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ABSTRACT: From 1989-2011 in Kuala Lumpur, Malaysia, multiple genotypes from both respiratory syncytial virus (RSV) subgroups were found co-circulating each year. RSV-A subgroup predominated in 12 out of 17 years with the remaining years predominated by RSV-B subgroup. Local RSV strains exhibited temporal clustering with RSV strains reported in previous epidemiological studies. Every few years, the existing predominant genotype was replaced by a new genotype. The RSV-A genotypes GA2, GA5 and GA7 were replaced by NA1 and NA2, while BA became the predominant RSV-B genotype. A unique local cluster, BA12, was seen in 2009, and the recently-described ON1 genotype with 72-nt duplication emerged in 2011. Our findings will have important implications for future vaccine intervention.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 01/2013; · 3.22 Impact Factor
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ABSTRACT: The prevalence of ceftriaxone resistance and the associated genes encoding extended-spectrum β-lactamase (ESBL) was determined in 149 non-duplicate non-typhoidal Salmonella isolated in 2008-2009 from patients in a tertiary care hospital in Kuala Lumpur, Malaysia. The resistance rate to ceftriaxone was 2.7% (2/74) in 2008, 4.0% (3/75) in 2009, and 3.4% (5/149) overall. CTX-M ESBL genes were detected in 2 of the 5 ceftriaxone-resistant isolates. The prevalence of ceftriaxone resistance, although low, is a concern because it limits therapeutic options. Continued surveillance of ceftriaxone resistance is important to monitor its trends.
Japanese journal of infectious diseases. 09/2012; 65(5):433-5.
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ABSTRACT: Viral respiratory tract infections (RTI) are relatively understudied in Southeast Asian tropical countries. In temperate countries, seasonal activity of respiratory viruses has been reported, particularly in association with temperature, while inconsistent correlation of respiratory viral activity with humidity and rain is found in tropical countries. A retrospective study was performed from 1982-2008 to investigate the viral etiology of children (≤ 5 years old) admitted with RTI in a tertiary hospital in Kuala Lumpur, Malaysia.
A total of 10269 respiratory samples from all children ≤ 5 years old received at the hospital's diagnostic virology laboratory between 1982-2008 were included in the study. Immunofluorescence staining (for respiratory syncytial virus (RSV), influenza A and B, parainfluenza types 1-3, and adenovirus) and virus isolation were performed. The yearly hospitalization rates and annual patterns of laboratory-confirmed viral RTIs were determined. Univariate ANOVA was used to analyse the demographic parameters of cases. Multiple regression and Spearman's rank correlation were used to analyse the correlation between RSV cases and meteorological parameters.
A total of 2708 cases were laboratory-confirmed using immunofluorescence assays and viral cultures, with the most commonly detected being RSV (1913, 70.6%), parainfluenza viruses (357, 13.2%), influenza viruses (297, 11.0%), and adenovirus (141, 5.2%). Children infected with RSV were significantly younger, and children infected with influenza viruses were significantly older. The four main viruses caused disease throughout the year, with a seasonal peak observed for RSV in September-December. Monthly RSV cases were directly correlated with rain days, and inversely correlated with relative humidity and temperature.
Viral RTIs, particularly due to RSV, are commonly detected in respiratory samples from hospitalized children in Kuala Lumpur, Malaysia. As in temperate countries, RSV infection in tropical Malaysia also caused seasonal yearly epidemics, and this has implications for prophylaxis and vaccination programmes.
BMC Pediatrics 03/2012; 12:32. · 1.88 Impact Factor
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The Journal of infection 03/2012; 64(6):633-6. · 4.13 Impact Factor
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Expert Review of Anticancer Therapy 01/2012; 10(1):5-7. · 3.28 Impact Factor
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I-Ching Sam,
Shih-Keng Loong,
Jasmine Chandramathi Michael,
Chong-Long Chua,
Wan Yusoff,
Wan Sulaiman,
Indra Vythilingam,
Shie-Yien Chan,
Chun-Wei Chiam,
Yze-Shiuan Yeong,
Sazaly Abubakar,
Yoke-Fun Chan
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ABSTRACT: Background: Mosquito-borne Chikungunya virus (CHIKV) has recently re-emerged globally. The epidemic East/Central/ South African (ECSA) strains have spread for the first time to Asia, which previously only had endemic Asian strains. In Malaysia, the ECSA strain caused an extensive nationwide outbreak in 2008, while the Asian strains only caused limited outbreaks prior to this. To gain insight into these observed epidemiological differences, we compared genotypic and phenotypic characteristics of CHIKV of Asian and ECSA genotypes isolated in Malaysia.
PLoS ONE 01/2012; · 4.09 Impact Factor
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I-Ching Sam,
Shih-Keng Loong,
Jasmine Chandramathi Michael,
Chong-Long Chua,
Wan Yusoff Wan Sulaiman,
Indra Vythilingam,
Shie-Yien Chan,
Chun-Wei Chiam,
Yze-Shiuan Yeong,
Sazaly Abubakar,
Yoke-Fun Chan
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ABSTRACT: Mosquito-borne Chikungunya virus (CHIKV) has recently re-emerged globally. The epidemic East/Central/South African (ECSA) strains have spread for the first time to Asia, which previously only had endemic Asian strains. In Malaysia, the ECSA strain caused an extensive nationwide outbreak in 2008, while the Asian strains only caused limited outbreaks prior to this. To gain insight into these observed epidemiological differences, we compared genotypic and phenotypic characteristics of CHIKV of Asian and ECSA genotypes isolated in Malaysia.
CHIKV of Asian and ECSA genotypes were isolated from patients during outbreaks in Bagan Panchor in 2006, and Johor in 2008. Sequencing of the CHIKV strains revealed 96.8% amino acid similarity, including an unusual 7 residue deletion in the nsP3 protein of the Asian strain. CHIKV replication in cells and Aedes mosquitoes was measured by virus titration. There were no differences in mammalian cell lines. The ECSA strain reached significantly higher titres in Ae. albopictus cells (C6/36). Both CHIKV strains infected Ae. albopictus mosquitoes at a higher rate than Ae. aegypti, but when compared to each other, the ECSA strain had much higher midgut infection and replication, and salivary gland dissemination, while the Asian strain infected Ae. aegypti at higher rates.
The greater ability of the ECSA strain to replicate in Ae. albopictus may explain why it spread far more quickly and extensively in humans in Malaysia than the Asian strain ever did, particularly in rural areas where Ae. albopictus predominates. Intergenotypic genetic differences were found at E1, E2, and nsP3 sites previously reported to be determinants of host adaptability in alphaviruses. Transmission of CHIKV in humans is influenced by virus strain and vector species, which has implications for regions with more than one circulating CHIKV genotype and Aedes species.
PLoS ONE 01/2012; 7(11):e50476. · 4.09 Impact Factor
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Expert Review of Anticancer Therapy 12/2011; 9(12):1089-91. · 3.28 Impact Factor
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ABSTRACT: Routine use of selective media improves diagnosis of Burkholderia pseudomallei, but resources may be limited in endemic developing countries. To maximise yield in the relatively low-prevalence setting of Kuala Lumpur, Malaysia, B. pseudomallei selective agar and broth were compared with routine media for 154 respiratory specimens from patients with community-acquired disease. Selective media detected three additional culture-positive specimens and one additional melioidosis patient, at a consumables cost of US$75. Burkholderia pseudomallei was not isolated from 74 diabetic foot ulcer samples. Following careful local evaluation, focused use of selective media may be cost-effective.
Transactions of the Royal Society of Tropical Medicine and Hygiene 11/2011; 106(2):131-3. · 2.16 Impact Factor
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ABSTRACT: Assessment of general public's knowledge and attitudes toward the development and prevention of new disease outbreaks is imperative because they have profound effects on health behaviors and may contribute to the control of the epidemic.
To investigate the level of knowledge and attitudes towards the influenza A(H1N1) outbreak across various ethnic groups and socio-demographic backgrounds in Malaysia.
A cross-sectional, population-based, computer-assisted telephone interview exploring knowledge and attitudes regarding influenza A(H1N1) was conducted in Malaysia. Between July 11 and September 12, 2009, a total of 1,050 respondents were interviewed (response rate 69.3%).
The mean total knowledge score for the overall sample was 7.30 (SD ± 1.961) out of a possible score of 13 (Chinese had the highest scores, followed by Indians, then Malays). Some erroneous beliefs about the modes of transmission were identified. The majority of the participants (73.8%) perceived the A(H1N1) infection as often deadly. Despite the overestimation of the severity of A(H1N1) infection, high confidence in preventing infection and low perceived susceptibility of infection were reported. Influenza A(H1N1)-related stigma was prevalent and exhibited differences across ethnic groups.
Findings suggest that provision of education and clear information are essential to correct the misconceptions, and increase perceived susceptibility to infection so that the general public will take precautions against A(H1N1) infection.
International Journal of Behavioral Medicine 06/2011; 18(2):112-21. · 2.63 Impact Factor
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ABSTRACT: In the setting of the new A(H1N1) outbreak, the study was conducted to assess: (1) fear of the A(H1N1) pandemic; (2) risk avoidance behavior; (3) health-protective behavior; and (4) psychosocial impact in the ethnically diverse population of Malaysia. A cross-sectional, computer-assisted telephone interview was conducted between July 11 and September 12, 2009. A total of 1,050 respondents were interviewed. Fear about the pandemic was high, with 73.2% of respondents reporting themselves as Slightly fearful/Fearful. High risk avoidance and health protective behavior were reported, with 78.0 and 99.0% reporting at least one avoidance and protective behavior respectively. Knowledge was a significant predictor for practice of healthprotective behavior across the three ethnic groups. Level of fear was significantly correlated with number of protective and avoidance behaviors. The study highlights the need for provision of accurate information that increases risk avoidance and health protective behaviors, while at the same time decreases fear or panic in the general public.
Journal of Behavioral Medicine 02/2011; 34(1):23-31. · 3.10 Impact Factor
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ABSTRACT: In 2006, an outbreak of Chikungunya virus (CHIKV) of the Asian genotype affected over 200 people in Bagan Panchor village in Malaysia. One year later, a post-outbreak survey was performed to determine attack rate, asymptomatic rate, and post-infection sequelae. Findings were compared with recent CHIKV outbreaks of the Central/East African genotype. A total of 180 residents were interviewed for acute symptoms and post-infection physical quality of life and depressive symptoms. Sera from 72 residents were tested for CHIKV neutralizing antibodies. The estimated attack rate was 55.6%, and 17.5% of infected residents were asymptomatic. Arthralgia was reported up to 3 months after infection, but there were no reports of long-term functional dependence or depression. Symptomatic and seropositive residents were significantly more likely to live in the area with the most dense housing and commercial activities. CHIKV had a high attack rate and considerable clinical impact during the Bagan Panchor outbreak.
The American journal of tropical medicine and hygiene 12/2010; 83(6):1245-8. · 2.59 Impact Factor
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ABSTRACT: Providing health information during disease outbreaks is a fundamental component of outbreak control strategies. This study aimed to explore sources of influenza A(H1N1)-related information, specific information needs and preferences of the lay public during the peak of the outbreak. A cross-sectional, population-based, computer-assisted telephone interview of 1,050 respondents was conducted in Malaysia between July 11 and September 12, 2009. Newspaper, television and family were three main sources of information about A(H1N1). There were substantial ethnic differences; the Malays were significantly more likely to identify television as main source, while newspapers and family were identified as the main sources by the Chinese and Indians, respectively. Overall, the two main information needs identified were prevention and treatment. The Malays expressed lesser need for overall information than other ethnic groups. The three most preferred sources of information were television, newspapers and healthcare providers. There were significant positive correlations between amount of information received with knowledge (r = 0.149), perceived susceptibility to infection (r = 0.177), and other behavioral responses. Health information dissemination should be dedicated to meeting the information needs of diverse sociodemographic and ethnic groups. The findings highlight the importance of providing information that increases awareness and behavioral changes in disease prevention yet reduce fear.
Journal of Community Health 12/2010; 35(6):676-82. · 1.28 Impact Factor
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The Journal of infection 11/2010; 61(5):440-2. · 4.13 Impact Factor
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ABSTRACT: This paper aimed to examine the temporal changes in psychobehavioral responses in relation to reported 2009 H1N1 influenza deaths.
Telephone interviews with 1050 members of the lay public in the Kuala Lumpur metropolitan area, Malaysia, were conducted between July 11 and September 12, 2009.
The study demonstrated that public psychobehavioral responses closely mirrored the daily number of reported deaths due to 2009 H1N1 influenza. During the weeks of escalating reported deaths, sharp rises of various domains of fear, health avoidance and protective behaviors, and impact were observed. In particular, health avoidance and protective behaviors decreases were consistent with the decline of reported deaths, indicating the paramount importance of efforts to sustain behavioral change in the general public.
These temporal trends provide important guidance toward health promotion and prevention initiatives in future outbreaks.
Preventive Medicine 07/2010; 51(1):92-3. · 3.22 Impact Factor
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ABSTRACT: The study aimed to determine factors influencing the uptake of 2009 H1N1 influenza vaccine in a multiethnic Asian population. Population-based, cross-sectional survey was conducted between October and December 2009. Approximately 70% of overall participants indicated willingness to be vaccinated against the 2009 H1N1 influenza. Participants who indicated positive intention to vaccinate against 2009 H1N1 influenza were more likely to have favorable attitudes toward the 2009 H1N1 vaccine. A halal (acceptable to Muslims) vaccine was the main factor that determined Malay participants' decision to accept vaccination, whereas safety of the vaccine was the main factor that influenced vaccination decision for Chinese and Indian participants. The study highlights the challenges in promoting the 2009 H1N1 vaccine. Ethnic-sensitive efforts are needed to maximize acceptance of H1N1 vaccines in countries with diverse ethnic communities and religious practices.
Vaccine 05/2010; 28(28):4499-505. · 3.77 Impact Factor
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Diagnostic microbiology and infectious disease 03/2010; 67(3):308-9. · 2.45 Impact Factor
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ABSTRACT: The clinical impact of seasonal influenza is understudied in tropical countries. The aim of this study was to describe the clinical features and seasonal pattern of influenza in children hospitalized in Malaysia, and to identify predictors of severe disease.
Children hospitalized with community-acquired, laboratory-confirmed influenza at a teaching hospital in Kuala Lumpur, Malaysia during 2002-2007 were identified retrospectively. Clinical data were collected, and predictors of severe disease were identified by multivariate logistic regression. All influenza cases from 1982 to 2007 were also analyzed for seasonal patterns.
A total of 132 children were included in the study, 48 (36.4%) of whom had underlying medical conditions. The mean age was 2.5 years and 116 (87.9%) were <5 years old. The most common presenting features were fever or history of fever, cough, rhinitis, vomiting, and pharyngitis. Severe influenza was seen in 16 patients (12.1%; nine previously healthy), including 12 (9.1%; eight previously healthy) requiring intensive care. There were three (2.3%) deaths. Severe disease was associated with age <12 months, female sex, and absence of rhinitis on admission. Influenza was seen year-round, with peaks in November-January and May-July.
Seasonal influenza has a considerable impact on children hospitalized in Malaysia, in both the healthy and those with underlying medical conditions.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 02/2010; 14 Suppl 3:e36-40. · 2.17 Impact Factor
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ABSTRACT: Cervical HPV is the most common sexually transmitted disease among college-age women. This study aimed to assess knowledge and attitudes towards HPV infection, HPV vaccination and cervical cancer among female university students, to provide insight into development of HPV educational information.
A cross-sectional survey using a convenience sample. A total of 1083 ethnically diverse female students attending a public university were approached and 650 were interviewed.
Knowledge regarding HPV, HPV vaccination, cervical screening and cervical cancer risk factors was remarkably poor. Across the sample, the mean total knowledge score (14-item) was only 3.25 (S.D. +/-2.41; 95% CI 3.07-3.44). Only 10.3% had heard of the newly released HPV vaccine. Approximately 48% of participants indicated an intention to receive an HPV vaccine. Intention to receive an HPV vaccine was significantly associated with knowledge of HPV and genital warts (OR 1.53; 95% CI 1.25-1.88), and knowledge of cervical screening and cervical cancer risk factors (OR 1.21; 95% CI 1.11-1.33). Of those who refused HPV vaccination, 50.9% doubted the safety and efficacy of the new vaccine, and 41.5% perceived themselves as not at risk of HPV infection.
The findings suggest that providing education about the etiology of cervical cancer and the HPV link is an essential component to enhance HPV vaccine uptake.
European journal of obstetrics, gynecology, and reproductive biology 11/2009; 148(1):90-5. · 1.97 Impact Factor
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ABSTRACT: Chikungunya virus (CHIKV) of the Central/East African genotype has caused large outbreaks worldwide in recent years. In Malaysia, limited CHIKV outbreaks of the endemic Asian and imported Central/East African genotypes were reported in 1998 and 2006. Since April 2008, an unprecedented nationwide outbreak has affected Malaysia.
To study the molecular epidemiology of the current Malaysian CHIKV outbreak, and to evaluate cross-neutralisation activity of serum from infected patients against isolates of Asian and Central/East African genotypes.
Serum samples were collected from 83 patients presenting in 2008, and tested with PCR for the E1 gene, virus isolation, and for IgM. Phylogenetic analysis was performed on partial E1 gene sequences of 837bp length. Convalescent serum from the current outbreak and Bagan Panchor outbreak (Asian genotype, 2006) were tested for cross-neutralising activity against representative strains from each outbreak.
CHIKV was confirmed in 34 patients (41.0%). The current outbreak strain has the A226V mutation in the E1 structural protein, and grouped with Central/East African isolates from recent global outbreaks. Serum cross-neutralisation activity against both Central/East African and Asian genotypes was observed at titres from 40 to 1280.
The CHIKV strain causing the largest Malaysian outbreak is of the Central/East African genotype. The presence of the A226V mutation, which enhances transmissibility of CHIKV by Aedes albopictus, may explain the extensive spread especially in rural areas. Serum cross-neutralisation of different genotypes may aid potential vaccines and limit the effect of future outbreaks.
Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 09/2009; 46(2):180-3. · 3.12 Impact Factor