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1.
Malawi Med J ; 28(3): 139-149, 2016 09.
Article in English | MEDLINE | ID: mdl-27895848

ABSTRACT

BACKGROUND: Information regarding the safety and efficacy of artemisinin combination treatments for malaria in pregnant women is limited, particularly among women who live in sub-Saharan Africa. METHODS: We conducted a multicenter, randomized, open-label trial of treatments for malaria in pregnant women in four African countries. A total of 3428 pregnant women in the second or third trimester who had falciparum malaria (at any parasite density and regardless of symptoms) were treated with artemether-lumefantrine, amodiaquine-artesunate, mefloquine-artesunate, or dihydroartemisinin-piperaquine. The primary end points were the polymerase-chain-reaction (PCR)-adjusted cure rates (i.e., cure of the original infection; new infections during follow-up were not considered to be treatment failures) at day 63 and safety outcomes. RESULTS: The PCR-adjusted cure rates in the per-protocol analysis were 94.8% in the artemether-lumefantrine group, 98.5% in the amodiaquine-artesunate group, 99.2% in the dihydroartemisinin-piperaquine group, and 96.8% in the mefloquine-artesunate group; the PCR-adjusted cure rates in the intention-to-treat analysis were 94.2%, 96.9%, 98.0%, and 95.5%, respectively. There was no significant difference among the amodiaquine-artesunate group, dihydroartemisinin-piperaquine group, and the mefloquine-artesunate group. The cure rate in the artemether-lumefantrine group was significantly lower than that in the other three groups, although the absolute difference was within the 5-percentage-point margin for equivalence. The unadjusted cure rates, used as a measure of the post-treatment prophylactic effect, were significantly lower in the artemether-lumefantrine group (52.5%) than in groups that received amodiaquine-artesunate (82.3%), dihydroartemisinin-piperaquine (86.9%), or mefloquine-artesunate (73.8%). No significant difference in the rate of serious adverse events and in birth outcomes was found among the treatment groups. Drug-related adverse events such as asthenia, poor appetite, dizziness, nausea, and vomiting occurred significantly more frequently in the mefloquine-artesunate group (50.6%) and the amodiaquine-artesunate group (48.5%) than in the dihydroartemisinin-piperaquine group (20.6%) and the artemether-lumefantrine group (11.5%) (P<0.001 for comparison among the four groups). CONCLUSIONS: Artemether-lumefantrine was associated with the fewest adverse effects and with acceptable cure rates but provided the shortest posttreatment prophylaxis, whereas dihydroartemisinin-piperaquine had the best efficacy and an acceptable safety profile. (Funded by the European and Developing Countries Clinical Trials Partnership and others; ClinicalTrials.gov number, NCT00852423.).

2.
N Engl J Med ; 374(10): 913-27, 2016 Mar 10.
Article in English | MEDLINE | ID: mdl-26962727

ABSTRACT

BACKGROUND: Information regarding the safety and efficacy of artemisinin combination treatments for malaria in pregnant women is limited, particularly among women who live in sub-Saharan Africa. METHODS: We conducted a multicenter, randomized, open-label trial of treatments for malaria in pregnant women in four African countries. A total of 3428 pregnant women in the second or third trimester who had falciparum malaria (at any parasite density and regardless of symptoms) were treated with artemether-lumefantrine, amodiaquine-artesunate, mefloquine-artesunate, or dihydroartemisinin-piperaquine. The primary end points were the polymerase-chain-reaction (PCR)-adjusted cure rates (i.e., cure of the original infection; new infections during follow-up were not considered to be treatment failures) at day 63 and safety outcomes. RESULTS: The PCR-adjusted cure rates in the per-protocol analysis were 94.8% in the artemether-lumefantrine group, 98.5% in the amodiaquine-artesunate group, 99.2% in the dihydroartemisinin-piperaquine group, and 96.8% in the mefloquine-artesunate group; the PCR-adjusted cure rates in the intention-to-treat analysis were 94.2%, 96.9%, 98.0%, and 95.5%, respectively. There was no significant difference among the amodiaquine-artesunate group, dihydroartemisinin-piperaquine group, and the mefloquine-artesunate group. The cure rate in the artemether-lumefantrine group was significantly lower than that in the other three groups, although the absolute difference was within the 5-percentage-point margin for equivalence. The unadjusted cure rates, used as a measure of the post-treatment prophylactic effect, were significantly lower in the artemether-lumefantrine group (52.5%) than in groups that received amodiaquine-artesunate (82.3%), dihydroartemisinin-piperaquine (86.9%), or mefloquine-artesunate (73.8%). No significant difference in the rate of serious adverse events and in birth outcomes was found among the treatment groups. Drug-related adverse events such as asthenia, poor appetite, dizziness, nausea, and vomiting occurred significantly more frequently in the mefloquine-artesunate group (50.6%) and the amodiaquine-artesunate group (48.5%) than in the dihydroartemisinin-piperaquine group (20.6%) and the artemether-lumefantrine group (11.5%) (P<0.001 for comparison among the four groups). CONCLUSIONS: Artemether-lumefantrine was associated with the fewest adverse effects and with acceptable cure rates but provided the shortest post-treatment prophylaxis, whereas dihydroartemisinin-piperaquine had the best efficacy and an acceptable safety profile. (Funded by the European and Developing Countries Clinical Trials Partnership and others; ClinicalTrials.gov number, NCT00852423.).


Subject(s)
Antimalarials/therapeutic use , Artemisinins/therapeutic use , Malaria, Falciparum/drug therapy , Pregnancy Complications, Parasitic/drug therapy , Adult , Africa , Amodiaquine/therapeutic use , Antimalarials/adverse effects , Artemether, Lumefantrine Drug Combination , Artemisinins/adverse effects , Drug Combinations , Ethanolamines/therapeutic use , Female , Fluorenes/therapeutic use , Humans , Plasmodium falciparum/genetics , Plasmodium falciparum/isolation & purification , Polymerase Chain Reaction , Pregnancy , Pregnancy Outcome , Quinolines/therapeutic use , Young Adult
3.
Malar J ; 14: 251, 2015 Jun 20.
Article in English | MEDLINE | ID: mdl-26088768

ABSTRACT

BACKGROUND: Ex vivo assays are usually carried out on parasite isolates collected from patients with uncomplicated Plasmodium falciparum malaria, from which pregnant women are usually excluded as they are often asymptomatic and with relatively low parasite densities. Nevertheless, P. falciparum parasites infecting pregnant women selectively sequester in the placenta and may have a different drug sensitivity profile compared to those infecting other patients. The drug sensitivity profile of P. falciparum isolates from infected pregnant women recruited in a treatment efficacy trial conducted in Burkina Faso was determined in an ex vivo study. METHODS: The study was conducted between October 2010 and December 2012. Plasmodium falciparum isolates were collected before treatment and at the time of any recurrent infection whose parasite density was at least 100/µl. A histidine-rich protein-2 assay was used to assess their susceptibility to a panel of seven anti-malarial drugs. The concentration of anti-malarial drug inhibiting 50% of the parasite maturation to schizonts (IC(50)) for each drug was determined with the IC Estimator version 1.2. RESULTS: The prevalence of resistant isolates was 23.5% for chloroquine, 9.2% for mefloquine, 8.0% for monodesethylamodiaquine, and 4.4% for quinine. Dihydroartemisinin, mefloquine, lumefantrine, and monodesethylamodiaquine had the lowest mean IC(50) ranging between 1.1 and 1.5 nM respectively. The geometric mean IC(50) of the tested drugs did not differ between chloroquine-sensitive and resistant parasites, with the exception of quinine, for which the IC(50) was higher for chloroquine-resistant isolates. The pairwise comparison between the IC(50) of the tested drugs showed a positive and significant correlation between dihydroartemisinin and both mefloquine and chloroquine, between chloroquine and lumefantrine and between monodesethylamodiaquine and mefloquine. CONCLUSION: These ex vivo results suggest that treatment with the currently available artemisinin-based combinations is efficacious for the treatment of malaria in pregnancy in Burkina Faso. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT00852423.


Subject(s)
Antimalarials/pharmacology , Antimalarials/therapeutic use , Drug Resistance , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Burkina Faso , Female , Humans , Inhibitory Concentration 50 , Malaria, Falciparum/parasitology , Parasitic Sensitivity Tests , Pregnancy , Seasons
4.
Antimicrob Agents Chemother ; 59(1): 734-7, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25403659

ABSTRACT

Plasmodium falciparum Pfcrt-76 and Pfmdr1-86 gene polymorphisms were determined during a clinical trial in Burkina Faso comparing the efficacies of dihydroartemisinin-piperaquine (DHA-PPQ) and artemether-lumefantrine (AL). Significant selection of Pfcrt-K76 was observed after exposure to AL and DHA-PPQ, as well as selection of Pfmdr1-N86 after AL but not DHA-PPQ treatment, suggesting reverse selection on the Pfcrt gene by PPQ. These results support the rational use of DHA-PPQ in settings where chloroquine (CQ) resistance is high.


Subject(s)
Antimanic Agents/therapeutic use , Artemisinins/therapeutic use , Ethanolamines/therapeutic use , Fluorenes/therapeutic use , Malaria, Falciparum/drug therapy , Membrane Transport Proteins/genetics , Multidrug Resistance-Associated Proteins/genetics , Plasmodium falciparum/genetics , Protozoan Proteins/genetics , Quinolines/therapeutic use , Antimanic Agents/administration & dosage , Artemether, Lumefantrine Drug Combination , Artemisinins/administration & dosage , Burkina Faso/epidemiology , Drug Combinations , Drug Resistance/genetics , Genetic Variation/drug effects , Genetic Variation/genetics , Humans , Malaria, Falciparum/epidemiology , Malaria, Falciparum/genetics , Plasmodium falciparum/drug effects , Quinolines/administration & dosage
5.
PLoS One ; 9(5): e96017, 2014.
Article in English | MEDLINE | ID: mdl-24830749

ABSTRACT

INTRODUCTION: Antibiotic therapy during pregnancy may be beneficial and impacts positively on the reduction of adverse pregnancy outcomes. No studies have been done so far on the effects of daily Co-trimoxazole (CTX) prophylaxis on birth outcomes. A phase 3b randomized trial was conducted to establish that daily CTX in pregnancy is not inferior to SP intermittent preventive treatment (IPT) in reducing placental malaria; preventing peripheral parasitaemia; preventing perinatal mortality and also improving birth weight. To establish its safety on the offspring by measuring the gestational age and birth weight at delivery, and compare the safety and efficacy profile of CTX to that of SP. METHODS: Pregnant women (HIV infected and uninfected) attending antenatal clinic were randomized to receive either daily CTX or sulfadoxine-pyrimethamine as per routine IPT. Safety was assessed using standard and pregnancy specific measurements. Women were followed up monthly until delivery and then with their offspring up to six weeks after delivery. RESULTS: Data from 346 pregnant women (CTX = 190; SP = 156) and 311 newborns (CTX = 166 and SP = 145) showed that preterm deliveries (CTX 3.6%; SP 3.0%); still births (CTX 3.0%; SP 2.1%), neonatal deaths (CTX 0%; SP 1.4%), and spontaneous abortions (CTX 0.6%; SP 0%) were similar between study arms. The low birth weight rates were 9% for CTX and 13% for SP. There were no birth defects reported. Both drug exposure groups had full term deliveries with similar birth weights (mean of 3.1 Kg). The incidence and severity of AEs in the two groups were comparable. CONCLUSION: Exposure to daily CTX in pregnancy may not be associated with particular safety risks in terms of birth outcomes such as preterm deliveries, still births, neonatal deaths and spontaneous abortions compared to SP. However, more data are required on CTX use in pregnant women both among HIV infected and un-infected individuals. TRIAL REGISTRATION: Clinicaltrials.gov NCT00711906.


Subject(s)
Antimalarials/administration & dosage , Malaria/complications , Malaria/prevention & control , Pregnancy Complications, Infectious/prevention & control , Pregnancy Complications, Parasitic/prevention & control , Trimethoprim, Sulfamethoxazole Drug Combination/administration & dosage , Adult , Antimalarials/adverse effects , Birth Weight , Drug Administration Schedule , Female , Gestational Age , HIV Infections/complications , Humans , Male , Maternal Exposure , Pregnancy , Pregnancy Outcome , Treatment Outcome , Trimethoprim, Sulfamethoxazole Drug Combination/adverse effects , Young Adult , Zambia
6.
Am J Trop Med Hyg ; 89(4): 721-723, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23980132

ABSTRACT

We have modified an existing semi-nested multiplex polymerase chain reaction (PCR) by adding one Plasmodium knowlesi-specific nested PCR, and validated the latter against laboratory and clinical samples. This new method has the advantage of being relatively affordable in low resource settings while identifying the five human Plasmodium species with a three-step PCR.


Subject(s)
Malaria/parasitology , Plasmodium/classification , Plasmodium/isolation & purification , Polymerase Chain Reaction/methods , Animals , Asia, Southeastern/epidemiology , Humans , Malaria/epidemiology
7.
Trop Med Int Health ; 18(2): 237-41, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23217117

ABSTRACT

The last decade has witnessed a substantial increase of multi-centre, public health-oriented clinical trials in poor countries. However, non-commercial research groups have less staff and financial resources than traditional commercial sponsors, so the trial teams have to be creative to comply with Good Clinical Practices (GCP) requirements. According to the recent experience of a large multicentre trial on antimalarials, major challenges result from the complexity of multiple ethical review, the costs of in-depth monitoring at several sites, setting up an adequate Good Clinical Laboratory Practices (GCLP) framework, lack of insurers in host countries, and lack of adequate non-commercial data management software. Public research funding agencies need to consider these challenges in their funding policies. They also could support common spaces where North-South collaborative research groups may share critical information, such as on research insurance and open-source, GCP-compliant software. WHO should update its GCP guidelines, which date back to 1995, to incorporate the perspectives and needs of non-commercial clinical research.


Subject(s)
Biomedical Research/standards , Clinical Laboratory Techniques/standards , Practice Guidelines as Topic/standards , Biomedical Research/methods , Clinical Trials as Topic , Cooperative Behavior , Humans , International Cooperation , World Health Organization
8.
Am J Trop Med Hyg ; 87(6): 989-995, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23128294

ABSTRACT

In Vietnam, Plasmodium falciparum and P. vivax are responsible for most malaria infections, and P. malariae and P. ovale infections are rarely reported. Nevertheless, species-specific polymerase chain reaction analysis on 2,303 blood samples collected during a cross-sectional survey conducted in a forest area of central Vietnam identified 223 (9.7%) P. falciparum, 170 (7.4%) P. vivax, 95 (4.1%) P. malariae, and 19 (0.8%) P. ovale mono-infections and 164 (7.1%) mixed infections. Of the 671 Plasmodium-positive samples by polymerase chain reaction, only 331 were detected by microscopy. Microscopy poorly diagnosed P. malariae, P. ovale, and mixed infections. Clinical and sub-clinical infections occurred in all age groups. The risk for infection and disease decreased with age, probably because of acquired partial immunity. The common occurrence of sub-patent infections seems to indicate that the malaria burden is underestimated and that diagnostic and therapeutic policies should be adapted accordingly.


Subject(s)
Aging , Malaria/parasitology , Plasmodium/classification , Adolescent , Adult , Child , Child, Preschool , Humans , Infant , Malaria/epidemiology , Multivariate Analysis , Plasmodium/genetics , Polymerase Chain Reaction , Prevalence , Risk Factors , Species Specificity , Vietnam/epidemiology , Young Adult
9.
Malar J ; 11: 279, 2012 Aug 17.
Article in English | MEDLINE | ID: mdl-22900750

ABSTRACT

BACKGROUND: Molecular tools are very sensitive and specific and could be an alternative for the diagnosis of malaria. The complexity and need for expensive equipment may hamper implementation and, therefore, simplifications to current protocols are warranted. METHODS: A PCR detecting the different Plasmodium species and differentiating between Plasmodium falciparum and Plasmodium vivax was developed and combined with a nucleic acid lateral flow immuno-assay (PCR-NALFIA) for amplicon detection. The assay was thoroughly evaluated for the analytical sensitivity and specificity in the laboratory, the robustness and reproducibility in a ring trial and accuracy and predictive value in a field trial. RESULTS: The analytical sensitivity and specificity were 0.978 (95% CI: 0.932-0.994) and 0.980 (95% CI: 0.924-0.997), respectively, and were slightly less sensitive for the detection of P. vivax than for P. falciparum. The reproducibility tested in three laboratories was very good (k = 0.83). This evaluation showed that the PCR machine used could influence the results. Accuracy was evaluated in Thailand and compared to expert microscopy and rapid diagnostic tests (RDTs). The overall and P. falciparum-specific sensitivity and specificity was good ranging from 0.86-1 and 0.95-0.98 respectively, compared to microscopy. Plasmodium vivax detection was better than the sensitivity of RDT, but slightly less than microscopy performed in this study. CONCLUSION: PCR-NALFIA is a sensitive, specific and robust assay able to identify Plasmodium species with good accuracy. Extensive testing including a ring trial can identify possible bottlenecks before implementation and is therefore essential to perform in additon to other evaluations.


Subject(s)
Malaria, Falciparum/diagnosis , Malaria, Vivax/diagnosis , Plasmodium falciparum/classification , Plasmodium falciparum/isolation & purification , Plasmodium vivax/classification , Plasmodium vivax/isolation & purification , Polymerase Chain Reaction/methods , Adolescent , Adult , Child , Child, Preschool , Diagnosis, Differential , Female , Humans , Immunoassay/methods , Malaria, Falciparum/parasitology , Malaria, Vivax/parasitology , Male , Middle Aged , Parasitology/methods , Plasmodium falciparum/genetics , Plasmodium falciparum/immunology , Plasmodium vivax/genetics , Plasmodium vivax/immunology , Predictive Value of Tests , Sensitivity and Specificity , Thailand , Young Adult
10.
Malar J ; 11: 139, 2012 Jul 10.
Article in English | MEDLINE | ID: mdl-22546009

ABSTRACT

BACKGROUND: Malaria is a leading cause of mortality, particularly in sub-Saharan African children. Prompt and efficacious treatment is important as patients may progress within a few hours to severe and possibly fatal disease. Chlorproguanil-dapsone-artesunate (CDA) was a promising artemisinin-based combination therapy (ACT), but its development was prematurely stopped because of safety concerns secondary to its associated risk of haemolytic anaemia in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. The objective of the study was to assess whether CDA treatment and G6PD deficiency are risk factors for a post-treatment haemoglobin drop in African children<5 years of age with uncomplicated malaria. METHODS: This case-control study was performed in the context of a larger multicentre randomized clinical trial comparing safety and efficacy of four different ACT in children with uncomplicated malaria. Children, who after treatment experienced a haemoglobin drop≥2 g/dl (cases) within the first four days (days 0, 1, 2, and 3), were compared with those without an Hb drop (controls). Cases and controls were matched for study site, sex, age and baseline haemoglobin measurements. Data were analysed using a conditional logistic regression model. RESULTS: G6PD deficiency prevalence, homo- or hemizygous, was 8.5% (10/117) in cases and 6.8% (16/234) in controls (p=0.56). The risk of a Hb drop≥2 g/dl was not associated with either G6PD deficiency (adjusted odds ratio (AOR): 0.81; p=0.76) or CDA treatment (AOR: 1.28; p=0.37) alone. However, patients having both risk factors tended to have higher odds (AOR: 11.13; p=0.25) of experiencing a Hb drop≥2 g/dl within the first four days after treatment, however this finding was not statistically significant, mainly because G6PD deficient patients treated with CDA were very few. In non-G6PD deficient individuals, the proportion of cases was similar between treatment groups while in G6PD-deficient individuals, haemolytic anaemia occurred more frequently in children treated with CDA (56%) than in those treated with other ACT (29%), though the difference was not significant (p=0.49). CONCLUSION: The use of CDA for treating uncomplicated malaria may increase the risk of haemolytic anaemia in G6PD-deficient children.


Subject(s)
Anemia, Hemolytic/epidemiology , Antimalarials/adverse effects , Artemisinins/adverse effects , Dapsone/adverse effects , Glucosephosphate Dehydrogenase Deficiency , Malaria/complications , Malaria/drug therapy , Proguanil/analogs & derivatives , Africa South of the Sahara , Anemia, Hemolytic/chemically induced , Antimalarials/administration & dosage , Artemisinins/administration & dosage , Artesunate , Case-Control Studies , Child, Preschool , Dapsone/administration & dosage , Drug Combinations , Drug Therapy, Combination/adverse effects , Drug Therapy, Combination/methods , Humans , Infant , Male , Proguanil/administration & dosage , Proguanil/adverse effects
11.
Am J Trop Med Hyg ; 83(3): 465-73, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20810805

ABSTRACT

Clinical malaria incidence was determined over 18 months in a cohort of 553 children living in a peri-urban area near Cotonou. Three cross-sectional surveys were also carried out. Malaria incidence showed a marked seasonal distribution with two peaks: the first corresponding to the long rainy season, and the second corresponding to the overflowing of Lake Nokoue. The overall Plasmodium falciparum incidence rate was estimated at 84/1,000 person-months, and its prevalence was estimated at over 40% in the two first surveys and 68.9% in the third survey. Multivariate analysis showed that girls and people living in closed houses had a lower risk of clinical malaria. Bed net use was associated with a lower risk of malaria infection. Conversely, children of families owing a pirogue were at higher risk of clinical malaria. Considering the high pyrethroids resistance, indoor residual spraying with either a carbamate or an organophospate insecticide may have a major impact on the malaria burden.


Subject(s)
Malaria, Falciparum/epidemiology , Suburban Population , Benin , Child, Preschool , Cross-Sectional Studies , Female , Humans , Incidence , Longitudinal Studies , Male , Prevalence
12.
Am J Trop Med Hyg ; 82(2): 223-7, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20133996

ABSTRACT

Fourteen published and three newly identified polymorphic microsatellites were used to genotype 69 Plasmodium vivax samples obtained from 39 patients detected over a period of two years who lived in a rural community of central Vietnam. All samples were polyclonal with an average expected heterozygosity of 0.86. Among the 39 patients, 16 experienced 1-5 recurrent episodes of P. vivax malaria, most of them (83%) with a different genotype profile compared with previous infections. The minimal set of microsatellites required for differentiating the genotype profiles of the recurrent infections compared with the full set of 17 microsatellites was explored. A combination of five markers was sufficient to identify all recurrent infections with an unrelated or different genotype profile compared with all previous episodes.


Subject(s)
Genotype , Malaria, Vivax/parasitology , Microsatellite Repeats , Plasmodium vivax/genetics , Adolescent , Female , Genetic Variation , Humans , Malaria, Vivax/epidemiology , Male , Vietnam/epidemiology , Young Adult
13.
Malar J ; 8: 249, 2009 Oct 30.
Article in English | MEDLINE | ID: mdl-19878553

ABSTRACT

BACKGROUND: Considering increasing reports on human infections by Plasmodium knowlesi in Southeast Asian countries, blood samples collected during two large cross-sectional malariometric surveys carried out in a forested area of central Vietnam in 2004 and 2005 were screened for this parasite. METHODS: Blood samples collected at the 2004 survey and positive for Plasmodium malariae were randomly selected for PCR analysis detecting P. knowlesi. Blood samples collected in 2005 from the same individuals were screened again for P. knowlesi. Positive samples were confirmed by sequencing. Family members of positive cases who participated in both surveys were also screened. RESULTS: Ninety-five samples with P. malariae mono- or mixed infections identified by species-specific PCR were screened for P. knowlesi. Among the five (5.2%) positive samples by PCR, three were confirmed to be P. knowlesi infections by sequencing, two young children (<5 years old) and a young man, all asymptomatic at the time of the survey and for the next six months after the survey. One of the two children was still positive one year later. No infection was found among the family members. CONCLUSION: Plasmodium knowlesi infections in humans can be found in central Vietnam. A small child was positive for P. knowlesi in both surveys at one year interval, though it is unclear whether it was the same or a new infection.


Subject(s)
Malaria/epidemiology , Malaria/parasitology , Plasmodium knowlesi/isolation & purification , Adult , Animals , Blood/parasitology , Child, Preschool , Cross-Sectional Studies , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , Female , Humans , Male , Plasmodium knowlesi/genetics , Plasmodium malariae/isolation & purification , Polymerase Chain Reaction/methods , Sequence Analysis, DNA , Vietnam/epidemiology
14.
Malar J ; 8: 192, 2009 Aug 10.
Article in English | MEDLINE | ID: mdl-19664280

ABSTRACT

BACKGROUND: Very few data on anti-malarial efficacy are available from the Democratic Republic of Congo (DRC). DRC changed its anti-malarial treatment policy to amodiaquine (AQ) and artesunate (AS) in 2005. METHODS: The results of two in vivo efficacy studies, which tested AQ and sulphadoxine-pyrimethamine (SP) monotherapies and AS+SP and AS+AQ combinations in Boende (Equatorial province), and AS+SP, AS+AQ and SP in Kabalo (Katanga province), between 2003 and 2004 are presented. The methodology followed the WHO 2003 protocol for assessing the efficacy of anti-malarials in areas of high transmission. RESULTS: Out of 394 included patients in Boende, the failure rates on day 28 after PCR-genotyping adjustment of AS+SP and AS+AQ were estimated as 24.6% [95% CI: 16.6-35.5] and 15.1% [95% CI: 8.6-25.7], respectively. For the monotherapies, failure rates were 35.9% [95% CI: 27.0-46.7] for SP and 18.3% [95% CI: 11.6-28.1] for AQ. Out of 207 patients enrolled in Kabalo, the failure rate on day 28 after PCR-genotyping adjustment was 0 [1-sided 95% CI: 5.8] for AS+SP and AS+AQ [1-sided 95% CI: 6.2]. It was 19.6% [95% CI: 11.4-32.7] for SP monotherapy. CONCLUSION: The finding of varying efficacy of the same combinations at two sites in one country highlights one difficulty of implementing a uniform national treatment policy in a large country. The poor efficacy of AS+AQ in Boende should alert the national programme to foci of resistance and emphasizes the need for systems for the prospective monitoring of treatment efficacy at sentinel sites in the country.


Subject(s)
Amodiaquine/therapeutic use , Antimalarials/therapeutic use , Artemisinins/therapeutic use , Malaria, Falciparum/drug therapy , Pyrimethamine/therapeutic use , Sulfadoxine/therapeutic use , Artesunate , Child , Child, Preschool , Democratic Republic of the Congo , Drug Combinations , Female , Humans , Infant , Male , Treatment Failure , Treatment Outcome
15.
Malar J ; 8: 37, 2009 Mar 03.
Article in English | MEDLINE | ID: mdl-19257898

ABSTRACT

BACKGROUND: A study carried out in 2003-2005 in Southern Benin showed a day-28 sulphadoxine-pyrimethamine (SP) monotherapy failure rate greater than 40%, while for SP combined with artesunate (SP-AS) the failure rate was 5.3%. Such a large difference could be explained by the relatively short 28-day follow-up period, with a substantial number of recurrent infections possibly occurring after day 28. This paper reports the treatment outcome observed in the same study cohort beyond the initial 28-day follow-up. METHODS: After the 28-day follow-up, children treated with either chloroquine alone (CQ), SP or SP-AS, were visited at home twice a week until day 90 after treatment. A blood sample was collected if the child had fever (axillary temperature > or =37.5 degrees C). Total clinical failure for each treatment group was estimated by combining all the early treatment failures and late clinical failures that occurred over the whole follow-up period, i.e. from day 0 up to day 90. Pre-treatment randomly selected blood samples were genotyped for the dhfr gene (59) and the dhps gene (437 and 540) point mutations related to SP resistance. RESULTS: The PCR-corrected clinical failure at day 90 was significantly lower in the SP-AS group (SP-AS: 2.7%, SP alone: 38.2%; CQ: 41.1%) (Log-Rank p < 0,001). The most prevalent haplotype was dhfr Arg-59 with the dhps Gly-437 mutant and the dhps 540 wild type (85.5%). The dhps 540 mutation could be found in only three (8.3%) samples. CONCLUSION: Combining artesunate to SP dramatically increased the treatment efficacy, even when extending the follow-up to day 90 post-treatment, and despite the high percentage of failures following treatment with SP alone. Such a good performance may be explained by the low prevalence of the dhps 540 mutation, by the rapid parasite clearance with artesunate and by the level of acquired immunity.


Subject(s)
Antimalarials/therapeutic use , Artemisinins/therapeutic use , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Pyrimethamine/therapeutic use , Sulfadoxine/therapeutic use , Analysis of Variance , Animals , Antimalarials/administration & dosage , Artemisinins/administration & dosage , Artesunate , Benin , Child, Preschool , Cohort Studies , Drug Combinations , Female , Fever/etiology , Fever/prevention & control , Follow-Up Studies , Genotype , Humans , Infant , Kaplan-Meier Estimate , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Male , Plasmodium falciparum/isolation & purification , Polymerase Chain Reaction , Pyrimethamine/administration & dosage , Sulfadoxine/administration & dosage , Treatment Outcome
16.
Malar J ; 7: 48, 2008 Mar 17.
Article in English | MEDLINE | ID: mdl-18346279

ABSTRACT

BACKGROUND: Sulphadoxine-pyrimethamine has been abandoned as first- or second-line treatment by most African malaria endemic countries in favour of artemisinin-based combination treatments, but the drug is still used as intermittent preventive treatment during pregnancy. However, resistance to sulphadoxine-pyrimethamine has been increasing in the past few years and, although the link between molecular markers and treatment failure has not been firmly established, at least for pregnant women, it is important to monitor such markers. METHODS: This paper reports a novel sensitive, semi-quantitative and specific real-time PCR and melting curve analysis (MCA) assay using fluorescence resonance energy transfer (FRET) for the detection of DHPS-540, an important predictor for SP resistance. FRET/MCA was evaluated using 78 clinical samples from malaria patients and compared to PCR-RFLP. RESULTS: Sixty-two samples were in perfect agreement between both assays. One sample showed a small wild type signal with FRET/MCA that indicates a polyclonal infection. Four samples were not able to generate enough material in both assays to distinguish mutant from wild-type infection, six samples gave no signal in PCR-RFLP and five samples gave no amplification in FRET/MCA. CONCLUSION: FRET/MCA is an effective tool for the identification of SNPs in drug studies and epidemiological surveys on resistance markers in general and DHPS-540 mutation in particular.


Subject(s)
Dihydropteroate Synthase/genetics , Drug Resistance , Fluorescence Resonance Energy Transfer/methods , Malaria, Falciparum/parasitology , Mutation , Plasmodium falciparum/genetics , Polymerase Chain Reaction/methods , Animals , Democratic Republic of the Congo , Humans , Plasmodium falciparum/enzymology , Polymorphism, Single Nucleotide , Sensitivity and Specificity , Transition Temperature
17.
Malar J ; 6: 170, 2007 Dec 21.
Article in English | MEDLINE | ID: mdl-18154655

ABSTRACT

BACKGROUND: Benin has recently shifted its national antimalarial drug policy from monotherapies to combinations containing artemisinin derivatives. When this decision was taken, the available information on alternatives to chloroquine and sulphadoxine-pyrimethamine, the first- and second-line treatment, was sparse. METHODS: In 2003 - 2005, before the drug policy change, a randomized, open-label, clinical trial was carried out on the efficacy of chloroquine, and sulphadoxine-pyrimethamine alone or combined with artesunate, with the aim of providing policy makers with the information needed to formulate a new antimalarial drug policy. Children between six and 59 months of age, with uncomplicated malaria and living in the lagoon costal area in southern Benin, were randomly allocated to one of the three study arms and followed up for 28 days. RESULTS: Treatment failure (PCR corrected) was significantly lower in the artesunate + sulphadoxine-pyrimethamine group (4/77, 5.3%) than in chloroquine group(51/71, 71.8%) or the sulphadoxine-pyrimethamine alone group (30/70, 44.1%) (p < 0.001). Despite high sulphadoxine-pyrimethamine failure, its combination with artesunate greatly improved treatment efficacy. CONCLUSION: In Benin, artesunate + sulphadoxine-pyrimethamine is efficacious and could be used when the recommended artemisinin-based combinations (artemether-lumefantrine and amodiaquine-artesunate) are not available. However, because sulphadoxine-pyrimethamine is also used in pregnant women as intermittent preventive treatment, its combination with artesunate should not be widely employed in malaria patients as this may compromise the efficacy of intermittent preventive treatment.


Subject(s)
Artemisinins/therapeutic use , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Pyrimethamine/therapeutic use , Sesquiterpenes/therapeutic use , Sulfadoxine/therapeutic use , Analysis of Variance , Anemia/chemically induced , Animals , Antimalarials/administration & dosage , Antimalarials/adverse effects , Antimalarials/therapeutic use , Artemisinins/administration & dosage , Artemisinins/adverse effects , Artesunate , Benin , Child, Preschool , Chloroquine/administration & dosage , Chloroquine/adverse effects , Chloroquine/therapeutic use , Drug Combinations , Drug Therapy, Combination , Female , Fever/etiology , Fever/prevention & control , Follow-Up Studies , Humans , Infant , Kaplan-Meier Estimate , Malaria, Falciparum/complications , Malaria, Falciparum/parasitology , Male , Pyrimethamine/administration & dosage , Pyrimethamine/adverse effects , Respiratory Tract Infections/chemically induced , Sesquiterpenes/administration & dosage , Sesquiterpenes/adverse effects , Sulfadoxine/administration & dosage , Sulfadoxine/adverse effects , Time Factors , Treatment Outcome
18.
Am J Trop Med Hyg ; 76(4): 608-13, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17426157

ABSTRACT

Sulfadoxine-pyrimethamine efficacy was determined with a 28-day follow-up in 97 children between 6 months and 15 years of age. The polymerase chain reaction (PCR)-corrected treatment failure was 8.2% and the uncorrected was 21.6%. The presence of the dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) mutations linked to sulfadoxine-pyrimethamine resistance before and after treatment was determined by PCR-restriction fragment length polymorphism (RFLP) and by a fluorogenic PCR assay. Before treatment, the prevalence of the triple DHFR mutations was higher among the patients having had a recurrent parasitemia (either recrudescence or new infection; 28.6% versus 9.3%), although the difference was not significant (P = 0.1). The double mutation Ala-436/Gly-437 was observed in 67% of samples, whereas no Glu-540 mutation was found. After treatment, the triple DHFR mutation was found in 76.2% of patients with recurrent parasitemia, recrudescence, and new infection alike. Such high prevalence of mutant parasites indicates that sulfadoxine-pyrimethamine should not be used as monotherapy.


Subject(s)
Malaria, Falciparum/drug therapy , Malaria, Falciparum/prevention & control , Plasmodium falciparum/genetics , Pyrimethamine/administration & dosage , Pyrimethamine/pharmacology , Sulfadoxine/administration & dosage , Sulfadoxine/pharmacology , Tetrahydrofolate Dehydrogenase/genetics , Adolescent , Animals , Antimalarials/pharmacology , Burkina Faso/epidemiology , Child , Child, Preschool , Chloroquine/pharmacology , Drug Administration Schedule , Drug Combinations , Drug Resistance/genetics , Female , Genotype , Humans , Infant , Male , Mutation , Plasmodium falciparum/drug effects , Pregnancy , Pregnancy Complications, Parasitic/prevention & control , Selection, Genetic
19.
Trans R Soc Trop Med Hyg ; 101(4): 344-50, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17005222

ABSTRACT

Coartem is a fixed-dose combination of artemether-lumefantrine that, given in six doses, provides effective treatment for children with uncomplicated Plasmodium falciparum infection in areas with highly endemic and multidrug-resistant malaria. In Rwanda since 2001, amodiaquine+sulfadoxine-pyrimethamine (AQ+SP) has been the first-line treatment, but resistance to this combination has rapidly emerged and spread. Coartem was considered as a possible alternative, and a randomised, open-label, clinical trial to test its safety, tolerability and efficacy was carried out in 2004-2005. Five hundred children aged 12-59 months with uncomplicated P. falciparum malaria were randomly allocated to AQ+SP or Coartem. Patients were followed up until day 28 after treatment. Adverse events and clinical and parasitological outcomes were recorded. Adequate clinical and parasitological response (ACPR) was significantly higher in children treated with Coartem than in those treated with AQ+SP: the PCR-adjusted 28-day ACPR was 96.68% for Coartem and 79.35% for AQ+SP. Both treatments rapidly cleared parasitaemia and fever, although parasite clearance was significantly faster in children treated with Coartem. Mean packed cell volume increased in all patients, with no significant differences between treatments. Coartem proved to be more efficacious than AQ+SP, with a good safety and tolerability profile.


Subject(s)
Antimalarials/adverse effects , Artemisinins/adverse effects , Ethanolamines/adverse effects , Fluorenes/adverse effects , Malaria, Falciparum/drug therapy , Amodiaquine/adverse effects , Amodiaquine/therapeutic use , Antimalarials/therapeutic use , Artemether, Lumefantrine Drug Combination , Artemisinins/therapeutic use , Child, Preschool , Drug Combinations , Ethanolamines/therapeutic use , Female , Fever/drug therapy , Fluorenes/therapeutic use , Follow-Up Studies , Humans , Infant , Malaria, Falciparum/parasitology , Male , Parasitemia/drug therapy , Pyrimethamine/adverse effects , Pyrimethamine/therapeutic use , Sulfadoxine/adverse effects , Sulfadoxine/therapeutic use , Treatment Outcome
20.
J Infect Dis ; 194(7): 917-25, 2006 Oct 01.
Article in English | MEDLINE | ID: mdl-16960779

ABSTRACT

BACKGROUND: Human immunodeficiency virus (HIV)-1 infected adults with low CD4 cell count have a higher risk of malaria infection and clinical malaria. We assessed the influence that HIV-1 immune suppression has on the efficacy of antimalarial treatment in adults with uncomplicated malaria. METHODS: This clinical trial included 971 Zambian adults with uncomplicated malaria. Patients were tested for HIV-1, and, if positive, a CD4 cell count was assessed. The primary outcome was recurrent parasitemia corrected by molecular genotyping within 45 days after treatment. RESULTS: HIV-1 infection was detected in 33% (320/971) of adult patients with malaria. Treatment failure was not associated with HIV-1 infection (relative risk [RR], 1.12 [95% confidence interval {CI}, 0.82-1.53]; P=.45). HIV-1-infected patients with a CD4 cell count <300 cells/microL had an increased risk of recurrent parasitemia, compared with those with a CD4 cell count >or=300 cells/microL (RR, 2.24 [95% CI, 1.20-4.14]; P=.01). After genotyping, the risk of recrudescence was higher in HIV-1-infected patients with a CD4 cell count <300 cells/microL than in the other patients with malaria (RR, 1.67 [95% CI, 1.13-2.47]; P=.02). CONCLUSION: HIV-1-infected patients with malaria with a CD4 cell count <300 cells/microL have a higher risk of experiencing a recrudescent infection, compared with those with a CD4 cell count >or=300 cells/microL or without HIV-1 infection. Trial registered at http://www.clinicaltrials.gov/; reference number NCT00304980.


Subject(s)
Antimalarials/therapeutic use , HIV Infections/immunology , HIV-1/pathogenicity , Immunosuppression Therapy , Malaria, Falciparum/drug therapy , Adolescent , Adult , Animals , Artemether , Artemisinins/therapeutic use , CD4 Lymphocyte Count , Drug Combinations , Ethanolamines/therapeutic use , Female , Fluorenes/therapeutic use , HIV Infections/physiopathology , HIV Infections/virology , Humans , Lumefantrine , Malaria, Falciparum/parasitology , Male , Middle Aged , Pyrimethamine/therapeutic use , Sulfadoxine/therapeutic use , Treatment Failure , Treatment Outcome , Zambia
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