If they lived in households without piped water or a toilet, Malaysian infants who did not breast-feed were five times more likely to die after 1 week of age than those who breast-fed, when other significant factors affecting infant mortality were taken into account. This is double the relative risk associated with not breast-feeding for infants born into households with toilets, whether or not they had piped water. Analogously, improvements in toilet sanitation appear to have reduced mortality twice as much among infants who did not breast-feed as among those who did. These findings, from a retrospective survey of infants born to a probability sample of 1,262 women in peninsular Malaysia, confirm the pernicious synergistic effect of poor sanitation and nonbreastfeeding that was postulated previously on theoretical grounds. Promoting and maintaining high initiation of breast-feeding is thus particularly important where poor sanitation is prevalent. Even more affluent areas should not be neglected, however, because socioeconomic improvement, including improved environmental sanitation, is often accompanied by decreased breast-feeding. Although the risk to each nonbreast-fed infant was less in those areas, infants there were less likely to breast-feed in Malaysia, and hence they made up a significant proportion of lives that could be saved by breast-feeding.
The effect of toilets, piped water, and maternal literacy on infant mortality was analyzed using data from the Malaysian Family Life Survey collected in 1976-1977. The effect of toilets and piped water on infant mortality was dependent on whether or not mothers were literate. The impact of having toilets was greater among the illiterate than among the literate, but the impact of piped water was greater among the literate than among the illiterate. The effect on the infant mortality rate for toilets decreased from 130.7 +/- 17.2 deaths in the absence of literate mothers to 76.2 +/- 25.9 deaths in the presence of literate mothers. The reduction in the mortality rate for maternal literacy dropped from 44.4 +/- 14.1 deaths without toilets to -10.1 +/- 23.9 deaths with toilets. Reductions in mortality rates for piped water increased from 16.7 +/- 12.7 deaths without literate mothers to 36.8 +/- 21.0 deaths with literate mothers. Similarly, reductions in the mortality rate for maternal literacy rose from 44.4 +/- 14.1 deaths in the absence of piped water to 64.5 +/- 19.5 deaths in the presence of piped water. The results from a logistic model provided inferences similar to those from ordinary least squares. The authors infer that literate mothers protect their infants especially in unsanitary environments lacking toilets, and that when piped water is introduced, they use it more effectively to practice better hygiene for their infants.
The gene encoding the 195,000-Da major merozoite surface antigen (gp195) of the FUP (Uganda-Palo Alto) isolate of Plasmodium falciparum, a strain widely used for monkey vaccination experiments, has been cloned and sequenced. The translated amino acid sequence of the FUP gp195 protein is closely related to the sequences of corresponding proteins of the CAMP (Malaysia) and MAD-20 (Papua New Guinea) isolates and more distantly related to those of the Wellcome (West Africa) and K1 (Thailand) isolates, supporting the proposed allelic dimorphism of gp195 within the parasite population. The prevalence of dimorphic sequences within the gp195 protein suggests that many gp195 epitopes would be group-specific. Despite the extensive differences in amino acid sequence between gp195 proteins of these two groups, the hydropathy profiles of proteins representative of both groups are very similar. The conservation of overall secondary structure shown by the hydropathy profile comparison indicates that gp195 proteins of the various P. falciparum isolates are functionally equivalent. This information on the primary structure of the FUP gp195 protein will enable us to evaluate the possible roles of conserved, group-specific and variable epitopes in immunity to the blood stage of the malaria parasite.
PIP: The influence of socioeconomic status (ethnicity, income and parity) on electrolyte composition (sodium and potassium) in human milk is little known. We have thus quantitatively analyzed approximately 700 samples of milk (1-90 days postpartum) obtained from healthy Malaysian mothers' (Malay, Chinese and Indians) of full term infants. Results show that the mean concentration (mmol/l) of sodium is highest (48.2+or-1.7, Mean+or-SEM) in the Malaysian mothers' colostrum and this value decreased by 30% in their transitional milk and remained constant throughout subsequent days of lactation (mature milk). Ethnically, it is found that the level of sodium in colostrum of Malay and Chinese mothers were similar while the Indian mothers' colostrum showed apparently higher value (52.7+or-3.4 mmol/l) that is statistically insignificant. The transitional milk of all 3 ethnic groups studied exhibited similar levels of sodium. On subsequent days of lactation (mature milk) the Malay mothers exhibited lowest concentration (25.9+or-2.6 mmol/l) of sodium that is significantly (P0.05) different from that of Chinese and Indian mothers. Income and parity do not significantly affect the sodium level in Malaysian mothers' milk during all stages of lactation studied. The level of potassium, however did not change significantly with days of lactation. Like sodium, potassium too was not influenced by income and parity. (Author's).
Chemical forms of copper and lead in river water of the Linggi River Basin have been fractionated into ASV labile, moderately labile, slowly labile, and inert metal species, based on a previously proposed scheme. Free (hydrated) metal ions were identified by a potentiometric method using an ion selective electrode. Speciation results showed that the soluble copper and lead species occurred mainly in the moderately labile and slowly labile fractions. The speciation results are primarily interpreted in terms of organic interaction due to agricultural based and light industries, and urban discharges. The measured metal complexing capacity (MCC) of the samples reveals consistency of the results with the nature of the discharge. MCC correlates reasonably well with the value from the permanganate test on the river water. In general, the speciation pattern was found to be consistent with the findings of other workers.
This paper reviews the literature on leptospirosis in Malaysia from its first description in 1928 until the present day. Most of the early reports were on investigations of leptospirosis in wildlife and man and up-to-date, thirty-seven leptospiral serovars from thirteen serogroups have been bacteriologically identified. The thirteen serogroups are: Australis, Autumnalis Bataviae, Canicola, Celledoni, Grippotyphosa, Hebdomadis, Icterohaemorrhagiae, Javanica, Pomona, Pyrogenes, Sejroe and Tarassovi. Rats have been ascribed as the principal maintenance host of leptospires in Malaysia. However, serovars from the Pomona, Pyrogenes and Sejroe serogroups have yet to be isolated from rats. It is considered that the majority of leptospirosis cases in man were due to association of man with an environment where rats were plentiful. Recent investigations on domestic animals disclosed a high prevalence of infection in cattle and pigs and they were suspected as being the maintenance host for serovar hardjo and pomona respectively. There is ample scope for research in leptospirosis, particularly in the epidemiology and control of the disease in domestic animals. The strategy to control the infection in domestic animals and man in Malaysia is bound to be different from that of the temperate countries, basically due to the presence of a large number of leptospiral serovars in wildlife, further confounded by geographical and financial constraints.
A stable population at risk of Malaysian schistosomiasis was studied. Census results indicated that approximately one-fourth of the inhabitants used a stream where Schistosoma malayensis-infected snails were present as their principal source of water for bathing, drinking, and household tasks. The general population also contacted this stream when fording it or while fishing. Serological surveys using enzyme-linked immunosorbent assay (ELISA) and the circumoval precipitin (COP) test revealed six (9%) and three (4%) positives, respectively, among 67 persons examined. No schistosome ova were found in a general survey of 56 persons which included five ELISA positive and two COP test positive patients. ELISA and COP test prevalences among those dependent on the foci of transmission for water, 13 and 7% respectively, were only slightly higher than prevalences among the remainder of the population, 8 and 4% respectively. These results indicate that even among a stable population at risk of Malaysian schistosomiasis the prevalence is low. Our findings support the hypothesis that S. malayensis is a zoonotic infection in man and that it is unlikely to become a significant public health problem.
A rapid method of assay, using a monoclonal antibody linked to alkaline phosphatase, was used for the detection of the Pontiac subgroup of Legionella pneumophila serogroup 1. It was tested for its specificity against 53 strains of Legionella recently isolated from the environment in Singapore and Malaysia. The specificity and sensitivity of this method of assay was confirmed, though there is some concern that the specificity was too narrow, and there are reservations about the criteria suggested for interpreting the results.
The membrane-filter assay, GM1-ELISA, and DNA-DNA hybridization assay, were used to detect enterotoxigenic Escherichia coli (ETEC) in samples of water, weaning food, food preparation surface swabs, fingerprints of mothers, and the fingerprints and stools of children under 5 years of age, in 20 households in a Malaysian village. Weaning food and environmental samples were frequently contaminated by faecal coliforms, including ETEC. The membrane-filter assay detected and enumerated faecal coliforms and LT-ETEC in all types of water and weaning food samples. Highest concentrations of faecal coliforms and LT-ETEC were found in weaning food, followed by well-water, stored water and stored drinking water. The GM1-ELISA detected LT-ETEC in weaning food, food preparation surfaces, fingerprints and stool samples. The DNA-DNA hybridization assay detected a larger proportion of STa2-ETEC than the other toxotypes, either singly or in combination. All the assays in combination detected the presence of ETEC in all types of samples on at least one occasion in each household. It was not possible to classify households as consistently more or less contaminated with ETEC. On individual occasions it was possible to show a significant association of the presence of LT-ETEC between the fingerprints of children and their stools, fingerprints of mothers and children, and weaning food and the stools of the child consuming the food.
Increased primary plankton productivity was observed in a brackish water lagoon of Terengganu during the study period between January 1988 to December 1988. The lagoon is also the site for the fish cage culture activities of sea bass during the study period. An examination of water quality at the sampling stations during the study period indicated that both the organic and inorganic nutrients were high during the pre-monsoon period. The source of the nutrient in the lagoon was believed to be derived from the agro-based industrial effluents, fertilisers from paddy fields as well as untreated human and animal wastes. This coincided with the peak production of plankton in the surface waters of the brackish water lagoon. During this period both cultured and indigenous fish species were seen to suffer from oxygen asphyxiation (suffocation due to lack of oxygen). The primary productivity values ranged from 9 to 22 μg/L/h during the peak period while the microplankton species were composed of diatom, flagellates and dinoflagellates. Reduction in the primary productivity values were obtained with reduction in sallinity, specially during the peak monsoon months (November to March) corresponding to the Northeast monsoon period.
In a case study involving preliminary investigations for the feasibility of a beach resort complex in the west coast of Sarawak, Malaysia, since the acceptable quality of recreational water quality had not been specified, existing international standards and practices were reviewed to arrive at acceptable microbiological and physicochemical parametric levels. Water samples were collected on a weekly basis in the proposed beach complex at Tanjong Batu Coastal Reserve and also along the nearby Sungei Batang Kemena and its estuary. It was ascertained that the swimming water quality was acceptable in terms of faecal Coliforms, temperature, pH and dissolved oxygen. However E. Coli counts did indicate a potential risk of 1.68% for gastrointestinal illness and the ubiquitous presence of faecal Streptococci pointed to recent pollution of human or animal origin. Besides, grease and oil contents exceeded the WHO Guideline values. It was hence recommended that an appropriate sanitation or pollution survey should be carried out in the adjacent coastal catchment area and the beach. Also routine water sampling should be undertaken. Such action will help to pinpoint sources of pollution and lead to antipollution measures, thus helping to upgrade swimming water quality and establish swimming water quality standards.
Phenolic chemicals with their very low taste and odour thresholds, high persistence and toxicity, are of growing concern as water pollutants. The compounds are known to exist in raw water as well as in treated water. The level of phenolic priority pollutants in water within the catchment area of the Linggi River Treatment Plant in Negeri Sembilan, Malaysia, which includes the Linggi river basin, was monitored. The 4-aminoantipyrin colourimetric method was used to determine total phenols whereas capillary column gas chromatography was used to determine the individual compounds. The results show that at most sampling stations, particularly those within the Seremban municipality, the level of phenols was found to exceed the recommended Malaysian standard of 2.0 μg/L(-1) for raw water. This is seen as the direct impact of industrial and urbanization of the area and clearly indicates the unhealthy state of the Linggi river. The results also indicate the need to improve the water quality if the river is going to be used as a source of raw water.
Matched MeSH terms: Water; Water Pollutants; Water Purification; Water Quality
Coastal waters in South Johore, Malaysia are polluted to various degrees. The major pollution sources are domestric wastes from human settlements, agro-based wastes from palm oil mills and rubber processing factories, industrial effluents from industrial estates and discharges from animal farms. These pollution problems have adversely affected resources such as fisheries, recreational potential as well as the general aesthetic quality of the coastal environment particularly the Inner Johore Strait. Hence proper management and control measures are urgently needed to protect and further enhance the water quality to ensure environmentally sustainable development. This study examines various management options to control the pollution in the Inner Johore Strait. The options involve partial opening as well as complete removal of the Causeway to improve the tidal flow for more effective dilution and dispersion of pollutants. Computer simulation models are used to assess the impacts of the proposed options.
Marine biofouling causes problems to marine structure and obstructs condenser tubes in cooling systems which use sea water as the coolant. The main purpose of this study is to investigate the seasonal ecology of biofouling organisms such as the green mussel, Perna viridis, the dominant fouling species in the Eastern Johore Straits at the Senoko Power Station. The spawning time and its relationship with environmental conditions were studied. The physical, chemical and biological conditions of the sea at Senoko were monitored for a year. Settling slides were used to study the fouling succession in different monsoon seasons. The study showed that there were two main spawning peaks for the green mussel and that these peaks occurred during the intermonsoon months of November and April. These peaks were also correlated with the bimodal patterns for salinity, dissolved oxyen, bivalve veliger larval density and total plankton biomass of the Eastern Johore Strait water. Succession patterns were similar during the two monsoon seasons, however, the rate of fouling was probably greater during the southwest monsoon months. It is therefore advisable that the control or reduction of biofouling in Eastern Johore Strait should take into account the seasonal fluctuations and spawning of the fouling organisms.
Due to the increasingly documented prevalence of diarrhoeal diseases in Malaysia, a number of water-related programmes have been implemented in an attempt to improve health status through the reduction of incidence of waterborne communicable diseases associated with poor public water supplies. The implicit assumption underlying these projects is that the enhancement of the physical infrastructure, and subsequent improvements in the quality of the water supply, will substantially reduce water-related disease. The present study questions this hypothesis and uses a socio-ecological model as a framework to assess risk factors associated with the increased probability of waterborne disease. Research is centred on Port Dickson, a district which typifies existing water and sanitation conditions in much of semi-rural Malaysia. Health services utilization data and a 268-household diarrhoeal morbidity survey were used to measure the burden of illness of waterborne disease within the district and to identify predictors of morbidity. It was concluded that although treatment facilities will reduce the health burden in the region, a number of behavioural and sanitation factors may be more important and could act to minimize the potential impacts of improved water quality.
Three building complexes in Kuala Lumpur were surveyed for the presence of legionellae in cooling towers. The organisms were grown from 12 out of 46 samples of water collected from 30 towers. L. pneumophila serogroups 1 and 7 were the commonest serogroups isolated. None belonged to the Pontiac subgroup of L. pneumophila serogroup 1.
The H2S water screening test and the membrane filtration faecal coliform count were compared with Escherichia coli counts for water samples collected from household water sources and domestic drinking water in rural Malaysia. Water samples were taken from 151 wells, 44 taps supplying water from the treated municipal supply and 192 domestic stored water supplies. E. coli were detected in 20% of the samples (42% of wells, 7% of tap water and 6% of drinking water). Excellent correlation (Spearman's rank correlation rs = 0.93) was found between the faecal coliform and E. coli counts for all sample types. The H2S method was poorly correlated whether read at 18 or 30 h. False positive rates were highest for well water, and false negative rates were highest for both well and drinking water samples, with low E. coli counts. The faecal coliform test was an excellent predictor of the presence of E. coli in these water samples, while the H2S test was very inadequate.
Matched MeSH terms: Water Microbiology/standards*; Water Supply/standards*
Solid-phase extraction (SPE) of organochlorine pesticide residues from environmental water samples was evaluated using octadecyl (C18)-bonded porous silica. The efficiency of SPE of these pesticide residues from reagent water samples at 1-5 micrograms dm-3 levels was compared with those obtained by solvent extraction with hexane and Freon TF (trichlorotrifluoroethane). Average recoveries exceeding 80% for these organochlorine pesticides were obtained via the SPE method using small cartridges containing 100 mg of 40 microns C18-bonded porous silica. The average recovery by solvent extraction with hexane and Freon TF exceeded 90% in both instances. It was concluded that the recoveries and precision for the SPE of organochlorine pesticides were poorer than those for the solvent extraction method. Organochlorine pesticide residue levels in environmental water samples from two major rivers flowing through predominantly rice-growing areas were monitored by gas chromatography using the solvent extraction method with hexane. Exceptionally high levels of organochlorine pesticide residues such as BHC, DDT, heptachlor, endosulfan and dieldrin were found in these water samples.
Matched MeSH terms: Water Pollutants, Chemical/analysis*