FORGING THE CHAIN

T
A DANGEROUS AND
WELL-TRAVELLED
SILENCE
Some years ago, WHO received a phone inquiry from
a well-known European hospital. Referred to the
Department of Control of Neglected Tropical Diseases,
the physician making the call asked for a specific medicine
against Chagas disease. He had a patient who
had recently received a heart-lung transplant. She had
briefly improved after the operation, but then developed
complications.
A mysterious infection was making her seriously
ill, and numerous efforts to identify the cause had
finally revealed Chagas disease. The medication was
dispatched, but the patient died several days later.
It turned out that she had emigrated from Latin
America 40 years before.
The case prompted WHO to alert non-endemic
countries to the dangers posed by Chagas disease.
The countries were told that diseases that could
be a hidden – in some cases for a long time – could
cause serious heart diseases, especially in individuals
from Latin America. In addition, WHO established
a network of services to help national blood banks
and organ-transplant programmes around the world
screen for the causative T. cruzi parasite, explaining
that it could be spread through transfusions and
transplants. Neonatal services worldwide were also
warned that the illness could be passed from mothers
to foetuses and infants.
As similar cases were discovered and reported far
from Latin America, it became clear that Chagas disease
is now a global problem. It only spreads endemically
in its traditional region, where triatomine bugs
serve as the vector. But with its vast estimated caseload
of some 7 million people, the long and largely
symptom-free duration of infection, and the propensity
of Latin Americans to travel and settle in other
countries, it can now re-emerge anywhere. Tourist,
immigrants, expatriates are also at risk of infection,
due to their high mobility. It arrives silently in people
infected long ago, disabling and killing in places where
doctors least expect to see or recognize it.
The vast Latin American diaspora, which grows
every year, means it is likely that hundreds of thousands
and perhaps millions of people have the disease
and are living undetected outside endemic areas.
Since the 1990s, intergovernmental initiatives have
included attempts to interrupt transmission through
blood transfusion – a step that applies equally to
countries inside and outside Latin America – and to
spread news of the disease far beyond its traditional
boundaries.
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