– A zoonosis caused by flagellate protozoan Trypanosoma cruzi, transmitted to humans through blood-sucking bugs (assassin bugs) on the occasion of skin abrasions or through mucous membranes. The transmission is also possible from tainted blood and, in the fetus via the placenta.
– Chagas disease is encountered only in the Americas, in the area between southern Mexico and the south of Argentina.
Clinical signs:
– Acute phase
• Depending on the site of inoculation, cutaneous chancre or unilateral purplish eyelid edema (Romaña sign) with local lymphadenopathy and fever 38 ° C (higher in children) for several weeks.
• Then, multiple lymphadenopathy, hepatosplenomegaly, myocarditis (chest pain, heart failure), meningoencephalitis sometimes (convulsions, paralysis). This phase may be asymptomatic or subclinical.
The transition from the first phase to the second phase is not systematic.
– Chronic Phase
• Separated from the acute phase of a long latency period: cardiac lesions (arrhythmias and conduction, cardiomyopathy, heart failure, angina pain, thromboembolism) and gastrointestinal (megaesophagus and megacolon).
• Most patients are asymptomatic.
Laboratory:
– In the acute phase
• Thin or thick film: research of the parasite in the blood or the lymph nodes.
• Serodiagnosis: search for antibodies to Trypanosoma cruzi.
• Xenodiagnosis: examination healthy assassin bugs droppings nourished with the blood of the patient.
– In the chronic phase
• Serodiagnosis: search for antibodies to Trypanosoma cruzi.
Treatment:
– Acute phase
nifurtimox PO (cons-indicated during the first trimester of pregnancy, breastfeeding or if psychiatric history or seizures)
Patient under 40 kg: 10 to 12 mg / kg / day divided in 2 to 3 divided doses for 30 to 60 days
Patient over 40 kg: 8 mg / kg / day in 2 divided to 3 doses for 30 to 60 days Adverse effects of nifurtimox (anorexia, nausea, gastric pain, agitation, sleep disturbances, seizures) occur in less than 20 %, and should not lead to discontinue treatment. Avoid alcohol during treatment.
or
benznidazole PO (cons-indicated during the first trimester of pregnancy and lactation)
Patient under 40 kg: 7.5 mg / kg / day divided in 2 to 3 divided doses for 30 to 60 days
Patients over 40 kg: 5 mg / kg / day divided in 2 to 3 divided doses for 30 to 60 days
Minor side effects of benznidazole (nausea, rash) occur in about 50% of patients. Discontinue treatment if purpura associated with a fever, paresthesia, peripheral neuritis.
– Chronic phase in children under 12 years benznidazole PO
Children under 40 kg, 7.5 mg / kg / day in 2 divided to 3 doses for 30 to 60 days
Children over 40 kg: 5 mg / kg / day in 2 divided to 3 doses for 30 to 60 days
– Chronic phase in children over 12 years and adults
Do not treat during pregnancy, lactation, liver or kidney failure, or severe associated pathology.
nifurtimox PO: 8 to 10 mg / kg / day divided in 2 to 3 divided doses for 60 to 90 days
or
benznidazole PO: 5 mg / kg / day in 2 divided to 3 doses for 60 days
– Symptomatic treatment
Convulsions, pain and heart failure.
Prevention:
– Home improvement and fight against the vector: plastered walls and floors paved with cement, roofing sheets, insecticide spraying.
– Control of blood transfusions: serological screening T. cruzi in donors.
