ABSTRACT
Two malaria rapid diagnostic tests (RDT), Parascreen Pan/Pf and Paracheck Pf, were tested in rural health centres in Ethiopia against independent expert microscopy (the gold standard). Participants (n =1997) presented with presumptive malaria to ten health centers in Amhara Regional State during the 2007 peak malaria season (October to December). By microscopy, 475 (23.8%) suspected malaria cases were positive, of which 57.7% were P. falciparum; 24.6% P. vivax and 17.7% mixed infections. Parascreen and Paracheck were positive for 442 (22.1%) and 277 (13.9%) febrile patients, respectively. For Parascreen, P. falciparum sensitivity was 79.6%, specificity 97.4%, positive predictive value (PPV) 86.9%, and negative predictive value (NPV) 95.6%. For Parascreen, P. vivax sensitivity was 74.4%, specificity 98.6%, PPV 76.3% and NPV 98.4%. For Paracheck, P. falciparum sensitivity was 73.7%, specificity 99.2%, PPV 95.3%, NPV 94.5%. Sensitivity was significantly higher for both tests (P<0.05) when parasite density was >100/microl of blood; in these cases Parascreen was 90.7% and 91.5% sensitive for P. falciparum and P. vivax, respectively, while Paracheck was 87.9% sensitive for P. falciparum. Parascreen thus performed adequately for both P. falciparum and P. vivax compared to expert microscopy and is more useful than Paracheck where microscopy is unavailable.
Subject(s)
Fever/etiology , Malaria, Falciparum/diagnosis , Microscopy/methods , Reagent Kits, Diagnostic , Adolescent , Adult , Animals , Child , Ethiopia/epidemiology , Fever/epidemiology , Humans , Malaria, Falciparum/epidemiology , Predictive Value of Tests , Sensitivity and Specificity , Surveys and QuestionnairesABSTRACT
We assessed malaria infection in relation to age, altitude, rainfall, socio-economic factors and coverage of control measures in a representative sample of 11437 people in Amhara, Oromia and SNNP regions of Ethiopia in December 2006-January 2007. Surveys were conducted in 224 randomly selected clusters of 25 households (overall sample of 27884 people in 5708 households). In 11538 blood slides examined from alternate households (83% of those eligible), malaria prevalence in people of all ages was 4.1% (95% CI 3.4-4.9), with 56.5% of infections being Plasmodium falciparum. At least one mosquito net or one long-lasting insecticidal net (LLIN) was present in 37.0% (95% CI 31.1-43.3) and 19.6% (95% CI 15.5-24.5) of households, respectively. In multivariate analysis (n=11437; 82% of those eligible), significant protective factors were: number of LLINs per household (odds ratio [OR] (per additional net)=0.60; 95% CI 0.40-0.89), living at higher altitude (OR (per 100 m)=0.95; 95% CI 0.90-1.00) and household wealth (OR (per unit increase in asset index)=0.79; 95% CI 0.66-0.94). Malaria prevalence was positively associated with peak monthly rainfall in the year before the survey (OR (per additional 10 mm rain)=1.10; 95% CI 1.03-1.18). People living above 2000 m and people of all ages are still at significant risk of malaria infection.
