Biweekly ovitrap surveillance (OS) was conducted for a year (August 2007 - September 2008) at two different dengue endemic sites in Shah Alam, Selangor, Malaysia, 50 km from Kuala Lumpur. Aedes aegypti collected from these 2 locations were raised to the F3 stage and subjected to a WHO standard bioassay method to determine lethal time (LT) against pyrethroids (permethrin 0.75%, cyfluthrin 0.15%), organophosphates (malathion 5.0%, fenitrothion 1.0%), carbamates (propoxur 0.1%, bendiocarb 0.1%) and organochlorine (DDT 4.0%). Insecticide susceptibilities were analyzed for one year. Aedes aegypti were resistant to DDT with a mortality range of 0 - 13.3% throughout the year at both sites. Susceptibilities to pyrethroids and carbamates varied throughout the year. In contrast, susceptibilities to pyrethroids and carbamates varied throughout the year: resistant to propoxur, bendiocarb and permethrin with mortality of < 80% in most months; but, showed incipient resistant to cyfluthrin in most months. Mosquitoes were consistently susceptible to malathion and fenitrothion, with complete mortality during most months. They were especially susceptible to malathion with LT50 values of 21.32 - 36.37 minutes, suggesting effectiveness of malathion for control of dengue.
Detection of Toxoplasma gondii infection is essential in pregnant women and immunosuppressed patients. Numerous studies have shown that the recombinant production of several Toxoplasma antigens, including dense granule antigens (GRAs) has high potential as diagnostic reagents. In the present study, we produced GRA2 using Pichia pastoris system. RNA of T. gondii RH strain tachyzoite was used as a template to produce cDNA clones of full-length GRA2 via reverse transcriptase PCR. Amplicons were inserted into pPICZalpha A and the recombinant plasmid transformed into P. pastoris, X-33 strain. The expressed recombinant protein was identified by SDS-PAGE and Western blotting. A recombinant protein of -28 kDa was produced, which could be detected by toxoplasmosis positive human sera indicating that the recombinant protein retained its antigenicity. The present study indicates that P. pastoris-expressed GRA2 should be useful for detection of Toxoplasma infection.
The World Health Organization (WHO) estimates that injury will be the second leading cause of morbidity of disease burden worldwide by the year 2020. We conducted a community-based survey to determine the prevalence of recent illness and injury, in Malaysia. The survey was a cross sectional population-based household survey conducted using face to face interviews. The information was on self-reported recent illness and injury (SRRII) over the previous 2 weeks. This study was conducted during April - August 2006 and as a part of the third National Health and Morbidity Survey of Malaysia. A total of 56,710 respondents were interviewed with a response rate of 98.2% (55,660/56,710). The overall prevalence of combined SRRII was 23.6%; for injuries the prevalence was 3.1%. The groups with the highest SRRII were children 0-5 years old (31.2%), males (24.3%), Indians (26.9%), those with secondary education level (22.9%), those earning RM 1,000/ month (25.0%) and rural dwellers (25.5%). Age, sex, ethnicity, and locality were significantly associated with SRRII while monthly household income and educational level were marginally associated. On multivariate analysis, age, gender, race, ethnicity, education, income and locality were significantly associated with SRRII. The most common reported recent illness was related to the respiratory system (42.0%). The information obtained from this survey is useful to policy makers in the Ministry of Health to review and strengthen existing health programs.
Study name: National Health and Morbidity Survey (NHMS-2006)
The aim of this study was to determine the prevalence of HCV infection and the signal/cutoff (S/CO) value for false reactive, false positive, indeterminate and true positive HCV infection among apparently healthy blood donors in our area. This retrospective study was conducted at the Transfusion Medicine Unit, Hospital Universiti Sains Malaysia from June 2008 to June 2009. Blood samples were screened for anti-HCV using enzyme immunoassay (EIA). Reactive cases were confirmed by recombinant immunoblot assay (RIBA). Sixty-one blood donors were found to be reactive after the first screening test. Twenty-nine blood donors had reactive repeat screening, with only 9 samples being true positives. The S/ CO for false reactive, false positive, indeterminate and true positive anti-HCV samples were 1.02 to 1.45, 1.01 to 2.09, 1.07 to 2.43 and 35.95 to 119.89, respectively. The analysis showed the low incidence of HCV infections among blood donors in our area, however, thorough donor screening and stringent selection criteria are still recommended to eliminate high risk donors to improve our blood transfusion service.
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.
Seven stains were studied to determine the best color and contrast for staining the developmental stages of free living pathogenic Acanthamoeba and Naegleria species. The acid-fast bacilli stain (AFB) produced a blue color without contrast; trichrome-eosin and modified Field's showed various color contrasts; Giemsa, iron-hematoxylin, modified AFB and Gram produced only one color which distinguished the nucleus, nucleolus, cytoplasm, food- and water-vacuoles. The motile organs (acanthopodia, pseudopodia, lobopodia and flagella) were also clearly differentiated but produced a similar color as the cytoplasm. These motile organelles were first induced by incubating at 37 degrees C for at least 15 minutes and then fixing with methanol in order to preserve the protruding morphology prior to staining. The trichrome-eosin and iron-hematoxylin stains showed good color contrast for detecting all three stages, the trophozoite, cyst and flagellate; Giemsa and Gram stained the trophozoite and flagellate stages; the modified Field's and modified AFB stains stained only the trophozoite stage. Depending on the purpose, all these stains (except the AFB stain) can be used to identify the developmental stages of Acanthamoeba and Naegleria for clinical, epidemiological or public health use.
Chloroquine (CQ) remains the first line drug for the prevention and treatment of malaria in Malaysia in spite of the fact that resistance to CQ has been observed in Malaysia since the 1960s. CQ-resistance is associated with various mutations in pfcrt, which encodes a putative transporter located in the digestive vacuolar membrane of P. falciparum. Substitution of lysine (K) to threonine (T) at amino acid 76 (K76T) in pfcrt is the primary genetic marker conferring resistance to CQ. To determine the presence of T76 mutation in pfcrt from selected areas of Kalabakan, Malaysia 619 blood samples were screened for P. falciparum, out of which 31 were positive. Blood samples were collected on 3 MM Whatman filter papers and DNA was extracted using QIAmp DNA mini kit. RFLP-PCR for the detection of the CQ-resistant T76 and sensitive K76 genotype was carried out. Twenty-five samples were shown to have the point mutation in pfcrt whereas the remaining samples were classified as CQ-sensitive (wild-type). In view of the fact that CQ is the first line anti-malarial drug in Malaysia, this finding could be an important indication that treatment with CQ may no longer be effective in the future.
About 1.8 million people die annually from acute diarrheal disease globally. A nationwide cross-sectional survey was conducted via face-to-face interview with eligible subjects to determine the incidence and health seeking behavior of Malaysians with acute diarrheal disease (ADD). An acute diarrheal episode was defined as having three or more loose stools in any 24 hour period during the four weeks period prior to the interview. The exclusion criteria included pre-existing chronic diarrhea, such as with cancer of the bowel, ulcerative colitis or Chrohn's disease. Forty three point three percent of those with ADD (95% CI 41.3-45.4) sought treatment for the illness. Younger age groups (0-4 years, 67.7%; 95% CI 61.5-73.4; 5-9 years, 56.5%; 95% CI 48.6-64.1) were more likely to seek care for ADD. Seventy-one point eight percent of those seeking treatment, (95% CI 69.0-74.4) did so within 12 hours of the onset of symptoms. Most people with ADD sought treatment at private clinics. The main reasons given for not seeking treatment were the illness was mild and did not warrant treatment and the practice of self-medication (22.4%; 95% CI 20.0-24.9). These findings show self-medication is a major health seeking behavior among Malaysians with ADD. Self-medication of ADD deserves more in-depth study to ensure it is safe.
Keywords: NHMS-2006
Study name: National Health and Morbidity Survey (NHMS-2006)
The aim of the present study was to evaluate Malaysian dyslipidemic patient treatment practices and outcomes. Factors contributing to success in reaching treatment goal were determined. A retrospective review of the records of dyslipidemic patients who attended the Universiti Sains Malaysia Hospital in 2007 was conducted. All the patients were receiving standard recommended doses of statins. Records were analysed for 890 patients. Patients were divided into three categories: 384 patients (43.1%) had coronary heart disease or coronary heart disease risk equivalents, 216 patients (24.3%) had moderate risk for coronary heart disease and 290 patients (32.6%) had low risk. Statins were the most commonly prescribed drug group (92%), of which atorvastatin was the most commonly prescribed drug (50.6%). The overall success rate for reaching goal was 64.2%. The percentages of patients achieving low-density lipoprotein cholesterol targets in the coronary heart disease and coronary heart disease risk equivalents, moderate, and low-risk groups were 50.5, 66.7, and 80.3%, respectively (p < 0.001). Multiple logistic regression showed achievement of therapeutic goal declined with increasing risk group. The baseline low-density lipoprotein cholesterol value was inversely related to therapeutic goal attainment. An inadequate proportion of dyslipidemic patients achieved the National Cholesterol Education Program therapeutic goals for low-density lipoprotein cholesterol, especially those in the coronary heart disease and coronary heart disease risk equivalent group. The achievement of this goal was dependent on baseline low-density lipoprotein cholesterol levels.
The aim of this study was to identify the major allergens of wildflower honey in local patients with atopic disease. SDS-PAGE revealed ten protein bands of 25 to 110 kDa, with a heavy cluster in region of 40-75 kDa. Immunoblotting demonstrated seven IgE-binding bands of 39 to 110 kDa. The 60 kDa protein had the highest frequency of IgE-binding (100%) followed by 54 kDa protein (95%), thus identified as the major allergens of wildflowerhoney. Our findings indicate that the allergen extract used for diagnosis of honey allergy contains both the 54 kDa and 60 kDa proteins.
The objective of this study was to determine the seroprevalence of cytomegalovirus (CMV) infections through antenatal screening data and the association of this virus with obstetric complications. Serum samples from 125 apparently healthy pregnant women sent for antenatal screening from various hospitals in Malaysia between January 2007 and December 2008, were examined for CMV specific IgM and IgG antibodies using an enzyme-linked immunosorbent assay method. Of the 125 pregnant women tested, anti-CMV IgG antibody was found in 105 (84%) of the cases and anti-CMV IgM in 9 cases (7.2%). Both CMV IgM and IgG were also found in another 37 women whose serum samples were sent for investigation of various obstetric complications: 17 cases of spontaneous abortions, 15 cases of fetal anomalies detected during ultrasound examination, 1 case of incomplete abortion, 3 cases with premature delivery of infant with congenital anomalies and 1 case of infertility. Our preliminary data which only represented a small study group has shown the prevalence of CMV infection among the local population and the association of CMV in obstetric complications.
Mosquitoes in malaria endemic areas needs to be monitored constantly in order to detect demographic changes that could affect control measures. A 12-month mosquito population survey was conducted in several malaria endemic areas in Pos Lenjang, Kuala Lipis, Pahang, Malaysia. Collection of mosquitoes using a human landing catch technique was carried out indoors and outdoors for 12 hours from 7:00 PM to 7:00 AM for 42 nights. Anopheles maculatus Theobald (31.0%), Armigeres flavus Leicester (11.3%), Armigeres annulitarsis Leicester (11.0%), Culex vishnui Theobald (9.6%) and Aedes albopictus Skuse (7.0%) were the predominant species caught in the study area. The salivary gland and midgut of all anopheline mosquitoes were dissected to determine the presence of malaria parasites but none were positive. A high rate of human biting by An. maculatus was detected during December, but the rate was lower in January. Mosquito larvae were carried by the rapid current of the river downstream causing a decrease in the larvae population. Of the five predominant species, only Ar. annulitarsis exhibited a significant positive correlation in numbers with monthly rainfall (p < 0.05). An. maculatus biting activity peaked during 10:00 PM to 11:00 PM. Ae. albopictus, Ar. annulitarsis, and Ar. flavus exhibited similar activities which peaked during 7:00 PM to 8.00 PM.
Toxoplasmosis is an important parasitic disease in immunosuppressed patients. This prospective study was conducted to determine the seroprevalence, associated risk factors and the incidence of clinically confirmed toxoplasmosis among renal patients at the University of Malaya Medical Center, Kuala Lumpur, Malaysia. We interviewed 247 renal patients, each of whom answered an epidemiological questionnaire, and collected blood samples for measurement of anti-Toxoplasma IgG and IgM antibodies by ELISA. Overall seroprevalence of latent toxoplasmosis was observed in 126 (51%) renal patients. Race (Malays), marital status (married) and primary level of education, were all factors associated with a greater chance of Toxoplasma infection. A case of clinically confirned toxoplasmosis was diagnosed in a renal transplant recipient as a result of immunosuppression. Based on the findings obtained, this preliminary study shows a high prevalence of latent toxoplasmosis in renal patients. Risk factors may have significantly contributed to Toxoplasma acquisition in these patients. We recommend further studies be carried out to monitor for trends in toxoplasmosis among immunosuppressed patients.
The objectives of this study were to describe the knowledge of sexual and reproductive health among adolescents attending school and to compare the levels of knowledge between males and females and between older and younger groups of adolescents. A cross-sectional study was conducted among 1,034 secondary school students using a self administered validated questionnaire. The items with the fewest correct responses included: whether one can get pregnant after a single act of sexual intercourse (30.4%), whether sexual intercourse causes sexually transmitted diseases (STDs) (12.4%) and whether washing the vagina after sexual intercourse prevents pregnancy (17.0%). Their main source of sexual information was friends (64.4%). An independent t-test revealed the mean knowledge score was significantly higher among females than males on items assessing whether the genitalia may be touched freely by family members, females having attained menarche may become pregnant if having sex, whether pregnancy will occur if there is penetration of the penis into the vagina, whether premarital sexual intercourse causes pregnancy and if there is a relationship between abandoned babies and premarital pregnancies. The mean knowledge score assessing whether pregnancy can be prevented using condoms was higher among males than females. The mean knowledge scores were significantly higher among form four and form five students than forms one, two and three students. Lack of knowledge regarding important aspects of sexual and reproductive health warrant the need to strengthen sexual and reproductive health education.
Accurate and timely diagnosis of dengue virus is important for early detection of dengue virus infection. In this study, the usefulness of the dengue NS1 antigen test was evaluated as a routine, rapid diagnostic test for dengue virus infection. A total of 208 sera from patients suspected of having dengue virus infection were collected and tested for dengue antibody, dengue genome and dengue NS1 antigen. Dengue antibody test, dengue PCR test and dengue antigen test were able to detect dengue virus infection from Days 1 to 8 in 72.8, 52.8 and 44.0% of samples, respectively. Of the 208 sera tested, 69.2% (144/208) of the acute sera were positive for dengue virus infection based on IgM antibody, IgG antibody, NS1 antigen and PCR tests. Thirty-two point two percent of the samples (67/208) were found positive for dengue NS1 antigen, 38.5% (80/208) were PCR positive, 40.9% (85/208) were IgM positive and 36.1% (75/208) were IgG positive for dengue virus. The results reveal the detection rate of dengue virus infection was similar for PCR and dengue antibody (65.9%) and for NS1 antigen and dengue antibody (62.0%) combinations. Therefore, the dengue NS1 antigen test can be used to complement the current antibody test used in peripheral laboratories. Thus, the combination of the NS1 antigen and antibody tests could increase the diagnostic efficiency for early diagnosis of dengue infection.
We reviewed the epidemiology of STH in Malaysia from the 1970s to 2009. High prevalence rates persist among the rural Aborigines, estate workers and in urban slums and squatter areas. Trichuris trichiura is the most prevalent helminth in Malaysia ranging from 2.1% to 98.2%. Ascaris lumbricoides follows closely with a prevalence rate of 4.6-86.7%, while hookworm is the least prevalent (0-37.0%). A countrywide control program with special emphasis on school-based intervention is highly recommended among aboriginal people.
Malaysia experienced its first outbreak of chikungunya virus (CHIKV) infection in late 1998 in Klang District in Selangor; six years later the virus re-emerged in the state of Perak. All the CHIKV isolates in 1988 and 2006 shared high sequence similarities and belonged to the Asian genotype. In 2007 and 2008 CHIKV infection again reemerged but the genotype was the Central/East African genotype. This strain was found to be similar to the strains causing outbreaks in the India Ocean. In 2009, the strains circulating in Malaysia, including the state of Kelantan, based on the partial E1 gene, also belong to the Central/East African genotype.
From 2005 to 2009, the Institute for Medical Research (IMR), Kuala Lumpur received a total of 7,117 respiratory specimens from patients with influenza-like illness (ILI) for influenza screening. Seasonal influenza virus was isolated from 17.3% of patients with ILI in 2005, 31.6% in 2006, 12.8% in 2007, 10.2% in 2008 and 13.5% in 2009. There were one or more influenza A and B virus strains circulating in Malaysia throughout the year, with distinctly a peak in May to August. The predominant circulating strains of seasonal influenza A were A/California/7/2004-like (H3N2) in 2005, A/New Caledonia/20/99-like (H1N1) in 2006, A/ Brisbane/10/2007-like (H3N2) in 2007 and 2008, and A/Perth/16/2009-like (H3N2) virus in 2009. The predominant circulating strains of influenza B were B/Hong Kong/330/2001-like in 2005, B/Malaysia/2506/2004-like in 2006, B/Florida/4/2006-like in 2007 and 2008, and B/Brisbane/60/2008-like in 2009.
Dermatophagoides pteronyssinus and Dermatophagoides farinae mites are commonly found in house dust, and are important sources of allergens affecting humans. Various approaches to killing the mites have been examined. This study investigated the mortalities of adult mites exposed to 2,450 MHz microwave radiation produced by 3 ovens at various exposure times and power settings. The ovens all had 3 power settings. The average maximum water temperatures generated at high, medium and low power settings were 99.4 +/- 0.2, 84.1 +/- 0.4 and 44.8 +/- 0.9 degrees C, respectively. At high and medium settings, there was 100.0% mortality in both species when exposed for 300 seconds. The mean mortality rates at low power were 10.8 +/- 0.7% for D. pteronyssinus and 9.7 +/- 2.6% for D. farinae. When mites were exposed in the presence of culture media, the mortality rates decreased with increasing weight of media. The mean mortality with the largest amount of media tested at high power setting was 61.4%.
This paper reports six male undergraduate students living at a local university hostel who were infested with cat fleas (Siphonaptera: Pulicidae: Ctenocephalides felis felis) in February 2009. All of them suffered from maculopapular rashes and severe pruritus after the bites. Investigation revealed the presence of a stray cat in the hostel building; five of the students had a history of contact with the cat. Six cat fleas were collected at the hostel and identified as C. felis felis. Most of the students were not aware of this infestation and did not seek medical treatment.