American Trypanosomiasis

Question 1

What is the organism that causes American trypanosomiasis?

Answer 1

Trypanosoma cruzi

Question 2

Which group of bugs are the vectors for American trypanosomiasis and how can you differentiate them?

Answer 2

Triatomine bugs

Triatoma- antennae insert midway
Rhodnius- antennae inserts at the end. Longest head
Panstrongylus- antennae inserts next to eyes. Short tubby head

Question 3

How can trypanosoma cruzi be transmitted?

Answer 3

Faeces of triatomine bugs ingested through food or rubbed into bite site or conjunctiva
Breastfeeding
Transfusions

Question 4

Does trypanosoma cruzi have an intracellular lifecycle?

Answer 4

Yes amastigotes replicate by binary fission in smooth muscle cells (heart and GI)

Question 5

What are the acute phase symptoms of Chagas’ disease?

Answer 5

90% asymptomatic
Mainly get symptoms in children
Chagoma at site of bite
Romanas sign if conjunctival entry
Fever, malaria, anorexia
Abdo and chest pain
Rarely meningoencephalitis

Question 6

How do you treat the acute phase of Chagas’ disease?

Answer 6

Benznidazole or nifurtimax
For 60days
Can’t give to pregnant women

Question 7

What are the side effects of benznidazole?

Answer 7

BM suppression
Nephrotoxicity
GI toxicity

Question 8

How do you diagnose a Chagas’ disease in the acute phase?

Answer 8

Blood film
PCR
Xenodiagnosis

Question 9

How long does the intermediate stage of Chagas’ disease last for?

Answer 9

10-30 years

Question 10

What are the symptoms of the chronic stage of Chagas’ disease?

Answer 10

In the gut, constipation from mega colon and reflux from megaoesophagus

In the heart, cardiac myopathy leading to arrythmias and sudden cardiac death

Ischaemic strokes

Question 11

What percentage of patients progress to chronic Chagas’ disease?

Answer 11

30-40%

Question 12

How do you investigate chronic Chagas’ disease?

Answer 12

Blood- unlikely to see parasites
IgG serology
ECG- RBBB, premature ventricular beats
ECHO
Barium enema/swallow

Question 13

How do you treat chronic Chagas’ disease?

Answer 13

Treat the manifestations
Amiodarone
Pacemaker
Surgery for GI

Question 14

How can we control Chagas’ disease

Answer 14

Education
Bug collection incentives
Home improvements
RIS
PCR screen prior to pregnancy
Screen blood transfusions and organs
Cover food and drink
Bednets
Screening and Tx of congenital Chagas

Question 15

How can Chagas present in PLHIV?

Answer 15

Atypical with intracranial mass or meningoencephalitis

Question 16

What are the Chagas’ disease objectives in the NTD roadmap?

Answer 16

Verification of the interruption of vectorial, transfusion and transplant transmission
Elimination of congenital Chagas
75% coverage of antiparasitic treatment of the eligible population