1. 1. The results of various studies by other workers on the spleen and parasite rates in Indians, Malays and Bantu are summarized. 2. 2. The results of our own observations on Khonds in India, and on Masai and Bantu in East Africa are also summarized and compared with the foregoing and with one another. 3. 3. It is pointed out that wide differences may be found in the malarial status of communities in the same country and, in the case of the Bantu, of the same race; while close similarities occur in different countries. 4. 4. The results of experimental infections in birds and monkeys are cited and interpreted in terms of the two states of allergy and immunity. The probable significance of these is illustrated by reference to the role of the two states in tuberculosis. 5. 5. It is suggested that the observed contrasts in the spleen and parasite rates in diverse communities may also be explained in terms of immunity and hypersensitivity. 6. 6. It is concluded that the immune status is dependent not on race but on the frequency of infection; and that the most accurate index of endemicity is the frequency of infections in the non-immune, that is the rate in early infancy. 7. 7. While a consideration of the Spleen Rate and Endemic Index may be of value in forming an estimate of endemicity and immunity when similar communities are being compared, these indices may be misleading when the epidemiological surroundings are dissimilar. 8. 8. A consideration of the variation with age in the spleen and parasite rates throws more light on endemicity and immunity and on such variation a rough classification may be made into immune and sub-immune communities. 9. 9. But it is suggested that by far the most sensitive index at present available for field studies is the average parasite count, and its variation with age. c 1937.
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.
The serious health hazards posed by adverse drug reactions have long been recognised, but the application of epidemiological principles to their studies is only a recent development. A total of 3160 patients admitted into Medical Unit I, General Hospital, Singapore were kept under surveillance for adverse reactions to drugs for six months in 1972. Fifty three of them (1.7%) were admitted with adverse drug reactions as the sole reason for admission. There were 25 males and 28 females. There were two deaths and ten life-threatening reactions, and hypersensitivity was the most common type of reaction encountered. Among the chief offending drugs were Chinese herbal medicines, digoxin, corticosteroids, antibiotics, phenothiazines, and hypoglycaemic agents. All doctors especially the general practitioners must be fully aware of these hazards so that they can help prevent un- necessary morbidity and mortality and also to avoid taxing heavily on the already over-burdened hospital service in a developing country.
Matched MeSH terms: Drug Hypersensitivity/epidemiology*
Three groups of people with different clinical histories and manifestations to house dust were skin tested with Dermatophagoides pteronyssinus extracts. The results showed close correlation between positive skin tests and clinical sensitivity to dust. The correlation was not, however, perfect and, although D. pteronyssinus is a major factor in house dust allergy, it does not appear to be the sole antigen involved.
The possible depression of cell-mediated immunity by long-term Brugia malayi infection in jirds (Meriones unguiculatus) was investigated. Different groups of infected jirds were sensitized with dinitrofluorobenzene, sheep red blood cells, Dirofilaria immitis adult antigens and B. malayi adult antigens. The 24-hour delayed type hypersensitivity skin response to testing with antigen was measured as an in vivo correlate of cell-mediated immunity. The delayed-type hypersensitivity responses to dinitrofluorobenzene, sheep red blood cells and D. immitis antigens were normal but the response to B. malayi antigens was significantly depressed, confirming that long-term B. malayi infection depresses cell-mediated immunity and that this depression is specific to B. malayi antigens.
Eighteen infants clinically suspected to be intolerant of cow's milk were placed on a milk-free formula and six to eight weeks later were orally challenged with cow's milk. Following challenge three groups were recognised. Group A: Four infants tolerated oral feeds ofcow's milk and lacked mucosal abnormality or clinical symptoms. Group B: Seven infants had mucosal deterioration but lacked clinical symptoms and tolerated cow's milk. Group C: Seven infants had mucosal abnormality, developed clinical symptoms and were intolerant of cow's milk. The intestinal transudation of IgA was increased in Group A and unchanged in Group Band C : the IgM levels in the duodenal juice was increased in Group A and B but unchanged in Group C : the IgG levels in the juice were increased in all Groups following challenge. It appears that increased transmission of IgA and IgM or IgM alone in the duodenal juice is associated with lack of development of clinical symptoms. Symptoms are present in infants in whom the IgA and IgM levels in duodenal juice remained unchanged after challenge. It is suggested that patients responding to cow's millt challenge with intestinal production of IgA and IgM (or IgM alone) are able to counter balance the deleterious mechanisms leading to clinical cow's milk intolerance whereas those who, for some unknown reason, do not mount a secretory immune response become ill.
Abnormal variants of plasma cholinesterase are a rarity in this region and to date there is only one reported case of suxamethonium sensitivity in a Malaysian population. We now report a case of a Malaysian Chinese patient who received suxamethonium, developed prolonged apnoea and on investigation found to be a homozygote for the silent gene. His family was screened for abnormal variants of plasma cholinesterase. The results are discussed.
Matched MeSH terms: Drug Hypersensitivity/genetics*
Infants, one to 56-weeks-old, presenting with persistent diarrhoea were placed on a diet free of cow's milk protein which improved their clinical condition. Six weeks later, 67 infants were challenged with a low-lactose cow's milk formula and jejunal biopsy was taken before and 24-hours after challenge. On the basis of histological changes in the intestinal mucosa and development of clinical symptoms the infants were categorised into three groups: Group 1 (n = 16) with no clinical or mucosal abnormality, Group 2 (n = 20) with mucosal abnormality but lacking clinical symptoms, and Group 3 (n 31) with manifestation of mucosal abnormality and clinical symptoms. In addition to the total IgE the radioallergosorbent test (RAST) was performed on sera from the infants taken before and after milk provocation. The mean total serum IgE level ranged from 288 to 560 IU/ml. In Groups 2 and 3 the prechallenge serum IgE levels were significantly higher than the postchallenge levels but in Group 1 the levels remained unchanged on challenge. A positive RAST to milk proteins was observed in five infants (7.4%), that is, one in Group 2 and four in Group 3, of 67 infants studied. In a survey of 405 consecutive paediatric-age patients admitted for a variety of symptoms, 90 were positive for RAST specific for milk proteins. Interestingly the majority of the patients positive for RAST presented with gastrointestinal ailments. The measurement of specific IgE appears not to be a useful adjunct in the diagnosis of CMPSE in Malaysian children.
A study was carried out to determine the health effects of rice husk dust in Malaysian rice millers. The study population consisted of 122 male Malay workers from three rice mills, with 42 controls of similar age, sex, ethnic group, and agricultural work background. Interviews using standardised questionnaires, physical examination, total and differential white cell counts, chest radiographs, and lung function tests were performed on each of the millers and the controls. Environmental dust monitoring was also carried out in the three rice mills. Clinical, haematological, and radiological findings suggest that a distinct clinical syndrome seems to be associated with exposure to rice husk dust. The manifestations of this "rice millers' syndrome" include acute and chronic irritant effects affecting the eyes, skin, and upper respiratory tract; allergic responses such as nasal catarrh, tightness of chest, asthma, and eosinophilia; and radiological opacities in the chest, probably representing early silicosis or extrinsic allergic alveolitis.
A detailed account and definition is given of the previously inadequately described "giant reactions" to tuberculin occasionally seen in leprosy patients. The reaction is an accelerated and exaggerated response to species-specific antigens of Mycobacterium tuberculosis found in both PPD and New tuberculin. Our studies were performed in Malaysia, Uganda, Spain, and England. There was a significantly higher incidence of the phenomenon in Malaysia than in the other centers, but this may have been because there alone previously untreated lepromatous (LL and BL) patients were serially tested for up to three years after starting chemotherapy. Of the 28 patients exhibiting giant reactions, 27 occurred among lepromatous patients (24 LL and 3 BL), of which only 3 (1 LL and 2 BL) were untreated. One treated BL patient had developed, and one untreated BL patient was a family contact of, active tuberculosis. Giant reactions are uncommon in untreated and in very long-term treated LL patients, but may occur in up to a fifth of those receiving their first 1-3 years of chemotherapy. Although the mechanism is not yet understood, it appears to be a coincidence of delayed hypersensitivity of the tuberculin type and a less-delayed phenomenon of excessive local edema associated with local lymphadenopathy and short-lasting symptoms of malaise and pyrexia. It is suggested that the majority of giant reactions occur during a period of temporary lack of immune regulation associated with changing levels of antigenic load.