhuo Lin Chong ;Mohd Hatta Abdul MutalipChiu-Wan NgDengue virus (DENV) infection is a major public health concern, posing huge economic and disease burdens globally. In Malaysia, the incidence of DENV infections has increased significantly over the years. Nevertheless, the passive surveillance mechanism applied may not capture the actual magnitude of DENV infection. There was also a paucity of community-based studies exploring DENV seroprevalence. This study aimed to determine the DENV seroprevalence and the associated factors among the urban population in Petaling district, Malaysia. A population-based cross-sectional study was conducted from 18 August to 26 October 2018 with 533 participants recruited. Blood samples were collected and analyzed for DENV seropositivity using a composite reference standard comprised of three dengue serological tests. Associated factors were identified by fitting Generalised Linear Mixed Models with binomial error structure and logit link function. DENV seroprevalence obtained was 79.0% (95% CI: 75.2–82.4%). The age-specific DENV seroprevalence showed an increasing trend with advancing age, from 22.7% (95% CI: 9.6–45.0%) for those aged below five years old to 94.9% (95% CI: 81.3–98.7%) for those aged ≥60 years old. Only age group and house level were found to be significant factors associated with DENV seropositivity. The odds of being DENV seropositive generally increased with age, from 13.43 (95% CI: 2.77–65.22) for the 5–9 years old age group to 384.77 (95% CI: 39.27–3769.97) for the ≥60 years old age group, as compared to those aged below 5 years old. For house level, those who lived on the first and second floor (OR: 8.98, 95% CI: 3.16–25.12) and the third floor and above (OR: 4.82, 95% CI: 1.89–12.32) had greater odds of being DENV seropositive compared to those living on the ground floor. This study demonstrated the persistently high DENV seroprevalence among the urban population in Petaling district, which could be useful to evaluate dengue control measures taken and estimate more accurate disease incidence. The associated factors with DENV seropositivity identified could also contribute to undertaking more targeted preventive and control measures. - PublicationDiagnostic accuracy and utility of three dengue diagnostic tests for the diagnosis of acute dengue infection in Malaysia(2020)
;Zhuo Lin Chong ;Shamala Devi Sekaran ;Hui Jen Soe ;Devi Peramalah ;Sanjay RampalChiu-Wan NgBackground: Dengue is an emerging infectious disease that infects up to 390 million people yearly. The growing demand of dengue diagnostics especially in low-resource settings gave rise to many rapid diagnostic tests (RDT). This study evaluated the accuracy and utility of ViroTrack Dengue Acute - a new biosensors-based dengue NS1 RDT, SD Bioline Dengue Duo NS1/IgM/IgG combo - a commercially available RDT, and SD Dengue NS1 Ag enzyme-linked immunosorbent assay (ELISA), for the diagnosis of acute dengue infection. Methods: This prospective cross-sectional study consecutively recruited 494 patients with suspected dengue from a health clinic in Malaysia. Both RDTs were performed onsite. The evaluated ELISA and reference tests were performed in a virology laboratory. The reference tests comprised of a reverse transcription-polymerase chain reaction and three ELISAs for the detection of dengue NS1 antigen, IgM and IgG antibodies, respectively. The diagnostic performance of evaluated tests was computed using STATA version 12. Results: The sensitivity and specificity of ViroTrack were 62.3% (95%CI 55.6–68.7) and 95.0% (95%CI 91.7–97.3), versus 66.5% (95%CI 60.0–72.6) and 95.4% (95%CI 92.1–97.6) for SD NS1 ELISA, and 52.4% (95%CI 45.7–59.1) and 97.7% (95%CI 95.1–99.2) for NS1 component of SD Bioline, respectively. The combination of the latter with its IgM and IgG components were able to increase test sensitivity to 82.4% (95%CI 76.8–87.1) with corresponding decrease in specificity to 87.4% (95%CI 82.8–91.2). Although a positive test on any of the NS1 assays would increase the probability of dengue to above 90% in a patient, a negative result would only reduce this probability to 23.0–29.3%. In contrast, this probability of false negative diagnosis would be further reduced to 14.7% (95%CI 11.4–18.6) if SD Bioline NS1/IgM/IgG combo was negative. Conclusions: The performance of ViroTrack Dengue Acute was comparable to SD Dengue NS1 Ag ELISA. Addition of serology components to SD Bioline Dengue Duo significantly improved its sensitivity and reduced its false negative rate such that it missed the fewest dengue patients, making it a better point-of-care diagnostic tool. New RDT like ViroTrack Dengue Acute may be a potential alternative to existing RDT if its combination with serology components is proven better in future studies. - PublicationDiagnostic Accuracy of Two Dengue NS1 Tests: New Biosensors-Based Rapid Diagnostic Test Versus Enzyme-linked Immunosorbent Assay(2020)
;Zhuo Lin Chong ;Shamala Devi Sekaran ;Hui Jen Soe ;Devi Peramalah ;Sanjay Rampal Lekhraj RampalChiu Wan NgDiverse clinical manifestation makes early dengue diagnosis difficult. Detection of dengue non structural antigen-1 (NS1) can confirm dengue diagnosis early. This study aimed to compare the diagnostic accuracy of a new biosensors-based rapid diagnostic test (RDT) and an enzyme-linked immunosorbent assay (ELISA) for the detection of dengue NS1 antigen. 91 archived serum samples previously collected from hospitalised patients with suspected dengue were used. 50 cases and 41 controls were ascertained using reverse transcription-polymerase chain reaction, Pan-E Dengue Early ELISA, Immunoglobulin M ELISA, and haemagglutination inhibition. The samples were tested on ViroTrack Dengue Acute and SD Dengue NS1 Ag ELISA by two independent researchers blinded to the reference standard. Statistical analysis was performed using STATA version 12. The sensitivity and specificity of ViroTrack were 92.0% (95%CI 80.8-97.8) and 95.1% (95%CI 83.5-99.4), as compared to 82.0% (95%CI 68.6-91.4) (p=0.03) and 92.7% (95%CI 80.1-98.5) (p=0.32) for the ELISA, respectively. The positive and negative predictive values were 95.8% (95%CI 85.7-99.5) and 90.7% (95%CI 77.9-97.4) for ViroTrack, versus 93.2% (95%CI 81.3-98.6) (p-0.58) and 80.9% (95%CI 66.7-90.9) (p=0.18) for the ELISA, respectively. The diagnostic accuracy of ViroTrack was comparable to ELISA. It may be a more efficient tool for the diagnosis of acute dengue in low resource settings - PublicationEvaluation of the Diagnostic Accuracy of a New Biosensors-Based Rapid Diagnostic Test for the Point-Of-Care Diagnosis of Previous and Recent Dengue Infections in Malaysia(2021)
;Zhuo Lin Chong ;Hui Jen Soe ;Amni Adilah Ismail ;Tooba Mahboob ;Samudi ChandramathiShamala Devi SekaranDengue is a major threat to public health globally. While point-of-care diagnosis of acute/recent dengue is available to reduce its mortality, a lack of rapid and accurate testing for the detection of previous dengue remains a hurdle in expanding dengue seroepidemiological surveys to inform its prevention, especially vaccination, to reduce dengue morbidity. This study evaluated ViroTrack Dengue Serostate, a biosensors-based semi-quantitative anti-dengue IgG (immunoglobulin G) immuno-magnetic agglutination assay for the diagnosis of previous and recent dengue in a single test. Blood samples were obtained from 484 healthy participants recruited randomly from two communities in Petaling district, Selangor, Malaysia. The reference tests were Panbio Dengue IgG indirect and capture enzyme-linked immunosorbent assays, in-house hemagglutination inhibition assay, and focus reduction neutralization test. Dengue Serostate had a sensitivity and specificity of 91.1% (95%CI 87.8–93.8) and 91.1% (95%CI 83.8–95.8) for the diagnosis of previous dengue, and 90.2% (95%CI 76.9–97.3) and 93.2% (95%CI 90.5–95.4) for the diagnosis of recent dengue, respectively. Its positive predictive value of 97.5% (95%CI 95.3–98.8) would prevent most dengue-naïve individuals from being vaccinated. ViroTrack Dengue Serostate’s good point-of-care diagnostic accuracy can ease the conduct of dengue serosurveys to inform dengue vaccination strategy and facilitate pre-vaccination screening to ensure safety. - PublicationHead and face anthropometric study for respirators in the multi-ethnic Asian population of Malaysia(2022)
;Yin Cheng Lim ;Ameerah Su'ad Abdul Shakor ;Nadia Mohamad ;Muhammad Alfatih Pahrol ;Rohaida Ismail ;Zhuo Lin Chong ;Mohd Hatta Abdul Mutalip ;Mohd Azahadi Omar ;Mahmoud Danaee ;Guo Tung WanRafiza ShaharudinBackground: Existing anthropometric studies for respirator designs are based on the head and facial dimensions of Americans and Chinese nationals, with no studies for multi-ethnic countries like Malaysia. This study aimed to create head and facial morphological database for Malaysia, specifically to identify morphological differences between genders, ethnicities, and birthplaces, as well as predictors of the dimensions. Design: A cross-sectional study. Setting: Malaysia. Participants: A nation-wide cross-sectional study using a complex survey design with two stage-stratified random sampling was conducted among 3,324 participants, aged 18 years and above who were also participants of the National Health and Morbidity Survey 2020. Primary and secondary outcomes. The study collected data on sociodemographic, measurement of Body Mass Index (BMI) and 10 head and facial dimensions (3 dimensions were measured using direct measurement, and 7 others using Digimizer software for 2-dimension images). Linear regression was performed to determine the association between gender, ethnicity, birthplace, age and BMI and the dimensions. Results: There were significant differences in all the dimensions between sex, birthplace and ethnicity (p 0.005). Further analysis using linear regression showed sex, ethnicity, birthplace, age and BMI were significant predictors of the dimensions. In comparison to studies from the United States and China, our study population had a wider interpupillary distance and nose breadth for both male and female participants, but smaller bigonial breadth and smaller minimal frontal breadth. Conclusion: These findings could assist in the design and sizing of respirators that will fit Malaysians and possibly other Southeast Asian population. - PublicationPreparing for and conducting the National Health and Morbidity Survey in Malaysia amid the COVID-19 pandemic: balancing risks and benefits to participants and society(2021)
;Zhuo Lin Chong ;Noor Aliza Lodz ;Mohd Hatta Abdul Mutalip ;Yin Cheng Lim ;Maznieda MahjomNoor Ani AhmadProblem: The novel coronavirus disease 2019 (COVID-19) pandemic adversely affected the preparation of Malaysia’s National Health and Morbidity Survey for 2020 because conducting it would expose data collectors and participants to an increased risk of infection. Context: The survey is nationally representative and community based and is conducted by the Institute for Public Health, part of the National Institutes of Health, to generate health-related evidence and to support the Malaysian Ministry of Health in policymaking. Its planned scope for 2020 was the seroprevalence of communicable diseases such as hepatitis B and C. Action: Additional components were added to the survey to increase its usefulness, including COVID-19 seroprevalence and facial anthropometric studies to ensure respirator fit. The survey’s scale was reduced, and data collection was changed from including only face-to-face interviews to mainly self-administered and telephone interviews. The transmission risk to participants was reduced by screening data collectors before the survey and fortnightly thereafter, using standard droplet and contact precautions, ensuring proper training and monitoring of data collectors, and implementing other administrative infection prevention measures. Outcome: Data were collected from 7 August to 11 October 2020, with 5957 participants recruited. Only 4 out of 12 components of the survey were conducted via face-to-face interview. No COVID-19 cases were reported among data collectors and participants. All participants were given their hepatitis and COVID-19 laboratory test results; 73 participants with hepatitis B and 14 with hepatitis C who had been previously undiagnosed were referred for further case management. Discussion: Preparing and conducting the National Health and Morbidity Survey during the COVID-19 pandemic required careful consideration of the risks and benefits, multiple infection prevention measures, strong leadership and strong stakeholder support to ensure there were no adverse events. - PublicationPrevalence and associated factors of moderate to severe erectile dysfunction among adult men in Malaysia(2023)
;Muhammad Solihin Rezali ;Mohamad Fuad Mohamad Anuar ;Mohamad Aznuddin Abd Razak ;Zhuo Lin Chong ;Azli Baharudin Shaharudin ;Mohd Shaiful Azlan Kassim ;Mohamed Ashraf Mohamed Daud ;Shaiful Bahari IsmailZakiah Mohd SaidErectile dysfunction (ED) is a pervasive problem among men, often shrouded in silence and stigma. This manuscript analysed the National Health and Morbidity Survey 2019 data to identify the prevalence of moderate to severe ED among men aged 18 and above in Malaysia and describe its associated factors. Self-administered questionnaire on ED utilised a locally validated International Index of Erectile Function. Variables on sociodemographics, risky lifestyles and comorbidities were obtained via an interviewer-administered questionnaire. The prevalence was determined using complex sampling analysis, and logistic regression was used to determine the associated factors of ED. A sample of 2403 men aged ≥ 18 participated, with a moderate to severe ED prevalence was 31.6% (95% CI 28.8, 34.6). The mean (± SD) of the total score of IIEF-5 for overall respondents was 18.16 (± 4.13). Multiple logistic regression analysis revealed a significant association between moderate to severe ED among men aged 60 years and above, single or divorcee, men without formal, primary, and secondary education, non-government employees, unemployed, and retiree, as well as physically inactive men. Focused public health interventions are necessary to improve education in sexual health, increase health promotion programs, and promote healthy ageing across the population. - PublicationSustaining effective COVID-19 control in Malaysia through large-scale vaccination(2021)
;Pavithra Jayasundara ;Kalaiarasu M. Peariasamy ;Kian Boon Law ;Ku Nurhasni Ku Abd Rahim ;Sit Wai Lee ;Izzuna Mudla M. Ghazali ;Milinda Abayawardana ;Linh-Vi Le ;Rukun K.S. Khalaf ;Karina Razali ;Xuan Le ;Zhuo Lin Chong ;Emma S. McBryde ;Michael T. Meehan ;Jamie M. Caldwell ;Romain RagonnetJames M. TrauerIntroduction: As of 3rd June 2021, Malaysia is experiencing a resurgence of COVID-19 cases. In response, the federal government has implemented various non-pharmaceutical interventions (NPIs) under a series of Movement Control Orders and, more recently, a vaccination campaign to regain epidemic control. In this study, we assessed the potential for the vaccination campaign to control the epidemic in Malaysia and four high-burden regions of interest, under various public health response scenarios. Methods: A modified susceptible-exposed-infectious-recovered compartmental model was developed that included two sequential incubation and infectious periods, with stratification by clinical state. The model was further stratified by age and incorporated population mobility to capture NPIs and micro-distancing (behaviour changes not captured through population mobility). Emerging variants of concern (VoC) were included as an additional strain competing with the existing wild-type strain. Several scenarios that included different vaccination strategies (i.e. vaccines that reduce disease severity and/or prevent infection, vaccination coverage) and mobility restrictions were implemented. Results: The national model and the regional models all fit well to notification data but underestimated ICU occupancy and deaths in recent weeks, which may be attributable to increased severity of VoC or saturation of case detection. However, the true case detection proportion showed wide credible intervals, highlighting incomplete understanding of the true epidemic size. The scenario projections suggested that under current vaccination rates complete relaxation of all NPIs would trigger a major epidemic. The results emphasise the importance of micro-distancing, maintaining mobility restrictions during vaccination roll-out and accelerating the pace of vaccination for future control. Malaysia is particularly susceptible to a major COVID-19 resurgence resulting from its limited population immunity due to the country’s historical success in maintaining control throughout much of 2020.