Imported cerebral malaria complicated with glucose 6 phosphate dehydrogenase deficiency

Two cases of cerebral malaria imported from Guyana and Ghana are reported. These are the first cases of cerebral malaria diagnosed and treated in Trinidad and Tobago since malaria was eradicated. The management of both these cases was complicated because the patients' erythrocytes were glucose-6-phosphate dehydrogenase-deficient, and by the occurrence of blackwater fever, cerebral manifestations, renal impairment, hyperglycaemia and thrombocytopenia. The symptoms of cerebral malaria resolved following treatment with quinidine and doxycycline and quinidine and clindamycin. (AU)

A model of the transmission of dengue fever with an evaluation of the impact of ultra-low volume (ULV) insecticide applications on dengue epidemics

We have developed a deterministic susceptible, exposed, infectious, resistant or removed (SEIR) model of dengue fever transmission that enables us to explore the behavior of an epidemic, and to experiment with vector control practices. Populations of both host and vector are divided into compartments representing disease status (susceptible, exposed, infectious, and , for humans, resistant), and the flow between compartments is described by differential equations. Examination of the equilibrium points leads to a formulation of the basic reproduction rate (Zo) of the dsease. With a base set of parameters, Zo=1.9 and the model realistically reproduces epidemic transmission in an immunologically naive population. Control of adult mosquitoes by ultra-low volume (ULV) aerosols is simulated by an abrupt decrease in vector densities, followed by gradual recovery of the vector population. The model indicates that ULV has little impact on disease incidence, even when multiple applications are made, although the peak of the epidemic may be delayed. Decreasing the carrying capacity of the environment for mosquitoes, and thus the basic reproduction rate of the disease, by source reduction or other means, is more effective in reducing transmission. (AU)

Intrinsic antibiotic resistance and streptomycin uptake in cowpea rhizobia

Uptake of [3H]dihydrostreptomycin in sensitive and resistant strains of cowpea rhizobia was examined to explain one of the possible mechanisms of intrinsic antibiotic resistance. The rate of acummulation of labelled streptomycin in resistant strains was drastically reduced when compared to that of sensitive strains. Our results indicated that high levels of intrinsic antibiotic resistance was due to decreased permeability causing failure to accumulate the drug. However, the causes for high levels of intrinsic resistance of rhizobia to any of the antibiotics are not known. One of the mechanisms of durg resistance in the lab isolates of enteric bacteria is decreased permeability resulting in failure to accumulate the drug. In this work, we investigated the uptake of labelled streptomycin in sensitive and resistant strains of cowpea rhizobia isolated in Jamaica and West Africa and showed that the high level of intrinsic resistance was due to the cell's inability to take up the drug (AU)

Tuberculosis among the Amerindians

There has been a substantial reduction in tuberculosis in British Guiana between 1949 and 1954 among the Indians and Africans but since then the figures have remained more or less stationary as the incidence in the Amerindians is virtually unaltered and remains substantially higher than that of the other racial groups. It seems apparent that tuberculosis is a new disease brought to them by the immigrant race groups and their natural resistance to it would seem to be low. Their general level of nutrition is also very poor. As it is not practicable to bring them up in large numbers to Georgetown where the facilities for investigation exist, the policy has been to visit them at their homes and examine them clinically and examine their sputum by direct smear and to give B.C.G. vaccination to all negative reactors. Some 30,000 Amerindians live in an area of few thousand square miles of a most difficult terrain. With liquid B.C.G. vaccines used during earlier campaigns the conversion rate has been poor but with freeze-dried vaccines used in more recent campaigns, better conversion rate has been achieved. Results of treatment in Amerindians are excellent and because domiciliary treatment is impractical in most of them, they complete their chemotherapy in hospital (AU)