Field Evaluation of the ICT Malaria P.f/P.v Immunochromatographic Test for Detection of Plasmodium falciparum and Plasmodium vivax in Patients with a Presumptive Clinical Diagnosis of Malaria in Eastern Indonesia

Abstract

In areas such as eastern Indonesia where both Plasmodium falciparum and Plasmodium vivax occur, rapid antigen detection tests for malaria need to be able to detect both species. We evaluated the new combined P. falciparum-P. vivaximmunochromatographic test (ICT Malaria P.f/P.v.) in Radamata Primary Health Centre, Sumba, Indonesia, from February to May 1998 with 560 symptomatic adults and children with a presumptive clinical diagnosis of malaria. Blinded microscopy was used as the “gold standard,” with all discordant and 20% of concordant results cross-checked blindly. Only 50% of those with a presumptive clinical diagnosis of malaria were parasitemic. The ICT Malaria P.f/P.v immunochromatographic test was sensitive (95.5%) and specific (89.8%) for the diagnosis of falciparum malaria, with a positive predictive value (PPV) and a negative predictive value (NPV) of 88.1 and 96.2%, respectively. HRP2 and panmalarial antigen line intensities were associated with parasitemia density for both species. Although the specificity and NPV for the diagnosis of vivax malaria were 94.8 and 98.2%, respectively, the overall sensitivity (75%) and PPV (50%) for the diagnosis of vivax malaria were less than the desirable levels. The sensitivity for the diagnosis of P. vivax malaria was 96% with parasitemias of >500/μl but only 29% with parasitemias of <500/μl. Nevertheless, compared with the test with HRP2 alone, use of the combined antigen detection test would reduce the rate of undertreatment from 14.7 to 3.6% for microscopy-positive patients, and this would be at the expense of only a modest increase in the rate of overtreatment of microscopy-negative patients from 7.1 to 15.4%. Cost remains a major obstacle to widespread use in areas of endemicity.

Rapid Diagnostic Devices for Malaria: Field Evaluation of a New Prototype Immunochromatographic Assay for the Detection of Plasmodium Falciparum and Non-Falciparum Plasmodium

“…Earlier versions of ICT tests were known for their limited sensitivity for P. vivax. 9,10 The high sensitivity and specificity for P. vivax observed in this study suggests that significant improvements have been made in this assay. Our findings have also confirmed the previous observation that the basic antigen detection system used by NOW ICT is capable of detecting P. malariae.…”

“…As in most earlier studies of the ICT test, both sensitivity and specificity for P. falciparum were excellent. 9,10 In many endemic areas outside Africa, P. vivax can be as prevalent, or more frequently found, than P. falciparum. The MRDDs capable of detecting only P. falciparum are of limited value in such areas.…”

Development of VHH Antibodies against Dengue Virus Type 2 NS1 and Comparison with Monoclonal Antibodies for Use in Immunological Diagnosis

“…ELISA absorbance data were analyzed using analysis of variance (ANOVA) and means were compared by the Student-Newman-Keuls test [28]. Clinical data were expressed with 95% confidence intervals (CIs) as suggested by Tjitra et al [29].…”

Malaria Rapid Tests - Perspectives for Malaria Endemic and Non-Endemic Regions. Malariaschnelltests - Perspektiven fur Regionen mit und ohne endemischer Malaria

“…According to a number of field trials, sensitivity decreases markedly (50±90 %) below parasite densities of 100/ml [9±17]. Of concern is the failure of the tests to detect individual cases of high parasitemia, pos-sibly due to the blocking of detection antibodies by excess antigen [9,16,18]. Some manufacturers recommend dilution with physiologic sodium chloride in these cases.…”

“…Trials on Plasmodiumvivax using the Now ICT Malaria Pf./P.v. â reported an overall sensitivity of 20 %-79 % [15,16,19,20]. The OptiMAL â test yielded a somewhat better sensitivity of 69 %-93 % [19,21,22].…”