Guidance

Chagas disease: migrant health guide

Advice and guidance on the health needs of migrant patients for healthcare practitioners.

Main messages

Chronic cases of Chagas disease are increasingly being reported in Europe in migrants from Latin America. So far, it has only rarely been reported in the UK, but may well be under-recognised.

Consider the possibility of Chagas disease in at risk migrants with cardiac and gastrointestinal symptoms, because patients may present with these symptoms in the chronic phase.

Refer the patient, where the disease is suspected, to:

Offer serological testing for Chagas disease to at risk pregnant women, and refer any positives to a specialist centre.

Follow up infants of seropositive mothers to detect and treat any cases of vertical transmission.

Be aware of the regulations around blood donation for migrants from countries which are endemic for Chagas disease.

Background

Chagas disease (American trypanosomiasis) is a zoonosis caused by the flagellated protozoan parasite Trypanosoma cruzi, which:

  • affects 6 to 7 million people worldwide
  • is endemic in large parts of Central and South America, especially in poor rural areas
  • kills more people than any other parasitic disease in Latin America
  • has only rarely been reported in the UK, and all cases identified have been migrants from Latin America

As a result of population movements, cases of Chagas disease are increasingly being recognized in European countries, mainly those with strong historical links to countries in South and Central America.

It is likely that this disease is currently under-recognized in the UK, based on the:

  • migration data
  • known prevalence of the disease in endemic countries

Prevalence of Chagas disease by country

Country Prevalence per 100 population
Bolivia 6.104
Argentina 3.64
Paraguay 2.13
Ecuador 1.379
El Salvador 1.297
Guatemala 1.23
Colombia 0.956
Honduras 0.917
French Guyana, Guyana & Suriname 0.838
Mexico 0.779
Venezuela 0.71
Chile 0.699
Nicaragua 0.522
Panama 0.515
Peru 0.439
Belize 0.33
Uruguay 0.237
Costa Rica 0.169
Brazil 0.03

Source: WHO. Chagas disease in Latin America: an epidemiological update based on 2010 estimates. Weekly epidemiological record 2015: volume 90, pages 33-44.

Transmission

Central and South America

Chagas disease is primarily transmitted to people by the infected faeces of a blood-sucking triatomine bug, through:

  • the site of the insect bite
  • another skin breach
  • mucous membranes, including:
    • conjunctiva
    • oral or digestive mucosa
  • contaminated food (only occasionally)

The triatomine bug thrives under poor housing conditions (for example, mud walls, thatched roofs).

UK

The triatomine bug does not occur in the UK, so ongoing transmission from infected people by this route is not an issue. However, transmission in the UK is possible through:

  • blood transfusion
  • pregnancy and delivery
  • organ transplantation
  • laboratory accident (less frequently)

Find out about prevention and control of Chagas disease.

Symptoms

Acute phase

The acute phase of infection commonly lasts around 2 months immediately after infection. Most cases have few or no symptoms, but there may be:

  • a skin chancre (chagoma)
  • unilateral purplish orbital oedema (Romaña’s sign) with local lymphadenopathy and fever over several weeks

More general symptoms include:

  • headache
  • pallor
  • myalgia
  • dyspnoea
  • oedema in inferior limbs or face
  • abdominal pain
  • cough
  • hepatomegaly
  • rash
  • painful nodules
  • splenomegaly
  • generalized oedema
  • diarrhoea
  • multiple lymphadenopathy
  • myocarditis (chest pain, heart failure)
  • more rarely meningoencephalitis (seizures, paralysis)

Chronic phase

The chronic phase is associated with no symptoms in the majority of patients, but 20 to 30% will go on to develop cardiac and/or digestive manifestations over the next decades.

Cardiac sequelae include:

  • conduction disorders
  • arrhythmia
  • cardiomyopathy
  • heart failure
  • cardiac aneurysm
  • secondary thromboembolism

Digestive lesions include:

  • megaoesophagus
  • megacolon

Testing

Consider the possibility of Chagas disease in migrants from endemic South and Central American countries.

If the disease is suspected, request serology for Chagas disease (clotted blood sample).

If positive, and dependent upon the individual clinical presentation, refer the patient for:

Treatment

Two treatments are available for Chagas disease, both of which are used on a named patient basis by specialist parasitology centres, and available on request from WHO:

  • benznidazole
  • nifurtimox

Treatment is generally considered to be more effective:

  • for those in the acute or early chronic phase
  • during reactivation if the patient becomes immunosuppressed

It is also used in cases of congenital infection.

The treatment schedule is long and is associated with frequent side effects. Once the characteristic pathology is established (eg dilated cardiomyopathy, mega-oesophagus), be aware that:

  • antiparasitic treatment will not reverse it
  • symptomatic treatment is the mainstay of management

Prevention and control

In the UK, the 2 main transmission risks are:

Transfusion or transplantation

Pre-donation (blood or transplant) screening has been in place in the UK since 1999.

In the UK, a potential donor must not donate if:

  • they were born in South America or Central America (including southern Mexico, but not the Caribbean Islands)

  • their mother was born in South America or Central America (including southern Mexico, but not the Caribbean Islands)

  • they had a blood transfusion in South America or Central America (including southern Mexico, but not the Caribbean Islands)

  • they lived and/or worked in rural subsistence farming communities in these countries for a continuous period of 4 weeks or more

However, a donor may donate, and the donation is used, if both of the following conditions apply:

  • at least 6 months have elapsed since the last exposure
  • a validated test for T.cruzi antibody is negative

Pregnancy

There is currently no routine antenatal screening programme for Chagas in the UK.

Offer serological testing to pregnant women from the at-risk groups.

Resources

The World Health Organization (WHO) has further information on Chagas disease.

The National Travel Health Network and Centre (NaTHNaC) provides country specific travel advice.

Published 31 July 2014
Last updated 7 March 2016 + show all updates
  1. Updates to epidemiology figures for Chagas disease worldwide, from WHO.
  2. First published.