Chemoresistance of Plasmodium falciparum and Plasmodium vivax parasites in Brazil: consequences on disease morbidity and control

Gama, Bianca Ervatti; Lacerda, Marcus Vinícius Guimarães; Daniel-Ribeiro, Cláudio Tadeu; Ferreira-da-Cruz, Maria de Fátima

doi:10.1590/s0074-02762011000900020

Cited by 31 publications

(37 citation statements)

References 87 publications

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“…The IC 50 values obtained for artemisinin against Amazonian field isolates exhibited low variation (average IC 50 = 2.1 ± 1.0 nM). Given the number of samples studied, the levels of sensitivity of Amazonian P. falciparum field isolates to artemisinin are in agreement with results for other field isolates reported in the literature (Jambou et al 2005, Ferreira et al 2007, Gama et al 2011). In Fig.…”

Section: Resultssupporting

confidence: 86%

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Silva

Magalhães

Costa

et al. 2012

Mem. Inst. Oswaldo Cruz

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Section: Resultssupporting

confidence: 86%

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Silva

Magalhães

Costa

et al. 2012

Mem. Inst. Oswaldo Cruz

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“…Starting in 2007, fixed-dose combinations of either artesunate plus mefloquine (in Acre) or artemether plus lumefantrine (in Amazonas) have been gradually introduced as the first-line therapy for P. falciparum infections. 6 There is no evidence of CQ resistance (defined as parasite recrudescence observed despite therapeutic whole-blood CQ levels) in P. vivax populations from this region. 19 Analysis of single-nucleotide polymorphism in P. vivax mdr-1.…”

Section: Methodsmentioning

confidence: 90%

“…6,7 Parasite samples described in this study were collected under protocols approved by the Institutional Review Board of the Institute of Biomedical Sciences, University of Sã o Paulo, Brazil (936/CEP, 2010). Written informed consent was obtained from adult patients and parents or guardians of minors.…”

Section: Methodsmentioning

confidence: 99%

“…3 Accordingly, whether CQ-resistant P. vivax represents a major reason for concern in Brazil remains unclear, 6 but parasite recrudescences despite adequate CQ levels were recently described in 11 of 109 P. vivax malaria patients treated in Manaus, Amazonas State. 7 The molecular mechanisms of CQ resistance in P. vivax are elusive, but genetic variation at loci encoding digestivevacuole membrane proteins may contribute to this phenotype.…”

Section: 2mentioning

confidence: 99%

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Single-Nucleotide Polymorphism and Copy Number Variation of the Multidrug Resistance-1 Locus of Plasmodium vivax: Local and Global Patterns

Vargas-Rodríguez

Bastos²,

Menezes³

et al. 2012

The American Journal of Tropical Medicine and Hygiene

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Abstract. Emerging resistance to chloroquine (CQ) poses a major challenge for Plasmodium vivax malaria control, and nucleotide substitutions and copy number variation in the P. vivax multidrug resistance 1 ( pvmdr-1) locus, which encodes a digestive vacuole membrane transporter, may modulate this phenotype. We describe patterns of genetic variation in pvmdr-1 alleles from Acre and Amazonas in northwestern Brazil, and compare then with those reported in other malaria-endemic regions. The pvmdr-1 mutation Y976F, which is associated with CQ resistance in Southeast Asia and Oceania, remains rare in northwestern Brazil (1.8%) and its prevalence mirrors that of CQ resistance worldwide. Gene amplification of pvmdr-1, which is associated with mefloquine resistance but increased susceptibility to CQ, remains relatively rare in northwestern Brazil (0.9%) and globally ( 4%), but became common ( 10%) in Tak Province, Thailand, possibly because of drug-mediated selection. The global database we have assembled provides a baseline for further studies of genetic variation in pvmdr-1 and drug resistance in P. vivax malaria.

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“…En el caso de P. vivax la situación es más notoria (24); aunque se están estudiando nuevos medicamentos con buenos resultados (25), por el momento sólo contamos con primaquina disponible en el mercado para eliminar los gametocitos e hipnozoítos (2,26). Debido a esta limitación en medicamentos gametocidas, es importante mejorar los tiempos entre el acceso al diagnóstico y el tratamiento.…”

Section: Discussionunclassified

Factors that delay malaria diagnosis and treatment in the municipality of Riberalta in Bolivia

Añez¹,

Suárez²,

Cuba³

2012

biomedica

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Introducción. Se publican pocos estudios sobre las causas del retardo del diagnóstico y el tratamiento de la malaria en Bolivia. Objetivo. Conocer los factores que retardan el diagnóstico y el tratamiento de la malaria en el servicio público del municipio de Riberalta, Bolivia. Materiales y métodos. Se calcularon los tiempos transcurridos entre el inicio de los síntomas y el tratamiento, entre el inicio de los síntomas y el diagnóstico, y entre el diagnóstico y el inicio del tratamiento; se compararon las medias de los tiempos calculados con el lugar de infección, la especie parasitaria, el nivel de atención, el lugar y el método de diagnóstico, y la edad se correlacionó con los tiempos calculados. Resultados. De 2.482 casos positivos válidos evaluados entre enero y diciembre de 2010, se encontró una media de 4,16 días entre el inicio de los síntomas y el inicio del tratamiento, de 4,07 días entre el inicio de los síntomas y el diagnóstico, y de 0,10 días entre el diagnóstico y el tratamiento. El retardo del diagnóstico y los factores, lugar de diagnóstico, lugar de infección, nivel de atención, especie parasitaria y método de diagnóstico, mostraron una diferencia estadística significativa (p<0,05). En el análisis de la covarianza se observó una asociación estadística con el nivel de atención y la especie parasitaria (p<0,05) Conclusión. Existe un retardo en el diagnóstico de la malaria, lo cual es influenciado por factores como el lugar de infección, lugar del diagnóstico, nivel de atención, especie parasitaria y método de diagnóstico.Palabras clave: malaria/diagnóstico, signos y síntomas, tratamiento, Plasmodium, Bolivia. Factors that delay malaria diagnosis and treatment in the municipality of Riberalta in BoliviaIntroduction. Few studies on the causes of the delay of malaria diagnosis and treatment in Bolivia are published. Objective. To know the factors that delay malaria diagnosis and treatment of malaria in the public service of the town of Riberalta, Bolivia. Materials and methods. The times between the onset of symptoms and treatment, between the onset of symptoms and diagnosis and between the diagnosis and the start of treatment were calculated. The averages of the calculated times were compared with respect to the site of infection, parasite species, level of care, place of diagnosis and diagnostic method and th patient's age was correlated with the calculated times. Results. Between January and December 2010, 2,482 positive valid cases were studied. An average of 4.16 days was found between the onset of symptoms and the start of treatment, the average time between the onset of symptoms and diagnosis was 4.07 days, and between diagnosis and the start of treatment 0.10 days. Statistically significant (p<0.05) differences were found for factors related to the delay of diagnosis such as place of diagnosis, site of infection, level of care, parasite species and diagnostic method. The analysis of covariance showed a statistical association with the level of care and the parasite species (p<0.05). Conclusio...

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Chemoresistance of Plasmodium falciparum and Plasmodium vivax parasites in Brazil: consequences on disease morbidity and control

Cited by 31 publications

References 87 publications

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

Single-Nucleotide Polymorphism and Copy Number Variation of the Multidrug Resistance-1 Locus of Plasmodium vivax: Local and Global Patterns

Factors that delay malaria diagnosis and treatment in the municipality of Riberalta in Bolivia

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