Habitat characterization and mapping of Anopheles maculatus (Theobald) mosquito larvae in malaria endemic areas in Kuala Lipis, Pahang, Malaysia

In Peninsular Malaysia, a large proportion of malaria cases occur in the central mountainous and forested parts of the country. As part of a study to assess remote sensing data as a tool for vector mapping, we conducted entomological surveys to determine the type of mosquitoes, their characteristics and the abundance of habitats of the vector Anopheles maculatus in malaria endemic areas in Pos Senderot. An. maculatus mosquitoes were collected from 49 breeding sites in Pos Senderot. An. maculatus preferred to breed in water pockets formed on the bank of rivers and waterfalls. The most common larval habitats were shallow pools 5.0-15.0 cm deep with clear water, mud substrate and plants or floatage. The mosquito also preferred open or partially shaded habitats. Breeding habitats were generally located at 100-400 m from the nearest human settlement. Changes in breeding characteristics were also observed. Instead of breeding in slow flowing streams, most larvae bred in small water pockets along the river margin.     

Relation of aortic valve calcium detected by cardiac computed tomography to all-cause mortality

Aortic valve calcium (AVC) can be quantified on the same computed tomographic scan as coronary artery calcium (CAC). Although CAC is an established predictor of cardiovascular events, limited evidence is available for an independent predictive value for AVC. We studied a cohort of 8,401 asymptomatic subjects (mean age 53 ± 10 years, 69% men), who were free of known coronary heart disease and were undergoing electron beam computed tomography for assessment of subclinical atherosclerosis. The patients were followed for a median of 5 years (range 1 to 7) for the occurrence of mortality from any cause. Multivariate Cox regression models were developed to predict all-cause mortality according to the presence of AVC. A total of 517 patients (6%) had AVC on electron beam computed tomography. During follow-up, 124 patients died (1.5%), for an overall survival rate of 96.1% and 98.7% for those with and without AVC, respectively (hazard ratio 3.39, 95% confidence interval 2.09 to 5.49). After adjustment for age, gender, hypertension, dyslipidemia, diabetes mellitus, smoking, and a family history of premature coronary heart disease, AVC remained a significant predictor of mortality (hazard ratio 1.82, 95% confidence interval 1.11 to 2.98). Likelihood ratio chi-square statistics demonstrated that the addition of AVC contributed significantly to the prediction of mortality in a model adjusted for traditional risk factors (chi-square = 5.03, p = 0.03) as well as traditional risk factors plus the presence of CAC (chi-square = 3.58, p = 0.05). In conclusion, AVC was associated with increased all-cause mortality, independent of the traditional risk factors and the presence of CAC.     

In vitro interactions between piperaquine, dihydroartemisinin, and other conventional and novel antimalarial drugs

In an in vitro assessment of antimalarial combinations, dihydroartemisinin (DHA) showed no interaction or was mildly antagonistic when combined with piperaquine, pyronaridine, or naphthoquine. Interactions between 4-aminoquinolines and related drugs were also indifferent/antagonistic. The clinical significance of mildly antagonistic DHA combinations is uncertain but may become important if parasite drug sensitivity declines.     

Risk modification of colorectal cancer susceptibility by interleukin-8 -251T>A polymorphism in Malaysians

AIM: To investigate the allele and genotype frequencies and associated risk of interleukin (IL)-8 -251T>A polymorphism on colorectal cancer (CRC) susceptibility risk.METHODS: Peripheral blood samples of 255 normal controls and 255 clinically and histopathologically confirmed CRC patients were genotyped for IL-8 -251T>A polymorphism employing allele-specific polymerase chain reaction. The relative association of variant allele and genotypes with CRC susceptibility risk was determined by calculating the odds ratios (ORs). Corresponding χ² tests on the CRC patients and controls were carried out and 95% confidence intervals (CIs) were determined using Fisher’s exact test. The allele frequencies and its risk association were calculated using FAMHAP, haplotype association analysis software.RESULTS: On comparing the frequencies of genotypes of patients and controls, the homozygous variant AA was significantly higher in CRC patients (P = 0.002) compared to controls. Investigation on the association of the polymorphic genotypes with CRC susceptibility risk, showed that the homozygous variant IL-8 -251AA had a significantly increased risk with OR 3.600 (95% CI: 1.550-8.481, P = 0.001). In the case of allele frequencies, variant allele A of IL-8 -251 showed a significantly increased risk of CRC predisposition with OR 1.32 (95% CI: 1.03-1.69, P = 0.003).CONCLUSION: Variant allele and genotype of IL-8 (-251T>A) was significantly associated with CRC susceptibility risk and could be considered as a high-risk variant for CRC predisposition.     

Latent tuberculosis infection among medical students in Malaysia

Objective: This study aimed to determine prevalence of latent tuberculosis infection among medical students and tuberculosis exposure at the health facilities. Methods: A cross-section of study year 1(n=68) and year 5(n=75) medical students in a local university were recruited for latent tuberculosis infection testing using QuantiFERON-TB Gold Plus and a questionnaire analyzed for multivariate risk. Results: The majority of the study were vaccinated with BCG. None of year 1 medical students were positive for latent tuberculosis infection, however, six(8.0%) year 5 students were tested positive for latent tuberculosis infection. A higher incidence of year 5 medical students claimed to be exposed to tuberculosis at health facility(65.3% vs. 4.4%) and a higher percentage reported contact with tuberculosis case over the preceding year compared to year 1 students(30.7% vs. 8.8%). Conclusion: We observed a higher incidence of latent tuberculosis infection and higher exposure to tuberculosis in health facilities among year 5 medical students. Baseline screening and monitoring for progression to tuberculosis infection may benefit tuberculosis management programs.     

Demodicosis among university medical students in Malaysia and the effects of facial cleanser and moisturizer usage

Demodicosis is an infestation of the skin with Demodex, an ectoparasite commonly found on the face. A cross-sectional study was conducted to detect the presence of the ectoparasite and the outcome of facial cleanser and moisturizer usage on its infestation. Universal sampling was performed among 390 medical students, age 20-25 years old in the Klang Valley of Malaysia. The biodata of the participants and information on the use of facial cleanser and moisturizer were obtained through questionnaire. Skin samples were obtained using both skin scraping and cellophane tape method and were subsequently examined directly by microscopy. The results show an overall prevalence of 17.2%. Males (21.5%) were affected more often than females (12.8%) (p = 0.022). There were no significant differences in the prevalence of the ectoparasite among different ethnic groups, age-groups and the presence of existing facial problems among the subjects. A lower infestation rate (11.45%) was found to be associated with the use of a moisturizer (p = 0.033). Both species of ectoparasites that infest man, Demodexfolliculorum and D. brevis, were detected in this study either as single or mixed infestations.     

Effects of physical activity on cardiovascular disease

Much attention has been directed toward lifestyle modifications as effective means of reducing cardiovascular disease risk. In particular, physical activity has been heavily studied because of its well-known effects on metabolic syndrome, insulin sensitivity, cardiovascular disease risk, and all-cause mortality. However, data regarding the effects of exercise on various stages of the atherosclerosis pathway remain conflicting. The investigators review previously published reports for recent observational and interventional trials investigating the effects of physical activity on markers of (or causal factors for) atherosclerotic burden and vascular disease, including serum lipoproteins, systemic inflammation, thrombosis, coronary artery calcium, and carotid intima-media thickness. In conclusion, the data show a correlation between physical activity and triglyceride reduction, apolipoprotein B reduction, high-density lipoprotein increase, change in low-density lipoprotein particle size, increase in tissue plasminogen activator activity, and decrease in coronary artery calcium. Further research is needed to elucidate the effect of physical activity on inflammatory markers and intima-media thickness.     

Cross-sectional assessment of prevalence and correlates of blood-borne and sexually-transmitted infections among Afghan National Army recruits

ABSTRACT: BACKGROUND: Few data are available in Afghanistan to shape national military force health practices, particularly with regard to sexually-transmitted infections (STIs). We measured prevalence and correlates of HIV, syphilis, herpes simplex 2 virus (HSV-2), and hepatitis C virus (HCV) among Afghan National Army (ANA) recruits. METHODS: A cross-sectional sample of male ANA recruits aged 18--35 years were randomly selected at the Kabul Military Training Center between February 2010 and January 2011. Participants completed an interviewer-administered questionnaire and serum-based rapid testing for syphilis, hepatitis C virus antibody on-site; HIV and HSV-2 screening, and confirmatory testing were performed off-site. Prevalence of each infection was calculated and logistic regression analysis performed to identify correlates. RESULTS: Of 5313 recruits approached, 4750 consented to participation. Participants had a mean age of 21.8 years (SD[PLUS-MINUS SIGN]3.8), 65.5% had lived outside Afghanistan, and 44.3% had no formal education. Few reported prior marijuana (16.3%), alcohol (5.3%), or opium (3.4%) use. Of sexually active recruits (58.7%, N = 2786), 21.3% reported paying women for sex and 21.3% reported sex with males. Prevalence of HIV (0.063%, 95% CI: 0.013- 0.19), syphilis (0.65%, 95% CI: 0.44 -- 0.93), and HCV (0.82%, 95% CI: 0.58 -- 1.12) were quite low. Prevalence of HSV-2 was 3.03% (95% CI: 2.56 - 3.57), which was independently associated with age (Adjusted Odds Ratio (AOR) = 1.04, 95% CI: 1.00 - 1.09) and having a television (socioeconomic marker) (AOR = 1.46, 95% CI: 1.03 -- 2.05). CONCLUSION: Though prevalence of HIV, HCV, syphilis, and HSV-2 was low, sexual risk behaviors and intoxicant use were present among a substantial minority, indicating need for prevention programming. Formative work is needed to determine a culturally appropriate approach for prevention programming to reduce STI risk among Afghan National Army troops.