Assessment of the accuracy of malaria microscopy in private health facilities in Entebbe Municipality, Uganda: a cross-sectional study

• Published in: Malaria Journal
• Main Authors: Tobius Mutabazi, Emmanuel Arinaitwe, Alex Ndyabakira, Emmanuel Sendaula, Alex Kakeeto, Paul Okimat, Philip Orishaba, Simon Peter Katongole, Arthur Mpimbaza, Pauline Byakika-Kibwika, Charles Karamagi, Joan Nakayaga Kalyango, Moses R. Kamya, Grant Dorsey, Joaniter I. Nankabirwa
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2021
• Subjects: Malaria; Diagnosis; Accuracy; Microscopy; Private health facilities; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-021-03787-y; https://doaj.org/article/0ada315ca4134bbbbbc5d6295478fa41

Abstract Background Although microscopy remains the gold standard for malaria diagnosis, little is known about its accuracy in the private health facilities in Uganda. This study evaluated the accuracy of malaria microscopy, and factors associated with inaccurate smear results at private health facilities in Entebbe Municipality, Uganda. Methods Between April and May 2018, all patients referred for a malaria smear in 16 private health facilities in Entebbe municipality were screened, and 321 patients were enrolled. A questionnaire was administered to collect demographic and clinical information, facility-based smear results were recorded from the participant’s consultation notes, and a research slide was obtained for expert microscopy during exit interview. A health facility assessment was conducted, and information on experience in performing malaria microscopy was collected from all facility personnel reading smears and the data was linked to the participant’s clinic visit. Results The test positivity rate of malaria parasitaemia was 15.0% by expert microscopy. The sensitivity, specificity and negative predictive value of the facility-based microscopy were high (95.8%, 90.1 and 99.2%, respectively). However; the positive predictive value (PPV) was low with 27/73 (63%) patients diagnosed with malaria not having the disease. Majority of the inaccurate results were from 2 of the 23 laboratory personnel reading the smears. The factors associated with inaccurate smear readings included being read by a technician; (1) who had less than 5 years’ experience in reading malaria smears (adjusted Odds Ratio [aOR] = 9.74, 95% confidence interval [CI] (1.06–89.5), p-value = 0.04), and (2) who was examining less than 5 smears a day (aOR = 38.8, 95% CI 9.65–156, p-value < 0.001). Conclusions The accuracy of malaria microscopy in this setting was high, although one third of the patients diagnosed with malaria did not have the disease. Majority of the errors in smear readings were made by two laboratory personnel, with the ...