Chagas' Disease: Treatment, clinical situations

1. Acute phase
   The acute phase lasts up to 60 days. All patients who are in this phase should be treated.

2. Congenital infection
   All infected children should be treated. The earlier therapy is begun, the better the results.

3. Chronic phase
   Aetiological drug treatment is indicated for "recent" chronic infections (a few years). In practice all children younger than 10 years are treated. If mega-oesophagus is already present, the dysphagia should be treated (the passage and absorption of oral medication may be severely impeded). Aetiological treatment in these latter patients was not advised formerly, but more recent data have brought this into question. In a study in Argentina, 131 patients with chronic Chagas’ disease were treated with benznidazole. After an average follow up of 8 years, 4.2% exhibited ECG changes compared to 30% in the untreated group. There was also considerably less clinical deterioration in the treated group (2.1% compared to 17%).

4. Accidental infection
   This may occur, for example in laboratory staff. A serum specimen should be frozen before beginning treatment and a second blood sample taken 4 weeks later. Serology is performed on these paired sera. Benznidazole 7-10 mg/kg/day x 10 days is the usual treatment regimen in this situation.

5. Transplant patients
   There are two possible situations: transplantation of an infected organ into a non-infected patient and transplantation of a healthy organ into an infected patient. A donor may be infected so that the recipient becomes infected. Normally the donor is tested beforehand, and positive donors are refused, but nevertheless these situations sometimes occur. Alternatively, a transplantation may be carried out on a patient who is a chronic carrier. The immune suppression that these patients undergo [steroids, azathioprine (Imuran®) and cyclosporin (Sandimmun®)], may lead to reactivation of Chagas’ disease. In both cases treatment with benznidazole 5 mg/kg/day x 60 days, is indicated.

6. HIV patients
   Infection with HIV may lead to significant flare-up of Chagas’ disease. In endemic regions all HIV patients should be monitored for Chagas’ disease. If positive, benznidazole is recommended. There are insufficient data concerning chemoprophylaxis.

7. Pregnancy

   Treatment during pregnancy is not recommended.

Category: Medicine Notes