Transcript Chagas Diseases in the traveler

Chagas Diseases in the
traveler
Andrés F. Henao
Assistant Professor
University of Colorado Denver
Sept 28, 2016
Chagas Disease:
 Introduction:
 Discovered
in 1909 by a
Brazilian Physician Carlos
Chagas.
 Paleoparasitology
recovered T.
cruzi in 9000 years old
mummies.
 Charles
Darwin quite possible
contracted Chagas disease.
Etiology/Life cycle:
Vector:

Transmitted to Humans and
more than 150 species of
domestic and wild animals
by large, blood sucking
reduviid bugs (Subfamily
Triatominae).
Epidemiology:

Chagas disease
infected 8 million
people in Latin
America by 2005
and about 20% of
the population is
at risk (~109
million of people).

It causes 12,500
deaths annually.
Epidemiology:

Chagas disease is now an emerging disease
associated with congenital, blood, and organ
transplantation transmissions in developed
countries, in which 1%–26% of immigrants are
infected.

In the US, approximately 300,000 individuals
are estimated to be infected with T. cruzi.
Clinical Infectious Diseases 2012;54(6):845–52
Traveling to areas with potential exposure:
Traveling epidemiology:

Rural areas in Mexico, and Central and South
America —highest concentration between central
Mexico and northern Argentina.

Excepts the Caribbean and Uruguay.

Symptomatic acquisition of acute Chagas' disease
in travelers is rare, with only 5 reported cases.

Sero surveys for asymptomatic infection due to
travel have not been performed.
Transmission risk in the Yucatán
peninsula of México:
Am J Trop Med Hyg 2004 ; 70 : 514 – 519 .
Transmission:





Vector—bites occur predominantly at night
and they are painless and then become
itchy.
Blood Transfusion or organ transplant.
Vertical (transplacental)
Accidental (Laboratory).
Oral: Reported in Brazil (primarily the
Amazon region) since the 1960s, and in
Bolivia, Colombia, and Venezuela in more
recent years.
Risk factors among travelers:

Travelers undertaking outdoor activities such as
hiking, camping, and ecotourism in endemic
countries in Central and South America.

Sleeping in poorly constructed houses—Huts made
of mud, palm thatch, or adobe brick.

Triatomines or their feces may be crushed and
mixed with freshly prepared sugar cane or acai
juices.

In certain areas of Bolivia, the sero positivity
among blood donors can be as high as 53%.
Transmission scenarios among travelers:

Acute infection following ingestion
of contaminated food.

Vector related.
 Sleeping
in small villages with lack
of netted windows and doors.
 Sleeping
outdoor on hammocks.
• J Infect Public Health. 2016 May 30.
• Am J Trop Med Hyg. 2012 Dec 5; 87(6): 1038–1040.
A Neglected Infection of Poverty :
Chagas in the US:
States with documented
mammalian reservoirs
*
* Published human vectorassociated cases
*
*
*
> 18 infected reservoir species identified
Natural course:
Expert Reviews in Molecular Medicine 2010 Published by Cambridge University Press.
Signs of acute infection:

Asymptomatic.

Fever/Chills.

Lympadenopathy.

Hepato-Splenomegaly.

CNS involvement (rare).

Unilateral palpebral swelling
(Romaña sign).
Clinical presentations among returning
travelers:

Acute Chagas disease
 Eye
swelling, pruritus, pain.
 Fever,
headaches, dyspnea on
exertion, rash, low appetite.
Am J Trop Med Hyg. 2012 Dec 5;
87(6): 1038–1040.
Acute Myocarditis:

Involvement of the myocardium with myocarditis
during the acute infection has been constantly
found through myocardial biopsies or at necropsy
even if patients are asymptomatic.
International journal of cardiology. 1997;60(1):49-54.
Acute Chagasic myocarditis:
Acute Chagas cardiac disease among
travelers:

Pericarditis

First AV block.

Pleural effusion.

LV dilation.
• J Infect Public Health. 2016 May 30.
• Am J Trop Med Hyg. 2012 Dec 5; 87(6): 1038–1040.
Natural history:
Lancet; Vol 375 April 17, 2010.
Chronic Chagas Disease:

Conduction system
abnormalities.

Cardiomegaly with heart
failure.

Apical aneurysms and
systemic/pulmonary
thromboembolism.

Sudden death.
Lancet; Vol 375 April 17, 2010.
Cardiac changes stages:
Lancet 2010; 375: 1388–402.
Continue:

Mega-esophagus

Megacolon
Lancet; Vol 375 April 17, 2010.
Diagnosis:

N Engl J Med 2011;364:2527-34.
Difficulties in diagnosis:

Observation of the parasites in blood
(only useful in the acute phase).

Xenodiagnosis.

Only 30 to 60% of untreated patients with
chronic T. cruzi infection have positive
results.

Inoculation of the patient's blood into a
susceptible laboratory animal.

Culture methods are not clinically useful
because parasites may not be seen for
several weeks.
Continue:

PCR:


Because the circulating parasite load is low in the chronic phase,
PCR sensitivity in untreated patients is not high
Serologies:

Testing for anti–T. cruzi IgM AB is not useful because tests for
this antibody isotype are not well-standardized.

No single assay has sufficient sensitivity and specificity to be
relied on alone.

Two tests based on different antigens, techniques:

(e.g., enzyme-linked immunosorbent assay [ELISA],
immunofluorescence antibody assay, and immunoblot assay).
Lab abnormalities in the returning traveler:

Mild anemia, atypical lymphocytes.

Mildly elevated liver enzymes.

EKG with low QRS voltage.

Echocardiogram diastolic left ventricular
dysfunction, dilated left atrium, thickened
pericardium and pericardial effusion.
Differential Diagnosis:

Acute infection: Acute HIV, malaria,
Viral infections—Zika, dengue,
CHIKV), leptospira, etc.

Chronic:
 Other
forms of dilated
Cardiomyopathy.
 Achalasia
of the esophagus.
 Hirschsprung’s
disease of the colon.
Chagas-HIV co-infection:

Reactivation of Chagas’ disease occurred in
15-35% in co-infected untreated HIV patients.

Chagas’ disease serology can be inconclusive
and, occasionally, non-reactive in untreated
HIV patients.

Clinical reactivation generally occurs in
persons with CD4+T cell counts <200
cells/mm3 and most commonly involves the
CNS.
Trans R Soc Trop Med Hyg. 2010 Jul;104(7):447-52.
Clin Infect Dis. 2007 Nov 1;45(9):1208-13.
General treatment:
 Nifurtimox
and Benznidazole.
 The
drugs have variable efficacy,
must be taken for extended
periods, and patients may
experience significant side
effects.
 Parasitological
cure is believed to
occur in 60-85% of persons with
acute infection.
Continue:

Benznidazole: 5 to 7
mg/kg per day orally in
two divided doses for 60
days.

Nifurtimox: 8 to 10
mg/kg per day orally in
three or four divided
doses for 90 to 120 days
N Engl J Med 2011;364:2527-34.
Indications for anti-trypanosomal
therapy:

Acute, congenital or reactivation in the
immunosuppressed patient.

All children 18 years or younger with chronic T.
cruzi infection.

Chronic infection up to 50-55 years of age
including those with evidence of early Chagas
heart disease (e.g. ECG abnormalities or LV
dysfunction without heart failure).

But not in those with advanced Chagas
cardiomyopathy.

SHOULD NEVER BE OFFERED in pregnancy or
marked liver or renal dysfunction.
Benznidazole for Chronic Chagas’
Disease:
Results at 1 year by PCR
detection and in patients with
mostly on indeterminate cardiac
forms (60%).
Treatment on chronic infection in
adults-I:
Ann Intern Med. 2006;144:724-734
Treatment on chronic infection in
adults-II:

Despite the evidence
that therapy reduced
parasite-related
outcomes, the low
quality and
inconsistency of the
data for patientimportant outcomes
must be treated with
caution.
Cochrane Database Syst Rev. 2014 May
27;5:CD003463
Treatment in adults-III:
Effectiveness of Benznidazole therapy:
Monitoring response to therapy:

Reduction on the titers or
negative seroconversion.

Quantitative PCR.

Xenodiagnosis after treatment.

Progression on cardiac disease.
N Engl J Med 2015;373:456-66.
Prognosis:
Lancet; Vol 375 April 17, 2010.
Prevention while traveling-I:

Do not sleep in natives' hut or outdoor hammocks.

Search for hidden insects— under the mattress, behind
pictures, in drawers, or dark corners of the room.

Carry repellents and insecticides.

Spray the walls around your bed, especially where
there are cracks.

Use bed nets.

If camping—stay away from palm trees, stones or wood
piles.
Prevention while traveling-II:

Unless a life-threatening emergency exists,
blood transfusions that have not been
assuredly screened for Chagas' disease should
be avoided.

Travelers should avoid freshly prepared fruit
and cane juices from unsanitary sources.
Thank you
Questions?