Assessing Asymptomatic Malaria Carriage of Plasmodium falciparum and Non-falciparum Species in Children Resident in Nkolbisson, Yaoundé, Cameroon.

Malaria is still a threat to public health as it remains the first endemic disease in the world. It is a pervasive parasitic disease in tropical and subtropical regions where asymptomatic malaria infection among humans serves as a significant reservoir for transmission. A rapid and correct diagnosis is considered to be an important strategy in the control of the disease especially in children, who are the most vulnerable group. This study assessed the prevalence of asymptomatic malaria in children at the Nkolbisson health area in Yaoundé, Cameroon. A cross-sectional study design and a convenience sampling plan were used. A total of 127 participants were recruited after informed and signed consent from parents and/or guardians. Blood samples were collected by finger-pricking and venipuncture from children aged 6 months to 10 years and then screened for asymptomatic parasitemia by a rapid diagnostic test (RDT), light microscopy (LM) staining with Giemsa and 18S rRNA polymerase chain reaction (PCR) for speciation. The data were analyzed using SPSS version 20 software. The study identified 85 children who were positive from the PCR, 95 positive from the RDT and 71 from the LM, revealing a malaria prevalence of 66.9%, 74.8% and 55.9%, respectively. The prevalence was not observed to be dependent on the sex and age group of the participants. Plasmodium falciparum was the predominant species followed by Plasmodium malariae and then Plasmodium ovale. The RDT and LM had the same sensitivity (90.6%) with a slight difference in their specificity (RDT: 57.1%; LM: 54.8%). The RDT also demonstrated higher positive and negative predictive values compared with those of the LM.

Host candidate gene polymorphisms and associated clearance of P. falciparum amodiaquine and fansidar resistance mutants in children less than 5 years in Cameroon.

BACKGROUND: In this post-hoc analysis, we determined the influence of single nucleotide polymorphisms in host candidate immune genes on the outcome of drug resistant malaria in Cameroon. METHODS: Human DNA from 760 patients from a previous clinical trial was subjected to mass spectrometry-based single nucleotide polymorphism (SNP) genotyping. Allele frequencies of candidate immune genes were calculated for 62 SNPs on 17 human chromosomes for their possible involvement in clearance of drug-resistant parasites with the triple mutations of pfcrt76T, pfmdr86Y, and pfmdr1246Y (TY) and pfdhfr51I, pfdhfr59R, pfdhfr108N, and pfdhps437G (IRNG) which were determined by dotblot or PCR-restriction analysis. Differences in SNP frequencies and association analysis were carried out by comparing Chi-square odds ratios (ORs) and stratified by Mantel-Haenzel statistics. An adjusted P value (OR) <0·0008 was considered significant. RESULTS: Post-treatment drug failure rates were amodiaquine (36·4%); sulpadoxine/pyrimethamine-amodiaquine combination (15·4%); and sulphadoxine/pyrimethamine (18·1%). SNPs in IL22, IL-4R1, and CD36 appeared to have been associated with clearance of resistant parasites [p  =  0·017, OR (C allele):1·44, 95% CI (OR): 1·06-1·95]; [P  =  0·014, OR  =  1·31, 95% CI (OR): 1·07-1·83]; [P  =  5·78×10(-5), OR  =  0·27, 95%CI (OR): 0·13-0·54], respectively, with high fever (>39°C for 48 hours) [IL-22, P  =  0·01, OR  =  1·5, 95% CI (OR): 1·8-2·1] and also in high frequency among the Fulani participants [P  =  0·006, OR  =  1·83, 95% CI (OR): 1·11-3·08)]. The CD36-1264 null allele was completely absent in the northern population. CONCLUSION: Independent association of SNPs in IL22 and IL-4 with clearance of amodiaquine- and sulphadoxine/pyrimethamine-resistant parasites did not reach statistical significance, but may suggest that not all drug-resistant mutants are adversely affected by the same immune-mediated mechanisms of clearance.

Basic or enhanced clinician training to improve adherence to malaria treatment guidelines: a cluster-randomised trial in two areas of Cameroon.

BACKGROUND: The scale-up of malaria rapid diagnostic tests (RDTs) is intended to improve case management of fever and targeting of artemisinin-based combination therapy. Habitual presumptive treatment has hampered these intentions, suggesting a need for strategies to support behaviour change. We aimed to assess the introduction of RDTs when packaged with basic or enhanced clinician training interventions in Cameroon. METHODS: We did a three-arm, stratified, cluster-randomised trial at 46 public and mission health facilities at two study sites in Cameroon to compare three approaches to malaria diagnosis. Facilities were randomly assigned by a computer program in a 9:19:19 ratio to current practice with microscopy (widely available, used as a control group); RDTs with a basic (1 day) clinician training intervention; or RDTs with an enhanced (3 days) clinician training intervention. Patients (or their carers) and fieldworkers who administered surveys to obtain outcome data were masked to study group assignment. The primary outcome was the proportion of patients treated in accordance with WHO malaria treatment guidelines, which is a composite indicator of whether patients were tested for malaria and given appropriate treatment consistent with the test result. All analyses were by intention to treat. This study is registered at ClinicalTrials.gov, number NCT01350752. FINDINGS: The study took place between June 7 and Dec 14, 2011. The analysis included 681 patients from nine facilities in the control group, 1632 patients from 18 facilities in the basic-training group, and 1669 from 19 facilities in the enhanced-training group. The proportion of patients treated in accordance with malaria guidelines did not improve with either intervention; the adjusted risk ratio (RR) for basic training compared with control was 1·04 (95% CI 0·53-2·07; p=0·90), and for enhanced training compared with control was 1·17 (0·61-2·25; p=0·62). Inappropriate use of antimalarial drugs after a negative test was reduced from 84% (201/239) in the control group to 52% (413/796) in the basic-training group (unadjusted RR 0·63, 0·28-1·43; p=0·25) and to 31% (232/759) in the enhanced-training group (0·29, 0·11-0·77; p=0·02). INTERPRETATION: Enhanced clinician training, designed to translate knowledge into prescribing practice and improve quality of care, has the potential to halve overtreatment in public and mission health facilities in Cameroon. Basic training is unlikely to be sufficient to support the behaviour change required for the introduction of RDTs.

Designing and implementing interventions to change clinicians' practice in the management of uncomplicated malaria: lessons from Cameroon.

BACKGROUND: Effective case management of uncomplicated malaria is a fundamental pillar of malaria control. Little is known about the various steps in designing interventions to accompany the roll out of rapid diagnostic tests (RDTs) and artemisinin-based combination therapy (ACT). This study documents the process of designing and implementing interventions to change clinicians' practice in the management of uncomplicated malaria. METHODS: A literature review combined with formative quantitative and qualitative research were carried out to determine patterns of malaria diagnosis and treatment and to understand how malaria and its treatment are enacted by clinicians. These findings were used, alongside a comprehensive review of previous interventions, to identify possible strategies for changing the behaviour of clinicians when diagnosing and treating uncomplicated malaria. These strategies were discussed with ministry of health representatives and other stakeholders. Two intervention packages - a basic and an enhanced training were outlined, together with logic model to show how each was hypothesized to increase testing for malaria, improve adherence to test results and increase appropriate use of ACT. The basic training targeted clinicians' knowledge of malaria diagnosis, rapid diagnostic testing and malaria treatment. The enhanced training included additional modules on adapting to change, professionalism and communicating effectively. Modules were delivered using small-group work, card games, drama and role play. Interventions were piloted, adapted and trainers were trained before final implementation. RESULTS: Ninety-six clinicians from 37 health facilities in Bamenda and Yaounde sites attended either 1-day basic or 3-day enhanced training. The trained clinicians then trained 632 of their peers at their health facilities. Evaluation of the training revealed that 68% of participants receiving the basic and 92% of those receiving the enhanced training strongly agreed that it is not appropriate to prescribe anti-malarials to a patient if they have a negative RDT result. CONCLUSION: Formative research was an important first step, and it was valuable to engage stakeholders early in the process. A logic model and literature reviews were useful to identify key elements and mechanisms for behaviour change intervention. An iterative process with feedback loops allowed appropriate development and implementation of the intervention. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01350752.