From the Microscope to the Telescope
The viewpoint of the chapters is similar to an optical device that begins as a microscope and ends as a telescope, going from the infinitesimal parasite to humans, communities, nations, and continents. The world of microbiology is an amazing universe continually being newly discovered. Chapter 1, Discovering Chagas’ Disease, reveals the medical history of this disease. Chapter 2, An Early Andean Disease, contains its history in the Andes. Chapter 3, Jampiris and Yachajs: Andean Ethnomedicine, looks at how Bolivian curanderos treat its symptoms. Chapter 4, The Crawling Epidemic: Epidemiology, deals with infestation by vinchucas, means of infection, and the extent of the epidemic. In Chapter 5, Cólico miserere: Enlarged Colon, and Chapter 6, Bertha: Mal de Corazon, one reads about the illness in its chronic stages of megacolon and heart disease. This is presented through the lives of people from two Bolivian families.
Reversing the microscope into a telescope to examine the environment relating to Chagas’ disease, Chapter 7, Cultural and Political Economy of Infested Houses, deals with the relationship of cultural and political-economic factors in bringing into physical proximity parasites, vectors, and hosts.
What can be done to prevent Chagas’ disease is considered in the last chapters. Housing improvement projects are described in Chapter 8, Pachamama Snatched Her: Getting Involved, and Chapter 9, Sharing Ideas. Chapter 10, A Culture Context Model, presents a model for future health projects. The concluding chapter, Solutions, contains answers to punctuated approaches, economic causes, and environmental issues precipitating Chagas’ disease. Humans have created the social and environmental context for the spread of this debilitating disease, and it is to be hoped that they can be as successful in eliminating such diseases as they are in proliferating them.
This book includes appendices to learn more about biomedical aspects of Chagas’ disease. These appendices provide information in the forms of tables and charts concerning the vector species and hosts of T. cruzi in the Americas. It includes a discussion of the strains of T. cruzi, vaccine development, and an important section of the immune response, coauthored with the noted parasitologist Dr. George Stewart.
The perspective of Kiss of Death: Challenging Chagas’ Disease is to look at the relationship of many factors, almost as if one were looking at it from a galactic point of view, with the details of the puzzle examined in Bolivia, a small country with a small population (seven million people) and a high rate of Chagas’ disease, a variety of climatic and geographic featurestropical forests, high plateaus, and still higher mountainscontaining varied ethnic groups, social classes, and economic systems. Bolivia gives us the gift of the dervish in A Thousand and One Nights who claimed the power of seeing all the world at once, or that of Jorge Luis Borges’s Aleph, the diameter of which “was only two or three centimeters, but the whole of space was in it, without sacrifice of scale” (Borges 1977:625, Fernández-Armesto 1995:19).
Reading about Chagas’ disease in Bolivia gives a perspective for understanding this disease throughout Latin America and for predicting what might happen in the United States and Europe, where it is spreading. Chagas’ disease is the space in which are encapsulated minutely infinite forces and from which we might get a broader perspective of the universe.
CHAPTER ONE
Discovering Chagas’ Disease
In 1909 Carlos Chagas discovered American trypanosomiasis by intuition, induction, scientific method, hard work, genius, and a pinch of luck.[4] Carlos Chagas represents a rare example of a medical scientist who described a disease after having found its causative agent, T. cruzi, in the intestines of triatomine insects. He observed its pathogenicity to mammals, located its domestic and wild reservoirs, and then went on to find infected humans. He finally documented its acute and chronic phases. Chagas ranks with the greatest scientists of the twentieth century; Chagas’ disease remains a scourge of this century and a battle of the next.
Chagas’ discovery coincided with conquests of the Amazon. It was a time when symbiotic microorganisms, living in animal reservoirs within the Amazon, became pathogenic for invading settlers. Such is now the case for Bolivians with Chagas’ disease.
As a budding parasitologist in that discipline’s age of discovery, Carlos Chagas realized that microbiology could reveal the causes of tropical diseases. The microscope was to biology what the telescope was to astronomy. Within a generation, scientists had discovered the world of microbiology and shattered many age-old aetiologies: Robert Koch discovered the tuberculin bacterium in 1882 and liberated tuberculosis from its association with consumption, vapors, and “bad air.” Louis Pasteur isolated the rabies virus and produced an attenuated strain or vaccine in 1884. Pasteur disproved the notion that the disease resulted from nervous trauma allegedly suffered by sexually frustrated dogs (rabid men were said to be priapic and sexually insatiable) (Geison 1995:179; Kete 1988). D.D. Cunningham described leishmania organisms found in skin lesions in India in 1885; F. Schaudinn depicted trophozoites and cysts of Entamoeba histolytica (amoebic dysentery) in 1903 (dying at thirty-five as a result of his self-experimentation). R.M. Forde showed that Trypanosoma bruceigambiense caused sleeping sickness in 1902, providing a pathogenic agent rather than African laziness as its cause. The microscope did for the minuscule world what the telescope did for the universe: it changed beliefs in origins of disease and cosmic phenomena. The sequel to these discoveries, however, is that tropical diseases remain as prevalent as ever. The impoverished tropics aren’t considered profitable enough for the investment of wide-scale remedies. The spectacular research mentioned above was primarily for the health of colonialists and workers in industrial expansion.
Figure 2.
Carlos Chagas examining parasites under the microscope at the Oswaldo Cruz Institute in Rio de Janeiro, where he studied in 1902. (Photo from Renato Clark Bacellar, Brazil’s Contribution to Tropical Medicine and Malaria, Rio de Janeiro, 1963)
Carlos Justiniano Ribeiro Chagas was born on July 9, 1879, in the small town of Oliveira, Minas Gerais, Brazil, of Portuguese farmers who were descendants of immigrants who had come to Brazil in the late seventeenth century (Lewinsohn 1981). His upper-class parents owned a small coffee plantation with a modest income. When he was four, his father died, and his mother, a strong-willed farmer, raised him and three younger children. She tried to persuade him to become a mining engineer, but he refused and instead chose medical school, being swayed by a physician uncle who convinced him that for Brazil to develop industrially it was necessary to rid the country of endemic diseases. (Many European ships refused to dock in Brazilian ports because of fear of contracting yellow fever, smallpox, bubonic plague, and syphilis).
Carlos Chagas studied at the Oswaldo Cruz Institute in 1902, where he wrote his M.D. thesis on the “Hematological Aspects of Malaria” (1903) under the leading Brazilian parasitologist, Oswaldo Cruz. Cruz tackled the task of ridding Rio de Janeiro of yellow fever by the systematic combat of the mosquito vector and the isolation of victims in special hospitals. He also provided vaccinations against the plague and smallpox. Eradication of vectors and mass vaccinations were revolutionary measures at this time. Many diseases were thought to be caused by vapors emanating from the hot and humid earth, such as mal de aire (“evil from the air”) or malaria. Cruz was successful fighting yellow fever in Rio, and similar methods also decreased the disease in Panama for the building of the canal. However, Cruz’s fight against mosquitos in Brazil continued for years.
When Cruz invited Chagas to work on malaria research, Chagas refused, saying that he was not cut out to do research and preferred to practice family medicine. Chagas worked in a hospital at Jurujuba from 1903 until 1905, where he introduced antipest serotherapy, which Cruz had modified from that introduced by Louis Pasteur in France around 1890. Pasteur led the way in germ therapy in opposition to theories of spontaneous generation as principles of life and causes of diseases (see Geison 1995). Following Pasteur’s and Cruz’s assumptions that
negative organic elements fermented positive organic elements, Chagas first prepared an antipestic serum, then cut into a patient’s swollen glands and inserted this serum to destroy the “peste” (see Chagas Filho 1993). Chagas was a very innovative and experimental doctor who looked for answers in practice rather than in the laboratory.
Malaria Closes Brazilian Ports
On March 30, 1905, the Santos Dock Company of Santos, near Sao Paulo, Brazil, hired Carlos Chagas to combat malaria. Its workers were so weakened by fever that they could not complete the port of Santos, the most important in Brazil. Carlos Chagas accepted the challenge to do fieldwork (“trabalhar no campo”) and to observe firsthand malaria within its natural and social environment. Chagas used his first paycheck to buy a microscope; he then had the only tool needed to examine the microcosm.
Carlos Chagas’ earlier studies of malaria and later studies of Chagas’ disease stimulated new concepts of these diseases that incorporated parasitology, entomology, and human physiology while studying relationships of parasites, vectors, and hosts. Vectors are carriers, usually arthropods or insects, that transmit causative organisms of disease, parasites, from infected to noninfected individuals. A parasite usually goes through one or more stages in its life cycle within the vector. The host is the organism in which parasites obtain nourishment and reproduce. Knowledge of the parasitic cycles enhances our understanding of tropical diseases and their relationship to the environment.
Carlos Chagas disagreed with the then-current practices of pouring toxic substances on lakes, reservoirs, and stagnant water to eliminate malaria. Doctors had used this method in Panama and Cuba under the assumptions of marasmus theory that attributed malaria to vapors. Chagas recognized that the use of smoke, toxic substances, and the drainage of swamps were ineffective remedies because they destroyed only the larvae of the mosquito. He also objected that such methods destroyed fish and reptiles and could never be applied to all the ponds, lakes, and waterholes in the tropics.
Because mosquito larvae are not infected with parasites, Carlos Chagas’ strategy against malaria in 1905 was to attack the adult vectors by preventing uninfected (also sometimes called sterile) mosquitos from coming into contact with infected humans and infected mosquitos from coming into contact with healthy humans (Chagas 1935). Chagas observed that after mosquito vectors acquire their fill of blood, they lose the ability to take off in flight and can hardly fly over the walls and furniture of a house to begin digestion of the ingested blood (Chagas Filho 1993:78). He advocated closing off houses with doors and screens and disinfecting houses by burning pyrethrum from chrysanthemum flowers, which kills mosquitos in flight.
Realizing the futility of trying to destroy mosquitos, Chagas devised ways to prevent mosquitos from coming into contact with malaria patients. He found that mosquitos ingest most parasites during the erythrocytic cycle, when merozoites abundantly attack the red blood cells. The erythrocytic cycle corresponds to parasitemia, characterized by high fever, which naturally attracts mosquitos. He advocated that these patients be quarantined in closed-off areas with walls, screens, ceilings, and caulked joints, as distant as possible from mosquitos. Moreover, Chagas treated patients with quinine to reduce fever and destroy parasites. Quinine is an Andean medicinal remedy for malarial fever from the bark of the Chinchona calasaya tree. Kallawaya herbalists have used it for centuries and brought it to workers of the Panama Canal (see Bastien 1987a).
Chagas devised a threefold program in Santos which became a protocol for malaria campaigns in other regions of Brazil by 1917. The approach consisted of 1) administration of quinine in dosages of 50 centigrams every three days, 2) isolation of patients from mosquitos in infirmaries with fine metal screens and continual treatment with quinine of other malarial patients in the region, and 3) periodic and systematic disinfecting of domiciles with pyrethrum. Chagas further contributed to malariology by describing the edematous form of Quartan fever (attacks occurring every fourth day), the bone-marrow lesions of malaria, and the description of the disease as a domiciliary infection, rarely contracted outdoors (Lewinsohn 1981:452).
Carlos Chagas succeeded against malaria primarily because he did fieldwork, observed the disease in its environment, and addressed the problem in a scientific and therapeutic way. He also worked with patients, parasites, and insects in epidemic settings to get an enlarged perspective of the disease. On returning to Rio from Santos, Chagas went to work on malaria control for the Xerem River dam and had similar success. In 1906 he became an associate of the Oswaldo Cruz Institute in Rio de Janeiro.
Railroad Stop at Lassance
At about the same time, Europeans and Brazilians intruded into the forests of Brazil to build a railroad connecting Rio de Janeiro with the northern city of Belem, near the mouth of the Amazon River. Indians, animals, insects, and parasites resisted the invaders, causing a standstill in Lassance, located on the banks of the Sâo Francisco River in Minas Gerais. Rail workers from Asia and Europe and slaves from Africa died by the thousands. In 1908, Estrada de Ferro Central do Brasil (the Central Railroad of Brazil) invited Carlos Chagas to come to Lassance.
Thirty-one years old, Carlos left his wife in Juiz de Fora, her native village, in December 1908. He traveled by train for twenty-four hours to Lassance, the end of the rail. Named after a French railroad engineer, Lassance had 1,500 people. African, Chinese, Irish, and Portuguese railroad workers lived in mobile encampments of boxcars fitted with bunks. Chagas was given one boxcar to serve as clinic, dormitory, and laboratory.
Lassance also had comfortable ranch homes and townhouses for the long-established Portuguese settlersmerchants, farmers, and rancherswho considered themselves a class apart. Socially positioned between the upper-class denizens and lower-class migrants were itinerant cowboys. The cowboys fought with each other and looked down upon the immigrants. The immigrants in particular suffered from the parasitic diseases of the tropics. They had not developed partial immunity, and many died from acute infections of parasitic diseases. (Partial immunity occurs when someone is already infected with parasites and usually will not suffer another acute attack because the parasites partially protect the host; this is the case with Chagas’ disease.)
Chagas had to treat the ailments of the people of Lassance. Parallel to the tracks lay the main street, Avenue Alfonso Pena, where the merchants, landowners, and authorities lived in townhouses, enclaves shut off from the bustle and dust of the street. Farther down were the infamously named streets, including Street of the Knife and Street of the Shot, all noted for their brothels, bars, and fights. Along these streets, merchants catered to the Brazilian cowboys, mixed breeds of blacks, Indians, and Portuguese, who herded cattle through Lassance while on the way to slaughterhouses in the southern cities of Curvelo and Belo Horizonte.
Carlos Chagas described Lassance years later to his son Carlos Chagas Filho (1988):
The village resembled the many movie versions of the settlement of the American West. The boisterous visitors considered me an “officer.” For several months none of those wounded during brawling (I could hear the shots in the distance) would come to the hospital I directed. After awhile, they came to me, and I treated their injuries.
Chagas treated the railroad workers so they could lay tracks. He treated them with arsenic for syphilis and quinine for malaria; he also advocated burning chrysanthemum to keep down the mosquitos. He employed a railroad car as a hospital and conducted research using another railway car as laboratory, clinic, and bedroom.
As Chagas treated the injured and diseased, he noticed that some symptoms were not from malaria. Like clockwork, the malarial parasite sporulates periodically with accompanying parasitemia (alternating chills and fevers). Latin Americans still refer to malaria as either M. quotidian (P. vivax causes paroxysms every twenty-four hours), M. tertian (P. falciparium causes paroxysms every forty-eight hours), and M. quartan (P. malariae causes paroxysms every four days). Chronic malaria also results in splenomegaly (enlargement of the
spleen). Unlike malaria with its violent attacks, some Lassance patients suffered arrhythmias and other cardiac disorders which resulted in a sudden and nonviolent death.
At first, Chagas figured it was morbus gallicus (French disease), as syphilis was popularly called in Brazil, and treated the patients with arsenic. He wrote (Chagas Filho 1993:81):
Faced with an unknown disease, one usually thinks of syphilis, especially for railroad workers, undernourished, ravaged by malaria, victims of morbusgallicus, which usually accompanies those laying iron tracks. A population complaining about irregular heartbeats and atypical arrhythmias, indications of cardiac insufficiencies, and frequently leading to sudden death… inexplicable! Barbeiros/Vinchucas: Triatoma infestans
A clue was provided by an engineer who showed Carlos an arthropod insect known as a barbeiro or vinchuca (Triatoma infestans) that infested the barracks and sucked blood from the workers during the night. The workers complained that barbeiros bit them nocturnally, drew blood, and caused painful welts. The engineer inquired whether barbeiros as well as anopheles mosquitos spread malaria, and Chagas knew that anopheles mosquitos transmitted plasmodium parasites whose sexual reproductive cycle was limited to the gut of the mosquito. “Knowing the domiciliary habits of the insect, and its abundance in all the human habitations of the region,” Chagas (1922) wrote, “we immediately stayed on, interested in finding out the exact biology of the barbeiro, and the transmission of some parasite to man or to another vertebrate.”
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