Does the availability of blood slide microscopy for malaria at health centers improve the management of persons with fever in Zambia?

Some Ministries of Health in Africa plan to make blood slide microscopy available in peripheral health centers to improve malaria diagnosis over the current practice, which relies solely on clinical findings. To assess whether microscopy improves the management of febrile persons in health centers, we prospectively reviewed medical records of all outpatients visiting six health centers with laboratories in Zambia during a 2-3-day period. Staff interviews and a blinded review of a series of blood slides from each facility by two expert microscopists were also conducted. Of 1,442 outpatients, 655 (45%) reported fevers or had a temperature > or = 37.5 degrees C. Blood slide microscopy was ordered in 28-93% of patients with fever (mean = 46%). Eighty-eight (35%) patients without parasitemia were prescribed an antimalarial drug. Antimalarial drugs were prescribed with equal frequency to those who were referred for a blood slide (56%) and those not referred (58%). The sensitivity of microscopy was 88% and the specificity was 91%. Use of malaria microscopy varied widely, indicating that clinicians are not using standard criteria for ordering this test. Although diagnosis by microscopy was generally accurate, it appeared to have had little impact on the treatment of persons with fever. Guidelines for using blood slide microscopy are needed and prescription of antimalarial drugs should be discouraged when slide results are negative.

The vitamin A status of Zambian children attending an under five clinic as evaluated by the modified relative dose response (MRDR) test.

The vitamin A status of 87 children, 7-29 months of age, who were randomly selected from attendees at a pediatric clinic in Ndola, Zambia, were evaluated by the modified relative dose response (MRDR) test. By using a MRDR ratio cut-off point of 0.06, 78% of the children had inadequate vitamin A status. Both male and female children were equally affected. Of those with inadequate vitamin A status, 82% were between 7-19 months of age. A significant inverse relationship (p < 0.005) existed between vitamin A inadequacy and Z scores for height for age, weight for age and weight for height. Children with lower Z scores showed a better vitamin A status in comparison to those with a higher Z score. This unexpected relationship is probably due to an increased demand for vitamin A in children with a higher weight and rapid growth rate. Serum vitamin A values correlated poorly with MRDR values except at extreme ends of the distribution. Although clinical vitamin A deficiency is relatively infrequent in Zambia, we conclude that the vitamin A status of our children nonetheless needs to be improved.

A comparison of three types of "M" traps for sampling tsetse fly (Diptera: Glossinidae) populations at south Luangwa game management area, Zambia.

A field trial was conducted between 27th July and 1st August, 1992 in Mfuwe, south Luangwa, Zambia to assess the effectiveness of locally developed "M" traps for suppressing and sampling the tsetse flies Glossina pallidipes Austen and Glossina morsitans morsitans Westwood. The tsetse catches in the "M" traps and the standard F3 traps were collected at 24 hour intervals. The highest catches of both tsetse species in the series of "M" traps were in the M3 trap. The numbers of female flies caught for both species in all the trap types were significantly higher than those for male flies (p < 0.001). Trap catches for G. pallidipes were uniformly distributed among the M2, M3 and F3 traps. In contrast, there was a significant drop in the M1 catches. For G. m. morsitans, the results were not significantly different between the M1 and the M3 catches. Based on the results of this trial, it is been recommended adopting the M1 trap, a more cost effective trap for suppression and the M3 trap for sampling of G. m. morsitans which is the only species in Kampumbu (our trial suppression area) in the Isoka district of Zambia.