Chagas in Colombia

Acute phase

• Confirm with direct parasitological methods: fresh examination and, after 30 days of symptoms, concentration methods (2010 Guide, pp. 28-29).
• Document seroconversion at 21 days with simultaneous serology (2010 Guide, p. 34).
• Do not order IgM: it is not available in the country (2010 Guide, p. 34).

Chronic phase

• Confirm with two serological tests of different principles (IgG anti-T. cruzi); ELISA is the initial test (2010 Guide, pp. 33 and 36).
• Consider a positive result an ELISA ≥2 times the cut-off or an IFA ≥1:32, according to the 2010 Guide (p. 33).
• Perform IFA or Immunoblot as a third test if the first two are discordant (protocol v04 2022, p. 11).

Rapid diagnostic tests

• 2025 update: in settings without ELISA, use RDTs with verified sensitivity and specificity ≥95 % (RDT guideline 2025, pp. 7, 13-14 and 16).
• Confirm with a second test (RDT or ELISA) and a third if discordant (pp. 13-14 and 16).
• Do not use them in suspected acute cases, immunosuppression, children under 10 months or blood banks (p. 14).

Reactivation and immunosuppression

• Look for the parasite with direct methods in blood, CSF or other fluids, with or without PCR (2010 Guide, p. 36).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)

Who to treat

• Treat every acute case: it is a medical emergency (2010 Guide, p. 40).
• Treat congenital infection (p. 40).
• Treat people under 18 years with chronic infection, regardless of clinical form (p. 40).
• Treat reactivation due to immunosuppression and accidental exposure (p. 40).
• In chronic adults the decision is individual; the benefit is greater with less than 15 years of exposure and no severe heart damage (p. 41).

Regimens and doses

• Benznidazole: 5-10 mg/kg/day in 2-3 doses for 60 days; in adults 5 mg/kg/day is usually sufficient (p. 42).
• In children doses close to 10 mg/kg/day are tolerated; maximum 300 mg/day (p. 42).
• Nifurtimox: adults 5-8 mg/kg/day and children 10 mg/kg/day, for 60 days in 2-3 doses (p. 44).
• Stepwise start: ¼ of the dose on day 1, ½ on days 2-3 and the full dose from day 4 (p. 44).

Contraindications and precautions

• Do not prescribe during pregnancy: aetiological treatment is contraindicated (p. 45).
• Contraindicate in severe neurological, hepatic or renal disorders (p. 45).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)

Monitoring during treatment

• Provide weekly medical follow-up (2010 Guide, p. 42).
• Request laboratory tests at baseline, at 20 days and at the end: blood count with platelets, AST, ALT, blood urea nitrogen and creatinine (p. 42).

Cure criterion

• Confirm with serological negativisation in two or more consecutive conventional tests (positive IFA ≥1:16) (p. 47).
• Repeat checks six-monthly or annually (p. 47).
• Expect negativisation in 1 year (congenital), 3-5 years (acute), 5-10 years (recent chronic) and more than 20 years (long-standing infection) (p. 47).

Cardiac assessment

• Perform baseline ECG and chest X-ray for every seropositive person (2010 Guide, pp. 68-69).
• In the indeterminate form, assess annually with ECG and chest X-ray; if the ECG is abnormal, refer to internal medicine or cardiology (pp. 68-69).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)

Screening in pregnancy

• Include serology in routine prenatal tests in at-risk areas (2010 Guide, pp. 71 and 73).
• Assess every seropositive pregnant woman with an electrocardiogram and Doppler echocardiogram from the first visits, because of the risk of decompensation (p. 71).

Treatment

• Do not treat during pregnancy: aetiological treatment is contraindicated (pp. 45 and 73).
• Treat the mother after breastfeeding (p. 73).

Newborn

• Look for trypomastigotes in cord blood at delivery (2010 Guide, p. 72).
• Under the current INS protocol: parasitology at birth, repeat at 3 or 6 months and serology at 10 months (v04 2022, p. 10).
• Bear in mind that the 2010 Guide varies between 6 and 9 months (p. 35) and 6 to 12 months (p. 72).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)

Who to treat

• Treat everyone under 18 years with chronic infection, regardless of clinical form (2010 Guide, p. 40).
• Children tolerate the drug better: benznidazole up to 10 mg/kg/day and nifurtimox 10 mg/kg/day for 60 days (pp. 42 and 44).

Active detection

• Prioritise detection of seropositive children with serology campaigns in children under 15 years (pp. 25, 49 and 51-52).
• In a 20-year series, efficacy was low in those treated after 3 years of age (2010 Guide, p. 48).

Newborn

• With compatible clinical signs and negative direct tests, use PCR before 6 months (p. 31).
• Repeat IgG serology at 10 months, under the current INS protocol (v04 2022, p. 10).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)

The therapeutic margin is narrow: adverse reactions are expected in all patients, especially adults (2010 Guide, p. 75).

Dermatitis

• Mild dermatitis, about 20 %, between the 5th and 10th day: continue treatment (pp. 42-43).
• Treat moderate dermatitis (less than 5 %) with temporary suspension, antihistamines or prednisolone 20 mg/day and reintroduction according to tolerability (pp. 42-43).
• Stop and hospitalise severe dermatitis (less than 1 %) (pp. 42-43).

Bone marrow depression

• Monitor neutropenia between the 20th and 30th day (less than 1 %) with leucocyte counts (p. 43).
• Warn the patient about fever or odynophagia because of the risk of agranulocytosis (p. 43).

Peripheral neuropathy

• High risk with 8 mg/kg/day for more than 30 days and a total dose above 15 g (p. 44).
• It may appear up to a week after finishing and leave paraesthesia (p. 44).

Other reactions

• Stop treatment if ageusia appears (0.5 % of cases) (p. 44).
• Nifurtimox causes fewer skin effects but worse digestive tolerance and psychiatric disturbances (p. 44).

Pharmacovigilance

• Notify adverse reactions under INVIMA and MinSalud rules; notification is mandatory for providers (2010 Guide, pp. 45 and 75).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)

Notification

• Notify Chagas disease to SIVIGILA (2010 Guide, p. 73).
• Notify immediately and individually every probable or confirmed acute case (protocol v04 2022, pp. 12 and 15).
• Notify chronic cases weekly, only in priority populations: pregnant women, people under 18 years, Indigenous populations and women of childbearing age (15-49 years) (p. 15).

Operational definitions

• Probable or confirmed acute: includes congenital transmission and outbreaks from oral transmission (protocol v04 2022, pp. 10-11).
• Probable chronic: one reactive ELISA/CLIA; confirmed chronic: two tests of different antigenic principles (pp. 10-11).
• If discordant, perform IFA or Immunoblot (pp. 10-11).

Targets and indicators

• Perform a direct parasitological test in 100 % of acute cases (protocol v04 2022, pp. 22-23).
• Perform a focus study in 100 % of outbreaks and isolated cases (pp. 22-23).
• Meet the 100 % target for the lethality indicator (pp. 22-23).

Laboratory

• Repeat direct parasitological tests serially, at least 3 times, in the acute phase (v04 2022, p. 20).
• Take part in annual external performance assessments with the network (LNR/INS, LSPD and local laboratories) (INS 2017, pp. 32-33).

Source: Clinical Care Guide for Chagas Disease (MinProtección Social/PAHO, 2010) and current INS documents (protocol v04 2022 and RDT guideline 2025)