Community-acquired pneumonia (CAP) is a major cause of adult mortality in Asia. Appropriate empirical treatment depends on knowledge of the pathogens commonly responsible. However, assessing the aetiological significance of identified organisms is often difficult, particularly with sputum isolates that might represent contamination with oropharyngeal flora.
The prevalence of resistance to rifampicin and fusidic acid among Malaysian strains of methicillin-resistant Staphylococcus aureus (MRSA) is increasing. This study aimed to determine the mechanisms of rifampicin and fusidic acid resistance and the genetic diversity of MRSA strains from a Malaysian tertiary hospital.
Dengue has emerged as one of the major public health problems in Malaysia. The Ministry of Health, Malaysia, is committed in monitoring and controlling this disease for many years. The objective of this study is to analyze the dengue outbreak pattern on a monthly basis in Subang Jaya in terms of their spatial dissemination and hotspot identification.
Dengue fever (DF) is an urban vector-borne disease transmitted by Aedes aegypti and Aedes albopictus. Both species deposit their eggs in favorable breeding sites either in natural or artificial containers. An understanding of their habitat characteristics is crucial in curbing DF outbreaks
Previous studies have shown that apoptosis-like features are observed in Blastocystis spp., an intestinal protozoan parasite, when exposed to the cytotoxic drug metronidazole (MTZ). This study reports that among the four subtypes of Blastocystis spp. investigated for rate of apoptosis when treated with MTZ, subtype 3 showed the highest significant increase after 72h of in vitro culture when treated with MTZ at 0.1mg/ml (79%; p<0.01) and 0.0001mg/ml (89%; p<0.001). The close correlation between viable cells and apoptotic cells for both dosages implies that the pathogenic potential of these isolates has been enhanced when treated with MTZ. This suggests that there is a mechanism in Blastocystis spp. that actually regulates the apoptotic process to produce higher number of viable cells when treated. Apoptosis may not just be programmed cell death but instead a mechanism to increase the number of viable cells to ensure survival during stressed conditions. The findings of the present study have an important contribution to influence chemotherapeutic approaches when developing drugs against the emerging Blastocystis spp. infections.
Cross neutralisation of venoms by antivenom raised against closely-related species has been well documented. The spectrum of paraspecific protection of antivenom raised against Asiatic Naja and Bungarus (krait) venoms, however, has not been fully investigated. In this study, we examined the cross neutralisation of venoms from common Southeast Asian cobras and kraits by two widely used polyvalent antivenoms produced in India: Vins Polyvalent Antivenom (VPAV) and Bharat Polyvalent Antivenom (BPAV), using both in vitro and in vivo mouse protection assays. BPAV was only moderately effective against venoms of N. kaouthia (Thailand) and N. sumatrana, and either very weakly effective or totally ineffective against the other cobra and krait venoms. VPAV, on the other hand, neutralised effectively all the Southeast Asian Naja venoms tested, as well as N. naja, B. candidus and Ophiophagus hannah venoms, but the potency ranges from effective to weakly effective. In an in vivo rodent model, VPAV also neutralised the lethality of venoms from Asiatic Naja and B. candidus. In anesthetised rat studies, both antivenoms effectively protected against the N. kaouthia venom-induced cardio-respiratory depressant and neuromuscular blocking effects. Overall, our results suggest that VPAV could be used as alternative antivenom for the treatment of elapid envenomation in Southeast Asian regions including Malaysia, Thailand and certain regions of Indonesia.
The present review aimed to synthesise available evidence on the efficacy of dihydroartemisinin-piperaquine (DP) in treating uncomplicated Plasmodium falciparum malaria in people living in malaria-endemic countries by performing a meta-analysis of relevant studies. We searched relevant studies in electronic data bases up to December 2011. Published results from randomised controlled trials (RCTs) comparing efficacy of DP with other artemisinin-based combination therapies (ACTs), or non-ACTs, or placebo were selected. The primary endpoint was 28-day and 42-day treatment failure. We identified 26 RCTs. Many of the studies included in the present review were of high quality. Overall, DP, artesunate-mefloquine (MAS3) and artemether-lumefentrine (AL) were equally effective for reducing the risk of recurrent parasitaemia. The PCR confirmed efficacy of DP (99.5%) and MAS3 (97.7%) at day 28 exceeded 90%; both are efficacious. Comparable efficacy was also found for DP (95.6%) and AL (94.3%). The present review has documented that DP is comparable to other currently used ACTs such as MAS3 and AL in treating uncomplicated falciparum malaria. The better safety profile of DP and once-daily dosage improves adherence and its fixed co-formulation ensures that both drugs are taken together. Our conclusion is that DP has the potential to become a first-line antimalarial drug.
Studies have reported that only a small fraction of fever cases in malaria-endemic areas are actually caused by malaria. Much greater emphasis is now needed to step up attention to the appropriate management of nonmalarial acute undifferentiated febrile illness. There is an overlap at the start of clinical manifestations of different febrile illnesses which makes it difficult to adhere to the clinical guidelines. The development of rigorous guidelines based on high quality research and a consensus from the core group of content experts are needed. An innovative financing mechanism for universal access to such appropriate management should also be considered.
Toxoplasma gondii is a public health risk in developing countries, especially those located in the tropics. Widespread infection may inflict a substantial burden on state resources, as patients can develop severe neurological defects and ocular diseases that result in lifelong loss of economic independence. We tested sera for IgG antibody from 493 eye patients in Malaysia. Overall age-adjusted seroprevalence was estimated to be 25% (95% CI: [21%, 29%]). We found approximately equal age-adjusted seroprevalence in Chinese (31%; 95% CI: [25%, 38%]) and Malays (29%; 95% CI: [21%, 36%]), followed by Indians (19%; 95% CI: [13%, 25%]). A logistic regression of the odds for T. gondii seroprevalence against age, gender, ethnicity and the occurrence of six types of ocular diseases showed that only age and ethnicity were significant predictors. The odds for T. gondii seroprevalence were 2.7 (95% CI for OR: [1.9, 4.0]) times higher for a patient twice as old as the other, with ethnicity held constant. In Malays, we estimated the odds for T. gondii seroprevalence to be 2.9 (95% CI for OR: [1.8, 4.5]) times higher compared to non-Malays, with age held constant. Previous studies of T. gondii seroprevalence in Malaysia did not explicitly adjust for age, rendering comparisons difficult. Our study highlights the need to adopt a more rigorous epidemiological approach in monitoring T. gondii seroprevalence in Malaysia.
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.
Chemotherapy can cause immunosuppression, which may trigger latent intestinal parasitic infections in stools to emerge. This study investigated whether intestinal parasites can emerge as opportunistic infections in breast and colorectal cancer patients (n=46 and n=15, respectively) undergoing chemotherapy treatment. Breast cancer patients were receiving a 5-fluorouracil/epirubicin/cyclophosphamide (FEC) regimen (6 chemotherapy cycles), and colorectal cancer patients were receiving either an oxaliplatin/5-fluorouracil/folinic acid (FOLFOX) regimen (12 cycles) or a 5-fluorouracil/folinic acid (Mayo) regimen (6 cycles). Patients had Blastocystis hominis and microsporidia infections that were only present during the intermediate chemotherapy cycles. Thus, cancer patients undergoing chemotherapy should be screened repeatedly for intestinal parasites, namely B. hominis and microsporidia, as they may reduce the efficacy of chemotherapy treatments.
A retrospective study was undertaken to determine the clinical features of cutaneous larva migrans (CLM) seen in the Department of Dermatology, Hospital Kuala Lumpur (Kuala Lumpur, Malaysia) and to assess the rate of correct diagnosis made by the referring primary care doctors. Clinical records of all 31 patients with CLM seen between January 2006 and June 2010 were retrieved. The majority of patients were male. The mean age was 32.2 years. Pruritus was reported in 83.9% of cases and serpiginous tracts in 100%. The mean lesion count was 4.4 and the mean duration of disease before presentation was 3.1 weeks. The majority of skin lesions were on the buttock and lower extremities. Only 45.2% of patients had the correct diagnosis made by the referring primary care doctors. Older age of patients and lower number of lesions were associated with a higher rate of correct diagnosis. The low rate of correct diagnosis made by the referring primary care doctors to the dermatologists in this study warrants the need for education of not only primary care doctors but also future primary care providers, consisting of medical students, house officers and junior medical officers.
Study site: Department of Dermatology, Hospital Kuala Lumpur
The HIV-positive population, due to their immuno-compromised nature, is considered more susceptible to parasitic infections than other populations. However despite the reports of other opportunistic pathogens such as Cryptosporidium and tuberculosis reported in vulnerable communities, microsporidia have not been highlighted in the local HIV-positive population in Malaysia. This study aimed to provide preliminary information on the prevalence of microsporidia in the local HIV-population. Microsporidia were detected in 21/247 (8.5%) stool samples from the HIV-infected individuals, a significantly higher (P-value <0.05) prevalence than in the control group, in which 5/173 (2.9%) were positive. HIV patients were 3x more at risk for acquiring microspordium (OR: 3.12; 95% CI 1.15-8.44). Spores were ellipsoid in shape with outlines that stained dark pink with the interior a lighter shade. Approximately 21% of the positive specimens were from individuals in the 40-49 years age group. Ten individuals who were positive for microsporidia were also positive for other enteric parasites such as Blastocystis hominis and Giardia lamblia. We detected Encephalitozoon intestinalis DNA following nested PCR from three of 10 samples analysed, as demonstrated by an amplicon of 370bp. From the findings reported, it appears that microsporidial infection in humans may actually be more common than reported. We strongly advocate greater emphasis on personal hygiene through public education on personal hygiene and the consumption of boiled or filtered water.
Chloroquine (CQ) is a relatively inexpensive drug for treatment of malaria. If efficacy of CQ is still assumed, then it should be indicated in malaria treatment policies as the drug of choice for uncomplicated Plasmodium vivax malaria in endemic countries with resource constraints. The objective of this review is to summarize the existing evidence on the relative efficacy and safety of CQ in treating patients with uncomplicated P. vivax malaria in endemic countries. We searched online data bases (PUBMED, MEDLINE, EMBASE, The Cochrane Library) and the reference lists of the retrieved articles. Fifteen randomized controlled trials (n=6215) assessing the relative efficacy and safety of CQ for treatment of uncomplicated P. vivax malaria were included. CQ monotherapy was compared to CQ plus primaquine (PQ), artemisinin/artemether, artemisinin based combination therapy, quinine, CQ plus tafenoquine, chlorguanil plus dapsone, azithromycin, or placebo. Treatment efficacy was not significantly different between the CQ monotherapy group and that of the CQ with PQ 14 day group at 28 day follow-up (55/711, 7.7% vs 35/712, 4.9%; P=0.16). Evidence from the trials identified for this review draw a fairly clear conclusion about the relative efficacy and safety of CQ for treating uncomplicated P. vivax malaria infection. However, further research in this field with well powered, randomized, non-inferiority design, using the standardized protocol is needed.
In contrast to many viruses that escape the host's immune responses by suppressing the major histocompatibility complex (MHC) class I pathway, flaviviruses have been shown to up-regulate the cell surface expression of MHC class I complex. The mechanism by which dengue virus (DV) achieves this up-regulation remains unclear. Our investigation on the HLA-A2 gene in human liver cells demonstrated that all four serotypes of dengue virus, DV1 to DV4, resulted in variable degrees of promoter induction. This illustrates the importance of MHC class I transcription regulation in primary infections by different DV serotypes that may have even greater impact in secondary infections, associated with increased disease severity.
Helicobacter pylori is one of the few remaining major pathogens that accompanied humans on their travels from Africa. A recently published study reports the unexpected finding of a low H. pylori prevalence among pregnant women in Zanzibar (Farag, T.H., Stolzfus, R.J., Khalfan, S.S., Tielsch, J.M., 2007. Unexpectedly low prevalence of Helicobacter pylori infection among pregnant women on Pemba Island, Zanzibar. Trans. R. Soc. Trop. Med. Hyg. 101). The apparent epidemiology of higher prevalence with higher socioeconomic status and decrease with age are unprecedented. As with many 'unexpected' events, a search of the literature reveals evidence of low prevalence populations in Java and Malaysia, with clues dating back to the mid-twentieth century. Why some populations apparently lost H. pylori infection remains an open question. However, the tools needed to resolve the dilemma are readily available and we hope investigators will soon rise to the challenge.
Vitamin A deficiency and malnutrition are still considered public health problems in rural areas of developing countries, including Malaysia. A cross-sectional exploration study was carried out on 281 Orang Asli (Aborigine) children aged between 2 and 15 years in Selangor, Malaysia. The overall prevalence of low serum retinol (<70 micromol/l) and hypoalbuminaemia (<35 g/l) were 25.2 and 7.8%, respectively. Univariate analysis showed that severe ascariasis, significant stunting and giardiasis were significantly associated with low concentration of serum retinol. As well as intestinal parasitic infections, low socio-economic status was a significant predictor of hypoalbuminaemia. Logistic regression analysis identified severe ascariasis and significant stunting as predictors of low serum retinol, while mixed intestinal parasitic infection and low household income were predictors of hypoalbuminaemia. In conclusion, control measures for intestinal parasitic infections should be included as one of the strategies for the prevention and control of malnutrition and vitamin A deficiency in this population.
This study evaluates and discusses the impact of the rural health improvement scheme in reducing the incidence of dysentery, enteric fever, cholera and viral hepatitis in Sarawak, Malaysia, using data compiled from state and federal health department reports. This study suggests that from 1963 to 2002, water supply intervention contributed to a more than 200-fold decrease in dysentery and a 60-fold decrease in enteric fever. Variations in reporting of viral hepatitis during that period make it difficult to detect a trend. Cholera was still endemic in 2002. Cholera and dysentery outbreaks, occurring when rural populations relied on contaminated rivers for their water supply, suggested that sanitation intervention was not as effective in reducing waterborne diseases. Recommendations are made for successive one-component interventions focusing on catchment management to ensure protection of current and alternative water supplies.
Four species of malaria parasites are known to infect humans. A fifth species, Plasmodium knowlesi, has been reported to infect humans in Malaysian Borneo. Here we report for the first time the incrimination of Anopheles latens as the vector of P. knowlesi among humans and monkeys in Sarawak, Malaysia.