Similar HLA association was found in patients with elephantiasis in Sri Lankans and Southern Indians. HLA-B15 was observed in 13/44 (30%) Sri Lankan patients with elephantiasis compared to 1/27 (4%) Sri Lankan controls (p = .0058; RR = 10.9) and in 5/8 (28%) Southern Indian elephantiasis compared to 10/101 (10%) Southern Indian controls (p = 0.04; RR = 3.5). In combining the data, the significance of the difference of the frequency of B15 between patients with elephantiasis and controls was even more marked (p = 0.00045; corrected p = 0.012; RR = 4.4).
Four of the five veterinary E. coli strains, which were unable to transfer their antibiotic resistance by conjugation, were found to harbour plasmids. Evidence from transformation, agarose gel electrophoresis and curing experiments showed that in strains KE-3, KE-4 and KE-14 a nonconjugative R plasmid carried the gene for resistance to tetracycline. The plasmids in KE-9 were cryptic.
Comparative laboratory bioassays of Tolypocladium cylindrosporum, California strain (Kal) was conducted against third instar larvae of four species of mosquito, viz. Aedes aegypti, Anopheles balabacensis, Culex quinquefasciatus and Mansonia uniformis in Malaysia. Of the four mosquito species tested, Ma. uniformis was found to be the most susceptible, followed by Cx. quinquefasciatus, An. balabacensis and Ae. aegypti, in a decreasing order. The LC50 values for Ma. uniformis, Cx. quinquefasciatus, An. balabacensis and Ae. aegypti after four days of exposure were 1.18 X 10(4), 2.02 X 10(5), 4.76 X 10(5) and 1.84 X 10(7) spores per ml test media, respectively. The high sensitivity of Ma. uniformis and its longer life cycle seems to indicate that T. cylindrosporum Kal has good potential as a biocontrol agent for this species of mosquito. But, for Ae. aegypti, this fungus appears to be less effective.
Studies on age groups within activity cycles, age composition and survivorship in natural populations of Mansonia in Kampung Pantai, Bengkoka Peninsula of Sabah state have been described. Early activity of 3-5 parous Ma. bonneae during the first hour after sunset was noted. Age composition of Ma. bonneae at forest shade, indoor and outdoor of house, comparative buffalo vs human bait outdoor in Kampung Pantai showed all round high parous rates ranging from 66.7 to 75.4%. Population 3-parous and older ranged from 18.8 to 26.7%. Nine of the 14 infective Ma. bonneae were 3-parous and this segment of the population was engaged in active transmission. High parous rates were observed in Ma. dives and Ma. uniformis taken in small numbers. Parous rates of Ma. bonneae taken in Kampung Delima and Kampung Taradas were also high. Estimates of daily survivorship of Ma. bonneae and Ma. dives determined by two methods were very high.
Using seven methods of surveillance, 58 species of mosquitoes from nine genera were in Pantai and the two neighbouring villages during two visits in 1982. Ma. bonneae was the most prevalent species attracted to man. In the forest shade Ma. bonneae and Ma. dives showed activity throughout the 24 hours with peak biting during 1900-2100 hours. An. balabacensis exhibited peak activity shortly after midnight. Inside and outside house, Ma. bonneae showed similar activity except that it ceased during the day. Mansonia was only mildly zoophilic. CDC light traps gave poor yields of mosquitoes. Pyrethrum spray catch inside houses early morning did not include any Mansonia. Outdoor day resting catch included Ma. bonneae fed on man. Transmission of Brugia, probably human filariasis, by Ma. bonneae occurred in Pantai and in the two neighbouring villages. One infection in Ma. dives was found in Pantai. The monthly infective biting rate and monthly transmission potential for Ma. bonneae were estimated at the forest shade and outside the house in Pantai.
The antibody titres to P. falciparum and Epstein-Barr Virus-associated antigens were assayed in 22 patients with NPC and 43 controls. All, but one patient had antimalarial titres; 14 had titres greater than 80 and 4 patients greater than 640. Compared to controls the mean anti-malarial titre for most age groups were higher in the patients. Those patients with high anti-malarial titres also had high IgA anti-VCA titre, an antibody which has been demonstrated to be diagnostic for NPC. The peak anti-VCA (IgG) and anti-EA (IgG) antibody titres were associated with anti-falciparum titres of 320-640 and 80-160, respectively. The results are discussed in relation to the possible association between malarial infection and etiology of NPC.
Laboratory experiments were carried out to study the susceptibility of snail vectors to Oriental anthropophilic Schistosoma. Oncomelania hupensis hupensis was readily infected with the local strain of Schistosoma japonicum (Chinese strain), and also infected with S. japonicum (Philippines strain). O.h. quadrasi was only susceptible to its S. japonicum (Philippines strain). The Oncomelania races were refractory to S. mekongi, S. japonicum-like species (Malaysian strain). Tricula aperta (beta race) was readily infected with S. mekongi, S. sinensium and S. japonicum-like species from Malaysia, but not S. japonicum. T. bollingi was susceptible to S. sinensium and S. mekongi. Robertsiella kaporensis was only susceptible to the local strain, S. japonicum-like species from Malaysia. Geographical isolation may be the cause of these differences in compatibility between the snail vectors and the schistosome parasites.
Sera were obtained from 494 non-icteric patients admitted with illnesses other than overt hepatitis into the medical wards of the rural and urban hospitals in Malaysia. They were tested for HBsAg, HBeAg, and anti-HBs by enzyme immunoassay. The overall HBsAg carrier rate was 18.0% ranging from 9.6% in children, (10 years and under), to a maximum of 23.5% in the adolescents (11 to 20 years), the rates decreasing subsequently to 16.5% and 20.8% in the adult and middle-age groups, respectively. The Chinese (18.6%) and Malays (19.9%) had similar HBsAg carrier rates but the rate in the Indians (9.0%) was distinctly lower. Similar rates were observed in the males (16.5%) and the females (19.8%). The carrier rate was 17.1% in rural patients compared with 21.4% in the urban ones. The 'e' antigen was found in 14 of the 89 HBsAg carriers (15.7%). The overall prevalence was 14/494 (2.8%) rising sharply from childhood (2.9%) to adolescence (5.3%), subsequently declining with advancing age. The Chinese had the highest rate (6.2%) followed by the Indians (1.5%) and the Malays (1.1%). Males had a rate of 3.3% compared to the females with 2.3%. Anti-HBs was found in 33.8% of the patients, increasing steadily from childhood (18.3%) to middle-age (46.4%). The Chinese had a higher prevalence rate (41.6%) than the Indians (32.8%) and the Malays (29.3%). The rates were similar for the males (35.6%) and the females (31.5%). Rural patients (46.1%) had a higher rate than urban patients (35.7%). Both areas showed rising prevalence with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)
Sera from 494 non-icteric patients admitted with illnesses other than overt hepatitis into the various hospitals in rural and urban Malaysia were tested for IgG antibody to hepatitis A virus. The overall antibody prevalence rate was 67.0% with rates increasing steadily from childhood 10 years old and under (39.4%) to middle-age and above (96.0%). No significant differences were noted between males (68.4%) and females (65.3%). The highest rate was in the Indians (80.6%), the lowest in the Chinese (55.9%) with Malays occupying intermediate position (70.3%). The rate in the rural patients (74.7%) was higher than that in the urban patients (65.5%) especially in the 21 to 40 year age-group where the rural patients had a rate of 96.7% compared with that in urban patients (61.1%). A comparison of antibody prevalence rates in different countries was made.
Icteric patients with clinical and biochemical evidence of liver disease, admitted into various hospitals in Malaysia, were investigated to determine the cause of their infection. Of these patients, 11.0% (16/145) were found positive for IgM anti-HAV (EIA), 4.1% (6/145) for IgM anti-HBc (EIA), 1.0% (1/102) for IgM anti-CMV (ELISA), 17.2% (16/64) for rising titres of leptospiral agglutinin, and none for heterophile antibody of EBV. Hepatitis NANB accounted for 67.9% of cases. The mean serum transaminases (ALT and AST) values in patients with hepatitis A and B were higher (more than 500IU) than in patients with leptospirosis or non-A, non-B hepatitis, whereas serum bilirubin levels were higher in patients with hepatitis A and leptospirosis than in patients with hepatitis B.
During 1984-1985, a total of 838 sera obtained from individuals of different age groups, mostly blood donors and those whose sera were received for VDRL tests and other serological investigations. The sera were titrated for complement fixing antibodies against cytomegalovirus (Ad169 strain). Three hundred and fifty two (41%) out of 838 sera showed significant antibody titre. The incidence of this virus infection varied form 26% in the age group of 11-20 years to 59% of those above 50 years of age. Geometric mean titre (GMT) was highest (22) in age groups of 11-20 years and those over 50 years indicating active viral infection in these two age groups. GMT was also significantly higher in females in all age groups except in the age group of 21-30 years and those above 50 years, indicating that active viral infection is more common in females.
Two hundred and eight patients underwent oesophago-gastro-duodenoscopy within the first year of its introduction at a peripheral general hospital in Malaysia. There were 7 cases of gastric cancer, proved histologically, as compared to 38 cases of benign gastric ulcer. The frequencies of the common symptoms and signs in the two conditions are compared. Of the 3 main ethnic groups, Malays, Chinese and Indians, the incidence of gastric ulcer was highest among the Chinese, next the Indians; however, the number of gastric cancers were too few for analysis of its racial incidence.
The prevalence rate of 749 cases of oral squamous cell carcinomas (SCC) recorded between 1978-1984 was studied. Results showed that the Indians formed the dominant group (63.8%) followed by the Malays (19.6%) and Chinese (16.6%). The peak incidences were generally located between the sixth and eighth decades. Only in the Chinese group a male preponderance was noted. In the Indians, the buccal mucosa was the most prevalent site; in the Malays and Chinese males, the gingiva and alveolus; and the Chinese female, the tongue. In all three groups, the well-differentiated SCC was the commonest type and the poorly differentiated least common.
Some information on cancer in Malaysia are available, and its epidemiology is described. There is a need for systematic and coordinated collection of cancer statistics which are essential to patient management, cancer control programme formulation, implementation and evaluation. The decision of the Ministry of Health to introduce National Cancer Registry and to encourage epidemiological studies, which will ultimately lead to the utilization of data and introduction of control and preventive activities for cancers are positive steps in the right direction. Meanwhile, curative and palliative treatment is available from the existing hospital facilities, and preventive activities such as actions on smoking and health will be continued until such time when a comprehensive prevention and control programme for cancers in the country is evolved.
A descriptive epidemiology of cancer in Sarawak, based on histopathology records in the Central Medical Laboratory, Kuching, Sarawsk, in 1981 and 1982 was presented. There were 8,219 patients from whom biopsies were taken and 485 from whom marrow biopsies were taken. Out of these, 1,326 were reported malignant. Most of the cases were from Kuching. There were slightly more males than females. The Chinese formed the majority of cases followed by the Sea Dayaks and Malays. The most common cancer sites among males were lymph nodes, nasopharynx, skin and stomach, while in the females the most common sites were the breast, cervix and lymph nodes. Among the Chinese the most common cancers were those of the nasopharynx in males, and breast in females. Among the Sea Dayaks, the most common cancers were those of the lymph nodes in males and cervix in females. Among the Malays, skin cancers were relatively common, and among the Land Dayaks nasopharyngeal cancers were common. Most of the patients were in the older age groups. The pattern of cancers has not changed much since 1966 and the findings of the present study are very similar to the series from the Institute of Medical Research, Kuala Lumpur, in 1969 to 1971.
An epidemio-meteorotropic analytical study of Selangor, in the Southwest coast of Peninsular Malaysia, examines the monthly incidence of dengue for the period 1973-1982 to assess possible quantitative association with the monthly rainfall. The relationships between rainfall, abundance of A. aegypti and dengue infection during 1982 in Jinjang, a dengue-prone area in Selangor, were also examined. A quantitative association between rainfall and the number of dengue cases was found during the first wet period. The lag time between the onset of heavy rain and dengue outbreak was about two to three months. A 120% increase in the number of dengue cases was observed when the monthly rainfall was 300 mm or more. Positive associations were seen between the incidence of dengue and the Aedes house index and the Breteau index in Jinjang. The relationships between these three variables and rainfall suggest that the latter might have exerted its effect on dengue infection partly through the creation of more breeding sites for A. aegypti. Assessment of the importance of A. aegypti in the transmission of dengue in this locality was not possible because of the lack of adjustment for A. albopictus, the other known vector of dengue in the state, and for social and other environmental factors influencing infection rates. In spite of this and the interpretational problems common in aggregate studies, the present analyses have provided relatively strong statistical evidence of an association between rainfall and dengue outbreaks in Selangor, thereby indicating that it is a factor worthy of careful surveillance and monitoring.
Two separate observations from recent electrophoretic studies of the systematics and population genetics of laboratory-reared populations which had a long history of colonization in various laboratories, were found to be inconsistent with the present study which used wild-caught populations from East Malaysia. Reanalysis of the two data sets generally indicated a low amount of genetic variation in laboratory colonies. The latter is characterized by higher frequency of monomorphic loci, low average heterozygosity values and, in one extreme case, no variability at two loci. However, natural populations of An. balabacensis and An. leucosphyrus showed more protein variability by the use of polyacrylamide gel electrophoresis. Since laboratory-maintained mosquitoes are genetically and phenotypically different from those in the field, results of laboratory studies on the systematics and population genetics of Anopheles species complexes may be biased.