| RESEARCH ARTICLE |
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| Year : 2019 | Volume
: 56
| Issue : 3 | Page : 237-243 |
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Nifurtimox response of Trypanosoma cruzi isolates from an outbreak of Chagas disease in Caracas, Venezuela
Arturo Munoz-Calderon1, Zoraida Díaz-Bello1, José Luis Ramírez2, Oscar Noya3, Belkisyolé Alarcón de Noya1
1 Sección de Inmunología, Instituto de Medicina Tropical, Facultad de Medicina, Universidad Central de Venezuela (IMT-FM-UCV), Caracas, Venezuela
2 Centro de Biotecnología, Fundación Instituto de Estudios Avanzados, Caracas, Venezuela
3 Sección de Biohelmintiasis, IMT-FM-UCV; Centro para Estudios sobre Malaria, Instituto de Altos Estudios “Dr. Arnoldo Gabaldón”, Instituto Nacional de Higiene ‘Rafael Rangel, Ministerio del Poder Popular para la Salud, Caracas, Venezuela
Correspondence Address:
Mr Arturo Munoz-Calderon
Sección de Inmunología, Instituto de Medicina Tropical, Facultad de Medicina, Universidad Central de Venezuela (IMT-FM-UCV), Zip–1041, Caracas
Venezuela
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0972-9062.289397
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Background & objectives: In Venezuela, Chagas disease (ChD) is considered a serious health problem, with about 6 million people at risk; and acute outbreaks due to oral transmission of Chagas Disease (OChD) are becoming increasingly important. In 2007 there was a major outbreak of OChD and although patients from this episode were treated with nifurtimox (Lampit®—Bayer), about 70% therapeutic failure was registered. These results led us to examine whether parasite’s drug susceptibility was related to this therapeutic failure.
Methods: The Trypanosoma cruzi parasites were isolated by haemoculture of the peripheral blood drawn from the pre- and post-nifurtimox treated patients infected in the 2007 OChD outbreak at Caracas, Venezuela. The in vitro assays for drug testing were performed by the MTT methodology followed by calculation of inhibitory concentration-50 (IC50) values.
Results: Parasite isolates obtained from the infected patients prior and after nifurtimox treatment when subjected to variable concentrations of the drug showed great heterogeneity in susceptibility with IC50 values ranging from 4.07 ± 1.82 to 94.92 ± 7.24 μM.
Interpretation & conclusion: The high heterogeneity in nifurtimox IC50 values in the isolates and clones from the OChD patients, suggests that the therapeutic failure to nifurtimox could be due in part to a phenotypic variability that existed in the wild parasite population at the original source of contamination. Though, further pharmacological studies are needed to confirm the existence of natural nifurtimox resistance in the parasite. |
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