Benznidazole and Posaconazole in Eliminating Parasites in Asymptomatic T. Cruzi Carriers: The STOP-CHAGAS Trial (original) (raw)

A parasite biomarker set for evaluating benznidazole treatment efficacy in patients with chronic asymptomatic Trypanosoma cruzi infection

Antimicrobial Agents and Chemotherapy

One of the current greatest challenges of Chagas disease is the establishment of biomarkers to assess the efficacy of drugs in a short period of time. In this context, the reactivity of sera from 66 adults with chronic indeterminate Chagas disease (IND) for a set of four Trypanosoma cruzi antigens (KMP11, PFR2, HSP70 and 3973d) was analyzed before and after benznidazole treatment. The results showed that the reactivity against these antigens decreased at 9, 24 and 48 months after treatment. Moreover, the 42.4% and 68.75% of IND patients met the established standard criteria of therapeutic efficacy (STEC) at 24 and 48 months posttreatment, respectively. Meeting the STEC implied that there was a continuous decrease in the reactivity of the patient sera against the four antigens after treatment and that there was a substantial decrease in the reactivity for at least two of the antigens. This important decrease in reactivity may be associated with a drastic reduction in the parasite loa...

Experimental benznidazole treatment of Trypanosoma cruzi II strains isolated from children of the Jequitinhonha Valley, Minas Gerais, Brazil, with Chagas disease

Memórias do Instituto Oswaldo Cruz, 2015

Trypanosoma cruzi strains from distinct geographic areas show differences in drug resistance and association between parasites genetic and treatment response has been observed. Considering that benznidazole (BZ) can reduce the parasite burden and tissues damage, even in not cured animals and individuals, the goal is to assess the drug response to BZ of T. cruzi II strains isolated from children of the Jequitinhonha Valley, state of Minas Gerais, Brazil, before treatment. Mice infected and treated with BZ in both phases of infection were compared with the untreated and evaluated by fresh blood examination, haemoculture, polymerase chain reaction, conventional (ELISA) and non-conventional (FC-ALTA) serologies. In mice treated in the acute phase, a significant decrease in parasitaemia was observed for all strains. Positive parasitological and/or serological tests in animals treated during the acute and chronic (95.1-100%) phases showed that most of the strains were BZ resistant. However, beneficial effect was demonstrated because significant reduction (p < 0.05%) and/or suppression of parasitaemia was observed in mice infected with all strains (acute phase), associated to reduction/elimination of inflammation and fibrosis for two/eight strains. BZ offered some benefit, even in not cured animals, what suggest that BZ use may be recommended at least for recent chronic infection of the studied region.

New scheme of intermittent benznidazole administration in patients chronically infected with Trypanosoma cruzi. A pilot short-term follow-up study in adult patients

Antimicrobial agents and chemotherapy, 2015

There is a clinical need to test new schemes of benznidazole, which are expected to be at least as effective as the current therapeutic scheme but safer. This study assessed a new scheme of benznidazole administration in chronic Chagas disease patients. A pilot study with intermittent doses of benznidazole at 5 mg/kg/day in two daily doses every 5 days, for a total of 60 days was designed. The main criterion of response was the comparison of qPCR findings prior and one week after the end of treatment. The safety profile was assessed by the rate of suspensions and severity of adverse effects. Twenty patients were analyzed for safety while qPCR was tested in17 of them. The average age was 43±7.9 years; 55% were female. Sixty five percent of treated subjects showed detectable qPCR prior to treatment, 1.45 (0.63-2.81) and 2.1 (1.18-2.78) Par.Eq./mL for kDNAqPCR and SatDNAqPCR, respectively. One patient showed detectable PCR at end of treatment (1/17), corresponding to 6% of treatment fa...

Use of polymerase chain reaction (PCR) and hybridization assays to detect trypanosoma cruzi in chronic chagasic patients treated with itraconazole or allopurinol

Diagnostic Microbiology and Infectious Disease, 2004

The presence of Trypanosoma cruzi in chronic chagasic patients with negative xenodiagnosis (XD) after 6 years following completion of therapy with either itraconazole or allopurinol was assessed by polymerase chain reaction (PCR) and hybridization assays. A 330-bp DNA fragment amplified from the hypervariable regions of T. cruzi kinetoplastid minicircles was hybridized with total 32 P-labeled kinetoplast DNA as probes. PCR alone enabled the identification of T. cruzi nucleotide sequences in 40% of the patients treated with itraconazole and in 60% of patients treated with allopurinol. PCR used in combination with hybridization detected parasite DNA in 60% and 53% of XD negative individuals treated with itraconazole or allopurinol, respectively. These results show that PCR and hybridization are more sensitive than conventional parasitological techniques in diagnosing patients that have undergone chemotherapy with itraconazole or allopurinol.

High seroconversion rates in Trypanosoma cruzi chronic infection treated with benznidazole in people under 16 years in Guatemala

Revista da Sociedade Brasileira de Medicina Tropical, 2016

Introduction: Geographical, epidemiological, and environmental differences associated with therapeutic response to Chagas etiological treatment have been previously discussed. This study describes high seroconversion rates 72 months after benznidazole treatment in patients under 16 years from a project implemented by Doctors without Borders in Guatemala. Methods: An enzyme-linked immunosorbent assay was used to detect Trypanosoma cruzi IgG antibodies in capillary blood samples from patients 72 months after treatment. Fisher's exact test was used to establish association between characteristics, such as sex, age, and origin of patients, and fi nal seroconversion. Kappa index determined concordance between laboratory tests. The level of signifi cance was set to 5%. Results: Ninety-eight patients, aged 6 months to 16 years, were available for follow-up. Sex and origin were not associated with seroconversion. Individuals older than 13 were more prone to maintain a positive result 72 months after treatment, although results were not highly signifi cant. Laboratory tests presented elevated Kappa concordance (95% CI) = 0.8290 (0.4955-1), as well as high (97%) seroconversion rates. Conclusions: The high seroconversion rate found in this study emphasizes the importance of access to diagnosis, treatment, and follow-up of individuals affected by Chagas disease. Moreover, it contradicts the idea that it is not possible to achieve a cure with the currently available drugs. This study strongly supports expanding programs for patients infected with T. cruzi in endemic and non-endemic countries.

Specific treatment for Trypanosoma cruzi: lack of efficacy of allopurinol in the human chronic phase of Chagas disease

The American journal of tropical medicine and hygiene, 2007

Thirty-five individuals from endemic areas of Central Brazil (age range, 18-64 years; 19 women) in the chronic phase of Chagas disease, with positive serology and presence of circulating parasites detected by one or more recent positive xenodiagnosis, were selected for this study. Allopurinol (900 mg/d) or placebo was administered in a double-blind clinical trial for 60 days. After codes were broken, 23 had been allocated to the intervention group and 12 to the placebo group. Side effects were observed in 11 patients in the intervention group and in 1 in the placebo group. Seventeen patients in the intervention group and 10 in the placebo group completed the trial. Follow-up was performed by monthly xenodiagnosis and serologic tests every 3 months during the first year and at the end of the trial. Xenodiagnosis remained positive in all 17 of the treated group and in all 10 of the placebo group. Serologic tests were persistently positive in both groups after treatment. We concluded t...

Course of Chronic Trypanosoma cruzi Infection after Treatment Based on Parasitological and Serological Tests: A Systematic Review of Follow-Up Studies

PLOS ONE, 2015

Background Chagas disease is caused by the flagellate protozoan Trypanosoma cruzi (T. cruzi). It is endemic in Latin American countries outside the Caribbean. The current criterion for cure in the chronic phase of the disease is the negativization of at least two serological tests such as enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IIF) and indirect hemagglutination assay (IHA). The serological evolution of treated subjects with chronic T. cruzi infection is variable. Treatment failure is indicated by a positive parasitological and/or molecular test (persistence of parasitemia). Objectives To summarize the pattern of response to treatment of parasitological, molecular and serological tests performed during the follow-up of subjects with chronic T. cruzi infection. Methods Electronic searches in relevant databases and screening of citations of potentially eligible articles were accomplished. Organizations focusing on neglected infectious diseases were asked for help in identifying relevant studies. Included studies were randomized controlled trials (RCTs), quasi-RCTs, and cohort studies involving adults and children with chronic infection who received trypanocidal treatment (benznidazole or nifurtimox) and were followed over time. The assessment of risk of bias was performed separately for each study design. The Cochrane Collaboration's tool PLOS ONE |