ABSTRACT
BACKGROUND: The need to start treatment early for pregnant women who present with clinical features of malaria usually conflicts with the need to confirm diagnosis by microscopy (MP) before treatment, due to delays in obtaining results. Parasite sequestration in the placenta is also a problem. Rapid diagnostic tests (RDT), which detect soluble antigens, are a valuable alternative. The objective of this study was to evaluate pretreatment parasite prevalence by microscopy and by RDT and to assess the accuracy of RDT with MP as reference. METHODS: A prospective cross-sectional study was carried out at the obstetrical unit of the Central Hospital in Yaoundé, during the period January-August 2015. Consenting patients with symptoms of suspected malaria in pregnancy were recruited and a blood sample taken for MP and RDT before treatment was started. The estimates of diagnostic performance (with 95% confidence interval) were calculated in OpenEpi online software using the Wilson's score. The agreement, as reflected by the Cohen's kappa, was calculated and interpreted using known intervals. RESULTS: The results showed that, out of the 104 patients recruited, 69.2% (95%CI: 59.1-77.5) were MP positive while 77.94% (95%CI: 63.1-80.9) were RDT positive. The sensitivity of the malaria RDT was 91.67% (95%CI: 83.69-96.77) while the specificity was 53.13% (95%CI: 31.39-65.57). The diagnostic accuracy of the RDT with MP as reference was 79.81% (95%CI: 70.0-86.1). All cases were due to Plasmodium falciparum. A Cohen's kappa of 0.45 (95%CI: 0.26-0.64) was obtained, consistent with a moderate agreement between the tests. CONCLUSIONS: The diagnostic accuracy of the CareStart™ malaria Pf/PAN compared to microscopy was high, but not as desirable, with a false negative RDT at very high parasitaemia. In tertiary facilities, RDTs appear to provide a better diagnostic solution compared to microscopy. However, future studies with larger sample sizes should make this observation more generalizable; as missing a case could have serious consequences on pregnancy outcome.
Subject(s)
Malaria, Falciparum , Malaria , Cameroon/epidemiology , Cross-Sectional Studies , Diagnostic Tests, Routine/methods , Female , Hospitals , Humans , Malaria/diagnosis , Malaria, Falciparum/diagnosis , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Microscopy/methods , Plasmodium falciparum , Pregnancy , Pregnant Women , Prospective Studies , Sensitivity and SpecificityABSTRACT
BACKGROUND: Malaria remains a burden for pregnant women and the under 5. Intermittent preventive treatment of pregnant women (IPTp) for malaria with sulfadoxine - pyrimethamine (SP) has since replaced prophylaxis and legislation has been reinforced in the area of insecticide treated mosquito nets (ITNs) in Cameroon. Clinical malaria despite all these measures remains a problem. We compared the socio-obstetrical characteristics of women who developed clinical malaria and those who did not though in the same regimen. METHODS: A 5 - year nested cohort study (2007 - 2011 inclusive) at the tertiary level hospitals in Yaounde. Pregnant women who willingly accepted to participate in the study were enrolled at booking and three doses of SP were administered between 18 - 20 weeks of gestation, between 26-28 weeks and between 32 - 34 weeks. Those who developed clinical malaria were considered as cases and were compared for socio - obstetrical characteristics with those who did not. Venous blood was drawn from the women in both arms for parasite density estimation and identification and all the clinical cases were treated conventionally. RESULTS: Each arm had 166 cases and many women who developed clinical malaria were between 15 and 19 years (OR 5.5, 95% CI 3.9 - 5.3, p < 0.001). They were of low gravidity (OR 6.5, 95% CI 3.8 - 11.3, p < 0.001) as well as low parity (OR 4.6, 95% CI 2.7 - 7.9, p < 0.001). The cases were single women (OR 4.58, 95% CI 2.54 - 8.26, p < 0.001) and had attained only primary level of education (OR 4.6, 95% CI 2.8 - 7.9, p < 0.001). Gestational ages were between 20 to 30 weeks during clinical malaria (OR 6.8, 95% CI 4.1 - 11.7, p < 0.001). The time between the first and second dose of SP was longer than ten weeks in the cases (OR 5.5, 95% CI 3.2 - 9.3, p < 0.001) and parasite density was higher also among the cases (OR 6.9, 95% CI 5.9 - 12.1, p < 0.001). CONCLUSION: Long spacing between the first and second dose of SP seemed to be responsible for clinical malaria in the cases.
