Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.
Inclusion criteria / eligibility
To be eligible for treatment in this program, the patient must:
Have a history consistent with exposure to T. cruzi and have laboratory evidence of T. cruzi infection, including either:
parasitologic/molecular evidence of infection (e.g., microscopic or molecular detection of T. cruzi in blood or tissues), and/or
serologic evidence of infection—i.e., positive results with 2 or more serologic tests based on different principles/antigens
Not have laboratory evidence of infection but have a documented history of exposure to T. cruzi (e.g., laboratory accident or receipt of blood, tissue, or an organ transplant from a person with laboratory-confirmed infection) in circumstances in which prophylaxis may be indicated. The decision to release benznidazole before (vs. only after) infection is documented and, if so, what dosage regimen to use, will be made in consultation with a CDC medical officer on a case-by-case basis.
The decision regarding eligibility, along with individualized consideration of the potential risks and benefits of treatment, will be made through discussion between a CDC medical officer in the Parasitic Diseases Branch (or his/her designee) and the treating physician. The patient will be required to sign an informed consent form (see Section 11.2). If unable to sign, the next of kin or legally authorized representative will be required to sign. Persons who otherwise are able to sign but who refuse to sign the consent form will be excluded from this program.
Persons who have severe cardiomyopathy/cardiac failure from advanced chagasic heart disease generally will be excluded from this program, taking into account an individual patient’s clinical manifestations, course, and circumstances.
The program also will exclude immunocompetent pregnant women with chronic asymptomatic T. cruzi infection (see Sections 4.4.3 and 5.5a). However, treatment may be considered for pregnant patients who have potentially life-threatening acute or reactivated infection or who are immunocompromised; the decision to give benznidazole during pregnancy will be made in consultation with a CDC medical officer on a case-by-case basis.
Precautions need to be taken with the following patient groups:
a) Women of child-bearing age, including women who are or might become pregnant
See Section 4.4.3 for additional perspective regarding benznidazole and pregnancy, and see Section 5.4 regarding women who already are pregnant.
Patients will be advised to avoid pregnancy while taking benznidazole.
- Before starting a course of benznidazole, a pregnancy test should be performed in women of child-bearing age or the patient should be counseled to delay initiation of therapy until after her next menstrual period.
- Adequate barrier contraception should be used during treatment; hormonal contraception is not recommended because potential drug interactions with benznidazole have not been investigated.
b) The decision to treat infants less than 7 months of age will be made in consultation with a CDC medical officer on a case-by-case basis.
c) Treatment of patients with severe hypersensitivity to nitroimidazoles should proceed only after careful consideration of risks and benefits.
d) Patients with hematologic, hepatic, or renal impairment may be at higher risk for adverse events. Risks and benefits for these patients should be carefully assessed. The decision whether to treat with benznidazole and, if so, with what dosage regimen, should be individualized, in consultation with a CDC medical officer.