Accuracy of malaria rapid diagnosis test Optimal-IT® in Kinshasa, the Democratic Republic of Congo

Abstract

BackgroundDespite some problems related to accuracy and applicability, malaria rapid diagnostic tests (RDTs), are currently considered the best option in areas with limited laboratory services for improving case management and reducing over-treatment. However, their performance must be established taking into the account the particularities of each endemic area. In the Democratic Republic of Congo, the validity of Optimal-IT® and Paracheck-Pf®, respectively based on the detection of lactate dehydrogenase and histidine-rich protein-2, was assessed at primary health care level (PHC).MethodsThis was a two-stage cluster randomized survey, conducted in one health centre in 12 health zones in Kinshasa city. All patients with malaria presumptive diagnosis were eligible. Gold standard was microscopy performed by experts from the parasitology unit, Kinshasa University.Results624 patients were enrolled. 53.4% (95% CI: 49.4-57.3) owed a bed net, obtained in 74.5% of cases (95% CI: 69.4-79.1) through community-based distribution by the National Malaria Control Programme. Microscopy expert reading confirmed 123 malaria cases (19.7%; 95% CI: 16.7-23.1). Overall sensitivity were 79.7% (95% CI: 72.4-86.8), 87.8% (95% CI: 81.9-93.6) and 86.2% (95% CI: 79.9-92.3), respectively, for Optimal-IT®, Paracheck-Pf® and microscopy performed at PHC. Specificity was 97.0% (95% CI: 95.5-98.5), 91.6% (95% CI: 89.1-94.0) and 49.1% (95% CI: 44.7-53.4). The proportion of confirmed cases seemed similar in under-fives compared to others. Any treatment prior to the current visit was a predictor for malaria (AOR: 2.3; 95% CI: 1.5-3.5), but not malaria treatment (AOR: 0.87; 95% CI: 0.4-1.8). Bed net ownership tended to protect against malaria (AOR: 0.67; 95% CI: 0.45-0.99).ConclusionAlthough microscopy is considered as the "gold standard" for malaria diagnosis at point of care level, this study showed that its accuracy may not always be satisfactory when performed in health centres.

External quality assessment of Giemsa-stained blood film microscopy for the diagnosis of malaria and sleeping sickness in the Democratic Republic of the Congo

“…On the other hand, the proportion of false-positive results was much lower than that observed in a study of the sensitivity and specificity of rapid diagnostic tests and malaria microscopy carried out in 2011 in the Democratic Republic of the Congo, in which the false-positive rate for routine microscopy was 70.6%. 17 The difference may be due to the poor quality of Giemsa staining and of the reagents used under routine conditions 8,18 or to the possibility that better laboratories are more likely to participate in external quality assessments.…”

Short communication: Non-malaria related acute fever, a preliminary study from Kinshasa the Democratic Republic of the Congo

“…[10,11] Nonetheless, they are more reliable at PHC for malaria diagnosis because of the poor quality of microscopy at that level. [12] …”

Elimination of sleeping sickness hindered by difficult diagnosis

“…8 In health centres, routine thick blood film examination for malaria had a false positivity rate of 66%. 9 Similar or poorer diagnostic quality can be expected in the case of HAT.…”