• Adherence to a Six-Dose Regimen of Artemether-Lumefantrine for Treatment of Uncomplicated Plasmodium Falciparum Malaria in Uganda.

      Fogg, C; Bajunirwe, F; Piola, P; Biraro, S; Checchi, F; Kiguli, J; Namiiro, P; Musabe, J; Kyomugisha, A; Guthmann, J P; Epicentre, Paris, France. (Published by: American Society of Tropical Medicine and Hygiene, 2004-11)
      Measuring baseline levels of adherence and identifying risk factors for non-adherence are important steps before the introduction of new antimalarials. In Mbarara in southwestern Uganda, we assessed adherence to artemether-lumefantrine (Coartem) in its latest World Health Organization blister formulation. Patients with uncomplicated Plasmodium falciparum malaria were prescribed artemether-lumefantrine and received an explanation of how to take the following five doses at home. A tablet count was made and a questionnaire was completed during a home visit. Among 210 analyzable patients, 21 (10.0%) were definitely or probably non-adherent, whereas 189 (90.0%) were probably adherent. Age group was not associated with adherence. Lack of formal education was the only factor associated with non-adherence after controlling for confounders (odds ratio = 3.1, 95% confidence interval [CI] = 1.1-9.7). Mean lumefantrine blood levels were lower among non-adherent (n = 16) (2.76 microg/mL, 95% CI = 1.06-4.45) than among adherent (n = 171) (3.19 microg/mL, 95% CI = 2.84-3.54) patients, but this difference was not statistically significant. The high adherence to artemether-lumefantrine found in our study suggest that this drug is likely to be very effective in Mbarara provided that patients receive clear dosage explanations.
    • Barriers to prompt and effective treatment of malaria in northern Sri Lanka.

      Reilley, B; Abeyasinghe, R; Pakianathar, M V; Medecins sans Frontieres, Colombo, Sri Lanka. (Wiley-Blackwell, 2002-09)
      BACKGROUND: For the past 18 years, northern Sri Lanka has been affected by armed ethnic conflict. This has had a heavy impact on displacement of civilians, health delivery services, number of health professionals in the area and infrastructure. The north of Sri Lanka has a severe malaria burden, with less than 5% of the national population suffering 34% of reported cases. Health care providers investigated treatment-seeking behaviour and levels of treatment failure believed to be the result of lack of adherence to treatment. METHODS: Pre- and post-treatment interviews with patients seeking treatment in the outpatient department (OPD) and focus groups. RESULTS: A total of 271 persons completed interviews: 54.4% sought treatment within 2 days of the onset of symptoms, and 91.9% self-treated with drugs with prior to seeking treatment, mainly with paracetamol. Self-treatment was associated with delaying treatment (RR 3.55, CI 1.23-10.24, P=0.002). In post-treatment interviews, self-reported default was 26.1%. The main reasons for not taking the entire regimen were side-effects (57.6%) and disappearance of symptoms (16.7%). Focus groups indicated some lack of confidence in chloroquine treatment and prophylaxis, and scant enthusiasm for prevention methods. CONCLUSIONS: A number of factors contribute to a lack of access and a lower quality of care for malaria: lack of medical staff and facilities because of the fighting; lack of confidence in treatment, and perception of malaria as a routine illness. Prevention efforts need to take into account certain beliefs and practices to be successful.
    • Case management of a multidrug-resistant Shigella dysenteriae serotype 1 outbreak in a crisis context in Sierra Leone, 1999-2000.

      Guerin, P J; Brasher, C; Baron, E; Mic, D; Grimont, F; Ryan, M; Aavitsland, P; Legros, D; Epicentre, 8 rue Saint Sabin, 75011 Paris, France. philippe.guerin@epicentre.msf.org (Elsevier, 2004-11)
      From December 1999 to the end of February 2000, 4218 cases of dysentery were reported in Kenema district, southeastern Sierra Leone, by a Médecins Sans Frontières team operating in this region. Shigella dysenteriae serotype 1 was isolated from the early cases. The overall attack rate was 7.5% but higher among children under 5 years (11.2%) compared to the rest of the population (6.8%) (RR = 1.6; 95% CI 1.5-1.8). The case fatality ratio was 3.1%, and higher for children under 5 years (6.1% vs. 2.1%) (RR = 2.9; 95% CI 2.1-4.1). A case management strategy based on stratification of affected cases was chosen in this resource-poor setting. Patients considered at higher risk of death were treated with a 5 day ciprofloxacin regimen in isolation centres. Five hundred and eighty-three cases were treated with a case fatality ratio of 0.9%. Patients who did not have signs of severity when seen by health workers were given hygiene advice and oral rehydration salts. This strategy was effective in this complex emergency.
    • Chloroquine, sulfadoxine-pyrimethamine and amodiaquine efficacy for the treatment of uncomplicated Plasmodium falciparum malaria in Upper Nile, south Sudan.

      van den Broek, I; Gatkoi, T; Lowoko, B; Nzila, A; Ochong, E; Keus, K; Médecins sans Frontières-Holland, South Sudan-Section, P. O. Box 4064, Nairobi, Kenya. ingrid_vandenbroek@yahoo.com (Elsevier, 2008-01-31)
      The current first-line and second-line drugs for Plasmodium falciparum malaria in South Sudan, chloroquine and sulfadoxine-pyrimethamine (SP), were evaluated and compared with amodiaquine, in an MSF-Holland-run clinic in eastern Upper Nile, South Sudan from June to December 2001. Patients with uncomplicated malaria and fever were stratified by age group and randomly allocated to one of 3 treatment regimes. A total of 342 patients was admitted and followed for 14 d after treatment. The dropout rate was 10.2%. Of those who completed the study, 104 were treated with chloroquine (25 mg/kg, 3 d), 102 with SP (25 mg/kg sulfadoxine and 1.25 mg/kg pyrimethamine, single dose) and 101 with amodiaquine (25 mg/kg, 3 d). Adequate clinical response was observed in 88.5% of patients treated with chloroquine, 100% of patients treated with SP and 94.1% of patients treated with amodiaquine. In children aged < 5 years, the success rate was lower: 83.3% for chloroquine and 93.0% for amodiaquine. In adults no treatment failures were found, but children aged 5-15 years showed intermediate levels. In addition, we determined the initial genotypes of dhfr and dhps of 44 isolates from the SP-treated group and > 80% were found to be wild type for dhfr and 100% for dhps. Two percent of isolates had a single mutation and 16% had double mutations of dhfr. These data are in full agreement with the clinical effectiveness of SP. A change in malaria treatment protocols for South Sudan is recommended.
    • Comparison of chloroquine, sulfadoxine/pyrimethamine, mefloquine and mefloquine-artesunate for the treatment of falciparum malaria in Kachin State, North Myanmar.

      Smithuis, F; Shahmanesh, M; Kyaw, M K K; Savran, O; Lwin, S; White, N J; Medecins sans Frontieres-Holland, Yangon, Myanmar. (Wiley-Blackwell, 2004-11)
      Multi-drug resistant falciparum malaria is widespread in Asia. In Thailand, Cambodia and Vietnam the national protocols have changed largely to artesunate combined treatment regimens but elsewhere in East and South Asia chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) are still widely recommended by national malaria control programmes. In Kachin State, northern Myanmar, an area of low seasonal malaria transmission, the efficacy of CQ (25 mg base/kg) and SP (1.25/25 mg/kg), the nationally recommended treatments at the time, were compared with mefloquine alone (M; 15 mg base/kg) and mefloquine combined with artesunate (MA; 15:4 mg/kg). An open randomized controlled trial enrolled 316 patients with uncomplicated Plasmodium falciparum malaria, stratified prospectively into three age-groups. Early treatment failures (ETF) occurred in 41% (32/78) of CQ treated patients and in 24% of patients treated with SP (18/75). In young children the ETF rates were 87% after CQ and 35% after SP. Four children (two CQ, two SP) developed symptoms of cerebral malaria within 3 days after treatment. By day 42, failure rates (uncorrected for reinfections) had increased to 79% for CQ and 81% for SP. ETF rates were 2.5% after treatment with M and 3.9% after treatment with MA (P > 0.2). Overall uncorrected treatment failure rates at day 42 following M and MA were 23% and 21%, respectively. Chloroquine and SP are completely ineffective for the treatment of falciparum malaria in northern Myanmar. Mefloquine treatment is much more effective, but three day combination regimens with artesunate will be needed for optimum efficacy and protection against resistance.
    • Drug resistance in Plasmodium falciparum from the Chittagong Hill Tracts, Bangladesh.

      van den Broek, I; van der Wardt, S; Talukder, L; Chakma, S; Brockman, A; Nair, S; Anderson, T C; Médecins sans Frontières-Holland, Gulshan, Dhaka, Bangladesh. ingrid.van.den.braek@london.msf.org (Wiley-Blackwell, 2004-06)
      OBJECTIVE: To assess the efficacy of antimalarial treatment and molecular markers of Plasmodium falciparum resistance in the Chittagong Hill Tracts of Bangladesh. METHODS: A total of 203 patients infected with P. falciparum were treated with quinine 3 days plus sulphadoxine/pyrimethamine (SP) combination therapy, and followed up during a 4-week period. Blood samples collected before treatment were genotyped for parasite mutations related to chloroquine (pfcrt and pfmdr1 genes) or SP resistance (dhfr and dhps). RESULTS: Of 186 patients who completed follow-up, 32 patients (17.2%) failed to clear parasitaemia or became positive again within 28 days after treatment. Recurring parasitaemia was related to age (chi(2) = 4.8, P < 0.05) and parasite rates on admission (t = 3.1, P < 0.01). PCR analysis showed that some of these cases were novel infections. The adjusted recrudescence rate was 12.9% (95% CI 8.1-17.7) overall, and 16.6% (95% CI 3.5-29.7), 15.5% (95% CI 8.3-22.7) and 6.9% (95% CI 0.4-13.4) in three age groups (<5 years, 5-14, > or =15). The majority of infections carried mutations associated with chloroquine resistance: 94% at pfcrt and 70% at pfmdr. Sp-resistant genotypes were also frequent: 99% and 73% of parasites carried two or more mutations at dhfr and dhps, respectively. The frequency of alleles at dhfr, dhps and pfmdr was similar in cases that were successfully treated and those that recrudesced. CONCLUSIONS: The clinical trial showed that quinine 3-days combined to SP is still relatively effective in the Chittagong Hill Tracts. However, if this regimen is continued to be widely used, further development of SP resistance and reduced quinine sensitivity are to be expected. The genotyping results suggest that neither chloroquine nor SP can be considered a reliable treatment for P. falciparum malaria any longer in this area of Bangladesh.
    • Effectiveness of five artemisinin combination regimens with or without primaquine in uncomplicated falciparum malaria: an open-label randomised trial

      Smithuis, Frank; Kyaw, Moe Kyaw; Phe, Ohn; Win, Thein; Aung, Pyay Phyo; Oo, Aung Pyay Phyo; Naing, Arkar Linn; Nyo, Mya Yee; Myint, Naing Zaw Htun; Imwong, Mallika; Ashley, Elizabeth; Lee, Sue J; White, Nicholas J; Médecins Sans Frontières—Holland, Yangon, Myanmar; Medical Action Myanmar, Yangon, Myanmar; Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford, UK (2010-09-09)
      BACKGROUND: Artemisinin-combination therapy (ACT) is recommended as first-line treatment of falciparum malaria throughout the world, and fixed-dose combinations are preferred by WHO; whether a single gametocytocidal dose of primaquine should be added is unknown. We aimed to compare effectiveness of four fixed-dose ACTs and a loose tablet combination of artesunate and mefloquine, and assess the addition of a single gametocytocidal dose of primaquine. METHODS: In an open-label randomised trial in clinics in Rakhine state, Kachin state, and Shan state in Myanmar (Burma) between Dec 30, 2008, and March 20, 2009, we compared the effectiveness of all four WHO-recommended fixed-dose ACTs (artesunate-mefloquine, artesunate-amodiaquine, dihydroartemisinin-piperaquine, artemether-lumefantrine) and loose artesunate-mefloquine in Burmese adults and children. Eligible patients were those who presented to the clinics with acute uncomplicated Plasmodium falciparum malaria or mixed infection, who were older than 6 months, and who weighed more than 5 kg. Treatments were randomised in equal numbers within blocks of 50 and allocation was in sealed envelopes. All patients were also randomly assigned to receive either a single dose of primaquine 0·75 mg base/kg or not. Patients were followed up for 63 days. Treatment groups were compared by analysis of variance and multiple logistic regression. The primary outcome was the 63 day recrudescence rate. This study is registered with clinicaltrials.gov, number NCT00902811. FINDINGS: 155 patients received artesunate-amodiaquine, 162 artemether-lumefantrine, 169 artesunate-mefloquine, 161 loose artesunate-mefloquine, and 161 dihydroartemisinin-piperaquine. By day 63 of follow-up, 14 patients (9·4%; 95% CI 5·7-15·3%) on artesunate-amodiaquine had recrudescent P falciparum infections, a rate significantly higher than for artemether-lumefantrine (two patients; 1·4%; 0·3-5·3; p=0·0013), fixed-dose artesunate-mefloquine (0 patients; 0-2·3; p<0·0001), loose artesunate-mefloquine (two patients; 1·3%; 0·3-5·3; p=0·0018), and dihydroartemisinin-piperaquine (two patients 1·3%; 0·3-5·2%; p=0·0012). Hazard ratios for re-infection (95% CI) after artesunate-amodiaquine were 3·2 (1·3-8·0) compared with the two artesunate-mefloquine groups (p=0·01), 2·6 (1·0-6-0) compared with artemether-lumefantrine (p=0·04), and 2·3 (0·9-6·0) compared with dihydroartemisinin-piperaquine (p=0·08). Mixed falciparum and vivax infections were common: 129 (16%) had a mixed infection at presentation and 330 (41%) patients had one or more episodes of Plasmodium vivax infection during follow-up. The addition of a single dose of primaquine (0·75 mg/kg) reduced P falciparum gametocyte carriage substantially: rate ratio 11·9 (95% CI 7·4-20·5). All regimens were well tolerated. Adverse events were reported by 599 patients, most commonly vomiting and dizziness. Other side-effects were less common and were not related to a specific treatment. INTERPRETATION: Artesunate-amodiaquine should not be used in Myanmar, because the other ACTs are substantially more effective. Artesunate-mefloquine provided the greatest post-treatment suppression of malaria. Adding a single dose of primaquine would substantially reduce transmission potential. Vivax malaria, not recurrent falciparum malaria, is the main complication after treatment of P falciparum infections in this region. FUNDING: Médecins sans Frontières (Holland) and the Wellcome Trust Mahidol University Oxford Tropical Medicine Research Programme.
    • Efficacy and effectiveness of dihydroartemisinin-piperaquine versus artesunate-mefloquine in falciparum malaria: an open-label randomised comparison.

      Smithuis, F; Kyaw, M K; Phe, O; Aye, K Z; Htet, L; Barends, M; Lindegardh, N; Singtoroj, T; Ashley, E A; Lwin, S; Stepniewska, K; White, N J; Médecins Sans Frontières (Holland), Yangon, Myanmar. (Elsevier, 2006-06-24)
      BACKGROUND: Artemisinin-based combinations are judged the best treatments for multidrug-resistant Plasmodium falciparum malaria. Artesunate-mefloquine is widely recommended in southeast Asia, but its high cost and tolerability profile remain obstacles to widespread deployment. To assess whether dihydroartemisinin-piperaquine is a suitable alternative to artesunate-mefloquine, we compared the safety, tolerability, efficacy, and effectiveness of the two regimens for the treatment of uncomplicated falciparum in western Myanmar (Burma). METHODS: We did an open randomised comparison of 3-day regimens of artesunate-mefloquine (12/25 mg/kg) versus dihydroartemisinin-piperaquine (6.3/50 mg/kg) for the treatment of children aged 1 year or older and in adults with uncomplicated falciparum malaria in Rakhine State, western Myanmar. Within each group, patients were randomly assigned supervised or non-supervised treatment. The primary endpoint was the PCR-confirmed parasitological failure rate by day 42. Failure rates at day 42 were estimated by Kaplan-Meier survival analysis. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN27914471. FINDINGS: Of 652 patients enrolled, 327 were assigned dihydroartemisinin-piperaquine (156 supervised and 171 not supervised), and 325 artesunate-mefloquine (162 and 163, respectively). 16 patients were lost to follow-up, and one patient died 22 days after receiving dihydroartemisinin-piperaquine. Recrudescent parasitaemias were confirmed in only two patients; the day 42 failure rate was 0.6% (95% CI 0.2-2.5) for dihydroartemisinin-piperaquine and 0 (0-1.2) for artesunate-mefloquine. Whole-blood piperaquine concentrations at day 7 were similar for patients with observed and non-observed dihydroartemisinin-piperaquine treatment. Gametocytaemia developed more frequently in patients who had received dihydroartemisinin-piperaquine than in those on artesunate-mefloquine: day 7, 18 (10%) of 188 versus five (2%) of 218; relative risk 4.2 (1.6-11.0) p=0.011. INTERPRETATION: Dihydroartemisinin-piperaquine is a highly efficacious and inexpensive treatment of multidrug-resistant falciparum malaria and is well tolerated by all age groups. The effectiveness of the unsupervised treatment, as in the usual context of use, equalled its supervised efficacy, indicating good adherence without supervision. Dihydroartemisinin-piperaquine is a good alternative to artesunate-mefloquine.
    • Efficacy of chloroquine + sulfadoxine--pyrimethamine, mefloquine + artesunate and artemether + lumefantrine combination therapies to treat Plasmodium falciparum malaria in the Chittagong Hill Tracts, Bangladesh.

      van den Broek, I; Maung, U A; Peters, A; Liem, L; Kamal, M; Rahman, M; Rahman, M; Bangali, A M; Das, S; Barends, M; Faiz, A M; MSF-UK, London, UK. ingrid.van.den.broek@london.msf.org (Elsevier, 2005-10)
      Bangladesh faces growing levels of Plasmodium falciparum resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP). Alternative antimalarial therapies, particularly combination regimens, need to be considered. Therefore, the efficacy of three antimalarial combination therapies was assessed in Chittagong Hill Tracts. A total of 364 P. falciparum patients were recruited and randomly assigned to either CQ + SP, mefloquine + artesunate (MQ + AS) or lumefantrine + artemether (Coartem). Results showed that CQ + SP therapy was less effective than the two artemisinin-based combination therapies. The day 42 PCR-corrected efficacy rate was 62.4% for CQ + SP, 100% for MQ + AS and 97.1% for Coartem. Failures occurred at a shorter interval after CQ + SP treatment than after Coartem. The artemisinin-based therapies effectively prevented development of gametocytes, whereas CQ + SP did not. All three therapies were well tolerated, although reports of mild complaints during treatment appeared higher with MQ + AS. We conclude that CQ + SP is not a viable option for replacing CQ monotherapy as first-line P. falciparum treatment in this area of Bangladesh. A change to artemisinin-based combination therapy is recommended. Both Coartem and MQ + AS appear to be good options, effective in curing P. falciparum malaria and in preventing recrudescences following treatment.
    • Environmental risk factors for clinical malaria: a case-control study in the Grau region of Peru.

      Guthmann, J P; Hall, A J; Jaffar, S; Palacios, A; Lines, J; Llanos-Cuentas, A; Department of Infectious and Tropical Disease, Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, UK. jguthmann@epicentre.msf.org (2001)
      The role of environmental risk factors in clinical malaria has been studied mainly in Africa and Asia, few investigations have been carried out in Latin America. Field observations in northern coastal Peru, where the prevalence of malaria is high during the agricultural season, suggested that the risk of disease varied according to the characteristics of the house and the house environment. Environmental determinants of the risk of clinical malaria were therefore investigated through a case-control study: 323 clinical cases of malaria, recruited through community-based active case-finding, and 969 age-, sex- and village-matched controls were recruited into the study over a period of 12 months ending June 1997. Residual spraying of houses in the previous 6 months, living more than 100 m from a canal, a level of education equal to primary school or above and working in agriculture conferred significant protection from the risk of developing clinical malaria. The presence of spaces between the wall and roof in the subject's bedroom (eaves) and a house aged > 4 years statistically significantly increased the risk of disease. Based on these results we discuss possible control measures for malaria in this area of the country.
    • Evaluation of three parasite lactate dehydrogenase-based rapid diagnostic tests for the diagnosis of falciparum and vivax malaria

      Ashley, Elizabeth A; Touabi, Malek; Ahrer, Margareta; Hutagalung, Robert; Htun, Khayae; Luchavez, Jennifer; Dureza, Christine; Proux, Stephane; Leimanis, Mara; Lwin, Myo Min; Koscalova, Alena; Comte, Eric; Hamade, Prudence; Page, Anne-Laure; Nosten, François; Guerin, Philippe J; Epicentre, Paris, France; Department of Microbiology, Hammersmith Hospital, Imperial College NHS Trust, London, UK; Médecins sans Frontières, Switzerland; Médecins sans Frontières, Myanmar; Research Institute for Tropical Medicine, Alabang, Muntinlupa City, Philippines; Shoklo Malaria Research Unit, Mae Sot, Thailand; Mahidol-Oxford Tropical Medicine Research Unit (MORU), Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, UK; Médecins sans Frontières Malaria Working Group, UK; Malaria Consortium, London, UK (2009-10-27)
      BACKGROUND: In areas where non-falciparum malaria is common rapid diagnostic tests (RDTs) capable of distinguishing malaria species reliably are needed. Such tests are often based on the detection of parasite lactate dehydrogenase (pLDH). METHODS: In Dawei, southern Myanmar, three pLDH based RDTs (CareStart Malaria pLDH (Pan), CareStart Malaria pLDH (Pan, Pf) and OptiMAL-IT)were evaluated in patients presenting with clinically suspected malaria. Each RDT was read independently by two readers. A subset of patients with microscopically confirmed malaria had their RDTs repeated on days 2, 7 and then weekly until negative. At the end of the study, samples of study batches were sent for heat stability testing. RESULTS: Between August and November 2007, 1004 patients aged between 1 and 93 years were enrolled in the study. Slide microscopy (the reference standard) diagnosed 213 Plasmodium vivax (Pv) monoinfections, 98 Plasmodium falciparum (Pf) mono-infections and no malaria in 650 cases. The sensitivities (sens) and specificities (spec), of the RDTs for the detection of malaria were- CareStart Malaria pLDH (Pan) test: sens 89.1% [CI95 84.2-92.6], spec 97.6% [CI95 96.5-98.4]. OptiMal-IT: Pf+/- other species detection: sens 95.2% [CI95 87.5-98.2], spec 94.7% [CI95 93.3-95.8]; non-Pf detection alone: sens 89.6% [CI95 83.6-93.6], spec 96.5% [CI95 94.8-97.7]. CareStart Malaria pLDH (Pan, Pf): Pf+/- other species: sens 93.5% [CI95 85.4-97.3], spec 97.4% [95.9-98.3]; non-Pf: sens 78.5% [CI95 71.1-84.4], spec 97.8% [CI95 96.3-98.7]. Inter-observer agreement was excellent for all tests (kappa > 0.9). The median time for the RDTs to become negative was two days for the CareStart Malaria tests and seven days for OptiMAL-IT. Tests were heat stable up to 90 days except for OptiMAL-IT (Pf specific pLDH stable to day 20 at 35 degrees C). CONCLUSION: None of the pLDH-based RDTs evaluated was able to detect non-falciparum malaria with high sensitivity, particularly at low parasitaemias. OptiMAL-IT performed best overall and would perform best in an area of high malaria prevalence among screened fever cases. However, heat stability was unacceptable and the number of steps to perform this test is a significant drawback in the field. A reliable, heat-stable, highly sensitive RDT, capable of diagnosing all Plasmodium species has yet to be identified.
    • Evaluation of Three Rapid Tests for Diagnosis of P. Falciparum and P. Vivax Malaria in Colombia.

      van den Broek, I; Hill, O; Gordillo, F; Angarita, B; Hamade, P; Counihan, H; Guthmann, J P; Médecins sans Frontières (MSF), London, UK. ingrid_vandenbroek@yahoo.com (2006-12)
      The diagnostic capacity of three malaria rapid diagnostic tests (RDTs), NOW-Malaria-ICT, OptiMAL-IT, and Paracheck-Pf, was evaluated against expert microscopy in Colombia. We tested 896 patients, of whom microscopy confirmed 139 P. falciparum, 279 P. vivax, and 13 mixed P.f/P.v infections and 465 negatives. Paracheck-Pf and NOW-malaria-ICT were more accurate in detecting P. falciparum (sensitivities 90.8% and 90.1%, respectively) in comparison with Optimal-IT (83.6%). NOW showed an acceptable Pf detection rate at low densities (< 500/microL), but resulted in a higher proportion of false positives. For P. vivax diagnosis, Optimal-IT had a higher sensitivity than NOW (91.0% and 81.4%, respectively). The choice between the two Pf/Pv detecting RDTs balances P. falciparum and P. vivax detection rates. Considering some degree of P. falciparum overtreatment and failure to detect all P. vivax cases as more acceptable than missing some cases of P. falciparum, we recommend careful implementation of NOW-malaria-ICT in areas where microscopy is lacking. The price is however still a constraint.
    • Identifying malaria control issues: a district hospital-based evaluation.

      Kimerling, M; Houth, H; Hilderbrand, K; Goubert, L; MSF Holland-Belgium, Phnom Penh, Cambodia. (1995-12)
      Chuk district hospital is centrally located in a rural malarious region in southern Cambodia. It was the site of a hospital-based evaluation (KAP assessment and in vivo i.v. quinine/oral tetracycline drug study) done to identify relevant issues for establishing a rational malaria control strategy. The KAP assessment identified the young, male forest worker as the highest risk group. Of 112 study patients, 73% were male and 82% reported various forest activities. The primary reason found for patient delay (8.9 days) in seeking hospital care was self-treatment at home (N = 102, 91%) with drugs purchased through private sellers (104/105). Using the 7-day WHO field test methodology, resistance rates were calculated (N = 22); S1/R1, 73%; R1, 9%; R2, 0%; R3, 18%. A modified version of the 7-day test was used to calculate its utility in this particular rural setting. It showed a negative predictive value of 93% and a positive predictive value of 71%. The case fatality rate for the study period was 2.7%. Information from this study, which correlates a confirmed malaria diagnosis with prior patient behavior and response to anti-malarial therapy, is intended for realizing the goals set forth by the national malaria control program.
    • Improving the Specificity of Plasmodium falciparum Malaria Diagnosis in High-Transmission Settings with a Two-Step Rapid Diagnostic Test and Microscopy Algorithm

      Murungi, M; Fulton, T; Reyes, R; Matte, M; Ntaro, M; Mulogo, E; Nyehangane, D; Juliano, J; Siedner, M; Boum, Y; Boyce, R (American Society for Microbiology, 2017-05)
      Poor specificity may negatively impact rapid diagnostic test (RDT)-based diagnostic strategies for malaria. We performed real-time PCR on a subset of subjects who had undergone diagnostic testing with a multiple-antigen (histidine-rich protein 2 and pan-lactate dehydrogenase pLDH [HRP2/pLDH]) RDT and microscopy. We determined the sensitivity and specificity of the RDT in comparison to results of PCR for the detection of Plasmodium falciparum malaria. We developed and evaluated a two-step algorithm utilizing the multiple-antigen RDT to screen patients, followed by confirmatory microscopy for those individuals with HRP2-positive (HRP2+)/pLDH-negative (pLDH-) results. In total, dried blood spots (DBS) were collected from 276 individuals. There were 124 (44.9%) individuals with an HRP2+/pLDH+ result, 94 (34.1%) with an HRP2+/pLDH- result, and 58 (21%) with a negative RDT result. The sensitivity and specificity of the RDT compared to results with real-time PCR were 99.4% (95% confidence interval [CI], 95.9 to 100.0%) and 46.7% (95% CI, 37.7 to 55.9%), respectively. Of the 94 HRP2+/pLDH- results, only 32 (34.0%) and 35 (37.2%) were positive by microscopy and PCR, respectively. The sensitivity and specificity of the two-step algorithm compared to results with real-time PCR were 95.5% (95% CI, 90.5 to 98.0%) and 91.0% (95% CI, 84.1 to 95.2), respectively. HRP2 antigen bands demonstrated poor specificity for the diagnosis of malaria compared to that of real-time PCR in a high-transmission setting. The most likely explanation for this finding is the persistence of HRP2 antigenemia following treatment of an acute infection. The two-step diagnostic algorithm utilizing microscopy as a confirmatory test for indeterminate HRP2+/pLDH- results showed significantly improved specificity with little loss of sensitivity in a high-transmission setting.
    • In vivo parasitological measures of artemisinin susceptibility

      Stepniewska, Kasia; Ashley, Elizabeth; Lee, Sue J; Anstey, Nicholas; Barnes, Karen I; Binh, Tran Quang; D'Alessandro, Umberto; Day, Nicholas P J; de Vries, Peter J; Dorsey, Grant; Guthmann, Jean-Paul; Mayxay, Mayfong; Newton, Paul N; Olliaro, Piero; Osorio, Lyda; Price, Ric N; Rowland, Mark; Smithuis, Frank; Taylor, Walter R J; Nosten, François; White, Nicholas J; Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Shoklo Malaria Research Unit, Mae Sot, Thailand; Menzies School of Health Research and Royal Darwin Hospital, Darwin, Australia; Division of Clinical Pharmacology, Department of Medicine, University (2010-01-19)
      Parasite clearance data from 18,699 patients with falciparum malaria treated with an artemisinin derivative in areas of low (n=14,539), moderate (n=2077), and high (n=2083) levels of malaria transmission across the world were analyzed to determine the factors that affect clearance rates and identify a simple in vivo screening measure for artemisinin resistance. The main factor affecting parasite clearance time was parasite density on admission. Clearance rates were faster in high-transmission settings and with more effective partner drugs in artemisinin-based combination treatments (ACTs). The result of the malaria blood smear on day 3 (72 h) was a good predictor of subsequent treatment failure and provides a simple screening measure for artemisinin resistance. Artemisinin resistance is highly unlikely if the proportion of patients with parasite densities of <100,000 parasites/microL given the currently recommended 3-day ACT who have a positive smear result on day 3 is <3%; that is, for n patients the observed number with a positive smear result on day 3 does not exceed (n + 60)/24.
    • Operational response to malaria epidemics: are rapid diagnostic tests cost-effective?

      Rolland, E; Checchi, F; Pinoges, L; Balkan, S; Guthmann, J P; Guerin, P J; Epicentre, Paris, France. (Wiley-Blackwell, 2006-04)
      OBJECTIVE: To compare the cost-effectiveness of malaria treatment based on presumptive diagnosis with that of malaria treatment based on rapid diagnostic tests (RDTs). METHODS: We calculated direct costs (based on experience from Ethiopia and southern Sudan) and effectiveness (in terms of reduced over-treatment) of a free, decentralised treatment programme using artesunate plus amodiaquine (AS + AQ) or artemether-lumefantrine (ART-LUM) in a Plasmodium falciparum epidemic. Our main cost-effectiveness measure was the incremental cost per false positive treatment averted by RDTs. RESULTS: As malaria prevalence increases, the difference in cost between presumptive and RDT-based treatment rises. The threshold prevalence above which the RDT-based strategy becomes more expensive is 21% in the AS + AQ scenario and 55% in the ART-LUM scenario, but these thresholds increase to 58 and 70%, respectively, if the financing body tolerates an incremental cost of 1 euro per false positive averted. However, even at a high (90%) prevalence of malaria consistent with an epidemic peak, an RDT-based strategy would only cost moderately more than the presumptive strategy: +29.9% in the AS + AQ scenario and +19.4% in the ART-LUM scenario. The treatment comparison is insensitive to the age and pregnancy distribution of febrile cases, but is strongly affected by variation in non-biomedical costs. If their unit price were halved, RDTs would be more cost-effective at a malaria prevalence up to 45% in case of AS + AQ treatment and at a prevalence up to 68% in case of ART-LUM treatment. CONCLUSION: In most epidemic prevalence scenarios, RDTs would considerably reduce over-treatment for only a moderate increase in costs over presumptive diagnosis. A substantial decrease in RDT unit price would greatly increase their cost-effectiveness, and should thus be advocated. A tolerated incremental cost of 1 euro is probably justified given overall public health and financial benefits. The RDTs should be considered for malaria epidemics if logistics and human resources allow.
    • Plasmodium vivax resistance to chloroquine in Dawei, southern Myanmar.

      Guthmann, J P; Pittet, A; Lesage, A; Imwong, M; Lindegardh, N; Min Lwin, M; Zaw, T; Annerberg, A; de Radiguès, X; Nosten, F; Epicentre, Paris, France. (Wiley-Blackwell, 2008-01)
      OBJECTIVE: To assess the efficacy of chloroquine in the treatment of Plasmodium vivax malaria in in Dawei District, southern Myanmar. METHODS: Enrolled patients at Sonsinphya clinic >6 months of age were assessed clinically and parasitologically every week for 28 days. To differentiate new infections from recrudescence, we genotyped pre- and post-treatment parasitaemia. Blood chloroquine was measured to confirm resistant strains. RESULTS: Between December 2002 and April 2003, 2661 patients were screened, of whom 252 were included and 235 analysed. Thirty-four per cent (95% CI: 28.1-40.6) of patients had recurrent parasitaemia and were considered treatment failures. 59.4% of these recurrences were with a different parasite strain. Two (0.8%) patients with recurrences on day 14 had chloroquine concentrations above the threshold of 100 ng/ml and were considered infected with chloroquine resistant parasites. 21% of failures occurred during the first 3 weeks of follow-up: early recurrence and median levels of blood chloroquine comparable to those of controls suggested P. vivax resistance. CONCLUSIONS: Plasmodium vivax resistance to chloroquine seems to be emerging in Dawei, near the Thai-Burmese border. While chloroquine remains the first-line drug for P. vivax infections in this area of Myanmar, regular monitoring is needed to detect further development of parasite resistance.
    • A randomized open study to assess the efficacy and tolerability of dihydroartemisinin-piperaquine for the treatment of uncomplicated falciparum malaria in Cambodia.

      Janssens, B; Van Herp, M; Goubert, L; Chan, S; Uong, S; Nong, S; Socheat, D; Brockman, A; Ashley, E A; Van Damme, W; Médecins Sans Frontières, Phnom Penh, Cambodia. b.janssens@bigfoot.com (Wiley-Blackwell, 2007-02)
      OBJECTIVES: To compare the efficacy and tolerability of dihydroartemisinin-piperaquine (DHA-PQP) with that of a 3-day regimen of mefloquine and artesunate (MAS3) for the treatment of uncomplicated falciparum malaria in Cambodia. METHOD: Randomized open-label non-inferiority study over 64 days. RESULTS: Four hundred and sixty-four patients were included in the study. The polymerase chain reaction genotyping-adjusted cure rates on day 63 were 97.5% (95% confidence interval, CI, 93.8-99.3) for DHA-PQP and 97.5% (95% CI, 93.8-99.3) for MAS3, P = 1. There were no serious adverse events, but significantly more episodes of vomiting (P = 0.03), dizziness (P = 0.002), palpitations (P = 0.04), and sleep disorders (P = 0.03) reported in the MAS3 treatment group, consistent with the side-effect profile of mefloquine. CONCLUSIONS: DHA-PQP was as efficacious as MAS3, but much better tolerated, making it more appropriate for use in a routine programme setting. This highly efficacious, safe and more affordable fixed-dose combination could become the treatment of choice for Plasmodium falciparum malaria in Cambodia.
    • A randomized trial comparing the efficacy of four treatment regimens for uncomplicated falciparum malaria in Assam state, India.

      Campbell, P; Baruah, S; Narain, K; Rogers, C C; Medecins sans Frontieres-Holland, India Section, R.G. Baruah Road, Guwahati, Assam 781024, India. patricia10334@yahoo.com (Elsevier, 2006-02)
      A four-arm drug sensitivity study compared chloroquine, sulfadoxine-pyrimethamine (SP), mefloquine and mefloquine-artesunate in Sonitpur and Karbi Anglong districts in Assam state, India. Two criteria were used to ascertain outcome: success of clinical treatment and parasitologic cure. In Sonitpur, at 14 days, there were 36/56 early and late treatment failures plus late parasitologic failures to chloroquine and 16/56 for SP. In Karbi Anglong, combined treatment failure at 14 days was 16/56 to chloroquine and 8/60 to SP. Mefloquine and mefloquine-artesunate demonstrated 93.9% and 93.6% sustained responses respectively at 42 days. High failure rates to both chloroquine and SP preclude the use of these drugs as first-line treatment for uncomplicated falciparum malaria in this region. A mefloquine-artesunate combination presents an effective alternative utilizing the currently recommended higher dose of mefloquine.
    • Ranking malaria risk factors to guide malaria control efforts in African highlands

      Protopopoff, Natacha; Van Bortel, Wim; Speybroeck, Niko; Van Geertruyden, Jean-Pierre; Baza, Dismas; D'Alessandro, Umberto; Coosemans, Marc; Department of Parasitology, Prince Leopold Institute of Tropical Medicine, Antwerp, Belgium; Medecins Sans Frontieres Brussels, Belgium; Department of Animal Health, Prince Leopold Institute of Tropical Medicine, Antwerp, Belgium; School of Public Health, Universite Catholique de Louvain, Brussels, Belgium; Programme de Lutte contre les Maladies Transmissibles et Carentielles, Ministry of Health, Bujumbura, Burundi; Department of Biomedical Sciences, Faculty of Pharmaceutical, Veterinary and Biomedical Sciences, University of Antwerp, Antwerp, Belgium (2009-11-25)
      INTRODUCTION: Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. METHODS AND FINDINGS: A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through "classification and regression trees", an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density. CONCLUSIONS: In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.