Microscopy Negative Malaria during a Peak Transmission Season in a Malaria Endemic Setting: Diagnostic Accuracy of RDTs, Expert Microscopy and the Value of Presumptive Treatment

Abstract

Aim: We investigated all malaria symptomatic patients with microscopy-negative results during a peak malaria transmission season to ascertain the need for presumptive treatment of malaria among these patients. Justification: Due to improved malaria control measures, the administration of anti-malarial drugs to symptomatic patients with negative microscopy results is uncalled for. However, in malaria endemic low resource settings, this practice is upheld especially during peak transmission seasons. There is paucity of data to either support or discourage this practice in these settings. Study Design: It was a cross-sectional study. Place and design of study: This study was conducted at Gulu regional referral hospital, Uganda, between October and November 2012. Methodology: A routine blood smear (BS) was examined for all the 542 malaria symptomatic participants. A rapid diagnostic test (RDT) was performed on all patients with negative BS results. All smears were later read by expert microscopists. Results: Of the 542 patients seen, 503 (92.8%) had negative routine BS results. Eighty nine (7.2%) were excluded due to history of treated fever in the previous two months. Of the 414 qualifying participants, 14 (3.4%) were positive by RDT and 6 (1.4%) were positive by expert microscopy. Nearly all participants (12/14) with microscopy-negative but RDT-positive results were children less than 5 years. Conclusion: At a rate of 3.4% true malaria cases, presumptive treatment of all malaria symptomatic cases offers a marginal benefit to children less than five years and is an uncalled-for expense among adults. Prescription practices consistent with these findings could greatly improve rational anti-malarial use and minimize costs, especially in sub-Saharan Africa.