Assessing Performance of HRP2 Antigen Detection for Malaria Diagnosis in Mozambique.

Rapid diagnostic tests (RDTs) that detect the Plasmodium falciparum-specific histidine-rich protein 2 (PfHRP2) antigen are the primary methods for malaria diagnosis in Mozambique. However, these tests do not detect infections with non-falciparum malaria or Pfhrp2- and Pfhrp3-deleted P. falciparum parasites. To assess the appropriateness of conventional PfHRP2-only RDTs for malaria diagnosis in Mozambique, samples collected during a health facility survey conducted in three provinces of Mozambique were screened using antigen detection methods and further characterized by molecular techniques. Samples from 1,861 outpatients of all ages and symptoms attending 117 randomly selected public health facilities in 2018 were analyzed with an ultrasensitive bead-based immunoassay for the presence of PfHRP2, pan-Plasmodium aldolase (pAldo), and pan-Plasmodium lactate dehydrogenase (pLDH). The presence of PfHRP2 in patient blood detected using the bead-based assay was compared to the results of PfHRP2-based RDTs performed during the routine health facility consult and during the survey reexamination at the exit interview. Samples with discordant antigen profiles (negative for PfHRP2 but positive for pAldo and/or pLDH) were further characterized by photoinduced electron transfer PCR (PET-PCR). Using the bead-based laboratory assay as the gold standard, the sensitivities of the conventional RDTs administered during the routine health facility consult and the exit interview were 90% and 83%, respectively, and the specificities were 91% and 97%, respectively. Of 710 samples positive for at least one antigen, 704 (99.2%) were positive for PfHRP2. Six (0.8% of total) discordant samples lacked PfHRP2 but were positive for pAldo and/or pLDH; 3 of these (0.4% of total) were Plasmodium ovale monoinfections or coinfections where P. ovale was the dominant species. The remaining 3 discordant samples were negative by PET-PCR. The sensitivity and specificity of the conventional RDTs performed in the routine health facility consults and survey exit interviews were acceptable, and there was no evidence of Pfhrp2- and Pfhrp3-deleted parasites. Monoinfections with non-falciparum malaria species comprised <1% of the total malaria infections. Nearly all malaria antigen-positive patients had detectable PfHRP2, confirming that this antigen remains an appropriate malaria diagnostic target in the surveyed provinces.

Quality of malaria services offered in public health facilities in three provinces of Mozambique: a cross-sectional study.

BACKGROUND: Fever associated with malaria is the leading cause of health care-seeking in Mozambique, yet there is limited evidence on the quality of malaria case management. This study evaluated the quality of malaria service provision offered in public health facilities in Mozambique. METHODS: A cross-sectional assessment was conducted in April-May 2018 in three provinces of Mozambique: Maputo Province (low malaria burden), Cabo Delgado (high), and Zambézia (high). The study included all secondary and tertiary facilities and a random sample of primary facilities in each province. Data collection included exit interviews and re-examinations of 20 randomly selected outpatient service patients, interviews with up to five health care providers and the health facility director, a stockroom inventory and routine data abstraction. RESULTS: A total of 319 health care providers and 1840 patients from 117 health facilities were included. Of these, 1325 patients (72%) had suspected malaria (fever/history of fever) and 550 (30%) had febrile, confirmed malaria with the highest burden in Cabo Delgado (43%), followed by Zambézia (34%) and Maputo Province (2%). Appropriate management of malaria cases, defined as testing malaria suspects and treating confirmed cases with the correct dose of anti-malarial, was highest in Zambézia and Cabo Delgado where 52% (95% CI 42-62) and 49% (42-57) of febrile malaria cases were appropriately managed, respectively. Only 14% (5-34) of febrile cases in Maputo Province were appropriately managed. The biggest gap in the malaria case management pathway was failure to test febrile patients, with only 46% of patients with this indication tested for malaria in Maputo Province. Additionally, anti-malarial treatment of patients with a negative malaria test result was common, ranging from 8% (2-23) in Maputo Province to 22% (14-32) of patients with a negative test in Zambézia. Only 58-62% of patients prescribed an anti-malarial correctly recited dosing instructions. Provider training and malaria knowledge was low outside of Zambézia and supervision rates were low in all provinces. Factors associated with correct case management varied by province and included patient age, facility type, treatment and testing availability, supervision, and training. CONCLUSION: These findings underscore the need to strengthen provider testing of all patients with fever, provider adherence to negative test results, and effective counselling of patients across epidemiological settings in Mozambique.

Estimation of Malaria-Attributable Fever in Malaria Test-Positive Febrile Outpatients in Three Provinces of Mozambique, 2018.

Like most malaria-endemic countries, Mozambique relies on tabulation of confirmed malaria test-positive febrile patients to track incidence of malaria. However, this approach is potentially biased by incidental malaria parasitemia in patients with fever of another etiology. We compared pan-Plasmodium aldolase and lactate dehydrogenase and Plasmodium falciparum histidine-rich protein 2 (PfHRP2) antigen concentrations measured using a laboratory bead-based assay of samples collected from 1,712 febrile and afebrile patients of all ages in Maputo, Zambézia, and Cabo Delgado provinces. We used a Bayesian latent class model to estimate the proportion of malaria-attributable fevers in malaria test-positive febrile patients. Depending on the antigen, estimated rates of malaria-attributable fever in malaria test-positive febrile patients were 100% in Maputo, 33-58% in Zambézia, and 63-74% in Cabo Delgado. Our findings indicate that most malaria test-positive febrile patients in the three provinces of Mozambique had a fever that was likely caused by the concurrent malaria infection. Counting malaria test-positive febrile patients for estimation of malaria incidence appears to be appropriate in this setting.