Clinical Trial: Optimization of PCR Technique to Assess Parasitological Response for Patients With Chronic Chagas Disease

Study Status: Completed
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Optimization of Sampling Procedure for PCR Technique to Assess Parasitological Response for Patients With Chronic Chagas Disease Treated With Benznidazole in Aiquile, Boli

Brief Summary: The purpose of this study is to estimate the gain in sensitivity of several multiple-sample strategies of PCR samples with respect to the current standard (single sample of 10 ml) to detect Chagas chronic stage at baseline and to identify the optimal sampling strategy based on the sensitivity, cost,the completeness of sampling and the acceptability for study patients.

Detailed Summary:

Chagas Disease (CD) ranks among the world's most neglected diseases. In Latin America, 21 countries are endemic for CD with an estimated 108 million people at risk of contracting the disease. Estimates from the 1980s indicated that some 16 -18 million individuals were infected. In the 1990s, after a series of multinational control initiatives, estimates of the number of infected people were revised to 9.8 million in 2001. The estimated burden of disease in terms of disability-adjusted life years (DALYs) declined from 2.7 million in 1990 to 586,000 in 2001. Recent estimates from Pan-American Health Organization (PAHO), 2006 indicate 7.54 million infected people and 55,185 new cases per year. CD,also known as American trypanosomiasis,is a zoonotic disease caused by the protozoan hemoflagellate Trypanosoma cruzi that is mainly transmitted by large, blood-sucking, reduviid bugs of the subfamily Triatominae. Clinically, human CD has two phases, acute and chronic. The acute phase, which lasts a few weeks, is a febrile and toxemic illness, during which the parasite can be detected by direct examination of fresh blood. In the chronic phase, the diagnosis depends on hemocultures of varying degree of sensitivities, xenodiagnosis, PCR or detecting IgG antibodies. Untreated, the chronic phase continues for the rest of a person's life. It begins with no specific symptoms or clinical manifestations for a period of approximately 10 or 15 years, the "indeterminate form" of the disease. About 20 to 50% of chronic Chagas patients over the ensuing years, depending on the endemic area analyzed, will develop involvement of the heart or gastrointestinal tract. Current therapy for CD is limited to two nitroheterocyclic drugs, Nifurtimox and Benznidazole, the later being the most widely used drug for Chagas disease treatment. The indications for treatment are acute disease (including congenital infection), and early chronic disease (t
Sponsor: Drugs for Neglected Diseases

Current Primary Outcome:

  • The primary endpoints are: - A positive or negative PCR at baseline (BL) among serology positive patients. [ Time Frame: Bloods will be at baseline and EOT (last day of treatment +10 + 5 days), 6 months and 12 months follow-up visits. ]
  • - Identification of the optimal relationship between sensitivity and feasibility at baseline. [ Time Frame: Bloods will be at baseline and EOT (last day of treatment +10 + 5 days), 6 months and 12 months follow-up visits. ]

    For BL and EOT visits, blood samples will be as follows: one initial blood of 10 mL (Sample 1), followed by 1 sample of 5mL collected immediately following (Sample 2); plus one blood sample of 10mL collected 1 week later (Sample 3).

    Once the optimal strategy has been defined for EOT visit (see section 10.7), this will be the strategy of blood collection to be used at the 6 and 12 months follow-up visits



Original Primary Outcome: Same as current

Current Secondary Outcome:

  • - Identification of the optimal relationship between sensitivity and Identification of the optimal relationship between sensitivity and feasibility at End Of Treatment (EOT) [ Time Frame: Bloods will be at baseline and EOT (last day of treatment +10 + 5 days), 6 months and 12 months follow-up visits. ]
  • - The proportion of patients who convert from PCR (+) at baseline to PCR (-) at EOT - to be estimated using 1) the current sampling schedule (CS), the most sensitive one and the optimal one. [ Time Frame: Bloods will be at baseline and EOT (last day of treatment +10 + 5 days), 6 months and 12 months follow-up visits. ]
  • - The proportion of patients who convert from PCR (+) at baseline to PCR (-) at 6 and 12 months follow-up - to be estimated using 1) the current sampling schedule (CS) and the optimal one (based on EOT data). [ Time Frame: Bloods will be at baseline and EOT (last day of treatment +10 + 5 days), 6 months and 12 months follow-up visits. ]
  • - Relative reduction [(parasite count at baseline - parasite count at EOT, 6 and 12 months)/parasite count at baseline] of parasitemia - to be evaluated through parasite load at EOT, 6 and 12 months through quantitative PCR. [ Time Frame: Bloods will be at baseline and EOT (last day of treatment +10 + 5 days), 6 months and 12 months follow-up visits. ]


Original Secondary Outcome: Same as current

Information By: Drugs for Neglected Diseases

Dates:
Date Received: March 1, 2012
Date Started: April 2011
Date Completion: April 2013
Last Updated: August 30, 2012
Last Verified: August 2012