ABSTRACT
Background: Malaria in pregnancy has significant adverse consequences for the mother, foetus and baby. Presumptive diagnosis continues despite recommendation for parasite-based diagnosis. We performed Paracheck-PfTM, an HRP-II based malaria Rapid diagnostic test (Paracheck-Pf RDT) and microscopy among pregnant women in a prospective, cross sectional study, at the University College Hospital in Ibadan, Nigeria. Methods: The study was conducted between 2009-2011. Consecutive pregnant women presumptively diagnosed as having malaria >18 years were enrolled after obtaining written informed consent. Demographic information, symptoms and clinical measurements were obtained. Capillary blood was obtained by finger prick for thick blood smear and RDT evaluation. Summary statistics included mean (standard deviation) for quantitative variables and percentages for categorical variables. Chi-square, analysis of variance (ANOVA), the odds ratio (OR) and 95% confidence intervals (CI) were computed with p-value less than 0.05 considered statistically significant. Results: Of the 746 pregnant women aged 30.9 ± 4.6 years enrolled, 243 (32.7%) were primigravida. The mean gestational age was 23.3 ± 9.2 weeks with about 81% in the second and third trimester. The prevalence of malaria parasitaemia by microscopy and Paracheck-PfTM were 22.8% and 24.5% respectively. The geometric mean parasite density was 2,091/µL (range 40-156,975/µL). HIV positivity rate was 8.1 % and 16.1% of patients were anaemic (PCV <30%). Women with axillary temperature >37.4°C were significantly more likely to have malaria parasitaemia [p<0.0001] by microscopy. Sensitivity and specificity of Paracheck overall were 69.9% and 88.2% respectively while those at of parasite densities ≥200/µL were 84.8% and 88.7% respectively. Positive and negative predictive values were 66.9% and over 90% respectively. Conclusion: RDTs are a reasonable alternative in view of the need for parasite-based diagnosis of malaria.
ABSTRACT
Febrile illnesses occur frequently among HIV positive patients and these are often treated presumptively as malaria in endemic areas. Parasite-based diagnosis of malaria will eliminate unnecessary treatment, reduce drug-drug interactions and the chances for the emergence of drug resistant Plasmodium. We evaluated finger prick blood samples from 387 people living with HIV (PLWHIV) and suspected of having malaria by expert microscopy and Paracheck-Pf(TM) - a histidine-rich protein-II based malaria rapid diagnostic test. The study was conducted at the PEPFAR supported AIDS Prevention Initiative in Nigeria (APIN) Clinic of the University College Hospital Ibadan, southwest Nigeria. Outcome parameters were prevalence of malaria parasitemia, sensitivity and specificity of Paracheck-Pf as well as the positive and negative predictive values for Paracheck-Pf using microscopy of Giemsa-stained blood film as gold standard. Malaria parasites were detected in 19·1% (74/387) of enrollees by microscopy and 19·3% (74/383) by Paracheck-Pf. Geometric mean parasite density was 501/µl (range 39-749 202/µl). Sensitivity and specificity of Paracheck-Pf at all parasite densities were 55·4% and 89·3% while corresponding figures at parasite densities ≥200/µl were 90·9% and 90·3%. Sensitivity and specificity at parasite densities ≥500/µl was 97·6% and 90·3%. Positive and negative predictive values for parasite density ≥200/µl were 55·4% and 98·7%, respectively. Paracheck-Pf was found to be a useful malaria diagnostic tool at parasite densities ≥200/µl facilitating appropriate clinical management.
