Comparison of rapid diagnostic test Plasmotec Malaria-3, microscopy, and quantitative real-time PCR for diagnoses of Plasmodium falciparum and Plasmodium vivax infections in Mimika Regency, Papua, Indonesia.

BACKGROUND: The World Health Organization recommends malaria be diagnosed by standard microscopy or rapid diagnostic test (RDT) before treatment. RDTs have been used with greater frequency in the absence of matching blood slide confirmation in the majority of RDT reported cases in Mimika Regency, Papua Province, Indonesia. Given the importance of RDT in current health system as point-of-care tool, careful validation of RDT product performance for providing accurate malaria diagnosis is critical. METHODS: Plasmotec Malaria-3 (XW-P07) performance was evaluated by comparing it with paired blood film microscopy and quantitative real-time PCR (qPCR). Consecutive whole blood samples were derived from one clinic in Mimika as part of routine passive malaria case detection. RDT results were read by two trained technicians and interpreted by consensus. Expert microscopic examination of blood slides was cross-checked by observer-blinded second reader and a third examiner if discordant between examinations. qPCR was used as the 'gold standard', followed by microscopy for the outcome/disease variable. Comparison analysis included sensitivity (Sn), specificity (Sp), positive and negative predictive values (PPV & NPV), and other diagnostic screening performance measures for detecting Plasmodium falciparum and Plasmodium vivax infections. RESULTS: Overall malaria positive samples from qPCR was 42.2% (175/415 samples); and from matching blood slides 40.5% (168/415) of which those infections with relatively low parasite densities ≤100/µl blood was 5.7% of P. falciparum and 16.5% of P. vivax samples examined. Overall RDT performance when compared with microscopy for detecting P. falciparum was Sn:92%, Sp:96.6%, PPV:88%, NPV:97.8%, Kappa:0.87; and for P. vivax Sn:72.9%, Sp:99.1%, PPV:95.4%, NPV:93.4%, Kappa:0.79. Overall RDT performance when compared with qPCR for detecting P. falciparum was Sn:92%, Sp:96.6%, PPV:88%, NPV:97.8%, Kappa:0.87; and for P. vivax Sn:66%, Sp:99.1%, PPV:95.4%, NPV:90.9%, Kappa:0.73. CONCLUSIONS: Plasmotec Malaria-3 test showed good overall performance scores in precision for detecting P. falciparum, but lower values regarding sensitivity and negative likelihood ratio for detecting P. vivax, a finding partly associated with greater frequency of lower density P. vivax infections compared to P. falciparum in this study. In particular, the negative likelihood ratio (>0.1) for P. vivax detection indicates RDT lacked sufficient discriminating exclusion power falling below general acceptance criteria.

HIV treatment outcomes following antiretroviral therapy initiation and monitoring: A workplace program in Papua, Indonesia.

BACKGROUND: Papua Province, Indonesia is experiencing an on-going epidemic of Human Immunodeficiency Virus (HIV) infection, with an estimated 9-fold greater prevalence than the overall national rate. This study reviewed the treatment outcomes of an HIV-infected cohort on Antiretroviral Therapy (ART) and the predictors in terms of immunological recovery and virological response. METHODS: ART-naïve individuals in a workplace HIV program in southern Papua were retrospectively analyzed. Patients were assessed at 6, 12 and 36 months after ART initiation for treatment outcomes, and risk factors for virological suppression (viral load (VL) <1,000 copies/ml), poor immune response (CD4 <200 cells/mm3) and immunological failure (CD4 <100 cells/ mm3) after at least 6 months on ART, using a longitudinal Generalized Estimating Equations multivariate model. RESULTS: Assessment of 105 patients were included in the final analysis with a median age of 34 years, 88% male, median baseline CD4 236 cells/ mm3, and VL 179,000 copies/ml. There were 74, 73, and 39 patients at 6, 12, and 36 months follow-up, respectively, with 5 deaths over the entire period. For the three observation periods, 68, 80, and 75% of patents achieved virological suppression, poor immune responders decreased from 15, 16 to 10%, whilst 15, 16, 10% met the immunological failure criteria, respectively. Using multivariate analysis, the independent predictor for viral suppression at 12 and 36 months was ≥1 log decrease in VL at 6 months (OR 19.25, p<0.001). Higher baseline CD4 was significantly correlated with better immunological outcomes, and lower likelihood of experiencing immunological failure (p <0.001). CONCLUSION: Virological response at six months after beginning ART is the strongest predictor of viral suppression at 12 and 36 months, and may help in identifying patients needing additional adherence therapy support. Higher baseline CD4 positively affects the immunological outcomes of patients. The findings indicate HIV control programs should prioritize the availability of VL testing and begin ART regardless of CD4 counts in infected patients.