As part of a large-scale international cooperative investigation into the side effects of thioacetazone-containing regimens in the treatment of tuberculosis, an evaluation has been made of the variation in the frequency of side effects between different countries and between different centres in the same country and of the likely reasons for this variation. In 3 countries patients of different racial origin were under observation in the same hospital. Over a 12-week period of treatment there was considerable variation between the countries and centres in the overall frequency of side effects and of those leading to a major departure from prescribed treatment, the variation being similar for the two thioacetazone-containing regimens and for the streptomycin plus isoniazid control regimen, though at a lower level for the latter. In Malaysia, Singapore, and Trinidad, where different racial groups were under treatment, there was no clear indication that race was an important factor in explaining the differences between countries, except for cutaneous side effects in Trinidad and possibly in Malaysia.It is concluded that the differences in the frequency of side effects to thioacetazone-containing regimens probably result from variation in the closeness of supervision of patients, in the recording and interpretation of side effects, and in environmental factors including the previous use of other medicaments or exposure to sensitizing substances.
Rubella antibody rates in the female population of Kuala Lumpur were lower than those reported from temperate countries, though similar to rates found in other tropical countries excepting Singapore. Among the major ethnic groups, the immunity status of the Chinese was higher than that of the Malay and Indian groups.
Although dengue haemorrhagic fever is widely established in South-East Asia, no cases have been reported from Borneo. In order to help to assess whether the infection could become established in Borneo, a survey was made, using the single-larva collection method, of the distribution and prevalence of the principal vector, Aedes aegypti, in Sabah and in a few towns and villages of Brunei and Sarawak. In addition, the prevalence of Ae. aegypti was compared with that of certain other species of Aedes.Ae. aegypti was found to be well established in the north, east, and south-west of Sabah but to be absent from almost all of the west coast. It was either uncommon in, or absent from, several small coastal villages; in others, very high Breteau indices were recorded. No reasonable explanation for this discontinuous distribution can be suggested. Large numbers of potential larval habitats were found, giving reason to believe that Ae. aegypti will spread further within these territories.
Surveys were conducted in the southern Malay peninsula to assess intestinal parasitism in the aboriginal ethnic minority groups. Faecal specimens from 1 273 persons were examined by the thiomersal-iodine-formol direct-smear technique. Prevalences are reported and, for helminth infections, data on worm burdens. The state of sanitation in each of 9 cultural-ecological groups was assessed by means of a simplified system of scoring for variables. Particular attention was paid to relationships between cultural and ecological factors, sanitation, and observed patterns of intestinal parasitism. The author also discusses the fact that the number of parasitic species diminishes in habitats simplified by man, whereas an increase occurs in the prevalence and intensity of the more adaptable species that persist in ecosystems of low complexity.
In connexion with the recent detection of cases of monkeypox in man in West and Central Africa, the frequency of monkeypox outbreaks in monkeys since 1958, when the disease was first recognized in captive animals, has been investigated. Special incidence surveys were made for this purpose. During the last 3 years, a serological survey has been conducted to find natural foci of monkeypox virus, and a total of 2 242 sera from monkeys of different species from various parts of Africa and Asia have been examined for poxvirus antibodies. The survey failed to detect any significant indication of poxvirus infections. The observations suggest that although a few human cases of monkeypox have been identified, monkeypox in the natural environment is not widespread and is perhaps localized in small areas.
A new enterovirus, now classified as enterovirus type 70, was isolated from the conjunctiva of patients with acute haemorrhagic conjunctivitis during the 1971 epidemics that occurred in Japan, Singapore, and Morocco. These epidemics were parts of a pandemic involving Africa (Algeria, Ghana, Morocco, Nigeria, and Tunisia), Asia (Cambodia, China (Province of Taiwan), Hong Kong, India, Indonesia, Japan, Malaysia, the Philippines, Singapore, and Thailand), and England during 1969-71. A representative strain from each of the three epidemic areas was studied cooperatively. The strains exhibited the physicochemical characteristics of enteroviruses. Cross-neutralization tests showed that these viruses were distinct from all known human enterovirus immunotypes, but that they were antigenically closely related. The human origin of the viruses was demonstrated by the appearance of homologous neutralizing antibodies during convalescence in patients with acute haemorrhagic conjunctivitis.
Paired sera from 101 Malaysian children aged up to 10 years and suffering from respiratory illnesses were examined serologically for evidence of respiratory viral infections. Of these children, 32.6% showed rising antibody titres for one or more of the test agents. Respiratory syncytial virus appeared to be the main respiratory pathogen involved, followed by Mycoplasma pneumoniae, parainfluenza viruses, adenoviruses, and influenza A virus. These findings are generally similar to those reported by others in temperate and tropical countries.
Healthy Malaysians from various parts of Peninsular Malaysia were examined for CF antibodies against cytomegalovirus (CMV) and herpes simplex virus (HSV) type 2. CMV antibodies were detected in 1114 out of 1556 persons (71.6%) and HSV antibodies were detected in 954 persons out of 1554 (61.4%). The age distribution patterns were similar for the two infections, with maximum prevalence at 5 - 14 years of age. Prevalence was higher in women than in men. There were no significant differences among the Malay, Chinese, and Indian groups of the population with respect to CMV, 72 - 78% possessing antibodies, but in the case of HSV, 76% of the Chinese had antibodies, compared with 57 - 60% of the Malays and Indians. More than 90% of newborn infants had CMV and HSV CF antibodies, confirming the highly immune status of childbearing women in Malaysia. No CMV-specific IgM was detected in the Malaysian neonates examined but this does not exclude the possibility of congenital infection.
The results of this study indicate that the important viral agents associated with lower respiratory tract infections in young children are respiratory syncytial virus, rhinovirus, and parainfluenza virus, particularly in those under 2 years of age. This is in close agreement with studies done in temperate climates. Influenza A virus is seasonal and plays an important role in upper respiratory tract infections in older children.
Study site: Inpatients and outpatients, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
The relationship between the timing of maternal tetanus toxoid immunization and the presence of protective antitoxin in placental cord blood was investigated among women admitted to the obstetrical service of the University Hospital in Kuala Lumpur, Malaysia. The 1st dose was given between 13-39 weeks of gestation, with a median of 29 weeks. The 2nd dose was given an average of 4 weeks later. Protection was conferred on 80% or more of newborns whose mothers received their 1st tetanus toxoid injection 60 days or more before delivery. Protective levels were seen in all cord blood samples from infants whose mothers had received their 1st injection 90 days before delivery. Similarly,protective titers were found in 100% of cord blood samples when the 2nd maternal injection was give 60 days or more before delivery. There was no significant degree of protection when immunization was carried out less than 20 days before delivery. A single-dose schedule provided no protection when less than 70 days before delivery. Cord and maternal antiotoxin titers differed by no more than 1 2-fold dilution for almost all of the individual paired sera. A cord: maternal antitoxin ratio of 2 was more likely to occur with increasing time between the 2nd injection and delivery. Overall, these findings indicate that the 1st injection of a 2-dose maternal tetanus toxoid schedule should be given at least 60 days and preferably 90 days before delivery.
Paddy fish (Trichogaster pectoralis Regan) were collected from five sampling locations in a major paddy-growing area of Malaysia and analysed for organochlorine residues. During the same period, ten farming families, chosen at random from each of the five sampling sites, were interviewed. Information was obtained about the quantity of paddy fish consumed, the amount and type of pesticide used on the paddy-field, and the frequency of application.The pesticide residues found in the fish samples were aldrin/dieldrin, chlordane, HCH, and DDT. Only the projected maximum intake level for aldrin/dieldrin approached the acceptable daily intake as recommended by FAO/WHO; other residue levels were relatively low. However, this study considered only fish; the total daily intake of pesticide residues by the Malaysian paddy farmer may be considerably increased by consumption of other contaminated food.
The study investigated the extent of acute pesticide poisoning in selected agricultural communities in Indonesia, Malaysia, Sri Lanka and Thailand, as well as the contributing factors, because it is believed that this type of poisoning is a major problem in developing countries, but not in the industrialized countries, despite their extensive use of pesticides. The study confirmed the existence of this problem, which was found to be due to inadequate knowledge of the safe practices in the use of pesticides among users and to the lack of suitable protective clothing for use by agricultural workers in hot and humid climates.
A dot enzyme immunoassay (DEIA) for the detection of antibodies to dengue virus was tested for use as a tool in the presumptive diagnosis of dengue fever and dengue haemorrhagic fever. Paired sera from the following groups of patients were tested using the DEIA and the haemagglutination inhibition (HI) test: those with primary dengue fever; those experiencing a second dengue infection; and febrile patients who did not have dengue. The data obtained show that the DEIA can be effectively used at a serum dilution of 1:1000 to confirm presumptive recent dengue in patients with a second dengue infection. However, demonstration of seroconversion proved necessary for patients with primary dengue. At a serum dilution of 1:1000 the DEIA has a specificity of 97.3%. The role of this simple and rapid test in improving the effectivity of programmes for the control of dengue virus infection is discussed.
A cross-sectional survey of 976 households in 41 villages covered by the Rural Health Improvement Scheme in Sarawak was carried out to determine the state of functioning and utilization of rural water supplies. The survey was carried out by inspection and interview. About one-third of the systems were functioning well, one-third imperfectly, and the remainder were no longer functioning. The coverage of households by water supply varied with the type of water supply, the overall coverage being 81.3%. Usage varied with the type of water supply and access, the overall figure being 87.1%, and the overall utilization was 70.8%. The study showed that it is important to account for water supply usage in impact evaluation because not all households have access and not all those with access use the water supply. It is also important to define water use, depending on whether the health outcome is a reduction in diseases that are water-borne or related to washing with water, because the percentage of households using the water for drinking is different from those using it for bathing.
Insecticide-impregnated bed nets act as a physical barrier to repel and kill mosquitos. Community intervention trials suggest that these nets are effective in preventing malaria-related mortality and morbidity--but not malaria infection--in areas of low and moderate transmission; the results from areas of high transmission are not so encouraging. Comparison of the results from these trials and their interpretation are difficult because of variations in the epidemiology of malaria and several methodological flaws. Problems such as defining appropriate health indicators, monitoring bed-net usage, introducing bed nets randomly, selecting adequate controls, performing statistical analysis, and comparing bed nets with other available interventions are considered. Further community intervention trials are needed, paying attention to the methods and to assessment of their impact on malaria.
Food-handling practices were studied in 119 and 158 households, respectively, in an urban and a rural community in Peninsular Malaysia. Hazard analyses, including microbiological analysis of foods, were carried out in two households in each community and in a house that prepared food for distribution in the urban area. Kitchen hygiene was generally acceptable, although rated "poor" in some instances in the rural area. Food prepared for lunch was usually sufficient for dinner also, the leftover items being stored at ambient temperature until required. In the house that prepared food for distribution, breakfast was prepared during the evening, stored at ambient temperature overnight, and reheated before sale the next morning. There was a local preference for cooking food at temperatures close to boiling point; this reduced the numbers of vegetative cells but not those of spores. In some stored foods the populations of Staphylococcus aureus, Bacillus cereus and mesophilic aerobic bacteria increased, the last-mentioned reaching spoilage levels. Reheating reduced the populations of proliferating bacteria in most foods to acceptable levels but would not have destroyed heat-resistant enterotoxins. Because of their importance in combating acute bacterial foodborne disease, the control of the temperature and time factors during the cooking and storage of food should receive special attention in education on health and food safety.
An analysis was carried out on a total of 883 cold chain monitor (CCM) cards, which had been attached to batches of poliomyelitis, measles, DPT (diphtheria, pertussis, tetanus) and hepatitis B vaccines, during their transport and storage from the central store in Kuala Lumpur to Kelantan, a state in north-eastern Malaysia; 234 freeze watches attached to hepatitis B vaccines were also analysed. The monitor cards and freeze watches were observed at six levels between the central store and the periphery during distribution of the vaccines, and a colour change in any of the four windows (A, B, C, D) on the CCM cards or the freeze watches was recorded. In addition, 33 unopened vials of oral poliovirus vaccine (OPV), collected from refrigerators in 29 health facilities in Kelantan, were tested for potency using the tissue culture infective dose 50 (TCID50) method; 14 of them (42%) did not meet the WHO criteria for potent vaccines. The results showed that at the final destination 13.4% of all cards remained white while a colour change to blue was observed in 65% in window A, 16.6% in window B, and 4.4% in window C; none had turned blue in window D indicating that the vaccine had not been subjected to temperatures > or = 34 degrees C for 2 hours. All but 2 of the 234 freeze watches had turned purple, which indicates exposure of the hepatitis B vaccines to temperatures below 0 degree C. These results will assist health planners to correct the weaknesses identified in the cold chain system.
This memorandum summarizes the report of a WHO Consultation on the Control of Cervical Cancer in Developing Countries, held on 6-7 November 1994, in New Delhi, India. Evaluated was the current situation with regard to cervical cancer and the relevance of current practices in screening. New pragmatic approaches to cervical cancer were proposed that are relevant for developing countries; this includes empowerment of women to come forward, and visual inspection-"downstaging".
One impact of socioeconomic progress on populations has been to reduce the number of cases due to diseases of undernutrition and microbial contamination of food, which affected mostly infants and young children, and to increase those due to diseases of excessive food consumption, which are affecting adults and a growing number of children. This article reviews the main dietary factors which have an influence on cardiovascular disease and cancer, and discusses the link between economic development and increased rates of chronic diseases. There is evidence that the noncommunicable diseases and their risk factors have risen rapidly in countries of the WHO Western Pacific Region. Data from 29 countries and areas in the region indicate that 70% of them show lifestyle diseases in three or more of the top five causes of death. While public health measures have been implemented by some countries to prevent and control nutrition-related chronic diseases, further action is needed.