Alexandra Bono
Chagas Disease in Bolivia
From: Secretary of Health, Bolivia
To: Minister of Finance, Bolivia
Introduction
Bolivia has the highest prevalence and incidence rates of Chagas disease in the world,
with approximately 1.8 million infected and 3.7 million at risk for infection.1 Error! Bookmark
not defined. Annually, 45,000 Bolivian deaths can be attributed to Chagas.1 3 The disease
disproportionately affects individuals of low socioeconomic status residing in rural areas.Error!
Bookmark not defined. 7 The risk factors for Chagas include poor-quality housing, endemic
residential location, lack of education, and receipt of blood or organ transplants.2 5 8 9 The
repercussions of Chagas are the annual loss of over $255 million in both medical costs and lost
revenue and the debilitating infections of millions.1 Error! Bookmark not defined.
Consequently, our ability to develop a productive workforce is diminishing, along with the
nation’s economic and social progress. In order to combat this growing problem, we must both
utilize prevention methods and invest in research to improve our diagnostics and treatments.
Nature and Magnitude of the Problem
The prevalence of Chagas disease in Bolivia is the highest in the world, affecting
approximately 1.8 million Bolivians—15% of our population.1 An additional 3.7 million
Bolivians are at risk of infection.2 In Bolivia, Chagas is ranked the fourth most common disease.3
Mortality related to T. Cruzi infection is 8.9 per 1000.2 Annually, 45,000 deaths can be attributed
to chronic Chagas, an advanced stage of the disease are developed by 20-30% of the infected.1 3
Diagnostic tests lack specificity and sensitivity, often requiring multiple blood tests before
diagnosis.4 Only half of people who are treated will be successfully cured, and no treatments
exist for pregnant women and children.6 When left untreated, the T. cruzi parasite attacks the
cardiac and digestive systems, leading to permanent heart, esophagus, and colon damage and/or
death.5 In young adults, heart failure is a common cause of death when the disease is
untreated.Error! Bookmark not defined. 6 Healthy adults most often die of complications from
Chagas without knowledge of their seropositive status.1
Affected Populations
Chagas disease affects many Bolivians. However, individuals of low socioeconomic status
residing in rural areas have disproportionally high prevalence rates.Error! Bookmark not
defined. 6 Impoverished populations are 30% more likely to be infected via triatomine bug
transmission and to develop chronic Chagas than higher socioeconomic classes. This is due to
higher frequency rate of home infestation by infected bugs in addition to limited access to
diagnostics and/or necessary treatment.5 9 The endemic area spans 60% of Bolivia, with T. cruziinfected vectors found in seven of nine Bolivian departments. In these regions, nearly 50% of
residences have triatomine infestation, with over 30% of those vectors carrying the T. cruzi
parasite.Error! Bookmark not defined. In Cochabamba, Chuquisaca, Tarija, and Santa Cruz,
prevalence of Chagas is 100% in individuals over 40.1 7 Throughout Bolivia, seroprevalence of
T. cruzi antigens ranges from 16 to 71% in children aged one to six years old and 32 to 93.5% in
adults.1 Prevalence among pregnant women ranges from 25 to 50%, and 8 to 38% in neonates
born to infected mothers. 1 Error! Bookmark not defined. 8
Risk Factors
The primary risk factors contributing to the contraction of Chagas disease include
endemic residential location, poor-quality housing, lack of education, and receipt of blood or
organ transplants.Error! Bookmark not defined. Error! Bookmark not defined. 8 9 Many
Chagas-endemic areas are located in rural regions of Bolivia, limiting access to medical services
that provide diagnostic and treatment services. Many houses owned by poor Bolivians consist of
adobe or straw.Error! Bookmark not defined. This type of housing greatly increases the
likelihood of infection due to structural cracks and crevices that can shelter the triatomine
bug.Error! Bookmark not defined. These two risk factors contribute to greater than 80% of
Chagas cases.1 The lack of education increases disease prevalence because individuals are
unaware of the various means of transmission and the ways by which they can prevent
infection.Error! Bookmark not defined.
Although less prevalent, mother-to-child transmission and receipt of a blood transfusion
or organ transplant from an infected individual significantly increase an individual’s risk of
developing Chagas. Currently, no treatment exists for pregnant mothers to cure Chagas, and
consequently her infant often contracts the disease during gestation, labor or while
breastfeeding.9 Additionally, 63% of potential donors in Bolivian blood banks carry the
infectious parasite.8 Blood transfusions and organ transplants seropositive for the T. cruzi
antigens are estimated to have a 14.8% and 7.2% risk of transmission, respectively.Error!
Bookmark not defined. Error! Bookmark not defined.
Economic and Social Consequences
Chagas has significant negative impacts on Bolivia’s progress and development, both
economically and socially. The physical disability and illness caused by Chagas prevent our
people from working, costing Bolivia revenue from productivity and earnings from days lost due
to illness. Due to high rates of absenteeism among workers with chronic Chagas, Bolivia loses an
estimated $5 million annually from potential profits.Error! Bookmark not defined. On average,
these workers are 25 years old—our most economically productive age group.2 Error!
Bookmark not defined. In addition to lost revenue, the annual cost of medical care in Bolivia
due to Chagas is $250 million.1 The World Health Organization estimates that disability adjusted
life years lost due to Chagas in Latin America are 2,740,000, the majority from Bolivia.Error!
Bookmark not defined. Social effects emerging due to Chagas include psychological stress on
individuals living in infested residences, in addition to the burden on families infected with
Chagas. Research shows a decline in mental health as a result of home infestation, associated
with the fear of infection.5 Lack of knowledge about disease status also harms mental
health.Error! Bookmark not defined. 5 The burden and stress of Chagas on an individual or
household also harms the overall health and well-being of a family.Error! Bookmark not
defined.
Priority Action Steps
Priority action steps to combat Chagas disease must include prevention and research. In
order to prevent Chagas disease, priority must be placed on utilizing insecticides, replacing
common structural materials, and providing education. Insecticides must be used to kill insect
vectors within residences, limiting the amount of insect-transmitted disease. Replacing standard
materials such as adobe and straw in homes with plaster and metal will also help prevent the
colonization of vectors. Additionally, by providing education on Chagas, awareness will be
raised about prevention, diagnostics, and treatment.
Currently, both diagnostics and treatment for Chagas are expensive, inaccessible, and
inefficient. Because the majority of the Chagas-infected population are impoverished and reside
in rural areas, new methods for ensuring both cheap and accessible diagnostics and treatment are
imperative. Diagnostics and treatment should be subsidized and medical centers should also
provide mobile medical services that provide diagnostics and treatment to all remote areas. By
helping individuals to learn their disease status transmission, we can reduce transmission via
pregnancy, blood transfusion or organ transplant.
Presently, we must continue to utilize available diagnostics and treatment. However,
research is crucial in order to find more efficient methods to improve the health of our people.
Diagnostics must be developed so that one test is sufficient to diagnose, eliminating the present
method of multiple serological tests. More efficient treatments must be developed that have both
high cure rates and can be given to infected mothers and infants. The long-term effects of this
research would be an increase in awareness of the disease and effective treatments that can be
given to all, thus decreasing Chagas prevalence in Bolivia.
Bibliography
1
Medrano-Mercado, N., Ugarte-Fernandez, R., Butrón, V., Uber-Busek, S., Guerra, H., Araújo-Jorge, T.,
& Correa-Oliveira, R. (2008). Urban transmission of Chagas disease in Cochabamba, Bolivia.
Memórias Do Instituto Oswaldo Cruz, 103(5), 423-430.
2
Bolivia ncap project: Vallegrande findings. (2011, March 30). Retrieved from
http://http://weadapt.org/knowledge-base/wikiadapt/bolivia-ncap-project-vallegrande-findings
3
Bolivia. (2005). Retrieved from http://www.betterbytheyear.org/bolivia/bolivia_health.htm
4
Time to treat chagas. (2009). Retrieved from http://www.treatchagas.org/fq_question.aspx
5
Chagas in Bolivia: In pursuit of an effective treatment. (2008, August 07). Retrieved from
http://www.msf.org.uk/bolivia_chagas_wilma_chambi_interview_20080708.news
6
UNDP / WORLD BANK / WHO Special Program for Research and Training in Tropical Disease
(TDR). Tropical Disease Progress in Research 1991-1992, WHO, Geneva
7
Arata AA, Balderrama F, Bermudez H, Navin T, Ormsby G, Torrico F, Velarde R 1994. Trabajo de la
SNS CCH/Programa Piloto de Control de Chagas. La Paz, Bolivia, Ministerio del Desarollo
Humano, Secretaria Nacional de Salud, 94 pp.
8
Pless M, Juranek D, Kozarsky P, Steurer F, Tapia G, Bermudez H 1992. The epidemiology of Chagas
disease in a hyperendemic area of Cochabamba, Bolivia: A clinical study including
electrocardiography, seroreactivity to Trypanosoma cruzi, xenodiagnosis, and domiciliary
triatomine distribution. Am J Trop Med Hyg 47: 539-546
9
Chagas disease. (2010). Retrieved from http://www.dhpe.org/infect/Chagas.html