Doxycycline in a single dose was found to be a valuable drug in the treatment of chloroquine-resistant falciparum malaria. It was less effective in a single daily dose of 4 mg/kg body-weight for four days, when it cured only five out of nine patients, while a dosage of 4 mg/kg body-weight for seven days cured 23 out of 26 patients.
A survey of 227 patients from 5-60 years of age revealed the presence of positive histoplasmin skin tests in 10.5 per cent. and positive complement-fixation tests in 19-8 per cent. Sputum from 13 of the 37 patients who had a positive complement-fixation test were cultured for H. capsulatum but with negative results. Exposure to infection by the fungus is equally distributed among the different race and age groups. A careful and constant watch should be kept for histoplasmosis in all chest hospitals as a certain number of cases may be present. It tends to elude diagnosis unless specially sought as it resembles the clinical picture of tuberculosis or other granulomatous disease. It presents a field for further investigation and research in Malaya.
Three cases of multiple drug resistant falciparum malaria in the same family are described. It is interesting to note that faIciparum malaria resistant to Fansidar has not as yet been reported in adults from West Malaysia up to the present time, although resistance to the drug in children is being encountered not infrequently. This presents a serious paediatric problem because malaria causes the highest incidence of mortality and morbidity in this age group in a proportion of the rural population.
A trial of suppression of malaria by administration of combined sulphadoxine-pyrimethamine tablets every 28 days was undertaken in West Malaysia during 1972. One thousand subjects were followed over a 10-month period, including control groups on placebo and on weekly chloroquine. Subjects were examined monthly for parasitaemia, drug reactions, leucopenia, teratogenicity and haemolysis among the subjects deficient in glucose-6-phosphate dehydrogenase. Rates of new infections in the placebo group were 8.0% with Plasmodium falciparum and 6.2% with P. vivax; in the group receiving weekly chloroquine, 5.1% P. falciparum and 0.3% P. vivax; and in the group receiving monthly sulphadoxine-pyrimethamine, 0.3% P. Falciparum and 1.0% P. vivax. The effective rate of cure of new infections with P. falciparum by a single suppressive dose of combined sulphadoxine-pyrimethamine given the following month was 88.7%. No serious side effects were observed.
In vivo chloroquine resistance surveys, which allowed for detection of late recrudescing RI resistance, were conducted in three regions of Peninsular Malaysia, which were previously not recognized as having appreciable drug resistance. Among the 485 Plasmodium falciparum infections tested resistance rates ranged locally from 20% to 67% in those with parasitaemias over 1,000 per mm3, and 5% to 59% in all parasitaemias. The region found to have the most serious resistance was western Pahang. In one study a combination of chloroquine and pyrimethamine proved no more efficacious than chloroquine alone. Most of the resistance encountered was the late recrudescing RI type. There was no apparent correlation between drug resistance and Anopheles balabacensis as this species was not found despite intensive collections in two of the three main regions. There was no evidence of resistance among the 222 P. vivax and 35 P. malariae infections also tested.