Carlos Chagas and the "Tropical Medicine Triple Play"

Carlos Chagas is an influential figure in Brazilian biomedical history, most notably recognized for his role in discovering Chagas disease. Chagas disease, which is also referred to as American trypanosomiasis, is a parasitic disease endemic to Latin America, affecting about 10 million people today (WHO, 2018). Transmission can occur through vectorial transmission, blood transfusion, organ transplantation, congenital transmission, contaminated food and drinks, and accidental lab exposure (WHO, 2018). The parasite causing the disease can remain dormant in the body for years before it can cause digestive and cardiac complications, at which point the disease is referred to as chronic Chagas disease.

Carlos Chagas was born July 8^th, 1878 near the city of Oliviera in Minas Gerais, Brazil (Moncayo, 2010). In 1897 he began studying at the School of Medicine of Rio de Janeiro. After performing well in school, he was accepted as a research assistant by the world-renowned researcher Oswaldo Cruz. Chagas did not do any postgraduate training abroad, in part because his mentor Miguel Couto encouraged him to conduct research in Rio de Janeiro, as there was already a lot of emphasis on and energy towards biomedical research right in his home country (Cueto & Palmer, 2014). His first major success was leading the prophylactic campaign in Santos, which led to malaria eradication in the region by 1905 (Sociedade Brasileira de Patologia Clínica, 2002).

The Oswaldo Cruz Institute provided an environment in which Carlos Chagas was able to investigate the peculiar health ailment affecting Brazilians that would later become known as Chagas disease. Chagas was responding to a malaria outbreak in 1909 in Minas Gerais, Brazil, where he noticed a strange condition afflicting the locals (Massad, 2007). It caused sudden cardiac arrest, and as Chagas began his investigation, he noticed an unusually large amount of triatomine insects in the vicinity. After consulting residents of Minas Gerais, he found out that these insects were known for biting people on the face. Chagas’s background training in vector-borne diseases such as malaria and yellow fever enabled him to recognize the potential for a connection between this mysterious disease and the triatomine bugs, which led to an examination of these insects under a microscope. Under a microscope, he found trypanosomes in the intestines of the triatomine bugs. He later examined a baby girl with a fever and a swollen eyelid, and upon examining a drop of her blood under a microscope, he confirmed that there were trypanosomes in her blood. He named this disease Chagas disease and named the trypanosome Trypanosoma cruzi after Oswaldo Cruz. Chagas took this discovery and argued that rural endemic diseases, not race or intelligence, were the cause of higher rates of poverty in Brazil’s interior (Kropf, 2009).

It often takes years, and multiple scientists, to discover the cycle of a vector-borne disease, including host, agent and environment, yet Carlos Chagas identified all three in a matter of weeks (Telleria and Tibayrenc, 2017). The discovery of a “tropical medicine triple play” (Cueto & Palmer, 2014) had never been done by one person in the history of medicine, and has yet to be accomplished again. This feat led to Carlos Chagas’s nominations for a Nobel Prize in 1913 and 1921, of which unfortunately he did not win either (Massad, 2007). The Karolinska Institute argues that the importance of the discovery of Chagas disease was not clear in 1912, and the impact of a discovery worthy of a Nobel Prize must be made clear a year in advance of the award. Various scholars argue that Chagas did not win the Nobel Prize because of prejudice towards scientific achievements in developing nations (Bestetti, 2015). Chagas did, however, earn the prestigious Schadinn Prize, which is only awarded every four years for the most compelling work in protozoology, by the Hamburg-based Institute for Tropical Medicine (Cueto & Palmer, 2014).

Chagas’ discovery was not without controversy. Argentina-based Austrian parasitologist Rudolf Kraus questioned whether the disease even existed. The aspect of Chagas’ discovery most criticized was his association between thyroid hypertrophy (goiter) and trypanosomiasis (Kropf, 2009). While Chagas correctly identified endocrinological, cardiological and neurological complications as a result of the disease, he was convinced that endemic goiter in these regions was actually a result of parasitism. “Parasitic thyroisis” in Chagas’s own words, was the “stamp of the disease” (Kropf, 2009). This was where his fellow physicians disagreed with him, as few cases of parasitic thyroiditis were proven, and this association almost jeopardized his discovery as a whole. However, at the first national medical conference in Buenos Aires in September 1916, sensing skepticism, Chagas emphasized the cardiac concern with trypanosomiasis. Overall, Chagas’s discovery mobilized the Brazilian government to attack the “disease of the sertão (backcountry)”, and influenced the 1916 sanitation movement.

The sanitation movement launched with Dr. Miguel Pereira’s declaration of Brazil as an “enormous hospital” and included social reforms aimed at healing the "diseased Brazil" (Kropf, 2009). Chagas disease was being framed as “Brazil’s disease,” and control had an almost nationalistic component to it. Chagas even referred to the disease as "Brazilian trypanosomiasis" in an effort to generate political will around control (Kropf, 2009). In 1917, after Cruz’s death, Chagas became the director of the Oswaldo Cruz Institute . He continued to broaden the institutes’ reach by advocating for accelerated research, and esteemed scientists from the United States and Germany came to study at the Institute, indicating the level of scholarship occurring in Brazil (Cueto and Palmer, 2014). However, controversy enveloped him there as well, as his association with the Rockefeller Foundation’s sanitation campaign was considered unpatriotic, as well as his frequent trips abroad (Kropf, 2009). Henrique Figueiredo de Vasconcellos, a fellow scientist, argued that it should be called "Cruz and Chagas' disease" to acknowledge that it was through Cruz's connections that Chagas even had the ability to discover this disease. Vasconcellos, as well as the chair of hygiene in Rio de Janeiro's medical school, Afrânio Peixoto, continued to voice concerns about the connection between endemic goiter and trypanosomiasis because of the risk to immigration and foreign investments if a disease was incorrectly identified as having a larger impact that it actually has (Kropf, 2009). Many of these critiques towards Chagas' discovery therefore had political connotations, and highlight how the way a disease is framed is often wrapped up in social and economic concerns.

Another of Chagas’s successes, however, was leading the campaign against Spanish influenza in Brazil in 1918, which led to an overall improvement in sanitation. He went on to teach medicine at Facultad de Medicina in Rio de Janeiro. Chagas was awarded various prizes at the international level and magister honoris causa titles from the University of Paris and Harvard University. He was also part of the academies of medicine in Lima, New York and Paris (Bestetti, 2015). He unfortunately died of a heart attack at the young age of 55. Despite his mistakes, Carlos Chagas made one of the most complete medical discoveries of our time, and undoubtedly deserved a Nobel Prize which he did not receive; however, he was given other forms of international attention. Beyond Chagas’s discovery, though, he was an influential figure in the world of public health research and policy in the early 20^th century, and one of the most successful Brazilian parasitologists of his day.

Related Articles

• Biomedical Research in Latin America
• Malaria
• Yellow Fever in Panama
• HIV/AIDS in Brazil: the Struggle for Affordable Anti-Retroviral Drugs
• HIV/AIDS in Brazil: Lessons for Policy

Additional Resources

Cappa, N. Carlos Chagas. (2002). Jornal Brasileiro De Patologia E Medicina Laboratorial, 38(4), 251-251.

Dias, J. C. P., & Schofield, C. J. (1999). The evolution of Chagas disease (American trypanosomiasis) control after 90 years since Carlos Chagas discovery. Memórias do Instituto Oswaldo Cruz, 94, 103-121.

Löwy, I. (2005). The controversy on the early history of Chagas disease. Parasitologia, 47(3-4), 329-333.

Moncayo, Á. (2010). Carlos Chagas: biographical sketch. Acta tropica, 115(1-2), 1-4.

Zabala, J.P. (2009). The history of Chagas' disease in Argentina: conceptual, institutional, and political evolution. História, Ciências, Saúde-Manguinhos, 16, 57-74.

References

Bestetti, Reinaldo B. (2015) The Non-Award of the Nobel Prize of 1921 to Carlos Chagas: A Tragic Mistake. J Infect Dis Ther 3:220.

Chagas disease (American trypanosomiasis). (2018, December 17). Retrieved April 10, 2019, from https://www.who.int/chagas/en/

Coutinho, M., Freire Jr, O., & Dias, J. C. P. (1999). The noble enigma: Chagas' nominations for the Nobel prize. Memórias do Instituto Oswaldo Cruz, 94, 123-129.

Cueto, M., & Palmer, S. (2015). Medicine and public health in latin america : A history (New approaches to the americas). New York, NY: Cambridge University Press.

Kropf, S. P. (2009). Carlos Chagas and the debates and controversies surrounding the disease of Brazil (1909-1923). História, Ciências, Saúde-Manguinhos, 16, 205-227.

Kropf, S. P., Azevedo, N., & Ferreira, L. O. (2003). Biomedical research and public health in Brazil: the case of Chagas' disease (1909–50). Social History of Medicine, 16(1), 111-129.

Massad, E. (2008). The elimination of Chagas' disease from Brazil. Epidemiology & Infection, 136(9), 1153-1164.

Telleria, J., & Tibayrenc, M. (Eds.). (2017). American trypanosomiasis Chagas disease: one hundred years of research. Elsevier.