Performance Characteristics of Malaria Rapid Diagnostic Test and Its Utilization in Management of Febrile Patients in Korogwe District (Tanga) Tanzania

Background: Malaria diagnosis continues to be the foremost among the challenge in malaria control strategies in Sub-Saharan countries including Tanzania. The World Health Organization changed malaria treatment Guidelines in 2010 to restrict the use of antimalarial drugs to parasitologically confirmed malaria cases in response to the overuse of antimalarial drugs. Malaria rapid diagnostic tests (mRDTs) are presented as a mean to implement the new guidelines for malaria parasitologically confirmed cases prior to initiating antimalarial drug therapy for mRDT positive patients. Methods: A hospital-based cross-sectional study among patients with fever and malaria-like symptoms was done between May and June, 2014 in Korogwe district hospital in a convenient manner. Data were cleaned and analysed in Epi-Info version 3.5.4 computer software, Chi-square test was used to compare proportions between two groups with P-value set at 0.05. Results: Results revealed that sensitivity, specificity, positive predictive value and negative predictive value of mRDT at 95% CI was 97.6%, 97.4%, 91.0% and 99.3% respectively. All patients with positive mRDT were treated with antimalarial drugs, while patients with negative mRDT results were treated with either antimalarial (P-value = 0.001) or antibiotics (P-value = 0.005) at 95% CI. The results of patients with negative mRDT results were less likely to be further investigated at 95% CI (P-value = 1.000). Conclusion: The mRDT had good sensitivity and specificity if compared with blood slide microscopy. Clinicians adhered to the 2010 World Health Organization guidelines adopted by the National Malaria Control Programme for patients with positive mRDT result; however, they did not adhere to malaria diagnosis and management guidelines in case of negative mRDT result

Malaria diagnosis and treatment practices following introduction of rapid diagnostic tests in Kibaha District, Coast Region, Tanzania

Background: The success of the universal parasite-based malaria testing policy for fever patients attending primary health care (PHC) facilities in Tanzania will depend highly on health workers\u27 perceptions and practices. The aim of this study was, therefore, to assess the present use of malaria diagnostics (rapid diagnostic tests (RDTs) and microscopy), prescription behaviour and factors affecting adherence to test results at PHC facilities in Kibaha District, Coast Region, Tanzania. Methods: Exit interviews were conducted with fever patients at PHC facilities and information on diagnostic test performed and treatment prescribed were recorded. Interviews with prescribers to assess their understanding, perceptions and practices related to RDTs were conducted, and health facility inventory performed to assess availability of staff, diagnostics and anti-malarial drugs. Results: The survey was undertaken at ten governmental PHC facilities, eight of which had functional diagnostics. Twenty health workers were interviewed and 195 exit interviews were conducted with patients at the PHC facilities. Of the 168 patients seen at facilities with available diagnostics, 105 (63%) were tested for malaria, 31 (30%) of whom tested positive. Anti-malarial drugs were prescribed to all patients with positive test results, 14% of patients with negative results and 28% of patients not tested for malaria. Antibiotics were more likely to be prescribed to patients with negative test results compared to patients with positive results (81 vs 39%, p \u3c 0.01) and among non-tested compared to those tested for malaria (84 vs 69%, p = 0.01). Stock-outs of RDTs and staff shortage accounted for the low testing rate, and health worker perceptions were the main reason for non-adherence to test results. Conclusions: Anti-malarial prescription to patients with negative test results and those not tested is still practiced in Tanzania despite the universal malaria testing policy of fever patients. The use of malaria diagnostics was also associated with higher prescription of antibiotics among patients with negative results. Strategies to address health system factors and health worker perceptions associated with these practices are needed. © 2013 Mubi et al.; licensee BioMed Central Ltd

Usefulness of Plasmodium falciparum-specific rapid diagnostic tests for assessment of parasite clearance and detection of recurrent infections after artemisinin-based combination therapy

Background: Rapid diagnostic test (RDT) is an important tool for parasite-based malaria diagnosis. High specificity of RDTs to distinguish an active Plasmodium falciparum infection from residual antigens from a previous infection is crucial in endemic areas where residents are repeatedly exposed to malaria. The efficiency of two RDTs based on histidine-rich protein 2 (HRP2) and lactate dehydrogenase (LDH) antigens were studied and compared with two microscopy techniques (Giemsa and acridine orange-stained blood smears) and real-time polymerase chain reaction (PCR) for assessment of initial clearance and detection of recurrent P. falciparum infections after artemisinin-based combination therapy (ACT) in a moderately high endemic area of rural Tanzania. Methods: In this exploratory study 53 children \u3c five years with uncomplicated P. falciparum malaria infection were followed up on nine occasions, i.e., day 1, 2, 3, 7, 14, 21, 28, 35 and 42, after initiation of artemether-lumefantrine treatment. At each visit capillary blood samples was collected for the HRP2 and LDH-based RDTs, Giemsa and acridine orange-stained blood smears for microscopy and real-time PCR. Assessment of clearance times and detection of recurrent P. falciparum infections were done for all diagnostic methods. Results: The median clearance times were 28 (range seven to \u3e42) and seven (two to 14) days for HRP2 and LDH-based RDTs, two (one to seven) and two (one to 14) days for Giemsa and acridine orange-stained blood smear and two (one to 28) days for real-time PCR. RDT specificity against Giemsa-stained blood smear microscopy was 21% for HRP2 on day 14, reaching 87% on day 42, and ≥96% from day 14 to 42 for LDH. There was no significant correlation between parasite density at enrolment and duration of HRP2 positivity (r = 0.13, p = 0.34). Recurrent malaria infections occurred in ten (19%) children. The HRP2 and LDH-based RDTs did not detect eight and two of the recurrent infections, respectively. Conclusion: The LDH-based RDT was superior to HRP2-based for monitoring of treatment outcome and detection of recurrent infections after ACT in this moderately high transmission setting. The results may have implications for the choice of RDT devices in similar transmission settings for improved malaria case management. Trial registration. Clinicaltrials.gov, NCT01843764. © 2013 Aydin-Schmidt et al.; licensee BioMed Central Ltd

Variant merozoite protein expression is associated with erythrocyte invasion phenotypes in Plasmodium falciparum isolates from Tanzania

[No abstract available

Impact of laboratory diagnosis for improving the management of uncomplicated malaria at peripheral health care settings in Coast region, Tanzania

Malaria is a disease caused by parasites of the genus Plasmodium. Five species cause human disease, but the most common in tropical areas, and the cause of severe disease is Plasmodium falciparum. Control of morbidity and mortality is mainly achieved through appropriate malaria case management, which includes prompt diagnosis and treatment with effective antimalarial drugs. While definitive diagnosis of malaria is made by demonstration of parasites in the patient blood through microscopic examination of giemsa stained blood smears, in most clinical settings in Africa, diagnosis is limited by lack of facilities and personnel. The availability of malaria rapid diagnostic tests (RDTs) offers an opportunity to extend diagnostic services to areas previously not covered by conventional microscopy services. Two intervention trials were conducted, one at primary health care (PHC) facilities using microscopy, and the other at community level, through community health workers (CHWs), using rapid diagnostic tests (RDTs) for malaria diagnosis, and the impact of the interventions on antimalarial drugs prescription practices, antibiotic prescriptions and health outcome was investigated (Study I and II). A descriptive, cross sectional study was conducted to assess health workers diagnostic and prescription practices following introduction of RDTs for universal testing of malaria at PHC level in Tanzania (Study III). An exploratory study was also carried out to assess the usefulness of Histidine rich protein 2 (HRP2) and lactate dehydrogenase (LDH) based RDTs for treatment monitoring and detection of recurrent infection following artemisinin-based combination therapy (ACT) during a 42 day follow up period (Study IV). The use of parasite-based diagnostics significantly reduced antimalarial prescriptions at health facility and community level without affecting the health outcome of patients not treated with antimalarials (study I and II). The prescriptions of antimalarial drugs were 61% at intervention health facilities, whereas in the clinical and control arms the prescription rates remained high, 95% and 99%, respectively (study I). Similarly, 53% of patients tested with RDT at community level were provided antimalarial drugs compared to 96% among patients treated based on clinical diagnosis only (Study II). The availability of parasite-based diagnostics and antimalarial drugs within the community allowed early access to treatment as 67% of patients consulted CHWs within 24 hours of onset of fever (Study II). The rate of non adherence to test results was low in both study I and II. Study III observed low use of parasite-based diagnostics among fever patients (63%), low non adherence to test results (14%), substantial prescription of antimalarial drugs to non-tested patients (28%) and high prescriptions of antibiotics among patients with negative RDT results (81%), as well as frequent stock outs of both RDTs and ACTs. HRP2 based tests performed poorly when compared to LDH based tests for treatment monitoring, with median clearance times of 28 (7-42) and 7 (2-14) days respectively (Study IV). HRP2 based tests were unable to detect 8/10 recurrent infections during follow up compared to only two recurrent infections missed by LDH based tests. These studies lead to a conclusion that the availability of parasite-based diagnostics helps to restrict treatment with antimalarial drugs to patients with malaria. However, non adherence to malaria test results could undermine the potential of RDTs, and in-depth studies should be conducted to identify its causes. As the relative contribution of malaria as a cause of fever is declining in Tanzania, there is need to improve the overall management of non-malarial fevers. The longer the persistence of HRP2 antigen in blood makes HRP2 based tests not suitable for treatment monitoring and detection of recurrent infection calling for alternative diagnostic strategies for this purpose

Diagnostic Testing of Pediatric Fevers: Meta-Analysis of 13 National Surveys Assessing Influences of Malaria Endemicity and Source of Care on Test Uptake for Febrile Children under Five Years.

In 2010, the World Health Organization revised guidelines to recommend diagnosis of all suspected malaria cases prior to treatment. There has been no systematic assessment of malaria test uptake for pediatric fevers at the population level as countries start implementing guidelines. We examined test use for pediatric fevers in relation to malaria endemicity and treatment-seeking behavior in multiple sub-Saharan African countries in initial years of implementation. We compiled data from national population-based surveys reporting fever prevalence, care-seeking and diagnostic use for children under five years in 13 sub-Saharan African countries in 2009-2011/12 (n = 105,791). Mixed-effects logistic regression models quantified the influence of source of care and malaria endemicity on test use after adjusting for socioeconomic covariates. Results were stratified by malaria endemicity categories: low (PfPR2-10<5%), moderate (PfPR2-10 5-40%), high (PfPR2-10>40%). Among febrile under-fives surveyed, 16.9% (95% CI: 11.8%-21.9%) were tested. Compared to hospitals, febrile children attending non-hospital sources (OR: 0.62, 95% CI: 0.56-0.69) and community health workers (OR: 0.31, 95% CI: 0.23-0.43) were less often tested. Febrile children in high-risk areas had reduced odds of testing compared to low-risk settings (OR: 0.51, 95% CI: 0.42-0.62). Febrile children in least poor households were more often tested than in poorest (OR: 1.63, 95% CI: 1.39-1.91), as were children with better-educated mothers compared to least educated (OR: 1.33, 95% CI: 1.16-1.54). Diagnostic testing of pediatric fevers was low and inequitable at the outset of new guidelines. Greater testing is needed at lower or less formal sources where pediatric fevers are commonly managed, particularly to reach the poorest. Lower test uptake in high-risk settings merits further investigation given potential implications for diagnostic scale-up in these areas. Findings could inform continued implementation of new guidelines to improve access to and equity in point-of-care diagnostics use for pediatric fevers