Chagas Disease

Question 1

What is Chagas disease caused by?

Answer 1

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi.

Question 2

How is Chagas disease transmitted to humans?

Answer 2

Chagas disease is transmitted by infected triatomine bugs, transfusion, organ transplant, from mother to infant, and ingestion of contaminated food or drink.

Question 3

In which geographical area does vector-borne transmission of Chagas disease occur?

Answer 3

Vector-borne transmission occurs only in the Americas.

Question 4

What is the estimated number of people with Chagas disease?

Answer 4

An estimated 6 million people have Chagas disease.

Question 5

What is the characteristic sign of acute Chagas disease when the conjunctiva is infected?

Answer 5

Romaña’s sign, characterized by unilateral painless swelling of the upper and lower eyelids.

Question 6

What are the common symptoms of acute Chagas disease?

Answer 6

Symptoms typically include a non-specific febrile illness, and in some cases, acute myocarditis or meningoencephalitis.

Question 7

What happens at the end of the acute phase of Chagas disease?

Answer 7

Parasitemia falls below levels detectable by microscopy, and the infection passes into the chronic phase.

Question 8

What is the indeterminate form of Chagas disease?

Answer 8

It is when most patients with chronic T. cruzi infection have no signs or symptoms.

Question 9

What is the most common complication of chronic Chagas disease?

Answer 9

Cardiomyopathy.

Question 10

What are the early manifestations of chronic Chagas disease?

Answer 10

Conduction system abnormalities, such as right bundle branch block.

Question 11

How is T. cruzi reactivation characterized during the chronic phase?

Answer 11

By a return to high levels of parasite replication and parasitemia, detectable by microscopy.

Question 12

What are common manifestations of reactivated Chagas disease in HIV patients?

Answer 12

• T. cruzi meningoencephalitis
• Acute myocarditis
• Skin lesions
• Erythema nodosum
• Parasitic invasion of the peritoneum, stomach, or intestine.

Question 13

What screening is recommended for individuals who have lived in endemic areas?

Answer 13

Serological testing for Chagas disease.

Question 14

What serological methods are used to diagnose chronic Chagas infection?

Answer 14

• Enzyme-linked immunosorbent assay (ELISA)
• Immunofluorescent antibody assay (IFA).

Question 15

What is required for a confirmed diagnosis of chronic T. cruzi infection?

Answer 15

Two serological tests based on different antigens and/or techniques.

Question 16

What is the role of polymerase chain reaction (PCR) in diagnosing chronic Chagas disease?

Answer 16

PCR is generally not useful as its sensitivity is highly variable.

Question 17

What should be considered in the differential diagnosis of CNS symptoms in patients with HIV?

Answer 17

Coinfection with T. cruzi and reactivation disease.

Question 18

What is the primary method for identifying reactivation of Chagas disease?

Answer 18

Identification of the parasite or its products in tissue, such as blood or CSF.

Question 19

What is the recommended treatment for individuals with T. cruzi infection living with HIV?

Answer 19

A single course of treatment with benznidazole or nifurtimox.

Question 20

What is the FDA-approved age range for using benznidazole?

Answer 20

Children 2 to 12 years of age.

Question 21

What is the recommended regimen for nifurtimox?

Answer 21

8 to 10 mg/kg/day in three divided doses with food for 60 days.

Question 22

What is a significant risk factor for reactivation of Chagas disease in people with HIV?

Answer 22

Low CD4 T lymphocyte cell counts (<200 cells/mm3).

Question 23

What is the recommended preventive measure for travelers to endemic areas of Chagas disease?

Answer 23

Avoid sleeping in rustic lodging and use insecticide-treated bed nets.

Question 24

True or False: There are currently drugs or vaccines available to prevent T. cruzi infection.

Answer 24

False.

Question 25

What is the typical presentation of reactivation in immunosuppressed patients compared to HIV patients?

Answer 25

Different; the most common in HIV patients is T. cruzi meningoencephalitis.

Question 26

What should be done for individuals with high clinical suspicion of reactivation of chronic Chagas disease?

Answer 26

Testing to identify T. cruzi should be considered.

Question 27

What must be carefully considered before initiating ART in people with HIV and reactivated T. cruzi infection involving the brain?

Answer 27

The decision to initiate ART must be carefully considered ## Footnote There is no known contraindication to starting or optimizing ART in patients with CNS Chagas disease.

Question 28

What is the recommendation regarding ART for patients with concomitant T. cruzi?

Answer 28

ART should be initiated in all patients with concomitant T. cruzi (AIII) ## Footnote IRIS is not recognized as a common manifestation in the setting of coinfection.

Question 29

What monitoring should be conducted for patients undergoing treatment with benznidazole?

Answer 29

Comprehensive metabolic panel (CMP) and complete blood count (CBC) should be monitored before initiation and during therapy ## Footnote Benznidazole is associated with significant toxicities.

Question 30

What are some benznidazole-associated adverse drug reactions?

Answer 30

Adverse reactions include: * Abdominal symptoms (pain, nausea, vomiting, diarrhea) * Reversible peripheral neuropathy * Rash * Granulocytopenia ## Footnote Co-administration with disulfiram, alcohol, and products containing propylene glycol should be avoided.

Question 31

What are the adverse drug reactions associated with nifurtimox?

Answer 31

Adverse reactions include: * Anorexia * Nausea * Vomiting * Abdominal pain * Weight loss * Rash * Restlessness * Tremors * Dose-dependent peripheral neuropathy ## Footnote Alcohol consumption should be avoided with nifurtimox.

Question 32

How frequently should CMP and CBC be monitored during treatment?

Answer 32

Generally every 2 weeks ## Footnote The frequency is not standardized.

Question 33

What is the concern regarding treatment failure in people with HIV and chronic T. cruzi infection?

Answer 33

Benznidazole and nifurtimox are only partially effective and may be suppressive rather than curative ## Footnote Expert advice should be sought due to the drugs' toxicity.

Question 34

What is unclear regarding secondary prophylaxis or chronic maintenance therapy in people with HIV with latent Chagas disease?

Answer 34

It is unclear whether secondary prophylaxis or chronic maintenance therapy should be used ## Footnote Particularly when potent ART is used.

Question 35

What should be considered for pregnant individuals with epidemiologic risk of Chagas disease?

Answer 35

Screening for maternal infection and possible risk of infection in offspring should be considered ## Footnote See the CDC resource for congenital Chagas disease.

Question 36

What percentage of infants born to mothers with T. cruzi have acute T. cruzi infection?

Answer 36

Between 1% to 10% ## Footnote Congenital infections are often asymptomatic or cause non-specific signs.

Question 37

What severe morbidities can congenital T. cruzi infection cause?

Answer 37

Severe morbidities include: * Low birthweight * Hepatosplenomegaly * Anemia * Meningoencephalitis * Respiratory insufficiency * High risk of mortality ## Footnote Limited data suggest higher rates of congenital transmission for women with HIV.

Question 38

What is the recommendation regarding treatment of acute T. cruzi infection in pregnant individuals?

Answer 38

Treatment should only be undertaken in consultation with a specialist ## Footnote Treatment of chronic disease should be considered only after pregnancy and breastfeeding.

Question 39

What is recommended for individuals with epidemiological risk factors for Chagas disease who test positive for antibody to T. cruzi?

Answer 39

They should be tested using at least two serological tests ## Footnote Tests should be based on different antigens and/or techniques.

Question 40

What is the recommended therapy for individuals with acute or reactivated T. cruzi infection?

Answer 40

Benznidazole 5–8 mg/kg/day PO in 2 divided doses for 60 days or Nifurtimox 8–10 mg/kg/day PO in 3 divided doses for 60 days ## Footnote Initiation or optimization of ART is also recommended.

Question 41

What is the indication for treating acute or reactivated T. cruzi infection?

Answer 41

Presence of parasitemia should be treated (AII) ## Footnote Treatment is not recommended for patients with advanced chagasic cardiomyopathy.