Sleeping sickness in Busoga, Uganda, 1976-1983.

Between 1976 and 1983 in the Busoga Region in Uganda 10,414 male and 9,560 female patients were detected with trypanosomiasis. Prior to the onset of the epidemic, Glossina f. fuscipes, the sole vector, had broken through the tsetse control barrier and had spread to cover most of the region. The fly was further observed to be resting in Lantana plants and coffee and banana plantations which are widespread in the area. A close and regular contact was thus established between man and fly. It was observed that the young and engergetic persons first became infected, but as the epidemic unfolded the older age-groups bore the brunt. The infection was also seen in all other age-groups indicating the closeness of contact between the fly and the local population.

Retrospective long-term study of effects of berenil by follow-up of patients treated since 1965.

99 persons, 67 males and 32 females, who had earlier been diagnosed as having early stage disease of African Trypanosomiasis (AHT) and been treated with berenil were traced and brought to UTRO (Uganda Trypanosomiasis Research Organisation) for examination. These patients had each received 3 doses of berenil 5 mg/kg body weight at one or two day intervals. Each patient had a thorough physical and laboratory examination. All the cases were found in good physical health. The laboratory investigations were all found within normal limits. The period between when the cases were last treated with berenil and this examination varied between 12 months and over 109 months. Although various side effects were seen during treatment, the same were not seen when these cases were re-examined. Berenil is certainly effective in the treatment of early stage AHT though it produces some side effects which are not permanent. Furthermore these side effects are no more serious than the side effects produced by other trypanocidal drugs such as suramin. Berenil should, therefore, be considered as an alternative drug for treatment of early stage AHT.

Tanzania filariasis project: studies on microfilaraemia and selected clinical manifestations of Bancroftian filariasis.

In a total of 1977 males aged 5 years and over examined in 21 cluster samples on the coast of Tanzania, the overall rate for microfilariae of Wuchereria bancrofti was 32%. Hydrocoele and elephantiasis rates were 39% and 3%, respectively. The rates and severity of these 2 clinical manifestations increased in the older age groups. Both the microfilarial density and prevalence increased rapidly in the early age groups, followed by a levelling off and then a slight fall in old age. There was no association between microfilarial densities or rates and the overall prevalence of hydrocoele, but a negative association was demonstrated between microfilaraemia and hydrocoeles and elephantiasis. A comparison between the length of residence in an endemic area and the microfilarial and clinical sign rates showed evidence for the long incubation period for W. bancrofti and for the slow development of hydrocoeles and elephantiasis.

Tanzania filariasis project. Survey methodology and clinical manifestations of bancroftian filariasis.

In a Bancroftian filariasis survey on the coast of Tanzania microfilaria rates rose with age reaching 53% in the 60-69 year group followed by a slight fall above this age. The most important clinical manifestations were hydrocoele, funiculitis and elephantiasis, with hydrocoele presenting the most serious public health problem. Hydrocoele rates increased with age reaching 90% above the age of 70. The highest proportion of large hydrocoeles were also in the older age groups. A satisfactory methodology was established for the planning of future surveys leading to control.

Bancroftian filariasis: a comparison of microfilariae counting techniques using counting chamber, standard slide and membrane (nuclepore) filtration.

Three techniques were compared for counting microfilariae of Wuchereria bancrofti in blood specimens--a standard slide method, the counting chamber technique (CCT) and a membrane filtration technique (MFCT). The CCT was much more sensitive than the slide method, the difference in sensitivity between these two methods probably being due mainly to the loss of microfilariae during the dehaemoglobinizing process prior to staining in the standard slide method. There was good correlation between the techniques when 0.1 ml of finger-prick blood was examined by the CCT and 1 ml of venous blood by the MFCT. The number of additional positives revealed by the MFCT was ten of 275 (3.6%) subjects examined. The use of venepuncture for MFCT is impractical for field surveys in East Africa whereas a microfilarial count on 0.1 ml of finger-prick blood meets most of the criteria required of a field technique. The method is simple, quantitative and acceptable to the population. The results are reproducible, can be readily checked, the technique provides a useful and practical method for obtaining prevalence information following control schemes. The finding of a relatively low prevalence of microfilariae seen by both MFCT and CCT in children aged five to nine years from a highly endemic filariasis area agrees with the results of previous East African surveys carried out by blood smear and CCT.

Metrifonate in onchocerciasis and lymphatic filariasis.

Metrifonate, in doses of 10 mg/kg for 3 consecutive days, demonstrated partial microfilaricidal activity against Onchocerca volvulus in humans. Higher doses were not investigated because of the toxic reactions obtained and the absence of monitoring of the blood cholinesterase levels. Spaced doses of 10 mg/kg every 2 weeks or once monthly up to 3 doses showed neither micro- nor macrofilaricidal activity against Wuchereria bancrofti.

A comparison of the efficiency of the Nuclepore and Millipore filtration systems for detecting microfilariae.

Using Brugia pahangi or Dirofilaria immitis as the test organisms no significant difference could be detected between Nuclepore and Millipore filters. It was found that 0.7% of microfilariae passed through the Millipore and 1% through the Nuclepore filters. No microfilariae were lost from the Nuclepore membrane during the staining process.

Laboratory evaluation of a new technique for counting microfilariae in blood.

The technique involves taking a measured volume of blood (20-40 mm3) from a finger or ear prick on to a conventional 3 X 1 in microscope slide and lysing it with water. Microfilariae could either be counted immediately, whilst still alive, or the smear dried, fixed and stained. A comparison between counts of microfilariae in freshly prepared slides and stained slides showed that few microfilariae were lost in the staining process.