The purpose of this study was to determine the indoor air quality (IAQ) status of an automotive assembly plant in Rawang, Selangor, Malaysia using selected IAQ parameters, such as carbon dioxide (CO2), carbon monoxide (CO), temperature, relative humidity (RH) and respirable particulate matter (PM10). A cross-sectional study was conducted in the paint shop and body shop sections of the plant in March 2005. The Q-TRAK Plus IAQ Monitor was used to record the patterns of CO, CO2, RH and temperature; whilst PM10 was measured using DUSTTRAK Aerosol Monitor over an 8-hour time weight average (8-TWA). It was found that the average temperatures, RH and PM10 in the paint shop section and body shop sections exceeded the Department of Safety and Health (DOSH) standards. The average concentrations of RH and CO were slightly higher in the body shop section than in the paint shop section, while the average concentrations of temperature and CO2 were slightly higher in the paint shop section than in the body shop section. There was no difference in the average concentrations of PM10 between the two sections.
We conducted mosquito surveillance at outdoor breeding habitat in 459 households at 7 urban locations in Putrajaya, Malaysia from January to December 2010 to determine the predominant species and breeding locations. The most common species found at all locations was Aedes albopictus. Gardening utensils were the most common breeding sites. Of the 1,885 mosquito larvae specimens found, 1,774 (94.1%) were Ae. albopictus larvae, 84 (4%) were Ae. aegypti larvae and 27 (1%) were Culex quinquefasciatus larvae. The Aedes index for each of the locations was higher than the goal set by the Ministry of Health for Malaysia. However, the container index at each of the locations was within the goal. The Breateau index was above the goal set by the Ministry of Health at Precinct 9B1 but the other locations were within the goal.
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.
A total of 52 clinical strains of Helicobacter pylori were characterized on the basis of preformed enzyme production with API ZYM kits. Using the biotyping schemes as defined by Reina and Alomar (1989), Kung et al (1989) and Matsumoto et al (1996), 15.3% (8/52), 13.5% (7/52) and 11.5% (6/52) of the isolates were not biotypable, respectively. Two enzymes, valine arylamidase and cystine arylamidase could be additionally used to differentiate between isolates. Our isolates were either negative or positive for both the enzymes or positive only for cystine arylamidase. We propose the incorporation of these two enzymes into the Matsumoto et al (1996) biotyping scheme to biotype strains into additional enzyme biotypes.
It is important to diagnose and treat urinary tract infection in children before renal damage has taken place. Hence a new screening procedure will be of interest. This study was conducted to evaluate the efficacy of urinary nitrite in screening for asymptomatic bacteriuria among school children compared to a more traditional method. Of the 44,816 school children investigated 240 (0.54%) students were judged to have bacteriuria ie 82 (0.19%) in boys and 158 (0.35%) in girls. Escherichia coli was the commonest organism isolated (28.75%). Urine dipstick testing for nitrite was found to have a low sensitivity and positive predictive value. While urinalysis for pyuria was noted to have a sensitivity of 77.9%, a specificity of 95.8% and a negative predictive value of 99.9%.
Until recently, very little was known of Anopheles species complexes and their relationships to epidemiology and malaria transmission in Southeast Asia. During the past eight years, extensive studies on the genetics of natural populations of anopheline mosquitoes in this region, involving the interdisciplinary efforts of taxonomists, operational entomologists and biologists, have revealed groups of cryptic species of Anopheles vectors, particularly the An. leucos phyrus group. This species group comprise seventeen species and two subspecies widely distributed in the forested areas of Southeast Asia. Among these species. An. dirus Peyton and Harrison, has been shown by cytogenetic and morphological studies to be a complex of at least seven isomorphic species, provisionally designated species A, B, C, D, E, F and takasagoensis, on the Southeast Asian mainland. Cytological identification of these species is based on distinct banding patterns of salivary gland polytene chromosomes as well as heterochromatin differences in mitotic karyotypes. The five species found in Thailand (A-D, F) exhibit distinct geographic distributions. Species A is widespread throughout Thailand except in the south. Species B had been found in sympatry with species C in southern Thailand and both seem to show north-south clinal geographic variation. Species D is common on the west side of southern Thailand and along the Thai-Burmese border in sympatry with species A. Species F, An. nemophilous Peyton and Ramalingam, has been found in a population at the Thai-Malaysian border in this study although it was known to be common in southern and western Thailand and Peninsular Malaysia. Species E is known only from western India. The five species found in Thailand also exhibit seasonal variation in relative abundance and different nocturnal biting cycles. Chromosomal polymorphisms have been observed in mitotic and polytene chromosomes of An. dirus A and D. Species B and C also show heterochromatin variation in the sex chromosomes, but are monomorphic for the standard sequence in polytene chromosomes. These biological characteristics of the An. dirus complex may have implications for understanding the epidemiology of malaria in Southeast Asia. Recent cytogenetic studies of wild-caught samples of An. leucosphyrus from Sumatra, Kalimantan and southern Thailand have revealed the presence of two distinct species within this taxon. Species A is widely distributed in southern Thailand, East Malaysia and Kalimantan, while species B is confined to Sumatra. The two isomorphic species are vectors of human malaria within their range of distribution.(ABSTRACT TRUNCATED AT 400 WORDS)
In acute severe anticholinesterase poisoning by organophosphate compounds, pralidoxime (P-2-AM, pyridine-2-aldoxime methiodide) used in the recommended doses, intravenously, has not been shown to reactivate the inhibited cholinesterase, as evidenced both clinically and biochemically. In vitro studies using pralidoxime iodide up to ten times the recommended concentrations, produced insignificant reactivation of cholinesterases inhibited by the organophosphate insecticide Bidrin (di-methyl-3-hydroxyl-N, N-dimethyl-crotonamide phosphate). This was even so despite prolonged exposure of the inhibited cholinesterases to the oxime. The value of pralidoxime as a reactivator of phosphorylated cholinesterases is therefore in doubt, and should not be used in preference to large doses of atropine and other supportive treatment in poisoning by organophosphate insecticides.
Life tables were constructed for twelve cohorts of immature stages of the dengue vector Ae. albopictus in a wooded area of Penang, Malaysia. The development time of Ae. albopictus ranged from 6 to 10 days depending on the mean environmental temperature (r = - 0.639, p < 0.05). Total cohort mortality was correlated with total development time (r = 0.713, p < 0.05) but not temperature (r = -0.477, p > 0.05). Rainfall was correlated with neither development time (r = 0.554, p > 0.05) nor mortality (r = 0.322, p > 0.05). There was a significant difference among the total mortality that occurred in the twelve cohorts (H = 119.783, df = 11, p < 0.05). There was also a significant difference in mortality among the different stages (H = 274.00, df = 4, p < 0.05).
A case of urogenital myiasis caused by Chrysomya bezziana (Diptera: Calliphoridae) was diagnosed in a 76-year old patient who had carcinoma of the rectum. A total of 35 larvae were obtained from ulcers near the external genitalia and urethra opening. Larvae pupated within 1 to 2 days and 6 days later emerged as adult males. These were identified as Chrysomya bezziana. Female flies possibly attracted by the fetid odour, laid eggs in the existing lesions in the urogenital area, the larvae invading and feeding on living tissue. Lack of personal hygiene was the contributing factor for the cause of urogenital myiasis in this patient.
The field bioefficacy of a wettable granule (WG) formulation of Bacillus thuringiensis israelensis (Bti), VectoBac WG (Bti strain AM65-52) against dengue vectors, Aedes aegypti and Ae albopictus; was evaluated in a suburban residential area (TST) and in a temporary settlement site (KB) in the state of Selangor, Malaysia. Pre-control ovitrap surveillance of the trial sites indicated a high population of both types of Aedes mosquitoes. The populations were monitored continuously by weekly ovitrapping. Bti was sprayed biweekly at a dosage of 500 g/ha by using a mist-blower. The spray application was targeted into outdoor larval habitats. If required, Bti formulation was also applied directly into indoor water-holding containers at 8 g/1,000 l. Based on ovitrap surveillance, a significant reduction in Aedes populations was evident 4 weeks after initiating the first Bti treatment. The ovitrap index (OI) and the larvae density decreased drastically in both trial sites. In TST, the indoor OI was significantly reduced from 57.50 +/- 7.50% to 19.13 +/- 5.49% (p<0.05), while the outdoor OI decreased from 38.89 +/- 11.11% to 15.36 +/- 5.93%. In KB, similarly, the OI was significantly reduced by more than half, from 66.66 +/- 6.67% to 30.26 +/- 2.99% (p< 0.05). In all cases, the reduction in OI was paralleled by reduction in larval density.
The larval growth of Liosarcophaga dux Thompson (Diptera: Sarcophagidae) was studied under varying indoor room temperatures in Malaysia. Five replicates were established. The immature growth of this species from first instar until adult emergence was 307.0+/-3.0 hours. The mean larval length measured for second instar, third instar, post-feeding stage and puparia were 6.5+/-0.5 mm (n=10), 11.8+/-3.7 mm (n=31), 12.7+/-0.8 mm (n=16), and 9.5+/-0.5 mm (n=15), respectively.
Malaysian infants would have to receive nine injections during the first few months of life in order to be protected against disease caused by hepatitis B (HBV), diphtheria, tetanus, pertussis and Haemophilus influenzae type b (Hib) if single HBV and Hib vaccines were used. We evaluated a combined DTPw-HBV/Hib vaccine administered at 1.5, 3 and 5 months after a birth dose of hepatitis B vaccine (HBV). One month after completion of the primary vaccination, 99% of subjects had seroprotective anti-HBV antibody levels, and at least 98% had seroprotective antibodies against diphtheria, tetanus, and Hib, and were seropositive for pertussis antibodies. The immune response to the combined vaccine was comparable to that induced by separate injections with DTPw, HBV and Hib vaccines. Overall, the DTPw-HBV/Hib vaccine was as well tolerated as separate administration of DTPw, HBV and Hib vaccines. The combined DTPw-HBV/Hib vaccine induces protection against five diseases as recommended in the Malaysian routine vaccination schedule. Use of the combined DTPw-HBV/Hib vaccine can reduce the required number of injections from nine to four in the first few months of life.
This study aimed to document the baseline incidence and epidemiology of intussusception (IS) in Malaysia. This retrospective surveillance examined hospital discharge data from three hospitals in Malaysia to identify IS cases over a 3-year period (2000-2003) in children <5 years of age. Identification of definite cases of IS was done through a search of computerized hospital discharge records (ICD-9-CM code 560.0) followed by confirmation of diagnosis through medical record review. The definition of IS was based on the clinical guidelines from the IS Brighton Collaboration Working Group, version 2002. During the 3-year study period, there were 62 cases hospitalized due to IS, of which 74.2% were < 1 year of age. The incidences for hospitalization due to IS in children < 1 year old and < 5 years old averaged 17.8 and 4.8 per 100,000 person-years, respectively. No IS-associated deaths were recorded and all IS cases had a favorable outcome. No distinct seasonality with IS occurrence was observed.