Using the role model approach to optimise caregiver administration of sulfadoxine-pyrimethamine amodiaquine to children aged 3-59 months in Burkina Faso, Chad and Togo: findings from an evaluation.

BACKGROUND: Seasonal malaria chemoprevention (SMC) is a World Health Organization-recommended intervention for the prevention of malaria among children at high risk in areas with seasonal transmission. During the coronavirus disease 2019 (COVID-19) pandemic, SMC drug distribution was rapidly adapted to reduce contact and mitigate the risk of transmission between communities and community distributors, with caregivers administering doses. To address the challenges and find local solutions to improve administration and adherence, the role model approach was designed, implemented and evaluated in selected communities of Burkina Faso, Chad and Togo. This paper describes the results of this evaluation. METHODS: Focus group discussions were held with primary caregivers in all three countries to understand their perceptions of the approach's acceptability and feasibility. In Burkina Faso and Togo, household surveys assessed the characteristics of caregivers reached by role model activities. Key indicators on SMC coverage and adherence allowed for an assessment of caregiver engagement outcomes related to participation in activities. Statistical associations between participation in study's activities and caregiver beliefs related to SMC had been tested. RESULTS: The majority of caregivers believed the approach to have a positive effect on drug administration, with most adopting the promoted strategies. Greater involvement of fathers in drug administration and acknowledgement of their joint responsibility was a notable positive outcome. However, several barriers to participation were noted and there was criticism of the group approach. In Burkina Faso and Togo, end-of-round survey results revealed that 98.4% of respondents agreed the approach improved their knowledge and skills in malaria prevention, while 100% expressed a desire to continue practicing the behaviours learned. However, there was a relatively low level of awareness of the approach among communities. Participation was strongly associated with participants' self-reported belief in ease of remembering to administer, and ease of administering, SMC medicines. CONCLUSION: Caregivers perceived the role model approach to be beneficial in aiding drug administration, with other positive impacts also reported. Replication and scale-up should utilize the most popular communication channels and existing community structures to ensure activities are promoted effectively. A mixture of group and one-on-one approaches should be used where appropriate and feasible.

Impact of seasonal malaria chemoprevention based on the number of medicines doses received on malaria burden among children aged 3-59 months in Nigeria: A propensity score-matched analysis.

BACKGROUND: Seasonal malaria chemoprevention using sulfadoxine-pyrimethamine plus amodiaquine (sulfadoxine-pyrimethamine plus amodiaquine on Day 1 and amodiaquine on both Day 2 and Day 3) is delivered to children aged 3-59 months in areas of highly season malaria transmission. While the overall population-level impact of seasonal malaria chemoprevention on malaria control has been documented in various countries and time periods, there is no clear evidence regarding seasonal malaria chemoprevention impact based on the number of medicine doses children receive in one cycle in routine programmatic conditions. METHODS: Data were extracted from Nigeria's routinely collected seasonal malaria chemoprevention end-of-round coverage surveys (2021, 2022). We matched seasonal malaria chemoprevention-targeted children who received specific numbers of seasonal malaria chemoprevention medicines with those who did not receive any doses of seasonal malaria chemoprevention medicines (non-sulfadoxine-pyrimethamine plus amodiaquine) using multiple sets of propensity score matches. We performed multilevel logistic regression for each matched group to evaluate the association between the number of doses of seasonal malaria chemoprevention medicines and monthly confirmed malaria cases (caregiver-reported malaria infection diagnosed by rapid diagnostic test at a health facility following the penultimate cycle of seasonal malaria chemoprevention). RESULTS: Among 21,621 SMC-targeted children, 9.7% received non-sulfadoxine-pyrimethamine plus amodiaquine, 0.5% received only Day 1 sulfadoxine-pyrimethamine plus amodiaquine, 1.0% received Day 1 sulfadoxine-pyrimethamine plus amodiaquine and either Day 2 amodiaquine or Day 3 amodiaquine (sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine), and 88.8% received Day 1 sulfadoxine-pyrimethamine plus amodiaquine and both Day 2 and Day 3 amodiaquine (sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine + amodiaquine). Children receiving only Day 1 sulfadoxine-pyrimethamine plus amodiaquine did not have significant lower odds of rapid diagnostic tests-confirmed malaria than those receiving non-sulfadoxine-pyrimethamine plus amodiaquine (OR 0.77, 0.42-1.42). However, children receiving sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine had significantly lower odds of rapid diagnostic tests-confirmed malaria than those receiving non-sulfadoxine-pyrimethamine plus amodiaquine (OR 0.42, 95% CI 0.28-0.63). Similarly, children receiving sulfadoxine-pyrimethamine plus amodiaquine + amodiaquine + amodiaquine also had significantly lower odds of rapid diagnostic test-confirmed malaria than those receiving non-sulfadoxine-pyrimethamine plus amodiaquine (OR 0.54, 95% CI 0.47-0.62). CONCLUSION: Adherence to at least one daily dose of amodiaquine administration following receipt of Day 1 sulfadoxine-pyrimethamine plus amodiaquine by eligible children is crucial to ensure the effectiveness of seasonal malaria chemoprevention. This demonstrates the importance of enhancing caregiver awareness regarding the importance of amodiaquine and identifying barriers toward amodiaquine administration at the community level.

Artemether-lumefantrine with or without single-dose primaquine and sulfadoxine-pyrimethamine plus amodiaquine with or without single-dose tafenoquine to reduce Plasmodium falciparum transmission: a phase 2, single-blind, randomised clinical trial in Ouelessebougou, Mali.

BACKGROUND: Artemether-lumefantrine is widely used for uncomplicated Plasmodium falciparum malaria; sulfadoxine-pyrimethamine plus amodiaquine is used for seasonal malaria chemoprevention. We aimed to determine the efficacy of artemether-lumefantrine with and without primaquine and sulfadoxine-pyrimethamine plus amodiaquine with and without tafenoquine for reducing gametocyte carriage and transmission to mosquitoes. METHODS: In this phase 2, single-blind, randomised clinical trial conducted in Ouelessebougou, Mali, asymptomatic individuals aged 10-50 years with P falciparum gametocytaemia were recruited from the community and randomly assigned (1:1:1:1) to receive either artemether-lumefantrine, artemether-lumefantrine with a single dose of 0·25 mg/kg primaquine, sulfadoxine-pyrimethamine plus amodiaquine, or sulfadoxine-pyrimethamine plus amodiaquine with a single dose of 1·66 mg/kg tafenoquine. All trial staff other than the pharmacist were masked to group allocation. Participants were not masked to group allocation. Randomisation was done with a computer-generated randomisation list and concealed with sealed, opaque envelopes. The primary outcome was the median within-person percent change in mosquito infection rate in infectious individuals from baseline to day 2 (artemether-lumefantrine groups) or day 7 (sulfadoxine-pyrimethamine plus amodiaquine groups) after treatment, assessed by direct membrane feeding assay. All participants who received any trial drug were included in the safety analysis. This study is registered with ClinicalTrials.gov, NCT05081089. FINDINGS: Between Oct 13 and Dec 16, 2021, 1290 individuals were screened and 80 were enrolled and randomly assigned to one of the four treatment groups (20 per group). The median age of participants was 13 (IQR 11-20); 37 (46%) of 80 participants were female and 43 (54%) were male. In individuals who were infectious before treatment, the median percentage reduction in mosquito infection rate 2 days after treatment was 100·0% (IQR 100·0-100·0; n=19; p=0·0011) with artemether-lumefantrine and 100·0% (100·0-100·0; n=19; p=0·0001) with artemether-lumefantrine with primaquine. Only two individuals who were infectious at baseline infected mosquitoes on day 2 after artemether-lumefantrine and none at day 5. By contrast, the median percentage reduction in mosquito infection rate 7 days after treatment was 63·6% (IQR 0·0-100·0; n=20; p=0·013) with sulfadoxine-pyrimethamine plus amodiaquine and 100% (100·0-100·0; n=19; p<0·0001) with sulfadoxine-pyrimethamine plus amodiaquine with tafenoquine. No grade 3-4 or serious adverse events occurred. INTERPRETATION: These data support the effectiveness of artemether-lumefantrine alone for preventing nearly all mosquito infections. By contrast, there was considerable post-treatment transmission after sulfadoxine-pyrimethamine plus amodiaquine; therefore, the addition of a transmission-blocking drug might be beneficial in maximising its community impact. FUNDING: Bill & Melinda Gates Foundation.

Effect of seasonal malaria chemoprevention plus azithromycin on Plasmodium falciparum transmission: gametocyte infectivity and mosquito fitness.

BACKGROUND: Seasonal malaria chemoprevention (SMC) consists of administration of sulfadoxine-pyrimethamine (SP) + amodiaquine (AQ) at monthly intervals to children during the malaria transmission period. Whether the addition of azithromycin (AZ) to SMC could potentiate the benefit of the intervention was tested through a double-blind, randomized, placebo-controlled trial. The effect of SMC and the addition of AZ, on malaria transmission and on the life history traits of Anopheles gambiae mosquitoes have been investigated. METHODS: The study included 438 children randomly selected from among participants in the SMC + AZ trial and 198 children from the same area who did not receive chemoprevention. For each participant in the SMC + AZ trial, blood was collected 14 to 21 days post treatment, examined for the presence of malaria sexual and asexual stages and provided as a blood meal to An. gambiae females using a direct membrane-feeding assay. RESULTS: The SMC treatment, with or without AZ, significantly reduced the prevalence of asexual Plasmodium falciparum (LRT X22 = 69, P < 0.0001) and the gametocyte prevalence (LRT X22 = 54, P < 0.0001). In addition, the proportion of infectious feeds (LRT X22 = 61, P < 0.0001) and the prevalence of oocysts among exposed mosquitoes (LRT X22 = 22.8, P < 0.001) was reduced when mosquitoes were fed on blood from treated children compared to untreated controls. The addition of AZ to SPAQ was associated with an increased proportion of infectious feeds (LRT X21 = 5.2, P = 0.02), suggesting a significant effect of AZ on gametocyte infectivity. There was a slight negative effect of SPAQ and SPAQ + AZ on mosquito survival compared to mosquitoes fed with blood from control children (LRTX22 = 330, P < 0.0001). CONCLUSION: This study demonstrates that SMC may contribute to a reduction in human to mosquito transmission of P. falciparum, and the reduced mosquito longevity observed for females fed on treated blood may increase the benefit of this intervention in control of malaria. The addition of AZ to SPAQ in SMC appeared to enhance the infectivity of gametocytes providing further evidence that this combination is not an appropriate intervention.

Effectiveness of seasonal malaria chemoprevention at scale in west and central Africa: an observational study.

BACKGROUND: Seasonal malaria chemoprevention (SMC) aims to prevent malaria in children during the high malaria transmission season. The Achieving Catalytic Expansion of SMC in the Sahel (ACCESS-SMC) project sought to remove barriers to the scale-up of SMC in seven countries in 2015 and 2016. We evaluated the project, including coverage, effectiveness of the intervention, safety, feasibility, drug resistance, and cost-effectiveness. METHODS: For this observational study, we collected data on the delivery, effectiveness, safety, influence on drug resistance, costs of delivery, impact on malaria incidence and mortality, and cost-effectiveness of SMC, during its administration for 4 months each year (2015 and 2016) to children younger than 5 years, in Burkina Faso, Chad, The Gambia, Guinea, Mali, Niger, and Nigeria. SMC was administered monthly by community health workers who visited door-to-door. Drug administration was monitored via tally sheets and via household cluster-sample coverage surveys. Pharmacovigilance was based on targeted spontaneous reporting and monitoring systems were strengthened. Molecular markers of resistance to sulfadoxine-pyrimethamine and amodiaquine in the general population before and 2 years after SMC introduction was assessed from community surveys. Effectiveness of monthly SMC treatments was measured in case-control studies that compared receipt of SMC between patients with confirmed malaria and neighbourhood-matched community controls eligible to receive SMC. Impact on incidence and mortality was assessed from confirmed outpatient cases, hospital admissions, and deaths associated with malaria, as reported in national health management information systems in Burkina Faso and The Gambia, and from data from selected outpatient facilities (all countries). Provider costs of SMC were estimated from financial costs, costs of health-care staff time, and volunteer opportunity costs, and cost-effectiveness ratios were calculated as the total cost of SMC in each country divided by the predicted number of cases averted. FINDINGS: 12 467 933 monthly SMC treatments were administered in 2015 to a target population of 3 650 455 children, and 25 117 480 were administered in 2016 to a target population of 7 551 491. In 2015, among eligible children, mean coverage per month was 76·4% (95% CI 74·0-78·8), and 54·5% children (95% CI 50·4-58·7) received all four treatments. Similar coverage was achieved in 2016 (74·8% [72·2-77·3] treated per month and 53·0% [48·5-57·4] treated four times). In 779 individual case safety reports over 2015-16, 36 serious adverse drug reactions were reported (one child with rash, two with fever, 31 with gastrointestinal disorders, one with extrapyramidal syndrome, and one with Quincke's oedema). No cases of severe skin reactions (Stevens-Johnson or Lyell syndrome) were reported. SMC treatment was associated with a protective effectiveness of 88·2% (95% CI 78·7-93·4) over 28 days in case-control studies (2185 cases of confirmed malaria and 4370 controls). In Burkina Faso and The Gambia, implementation of SMC was associated with reductions in the number of malaria deaths in hospital during the high transmission period, of 42·4% (95% CI 5·9 to 64·7) in Burkina Faso and 56·6% (28·9 to 73·5) in The Gambia. Over 2015-16, the estimated reduction in confirmed malaria cases at outpatient clinics during the high transmission period in the seven countries ranged from 25·5% (95% CI 6·1 to 40·9) in Nigeria to 55·2% (42·0 to 65·3) in The Gambia. Molecular markers of resistance occurred at low frequencies. In individuals aged 10-30 years without SMC, the combined mutations associated with resistance to amodiaquine (pfcrt CVIET haplotype and pfmdr1 mutations [86Tyr and 184Tyr]) had a prevalence of 0·7% (95% CI 0·4-1·2) in 2016 and 0·4% (0·1-0·8) in 2018 (prevalence ratio 0·5 [95% CI 0·2-1·2]), and the quintuple mutation associated with resistance to sulfadoxine-pyrimethamine (triple mutation in pfdhfr and pfdhps mutations [437Gly and 540Glu]) had a prevalence of 0·2% (0·1-0·5) in 2016 and 1·0% (0·6-1·6) in 2018 (prevalence ratio 4·8 [1·7-13·7]). The weighted average economic cost of administering four monthly SMC treatments was US$3·63 per child. INTERPRETATION: SMC at scale was effective in preventing morbidity and mortality from malaria. Serious adverse reactions were rarely reported. Coverage varied, with some areas consistently achieving high levels via door-to-door campaigns. Markers of resistance to sulfadoxine-pyrimethamine and amodiaquine remained uncommon, but with some selection for resistance to sulfadoxine-pyrimethamine, and the situation needs to be carefully monitored. These findings should support efforts to ensure high levels of SMC coverage in west and central Africa. FUNDING: Unitaid.

Adherence and Population Pharmacokinetic Properties of Amodiaquine When Used for Seasonal Malaria Chemoprevention in African Children.

Poor adherence to seasonal malaria chemoprevention (SMC) might affect the protective effectiveness of SMC. Here, we evaluated the population pharmacokinetic properties of amodiaquine and its active metabolite, desethylamodiaquine, in children receiving SMC under directly observed ideal conditions (n = 136), and the adherence of SMC at an implementation phase in children participating in a case-control study to evaluate SMC effectiveness (n = 869). Amodiaquine and desethylamodiaquine concentration-time profiles were described simultaneously by two-compartment and three-compartment disposition models, respectively. The developed methodology to evaluate adherence showed a sensitivity of 65-71% when the first dose of SMC was directly observed and 71-73% when no doses were observed in a routine programmatic setting. Adherence simulations and measured desethylamodiaquine concentrations in the case-control children showed complete adherence (all doses taken) in < 20% of children. This result suggests that more efforts are needed urgently to improve the adherence to SMC among children in this area.

Population Pharmacokinetic Properties of Sulfadoxine and Pyrimethamine: a Pooled Analysis To Inform Optimal Dosing in African Children with Uncomplicated Malaria.

Sulfadoxine-pyrimethamine with amodiaquine is recommended by the World Health Organization as seasonal malaria chemoprevention for children aged 3 to 59 months in the sub-Sahel regions of Africa. Suboptimal dosing in children may lead to treatment failure and increased resistance. Pooled individual patient data from four previously published trials on the pharmacokinetics of sulfadoxine and pyrimethamine in 415 pediatric and 386 adult patients were analyzed using nonlinear mixed-effects modeling to evaluate the current dosing regimen and, if needed, to propose an optimized dosing regimen for children under 5 years of age. The population pharmacokinetics of sulfadoxine and pyrimethamine were both best described by a one-compartment disposition model with first-order absorption and elimination. Body weight, age, and nutritional status (measured as the weight-for-age Z-score) were found to be significant covariates. Allometric scaling with total body weight and the maturation of clearance in children by postgestational age improved the model fit. Underweight-for-age children were found to have 15.3% and 26.7% lower bioavailabilities of sulfadoxine and pyrimethamine, respectively, for each Z-score unit below -2. Under current dosing recommendations, simulation predicted that the median day 7 concentration was below the 25th percentile for a typical adult patient (50 kg) for sulfadoxine for patients in the weight bands of 8 to 9, 19 to 24, 46 to 49, and 74 to 79 kg and for pyrimethamine for patients in the weight bands of 8 to 9, 14 to 24, and 42 to 49 kg. An evidence-based dosing regimen was constructed that would achieve sulfadoxine and pyrimethamine exposures in young children and underweight-for-age young children that were similar to those currently seen in a typical adult.

Novel anti-adipogenic activity of anti-malarial amodiaquine through suppression of PPARγ activity.

Amodiaquine (AQ) was developed as a selective drug against Plasmodium falciparum malaria infection and has received increasing attention as a therapeutic agent for the treatment of rheumatoid arthritis, Parkinson's disease, and cancer due to its anti-inflammatory, anti-proliferative, and autophagic-lysosomal blockade properties. As autophagy activation is involved in promoting adipogenic differentiation, we examined whether anti-autophagic AQ affected adipocyte differentiation of 3T3-L1 pre-adipocytes. AQ dose-dependently and significantly suppressed adipocyte differentiation in conjunction with decreases in lipid droplet formation and expression of adipogenic markers including adiponectin, adipocyte fatty acid-binding protein 2 (aP2), resistin, and leptin. Although peroxisome proliferator-activated receptor γ (PPARγ) decreases by inhibition of autophagy, AQ treatment did not induce PPARγ degradation despite the suppression of autophagolysosomal degradation. Instead, AQ suppressed the PPARγ activity to transcriptionally activate the aP2 gene transcription through the selective prevention of nuclear localization of PPARγ. These results demonstrated the novel anti-adipogenic activity of AQ and identified its underlying mechanism that AQ suppressed adipogenic gene expression and lipid formation by inhibiting nuclear localization of PPARγ in an autophagy-independent manner. AQ is recommended as a safe and effective anti-obesity drug for controlling overweight and obesity.

Supernatant from Hepatocyte Cultures with Drugs That Cause Idiosyncratic Liver Injury Activates Macrophage Inflammasomes.

There is increasing evidence that most idiosyncratic drug-induced liver injury (IDILI) is immune mediated, and in most cases, reactive metabolites appear to be responsible for the induction of this immune response. Reactive metabolites can cause cell damage with the release of damage-associated molecular patterns (DAMPs), which is thought to be involved in immune activation. Presumably, the reason that the liver is a common target of idiosyncratic drug reactions is because it is the major site of drug metabolism and reactive metabolite formation. Inflammasomes can be activated by DAMPs, and this may be a common mechanism by which DAMPs initiate an immune response. In this study, we tested the ability of drugs to induce the release of DAMPs that activate inflammasomes. The drugs tested were amodiaquine and nevirapine; both are associated with significant incidences of severe IDILI. The hepatocytes were a human hepatocarcinoma functional liver cell-4 (FLC-4) cell line. For the detection of inflammasome activation, we used the human macrophage cell line, THP-1 cells. We found that the supernatant from the incubation of both drugs with FLC-4 cells for 7 days led to increased caspase-1 activity and production of IL-1ß by THP-1 cells. However, amodiaquine alone also directly activated THP-1 cells. This is presumably because the myeloperoxidase in THP-1 cells can bioactivate amodiaquine to a reactive metabolite. In contrast, nevirapine requires cytochromes P450 for reactive metabolite formation and therefore required incubation with hepatocytes. These results support the hypothesis that reactive metabolites of drugs can cause the release of DAMPs, which in turn can activate inflammasomes. Inflammasome activation may be an important step in the activation of the immune system by drugs, which in some patients can lead to IDILI. Our in vitro model is simple and convenient for evaluating inflammasome activation, and this may be a method to screen drugs for IDILI risk.

The effect of iron-fortified complementary food and intermittent preventive treatment of malaria on anaemia in 12- to 36-month-old children: a cluster-randomised controlled trial.

BACKGROUND: Iron deficiency (ID) and malaria co-exist in tropical regions and both contribute to high rates of anaemia in young children. It is unclear whether iron fortification combined with intermittent preventive treatment (IPT) of malaria would be an efficacious strategy for reducing anaemia in young children. METHODS: A 9-month cluster-randomised, single-blinded, placebo-controlled intervention trial was carried out in children aged 12-36 months in south-central Côte d'Ivoire, an area of intense and perennial malaria transmission. The study groups were: group 1: normal diet and IPT-placebo (n = 125); group 2: consumption of porridge, an iron-fortified complementary food (CF) with optimised composition providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferrous fumarate 6 days per week (CF-FeFum) and IPT-placebo (n = 126); group 3: IPT of malaria at 3-month intervals, using sulfadoxine-pyrimethamine and amodiaquine and no dietary intervention (n = 127); group 4: both CF-FeFum and IPT (n = 124); and group 5: consumption of porridge, an iron-fortified CF with the composition currently on the Ivorian market providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferric pyrophosphate 6 days per week (CF-FePP) and IPT-placebo (n = 127). The primary outcome was haemoglobin (Hb) concentration. Linear and logistic regression mixed-effect models were used for the comparison of the five study groups, and a 2 × 2 factorial analysis was used to assess treatment interactions of CF-FeFum and IPT (study groups 1-4). RESULTS: After 9 months, the Hb concentration increased in all groups to a similar extent with no statistically significant difference between groups. In the 2 × 2 factorial analysis after 9 months, no treatment interaction was found on Hb (P = 0.89). The adjusted differences in Hb were 0.24 g/dl (95 % CI -0.10 to 0.59; P = 0.16) in children receiving IPT and -0.08 g/dl (95 % CI -0.42 to 0.26; P = 0.65) in children receiving CF-FeFum. At baseline, anaemia (Hb <11.0 g/dl) was 82.1 %. After 9 months, IPT decreased the odds of anaemia (odds ratio [OR], 0.46 [95 % CI 0.23-0.91]; P = 0.023), whereas iron-fortified CF did not (OR, 0.85 [95 % CI 0.43-1.68]; P = 0.68), although ID (plasma ferritin <30 µg/l) was decreased markedly in children receiving iron fortified CF (OR, 0.19 [95 % CI 0.09-0.40]; P < 0.001). CONCLUSIONS: IPT alone only modestly decreased anaemia, but neither IPT nor iron fortified CF significantly improved Hb concentration after 9 months. Additionally, IPT did not augment the effect of the iron fortified CF. CF fortified with highly bioavailable iron improved iron status but not Hb concentration, despite three-monthly IPT of malaria. Thus, further research is necessary to develop effective combination strategies to prevent and treat anaemia in malaria endemic regions. TRIAL REGISTRATION: http://www.clinicaltrials.gov ; identifier NCT01634945; registered on July 3, 2012.

Artesunate + amodiaquine versus artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria in the Colombian Pacific region: a noninferiority trial / Artesunato + amodiaquina versus artemether-limefantrina para o tratamento da malaria não complicada por Plamodium falciparum no Pacifico Colombiano: um estudo de não inferioridade

INTRODUCTION: In Colombia, there are no published studies for the treatment of uncomplicated Plasmodium falciparum malaria comparing artemisinin combination therapies. Hence, it is intended to demonstrate the non-inferior efficacy/safety profiles of artesunate + amodiaquine versus artemether-lumefantrine treatments. METHODS: A randomized, controlled, open-label, noninferiority (Δ≤5%) clinical trial was performed in adults with uncomplicated P. falciparum malaria using the 28‑day World Health Organization validated design/definitions. Patients were randomized 1:1 to either oral artesunate + amodiaquine or artemether-lumefantrine. The primary efficacy endpoint: adequate clinical and parasitological response; secondary endpoints: - treatment failures defined per the World Health Organization. Safety: assessed through adverse events. RESULTS: A total of 105 patients was included in each group: zero censored observations. Mean (95%CI - Confidence interval) adequate clinical and parasitological response rates: 100% for artesunate + amodiaquine and 99% for artemether-lumefantrine; the noninferiority criteria was met (Δ=1.7%). There was one late parasitological therapeutic failure (1%; artemether-lumefantrine group), typified by polymerase chain reaction as the MAD20 MSP1 allele. The fever clearance time (artesunate + amodiaquine group) was significantly shorter (p=0.002). Respectively, abdominal pain for artesunate + amodiaquine and artemether-lumefantrine was 1.9% and 3.8% at baseline (p=0.68) and 1% and 13.3% after treatment (p<0.001). CONCLUSIONS: Uncomplicated P. falciparum malaria treatment with artesunate + amodiaquine is noninferior to the artemether-lumefantrine standard treatment. The efficacy/safety profiles grant further studies in this and similar populations.

INTRODUÇÃO: Na Colômbia não existem estudos publicados sobre o tratamento da malária não complicada por Plasmodium falciparum comparando as terapias combinadas com artemisinina. Destarte, quer se demonstrar a não inferioridade dos perfis de eficácia/segurança dos tratamentos com artesunato+amodiaquina versus artemeter-lumefantrina. MÉTODOS: Foi realizado um estudo clínico de não inferioridade (∆≤5%), aleatório, controlado, aberto, em adultos com malária não complicada por P. falciparum usando o desenho validado de 28 dias e os desenhos validados/definidos pela Organização Mundial da Saúde. Os pacientes foram aleatorizados (1:1) para ambos artesunato+amodiaquina ou artemeter-lumefantrina orais. Critérios primários de eficácia: resposta clínica e parasitológica adequada; Criterios de eficácia secundários: as falhas de tratamento definidos pela Organização Mundial da Saúde. A segurança: avaliada através de eventos adversos. RESULTADOS: Foram incursos 105 pacientes em cada grupo: zero observações censuradas. As taxas médias da resposta clínica e parasitológica adequada (95% IC - intervalo de confiança): 100% para artesunato+amodiaquina e 99% para artemeter-lumefantrina; atingiu-se o critério de não inferioridade (∆=1.7%). Houve uma falha terapêutica parasitológica tardia (1%; grupo artemeter-lumefantrina), caracterizada mediante reação em cadeia da polimerase como o alelo MAD20 MSP1. Tempo de remissão da febre (grupo artesunato+amodiaquina), foi significativamente mais curto (p=0.002). Dor abdominal, para artesunato+amodiaquina e artemeter-lumefantrina, respectivamente, 1.9% e 3.8% (p=0.68) na linha de base, 1% e 13.3% pós-tratamento (p<0.001). CONCLUSÕES: O tratamento com artesunato+amodiaquina da malária não complicada por P. falciparum é não inferior ao tratamento normal com artemeter-lumefantrina. Os perfis de eficácia/segurança justificam estudos adicionais nesta e outras populações semelhantes.

Two-year evaluation of Intermittent Preventive Treatment for Children (IPTc) combined with timely home treatment for malaria control in Ghana.

BACKGROUND: Intermittent preventive treatment (IPT) has recently been accepted as an important component of the malaria control strategy. Intermittent preventive treatment for children (IPTc) combined with timely treatment of malaria related febrile illness at home to reduce parasite prevalence and malaria morbidity in children aged between six and 60 months in a coastal community in Ghana. This paper reports persistence of reduced parasitaemia two years into the intervention. The baseline and year-one-evaluation findings were published earlier. OBJECTIVE: The main objective in the second year was to demonstrate whether the two interventions would further reduce parasite prevalence and malaria-related febrile illness in the study population. METHODS: This was an intervention study designed to compare baseline and evaluation findings without a control group. The study combined home-based delivery of intermittent preventive treatment for children (IPTc) aged 6 - 60 months and home treatment of suspected febrile malaria-related illness within 24 hours. All children aged 6-60 months received home-based delivery of intermittent preventive treatment using amodiaquine + artesunate, delivered at home by community assistants every four months (6 times in 24 months). Malaria parasite prevalence surveys were conducted before the first and after the third and sixth IPTc to the children. The evaluation surveys were done four months after the third and sixth IPTc was given. RESULTS: Parasite prevalence which reduced from 25% to 3.0% at year-one evaluation had reduced further from 3% to 1% at year-two-evaluation. At baseline, 13.8% of the children were febrile (axilary temperature of ≥ 37.5 °C) compared to 2.2% at year-one-evaluation while 2.1% were febrile at year-two-evaluation. CONCLUSION: The year-two-evaluation result indicates that IPTc given three times in a year (every four months) combined with timely treatment of febrile malaria illness, is effective to reduce malaria parasite prevalence in children aged 6 to 60 months in the study community. This must give hope to malaria control programme managers in sub-Saharan Africa where the burden of the disease is most debilitating.

High prevalence of CYP2A6*4 and CYP2A6*9 alleles detected among a Malaysian population.

BACKGROUND: CYP2A6 gene encodes the principal enzyme involved in the metabolism of many drugs including artesunate. We developed a simplified duplex nested PCR method for the detection of the CYP2A61B, CYP2A62, CYP2A64, CYP2A67, CYP2A68 and CYP2A69 variant alleles highly prevalent among Malaysian population. METHODS: Genomic DNA was isolated from peripheral blood of patients treated with artesunate by using a DNA extraction kit. Fragments from TATA box in 5' flanking region, exons 1 to 4 and exon 8 to 3' UTR of the gene were amplified using a first PCR step (PCR1). Products from PCR1 were then used to run a duplex PCR (PCR2) for detecting the selected variant alleles. RESULTS: All 6 CYP2A6 alleles were successfully amplified and confirmed by sequencing. The frequency of the alleles were 14.6% for CYP2A61B, 16.7% for CYP2A64, 4.2% for CYP2A68 and 10.4% for CYP2A69. CONCLUSION: High frequencies of the CYP2A64 and CYP2A69 alleles which contribute to the poor metabolism status may impact treatment of patients receiving drugs metabolized by CYP2A6 such as artesunate among Malaysians.

Effect of concomitant artesunate administration and cytochrome P4502C8 polymorphisms on the pharmacokinetics of amodiaquine in Ghanaian children with uncomplicated malaria.

Artesunate (AS) is used in combination with amodiaquine (AQ) as first-line treatment for uncomplicated malaria in many countries. We investigated the effect of concomitant AS administration on the pharmacokinetics of AQ and compared concentrations of desethylamodiaquine (DEAQ), the main metabolite of AQ, in plasma between patients with different variants of the cytochrome P4502C8 (CYP2C8) gene. A two-compartment model was fitted to 169 plasma DEAQ concentrations from 103 Ghanaian children aged 1 to 14 years with uncomplicated malaria treated either with AQ alone (n = 15) or with AS plus AQ (n = 88). The population clearance of DEAQ appeared to increase nonlinearly with body weight, and the central volume of distribution of DEAQ was higher (P < 0.001) in the AS-plus-AQ group than in the AQ-only group. The maximum plasma DEAQ concentration was higher (P < 0.001), and the population distribution half-life was shorter (P < 0.01), in the AQ-only group than in the AS-plus-AQ group. The total areas under the plasma DEAQ concentration-time curves (P = 0.68) and elimination half-lives (P = 0.39) were similar for the two groups. There was a high frequency (0.179) of the non-wild-type allele of CYP2C8, but no differences between CYP2C8 genotypes with regard to AQ efficacy or safety were evident. The sample size, however, was limited, so monitoring of AQ toxicity in the study area is still indicated. The nonlinear clearance of DEAQ and the wide variability in kinetic parameters have safety implications for weight-based dosing of higher-body-weight children with AQ. The pharmacokinetics of artemisinin combination therapies should be studied in malaria patients, because the rapid parasite clearance caused by the artemisinin may affect the kinetics of the partner drug and the combination.

Chloroquine resistant Plasmodium falciparum malaria in Osogbo Nigeria: efficacy of amodiaquine + sulfadoxine-pyrimethamine and chloroquine + chlorpheniramine for treatment

Chloroquine (CQ) resistance in Plasmodium falciparum contributes to increasing malaria-attributable morbidity and mortality in Sub-Saharan Africa. Despite a change in drug policy, continued prescription of CQ did not abate. Therefore the therapeutic efficacy of CQ in uncomplicated falciparum malaria patients was assessed in a standard 28-day protocol in 116 children aged between six and 120 months in Osogbo, Southwest Nigeria. Parasitological and clinical assessments of response to treatment showed that 72 (62.1 percent) of the patients were cured and 44 (37.9 percent) failed the CQ treatment. High initial parasite density and young age were independent predictors for early treatment failure. Out of the 44 patients that failed CQ, 24 received amodiaquine + sulphadoxine/pyrimethamine (AQ+SP) and 20 received chlorpheniramine + chloroquine (CH+CQ) combinations. Mean fever clearance time in those treated with AQ+SP was not significantly different from those treated with CH+CQ (p = 0.05). There was no significant difference in the mean parasite density of the two groups. The cure rate for AQ+SP group was 92 percent while those of CH+CQ was 85 percent. There was a significant difference in parasite clearance time (p = 0.01) between the two groups. The 38 percent treatment failure for CQ reported in this study is higher than the 10 percent recommended by World Health Organization in other to effect change in antimalarial treatment policy. Hence we conclude that CQ can no more be solely relied upon for the treatment of falciparum malaria in Osogbo, Nigeria. AQ+SP and CH+CQ are effective in the treatment of acute uncomplicated malaria and may be considered as useful alternative drugs in the absence of artemisinin-based combination therapies.

[Assessing the application of Rwanda's national protocol for uncomplicated malaria treatment in healthcare institutions in Kigali City, Rwanda]. / Evaluation de l'application du protocole national de traitement du paludisme simple dans les formations sanitaires de la ville de Kigali, Rwanda.

UNLABELLED: In November 2001, the National Health Ministry of Rwanda advocated a new therapeutic protocol replacing chloroquine by an amodiaquine+sulfadoxine-pyrimethamine combination for the treatment of uncomplicated malaria. OBJECTIVES: This study had for aim to assess the application of this new protocol in Kigali healthcare institutions. POPULATION AND METHODS: A knowledge, attitudes and practices study (KAP) was carried out between June and August 2003. A questionnaire was answered by 120 care providers working in 15 healthcare institutions selected randomly in health facilities treating uncomplicated malaria. Antimalarial treatments prescribed to 150 patients were also reviewed from consultation files and analyzed. RESULTS: After analysis, 63.3% prescriptions were in line with the national protocol. Factors associated to the nonobservance of the national protocol were: the carer's ignorance of any recommended treatment, his doubt of efficacy of recommended drugs, and his fear of adverse effects. CONCLUSIONS: The authors recommend informing the care providers about the national protocol. Findings also demonstrate the need to include care providers in any modifications of the national policy in terms of drug efficacy and potential adverse effects of the new strategy.

Enhancement of the antimalarial efficacy of amodiaquine by chlorpheniramine in vivo

Resistance in Plasmodium falciparum to amodiaquine (AQ) can be reversed in vitro with with antihistaminic and tricyclic antidepressant compounds, but its significance in vivo is unclear. The present report presents the enhancement of the antimalarial efficacy of AQ by chlorpheniramine, an H1 receptor antagonist that reverses chloroquine (CQ) resistance in vitro and enhances its efficacy in vivo, in five children who failed CQ and/or AQ treatment, and who were subsequently retreated and cured with a combination of AQ plus CP, despite the fact that parasites infecting the children harboured mutant pfcrtT76 and pfmdr1Y86 alleles associated with AQ resistance. This suggests a potential clinical appliation of the reversal phenomenon.

Artemisinin-based combination therapy for uncomplicated Plasmodium falciparum malaria in Colombia.

BACKGROUND: Artemisinin-based combination therapy (ACT) is being widely promoted as a strategy to counteract the increase in Plasmodium falciparum antimalarial drug resistance. METHODS: A randomized, double-blind, placebo-controlled, clinical trial of the efficacy, effect on gametocytes and safety of the addition of artesunate/placebo (4 mg/kg/day x 3 d) to amodiaquine (10 mg/kg/day x 3 d) was conducted in Choco department, a low intensity transmission area in northwest Colombia. RESULTS: From 2,137 screened subjects, 85 entered the study: 43 in the amodiaquine plus placebo and 42 in the amodiaquine plus artesunate groups. Potentially eligible cases failed to qualify mostly because they were not available for follow-up visits (73%). Based on a per protocol analysis, the therapeutic response to both treatments was high: amodiaquine/placebo 35/36, 97.2% (95% CI 85.5-99.9), and amodiaquine/artesunate 32/32, 100% (89.1-100) after PCR genotyping. The Kaplan-Meier survival estimates based on all eligible patients enrolled (amodiaquine/placebo: n = 42; amodiaquine/artesunate: n = 41) were similar in the two study groups (P = 0.3). The addition of artesunate significantly decreased gametocyte carriage on Day 4 (OR = 0.1 95% CI 0.02-0.6), Day 7 (OR = 0.2 95%CI 0.04-0.9), Day 14 (OR = 0.09 95% CI 0-0.8), and Day 21 (OR95%CI 0-0.9). Most subjects in both groups (81% in amodiaquine/placebo and 75.6% in amodiaquine/artesunate) reported at least one drug related adverse event. Symptoms were generally mild and self-limiting and there was no serious adverse event. Two patients on amodiaquine/artesunate voluntarily withdrew from study because they could not tolerate the medication. CONCLUSION: Both drug regimens were effective in this area of Colombia. The addition of artesunate reduced gametocyte carriage and did not adversely affect tolerability. In this set of patients, the rate of adverse events was higher than in other studies. Patients' follow-up is problematic in areas with dispersed population and affects the conduct of clinical studies and monitoring of treatment effects. The results are discussed in the light of concurrent increase resistance to amodiaquine in other endemic areas in Colombia and the factors that may influence a change in the national antimalarial drug policy.

Effects of pyrimethamine-sulphadoxine, chloroquine plus chlorpheniramine, and amodiaquine plus pyrimethamine-sulphadoxine on gametocytes during and after treatment of acute, uncomplicated malaria in children

The effects of pyrimethamine-sulphadoxine (PS), chloroquine plus chlorpheniramine, a H1 receptor antagonist that reverses chloroquine resistance in Plasmodium falciparum in vitro and in vivo (CQCP), and amodiaquine plus pyrimethamine-sulphadoxine (AQPS) on gametocyte production were evaluated in 157 children with acute, symptomatic, uncomplicated falciparum malaria who were treated with these drugs. PS was significantly less effective than CQCP or AQPS at clearing asexual parasitaemia or other symptoms of malaria. Gametocyte carriage on days 3, 7, and 14 were significantly higher in those treated with PS. The ratio of the density (per æl blood) of peripheral young gametocyte (PYG), that is, < stage III to peripheral mature gametocyte (PMG), that is, stage IV and V, an index of continuing generation of gametocytes, rose to 1 by day 7 of treatment in those treated with PS, but remained consistently below 1 in the other treatment groups. PYG-PMG density ratio increased significantly from day 0-14 in those treated with PS and CQCP (chi2 = 76, P = 0.000001 and chi2 = 42.2, P = 0.00001, respectively) but decreased significantly in those treated with AQPS (chi2 = 53.2, P = 0.000001). Both PS-sensitive and -resistant infections generated PYG (18 of 29 vs 13 of 20, chi2 = 0.04, P = 0.93) but PYG was present only in those with resistant response to CQCP. Combination of PS with amodiaquine (AQ), that is, (AQPS) resulted in less production of PYG, but in this setting, PYG was not indicative of response to AQPS. These data indicate that PS enhanced production or release of young gametocytes when used alone, but generated less young gametocytes when used in combination with AQ. PYG may be used as an indicator of response to CQCP but not PS or PS-based combination drugs.