Comparative Diagnostic Performance of Microscopy, SD-Bioline Rapid Diagnostic Test, and Polymerase Chain Reaction in the Detection of Malaria Infection among Pregnant Women at Delivery in Kumba Health District Area in the Southwest Region of Cameroon

Abstract

Introduction. Malaria during pregnancy is a major cause of morbidity and mortality in sub-Saharan Africa. Microcopy and rapid diagnostic test (RDT) recommended by the World Health Organization for clinical diagnosis have poor sensitivity to detect individuals with very low levels of parasitemia. Previous studies have shown that malaria in pregnancy is associated with mastitis and excessive uterine blood loss during delivery. However, information evaluating the performance of these tools in detecting malaria in pregnancy at the national level is limited. This study therefore evaluates the performance of microscopy, RDT, and nested polymerase chain reaction (nPCR) in the detection of pregnancy-associated malaria at delivery. Methods. A total of 227 participants constituting of 201 pregnant women without and 26 with HIV were recruited from five health facilities within the Kumba health district area. Mother venous and cord blood were collected at delivery to test for malaria using the thick-film microscopy, SD-bioline RDT, and 18SrRNA-nested PCR. Results. The percentage of malaria-positive cases detected by thick-film microcopy (TFM), RDT, and PCR in pregnant women with and without HIV was 7.69%, 53.85%, and 50% and 3.48%, 23.38%, and 49.25%, respectively. Plasmodium falciparum was detected in 1.99% cord blood samples of women without HIV by PCR. The positivity rate in at least two of the test methods (composite positive) was 42.31% for women with and 19.90% for women without HIV. The sensitivity of TFM and RDT when using PCR as a reference was 7.21% and 49.00%, respectively, in all samples. The specificity was 99.14% and 90.55% with kappa values of 0.064 and 0.461, respectively. When using the composite test as a reference, the sensitivity of TFM, RDT, and nPCR was 15.69%, 94.12%, and 100%, respectively. Specificity was 99.43%, 93.18%, and 65.34% with kappa values of 0.213, 0.821, and 0.458, respectively. Conclusion. This study shows that PCR is more sensitive in the detection of malaria parasite followed by SD-bioline RDT kit. However, in resource-limited settings where access to molecular diagnosis of malaria is a problem, RDT should be considered as the first option to microscopy in the diagnosis of malaria.