Diagnostic performance of CareStart™ malaria HRP2/pLDH test in comparison with standard microscopy for detection of uncomplicated malaria infection among symptomatic patients, Eastern Coast of Tanzania.

BACKGROUND: CareStart™ malaria HRP2/pLDH (Pf/pan) combo test is one of the several rapid diagnostic tests (RDT) approved for diagnosis of malaria at the point of care in Tanzania. However, there are limited studies on the diagnostic performance of RDT after wide scale use in primary health care facilities in Tanzania. Therefore, this study was carried out to determine the diagnostic performance of RDT when compared with blood smear (BS) microscopy as a reference standard. METHODS: A cross-sectional study was conducted between March and August 2019 at Kibiti Health Centre, Pwani region, Tanzania. Blood samples for malaria tests were collected from patients with malaria symptoms. Diagnostic performance parameters of RDT, i.e. sensitivity, specificity, positive and negative likelihood ratios (LR+/-), diagnostic accuracy and predictive values were determined using contingency table. An agreement between RDT and microscopy was statistically determined by Cohen's kappa test. RESULTS: Of 980 patients screened, 567 (57.9%) were found to be malaria positive by RDT, whereas 510 patients (52%) were positive by microscopy. Of the 510 microscopy-positive patients, 487 (95.5%) were infected with Plasmodium falciparum. The geometric mean parasite density was 2921parasites/µl, whereas majority (68.6%) of patients had parasite density greater than 10,000/µl. The sensitivity, specificity, positive and negative predictive values of CareStart™ were 99.8%, 87.6%, 89.8%, and 99.8%, respectively. The LR+ and LR- were 8.0 and 0.002, respectively. The diagnostic accuracy was 0.5. There was a strong agreement between the results obtained using CareStart™ and BS microscopy (kappa = 0.863, P < 0.0001). CONCLUSION: CareStart™ malaria HRP2/pLDH (Pf/pan) had high sensitivity and strong agreement with microscopy results. However, moderate specificity of RDT resulted in a substantial number of patients with false positive malaria test. Wherever available, microscopy should be used to confirm RDT test results.

Utilization patterns of malaria chemoprophylaxis among Tanzanian children attending sickle cell clinic in Dar es Salaam tertiary hospitals.

BACKGROUND: Malaria is among the leading cause of infection in individuals with sickle cell disease (SCD) living in sub-Saharan Africa, including Tanzania. However, after 2005 the standard treatment guidelines (STGs) on malaria chemoprevention for SCD patients were non-existent, and at present no medicine is recommended for SCD patients. Since several anti-malarials have been approved for the treatment of malaria in Tanzania, it is important to establish if there is a continued use of chemoprevention against malaria among SCD children. METHODS: A cross-sectional, hospital-based study was conducted between January and June 2019 at tertiary hospitals in Dar es Salaam. Data were collected using a semi-questionnaire and analysed using SPSS software version 25. The descriptive statistics were summarized using proportions, while factors associated with the use of chemoprophylaxis were analysed using multivariate logistic regression. Statistical significance of p < 0.05 was accepted. RESULTS: A total of 270 SCD children were involved. The median age of SCD children was 6 years (interquartile range (IQR): 3-11 years). Of 270 SCD children, 77% (number (n) = 218) of children with SCD had not been diagnosed with malaria in the previous year, whereas 12.6% (n = 34) of children were admitted because of malaria in the previous year. Regarding the use of chemoprophylaxis in SCD children, 32.6% (n = 88) of parents were aware that, chemoprophylaxis against malaria is recommended in SCD children. Of the 270 participants, 17% (n = 46) were using malaria chemoprophylaxis. A majority used artemisinin combination therapy (ACT), 56.8% (n = 26). Of 223 parents who did not give chemoprophylaxis, the majority (n = 142, 63.7%) indicated unavailability at clinics as the reason. Children whose parents were primary level educated were 9.9 times more likely to not use chemoprophylaxis (adjusted odds ratio (AOR); 9.9, 95% CI 1.8-56.5, P = 0.01) compared to those whose parents had tertiary education. CONCLUSION: Despite the lack of STGs, a small proportion of children with SCD were using malaria chemoprophylaxis where the majority used ACT, i.e., dihydroartemisinin-piperaquine.