Insects, people and disease: Adolpho Lutz and tropical medicine

In August 1902, Lutz returned to Rio de Janeiro and on the 30th of that month freely vented his frustration:

I no longer have any hope of finding a case in favorable

conditions because there have been no more admissions in the

last few days and there are only two cases in the infirmaries of

cachexia following yellow fever. The case in which I applied the

mosquitoes was not yellow fever, but influenza … The weather

has been consistently cool lately and mosquitoes are extremely

rare; I have not been able to find a single Stegomyia … There is

nothing useful that can be done here, and it would be easier to

return here when the first cases of the new season turn up,

these being expected approximately a month from today. I was

also unprepared for such a long absence.

 

São Sebastião Hospital, Women's Ward (Musée de l'Institut Pasteur,

MP31335).

In this letter, Lutz refers to the efforts he had been making to keep his specimens captured in Rio alive.

I still have quite a few, except that I was forced to feed them.

This may result in a refusal to bite a case immediately [when] it

is presented. I keep a few unfed but some of these always die. I

apologize for not having been able to get anything. If you would

like me to borrow mosquitoes from the Frenchmen, or to wait

longer, I ask you to send me a telegram early Monday morning.

That same day, when his assistant Getulino was getting ready to return to São Paulo with some dispatches of Lutz's, the latter received a message from Ribas referring to another question that had been asked about the French mission. Lutz reopened his own letter and added this postscript: “I have not yet spoken with Dr. Simond about the topic because I was awaiting your instructions; if no case turns up by Monday, I will make arrangements with him as mentioned, which probably will not present any problem. He has already offered me mosquitoes.”

There is a third letter from Lutz to Ribas at the Museu Nacional's archive on Adolpho Lutz, typewritten in the 1950s at the time that Bertha Lutz organized her father's files for the celebrations of the

centennial of his birth.130 It is dated 28.II.1902, but there are clear indications that the typist mistakenly typed February when it ought to have been November. We are led to this conclusion by one of Lutz's comments: “The epidemic is declining but there are still cases.” In February 1902, it was reaching its apex, with a daily average of ten hospitalizations at São Sebastião Hospital.

On the other hand, if the letter was written on 28 November, it means that Lutz last stayed in Rio de Janeiro on the eve of beginning the experiments in São Paulo. It was a Friday, and he promised “to return on the Monday night train, arriving in São Paulo Tuesday morning.”

A disinfector with the Sanitation Service of São Paulo had just brought him mosquitoes that “had arrived alive but were mostly male, which do not produce any results.” Lutz hoped that Ivo Bandi would bring him more. The ones he had been able to infect were alive and well, and the bacteriologist from São Paulo referred to them in terms that show he expected to use them soon: “The four mosquitoes from the first case will be good in a few days; the patient has already been cured, having suffered an attack characteristic in all aspects, but not critical. We have some mosquitoes from two other cases, of which one mild, and the other fatal, and I have kept them separately.”

It was raining heavily, and the scientist once more complained that in Rio “one spends half the time traveling to and fro, or waiting for others.” During his previous visit he had tried to meet with Nuno de Andrade, the Director General of Public Health, and with the surgeon Pedro Affonso, Director of the Municipal Vaccinogen Institute and of the Manguinhos Serum Therapy Institute. He missed them again but was able to meet with Simond, from the French mission, “who seemed to me the most knowledgeable of the three” (the other two were Marchoux and Salimbeni). “They are very committed to the issue of the mosquitoes, which they award great importance.”

At the Bacteriological Institute, Lutz had begun controlled reproduction from the larvae stage of the Stegomyia fasciata captured in Rio de Janeiro, feeding them substances that were not blood, so as to exclude any other unwanted infections.

On 28 November, sample mosquitoes were sent to Meyer, who was at São Simão at the time, in the middle of a new outbreak of yellow fever. His mission there was to infect mosquitoes by having them draw blood from recent arrivals at the town's isolation hospital, 730 kilometers away from the capital of São Paulo by rail. In a letter to Lutz dated 1 December, Meyer mentioned the clinical conditions of the patients submitted to the procedure, the difficulties involved in having the mosquitoes bite them appropriately, and the problems in keeping the insects alive until the trip back to the capital. Received at the Bacteriological Institute on 2 December, they were kept on a diet of honey and dates for over twelve days, the minimum period of time considered necessary for making them agents of infection. Three more were added to compensate for the temperature, which was lower than that in Havana during Reed's stay.

Experiments carried out in the Isolation Hospital in São Paulo employed mosquitoes infected on Alexandrina, Joaquim Farquinio, and Nicola Razzoti (the latter classified as a case of “long duration and serious in nature”); the records for each session always specify the day of the contamination procedure, the day the patients fell ill, and their clinical conditions expressed in two numbers: pulse and temperature. Details of these experiments were compiled in records signed by Ribas, Lutz, Carlos H. Meyer (an aid at the Bacteriological Institute), Candido Espinheira (director of the Isolation Hospital), Victor Godinho (a doctor at the same hospital), and a “commission of clinical doctors” made up of Antonio Gomes Silva Rodrigues, Adriano Julio de Barros, and Luiz Pereira Barreto.

A militant of the Republican Movement, Barreto had presided over the State Constitutional Assembly in 1891 and had been the first president of the Society of Medicine and Surgery of São Paulo. He had been a passionate supporter of the transmission of yellow fever by water. Telarolli Junior (1993, p.153-4) analyzed the heated controversy in the São Paulo newspapers in 1896, which largely mirrored the one that had taken place in Rio de Janeiro: “It was common at the time, for example, for well-to-do families traveling by rail to the interior of the state to take a stock of mineral water from Minas Gerais, in order to avoid catching yellow fever.”

Luiz Pereira Barreto was at that point the president of the State Senate, honorary professor at the Polytechnic School of São Paulo, and author of well-known articles on medicine, philosophy, politics, and religion. He exerted all the authority he had to legitimize the experiments on mosquito transmission.

The first series of experiments aimed at proving that Stegomyia were the agents of transmission of yellow fever; it involved five sessions between 15 December 1902 and 20 January 1903.

The preferences to use volunteers who had already been ‘acclimated’, to infect mosquitoes with mild cases of the disease, and to rely on an extended maturation period for the germ within the mosquito's organism were all aimed at producing low-risk infections in the human subjects. There was no treatment for yellow fever, and one death would spell disaster.

 

Isolation Hospital physicians, pharmacists and nurses, at the back of

the Bacteriological Institute of São Paulo (Algumas Instalações do

Serviço Sanitário de São Paulo. São Paulo: Vanorden, 1905. Museu

Emílio Ribas).

São Paulo Isolation Hospital, now the Emílio Ribas Hospital. One of

the infirmaries (Algumas Instalações do Serviço Sanitário de São

Paulo. São Paulo: Vanorden, 1905. Museu Emílio Ribas).

At eleven o'clock on the morning of 15 December in the presence of the medical commission mentioned above, statements were read and signed by Oscar Marques Moreira and Domingos Pereira Vaz (the latter a single 22-year-old from Paraná), according to which they submitted themselves to these experiments “of their own free will and solely their responsibility.” A document describing the conditions for carrying out the experiment was then read and signed by all. That done, they proceeded to have two mosquitoes bite Ribas’ arm and two others, Lutz's arm, and only then did they perform this operation on Moreira and Vaz. “It was verified by all,” records of that session show, “that the mosquitoes bit well, given the amount of blood observed in their abdomens and the evident marks they left in the areas of bitten skin.”

The two volunteers remained under observation in the Isolation Hospital until the following session. Their case histories lead to believe that they were not immune to yellow fever, but Ribas and Lutz had probably already acquired immunity from fighting epidemics in the past.

The second session began three days later (18 Dec.), at practically the same time of day. The doctors present verified that none of the bitten subjects showed any changes in their states of health. Ribas, Lutz, and both volunteers submitted themselves to Stegomyia bites once more. The records of that session again include entries on the history of each mosquito being used and the state of health of the patients from which they had acquired their infection. During the third session, on 22 December, the human subjects once again showed themselves to be “enjoying the best of health.” Beginning at midday, the session lasted longer because the mosquitoes seemed less interested in biting. It was necessary to repeat the applications at five in the afternoon, at which time “they bit well, as was verified by all.” On 12 January 1903 (the fourth session), the human subjects continued “enjoying good health, the previous sessions therefore having had negative results as far as the Stegomyia applications of the three previous sessions.” It was 12:30 p.m. when four mosquitoes sucked Domingos Vaz's blood. Other insects, of the same origin, refused to bite Oscar Moreira. A second fruitless attempt was made at 4:30 p.m. It was only at 7:00 the next morning that Meyer managed to get an infected mosquito to draw blood from Moreira. Half an hour later, another bit him twice but did not draw blood. The operation was repeated at midday, unsuccessfully, even though the mosquito had not been fed during the previous fifty-three hours. The records were duly registered and certified by all present, who were surely exhausted. They decided to repeat the procedure with infected Stegomyia on the morning of 20 January 1903. This fifth session saw the inclusion of two new volunteers, Januário Fiori (Italian, unmarried, 23 years old, residing in Brazil for the previous eleven years) and André Ramos (“mulatto, Brazilian, 40 years old, married”). They were exposed to mosquitoes whose larvae had been brought to São Paulo from Itú, and the grown mosquitoes had then been infected in São Simão. All of them bit well, to judge from the signs left on arms and the blood contained in their abdomens. According to Lemos (1954), three of the four volunteers contracted yellow fever, but there were no signs in the fourth one or in the two extra subjects, Lutz and Ribas.

Truth be told, the materials assembled in the current volume reveal a few discrepancies not entirely in keeping with such a ‘conclusive’ version of the facts. According to one of the manuscripts attached to the records of the experiments, concerning Domingos Pereira Vas, he was bitten on 12 January (fourth session) by four mosquitoes that had been infected by Benjamim Rosanini on 24 December. On 15 December (therefore between the fourth and fifth session), he was “bitten again by three of the same mosquitoes at 1:15 in the afternoon.” On 15 December, at 2:45 p.m., he began to feel ill, complaining of: “lack of appetite, headache, photophobia, especially in the frontal region, pain all over his body, and a strong backache. The symptoms increased progressively, matching his rise in temperature.”

The three members of the physicians commission presented this

case in a report to Emilio Ribas,131 without, however, making any reference to the mosquito procedure of 15 December. It in fact reads that the “brave young man” had begun to feel “slightly unwell” the previous night, when he “threw up three times until 10 p.m.” Although they classified it as “a typically benign case of yellow fever,” they admitted it did leave room for doubt: “The absence of albumins in his urine could, to some more rigorous people, present a serious motive for doubting the precision of the diagnosis.”

Another equally questionable benign case was that of André Ramos. Bitten on the 20th, his legs began hurting four days later; he experienced stomach and back pains, burning eyes, and intense hyperemia in the conjunctiva and thorax. He was sick the night of the 25 th, with strong headaches and stomach aches, and precordial anxiety. Despite these symptoms, urine tests “never showed the presence of albumins.”

If we read between the lines, the tone in which the members of the medical commission report on the third case reveals questionable aspects that they attempted to hide in the other two: Januário Fiori's case “does not allow for hesitation in the diagnosis. Absolutely nothing was missing to complete the morbid syndrome of yellow fever.” Bitten the same day as Ramos, he began to feel sick on the 23 rd. “He still had his 7 o'clock tea but he did not have an appetite. At 7:30, he felt a headache. He then complained of strong shivers, a headache above the eyes, and pain in his legs. At nine o'clock, hyperemia of the conjunctiva, face, and thorax was already quite visible.”

The irony of the story is that the most dramatic experimental evidence developed behind the backs of the medical commission. The reports on patients’ urine (like the one we see attached to the records, in this volume) were written by Bonilha de Toledo, who died 24 April 1903 of yellow fever, probably infected in his own laboratory (Lemos, p.74).

The second series of experiments – eleven sessions that extended from April to 10 May 1903 – intended to demonstrate “the contagion or non-contagion of yellow fever through clothing used by victims of the disease.” It involved three Italians who were kept secluded in Pavilion II of the São Paulo Isolation Hospital, in a room protected against mosquitoes with a metal screen and filled with clothes and objects soiled with the urine, vomit, and excrement of yellow fever patients. They submitted to this torment without showing any signs of the disease, which in this case was the desired outcome.

The first volunteer, Giuseppi Malagutti, son of Antonio Malagutti, was a native of the province of Emilia and a 31-year-old widowed mechanic. He had arrived in Brazil on 30 or 31 March 1902, and lived at 5 Américo Brasiliense Street. Angelo Paroletti came from Milan; son of João Paroletti, he was 43 years old, unmarried, and worked as a mason. He had been in Brazil since 15 or 20 June 1902, residing at 117 Libero Badaró Street. The third volunteer was Giovanni Siniscalchi, son of Fu Pascholi, born in Lombardy. Married, 41 years old, he was a “technical teacher” and had been in Brazil longer: he had arrived on 30 August 1901. At the time of the experiments, he lived at 12 Conselheiro Crispiano Street. All three had embarked in Genoa as 3 rd-class passengers destined for the port of Santos.

Only Malagutti turned up at the first session, on the night of 20 April 1903. Under the watchful eyes of the doctors of the Sanitation Service and the medical commission, he was taken to a room that had been purged with sulphur the day before to eliminate any potentially remaining mosquitoes. A gas heater kept room temperature above the outside environment, so that it served as a hot-house, favorable to the activity of microorganisms supposedly responsible for contagion of the disease. During this series of experiments, the temperature was monitored and recorded with the same care awarded to the conditions of infection of the mosquitoes in the previous series. Malagutti then removed from a box two bags

of clothing that had been worn by recent victims of yellow fever. 132 He next covered his bed with clothes stained with blood and vomit, and spread the rest about the floor. An employee spent the night observing him to make sure that he stayed in his polluted bed.

Giuseppi Malagutti and Angelo Paroletti took part in the second and third sessions (21 and 22 Apr.). The fourth, which occurred the next day, included the presence of Giovanni Siniscalchi. In addition to the clothes used the previous nights, they covered their pillows with cases stained with the vomit of sick people from Taubaté. Paroletti put on a contaminated jacket. In the fifth session, on 24 April, the three Italians repeated the previous nights’ ritual, with a new observer as a witness: Vital Brasil, director of the Butantan Serum Therapy Institute. The sanitary inspector Theodoro Bayma was among those present at the sixth session (25 Apr.), along with the doctors mentioned earlier. On the night of 26 April, the only variation was the requirement to wear new nightclothes that had been added to their supply of polluted clothes. During the eighth session (27 Apr.), they had to shake these vigorously before lying down. They then opened three flasks, one containing urine from a man from Casa Branca, sick with yellow fever, and the other two, black vomit and bloody stools from Ribeirão Preto. These repugnant substances were poured over the clothing. The ninth session (28 Apr.) presented no novelties. During the tenth, observers of this series of experiments declared that the three Italians continued to be in perfectly good health and they were allowed to go, since it was considered that enough time had elapsed to exclude incubation and contagion by yellow fever fomites.

 

Vital Brazil Mineiro da Campanha (1865-1950) in 1919 (Arquivo

Histórico, Instituto Butantan)

The doctors in charge of reporting on the results were categorical in their final report:

The experiments conducted by the North Americans in Havana

and ours … demonstrate that the yellow fever germ can only

find the necessary conditions for its reproduction within the

mosquito's body.

It has been definitively proven and beyond any possibility of

being contested that a mosquito – Stegomyia fasciata – can

transport yellow fever across great distances and transmit it

from a sick person to a healthy one. The experiment carried out

here in the capital city of São Paulo forever dispels all

objections. Here, we do not suffer the tumultuous aggression of

the climatological and mesological factors that are found in

many stricken places [and would] confound our conclusions.

The admirable experiments by the North American doctors in

Havana … were not able to bring all controversies to an end, for

the simple fact that that heavily populated city is a place where

yellow fever has reigned endemically for over a century.

Objections were raised because experimental cases observed

there did not constitute absolute proof, since individuals could

have contracted the infection by means other than mosquitoes.

If this objection were raised in São Paulo, it would simply

constitute scientific improbity. (cited in Lemos, 1954, p.73, 75-7)

Still sub judice, the conclusions reached by the Reed commission were checked by other commissions in places where yellow fever's roots were as ancient as those in Cuba. The Public Health and Marine Hospital Service (created on 1 July 1902) sent to Vera Cruz, Mexico, Drs. Herman B. Parker from the service's hygiene lab; George E. Beyer, professor of Hygiene from Louisianas Tulane University; and Oliver L. Pothier, pathologist from the New Orleans

Charity Hospital. 133 We will comment later on the conclusions they reached. In the series of articles that he published in mid 1901 on the role of mosquitoes on propagating diseases (Brazil-Medico, Jun. 1901, p.208-10), Hilário de Gouveia referred to research carried out in the state of Pará by Liverpoodlian doctors. Their initial conclusions clashed with Reed's. According to an article published in The Lancet in early 1901, the Englishmen had abandoned protozoa as agents of yellow fever, and only found bacilli in the organs of dead victims. Apart from not fitting in with bacterial diseases, transmission via the mosquito did not seem to fit certain “endemiological” characteristics observed in the state of Pará.

A German mission had also been to Brazil, organized by the Sailor's Hospital (Seemannkrankenhauses) and the Institute for Tropical and Marine Diseases (Institutes für Schiffs-und Tropenkrakheiten), both from Hamburg. Businessmen from this German city had long maintained close ties with Brazil, and the mission was almost private in nature. For nearly five months (from 10 February to 4 July 1904), Drs. Hans Erich Moritz Otto and Rudolf Otto Neumann visited a few Brazilian cities, especially Rio de Janeiro.

Three researchers from the Pasteur Institute were already in Rio: Émile Marchoux, Paulo-Louis Simond, and A. Tourelli Salimbeni. Their trip had been sponsored by the French government, which was, like the German government, greatly interested in applying the new prophylactic strategies that would eliminate the damaging quarantines imposed on merchant ships in French colonies, especially Senegal. During their time in the Brazilian capital, the French and Germans could observe first hand the social and biological reality of the city that served as the first open-air laboratory for testing a campaign based on the Culex theory, under conditions that did not entail military occupation and without previous sanitation efforts that might cloud the results (in reality, the concomitant urban reform created problems for Oswaldo Cruz's campaign).

 

Hans Erich Moritz Otto (1869-1918) (Olpp, 1932, S.305).

Rudolf Otto Neumann (1868-1952) (Olpp, 1932, S.294).

 

The Pasteur Mission in Rio (1901-05) 134

After completing his medical studies in Paris in 1887, with a thesis on the typhoid fever epidemics experienced by the Navy contingent based in the East, Émile Marchoux (1862-1943) worked as a Navy doctor in the French colonies of Daomé and Indochina (1888-93); soon after, he directed the Saint-Louis laboratory in Senegal (1895-99).

Letter from General George M. Sternberg to Adolpho Lutz, dated 7

June 1903, expressing gratitude for offprints of articles that he had

sent him, as well as praising Lutz's experiments to confirm results

obtained by the US Commission in Cuba (BR. MN. Fundo Adolpho

Lutz, pasta 215, maço 1).

Paul Louis Simond (1858-1947) also joined the Navy, in 1882, after working as a natural history assistant at the Bordeaux School of Pharmacy and Medicine. He obtained a doctorate in medicine only in 1887, with a thesis on leprosy. His missions as a Navy doctor took him to Guiana, Indochina, and China, where in 1893 he had his first contact with the plague. On returning to Paris, he joined the Pasteur Institute. His first works in microbiology were on the haematozoons of paludism and on coccidia in general, and he was the first to prove the existence of a sexual cycle in these parasites. He was sent to India in 1897 to continue the anti-plague serum campaign that had been started the year before by Alexandre Yersin (1863-1943). He then made an important discovery: the role played by the rat flea in transmitting the disease. Before coming to Brazil, he was director of the Pasteur Institute of Saigon (1898-1900).

 

Paul-Louis Simond in military dress in Valence, France. Studio ‘Blain

Frère’, 1905-1910 (Musée de l’Institut Pasteur, D2089).

The third member of the French medical mission, Alexandre Salimbeni (1867-1942), was an Italian doctor who had graduated from the University of Siena and become a professor there, specialized in pathological anatomy. He joined the Pasteur Institute in November 1895, working initially at the laboratory of Elie Metchnikoff (1845-1916) and then as an assistant to Émile Roux (1853-1933). In 1898, together with them, he published his first paper on the cholera toxin and anti-toxin. During that same period he collaborated with Amédée Borrel (1867-1936) and Edouard Dujardin-Beaumetz (1868-1947) in a study on the peripneumonia microbe, published by Roux and Edmond Nocard (1850-1903). In 1899 he was sent to Portugal along with Alvert Calmette (1863-1933) to investigate the pandemic plague that had reached Porto and which would reach Santos that same year, brought by a ship transporting immigrants from Porto. Salimbeni helped to improve the anti-plague serum preparation technique, at the same time that the serum therapy institutes of Manguinhos and Butantan were being created in

Brazil.135

Simond and Marchoux left Bordeaux on 4 October 1901, in the company of sergeant nurse Hébrard. Salimbeni left three weeks later. They stopped briefly in Dakar, Senegal, where they gathered information about the yellow fever epidemic that was sweeping through that colony. On 3 November they arrived in the capital of Brazil. Nuno de Andrade, Director General of Public Health, and Carlos Seidl, Director of São Sebastião Hospital, put a hospital pavilion at their disposal so they could set up their laboratories. A small boat was also at their disposal to take them daily to Prainha (currently Praça Mauá), where they could catch the steamboat to the other side of the bay, where a train left for Petrópolis. Following the advice of Dr. Brissay, a doctor with the French delegation, Simond, Marchoux, and Salimeni took up residence in that city in the hills, where ever since the previous century, Brazil's elites had taken refuge from yellow fever during the muggy season.

The date for commencement of the mission was established through a law promulgated on 7 December 1901, which did not define its duration. Pulmonary tuberculosis forced Salimeni to return to France on 7 March 1903. Concerns about the mission's finances that year led Dr. Émile Roux, vice-director of the Pasteur Institute, to schedule his companions’ return for July, but their resistance and the fact that the Brazilian sanitary authorities were interested in prolonging their stay led to a compromise: they would leave Brazil temporarily to return in December 1903. Simon would be away from April to December 1904 due to his wife's state of health. Only Marchoux remained in Rio de Janeiro throughout the thirty-seven months of the mission, until its definitive departure on 3 May 1905.

 

In the living room of the Simond residence, from left to right,

Salimbeni, Mme Simond, her husband and, standing, Marchoux.

Petrópolis, 19011905 (Musée de l'Institut Pasteur, D803).

In December 1901, a month after arrival of the French researchers, the first yellow fever patients admitted to São Sebastião Hospital began to be used to infect mosquitoes for inoculation experiments. During 1902, more than 800 people were hospitalized, most of them during the first six months. In February and March – the period when Adolpho Lutz made his first trip to Rio de Janeiro to capture and infect samples of Stegomyia fasciata -hospitalizations reached ten a day. In a letter to his friend Dr. Charrin (dated 9 Sep. 1902), Simond commented that until July the hospital had received on average over fifty yellow fever patients a week, the vast majority immigrants who had been in the city for less than a year.

 

At the Simond residence in Petrópolis, seated from left to right,

Salimbeni, Paretti de la Roca, Mme Simond and Paul-Louis Simond, with two unidentified people standing; 1901-1905 (Musée de l'Institut

Pasteur, MP31354).

The Simond residence on Rua Monte Caseiros in Petrópolis (Musée

de l'Institut Pasteur, D2097).

It is this fluctuating population that, almost exclusively, keeps the

epidemic going. One should not estimate it to exceed seven to

eight thousand … perhaps ten thousand at most. If one bears in

mind that the number of hospitalized people does not represent

more than one-third of the total number of sick people, one can

begin to appreciate the epidemic's intensity. At a conservative

estimate, one hundred and fifty people stricken per week for six

months … This should be enough, do you not think, to

discourage any foreigner from setting foot in Rio. (cited in Tran,

1998, p.58)

São Sebastião Hospital, façade of the central ward. Rio de Janeiro,

1901-1905 (Musée de l'Institut Pasteur, PLS29).

Yellow fever ward (infirmary 11) and, in the foreground, infirmary for

women with smallpox at the São Sebastião Hospital, Rio de Janeiro,

1901-1905. (Musée de l'Institut Pasteur, MP31336).

The research program they drew up was of broader scope than the one carried out in São Paulo. It went further than verifying the results of the Reed commission and, as we shall see, went well beyond the ethical boundaries that Ribas and Lutz had established in dealing with their volunteers. Its principal aims were the microscopic study of patients’ blood and the pathological anatomy and clinical study of yellow fever; the study of the biology and parasitology of Stegomyia fasciata, especially after it was infected with blood from patients; research on the behavior of this blood when injected into animals; and attempts to culture the yellow fever ‘virus’ in vitro and in vivo, including in humans, who would serve as subjects of experiments into transmission, serum therapy as a treatment, and prevention through a vaccine.

Marchoux, Salimbeni, and Simond published four reports in the Annales de L'Institut Paster, O Brazil-Medico, and Revista Médica de São Paulo. In Brazil, Marchoux and Salimbeni also published studies on “O garrotilho” (Equine adenitis, Brazil-Medico, 8 Oct. 1903) and “A espirilose das galinhas” (Spirillosis of chickens, Brazil-Medico, 15 Nov. 1903), while Marchoux published “Febre amarela e malária em Veracruz e no México” (Yellow fever and malaria in Veracruz and in Mexico, Imprensa Médica, 1906).

 

Nurse Hébrard cares for a yellow fever patient on the sixth day of the

disease, at the São Sebastião Hospital, 1901-1905 (Musée de

l'Institut Pasteur, MP31342).

Otto and Neumann, from the German mission, visited Brazil when the French research program was about to end, at the height of the campaign against Stegomyia fasciata led by Oswaldo Cruz. This was also the time of other sanitary actions and the urban reform of Rio de Janeiro.

Hans Erich Moritz Otto (1869-1918) had been an assistant at the Eppendorf General Hospital in Hamburg from 1895 to1900, subsequently joining the Hamburg's Marine and Tropical Diseases Institute, inaugurated 1 October 1900. When he traveled to Brazil, he also introduced himself as a clinical assistant at the Sailor's Hospital in Hamburg, which began its activities on 1 January 1901.

Rudof Otto Neumann, on the other hand, had graduated as a pharmacist in Erlangen in 1894. His talent for drawing and his perseverance impressed professor Karl B. Lehmann, who had hired him to work on the bacteriological atlas he was organizing: Atlas und Grundriss der Bakteriologie und Lehrbuch der speciellen bakteriologischen Diagnostik. This was a seminal work with seven printings and translations into four languages. As we saw in the previous volume of The Complete Works of Adolpho Lutz, in 1896 Lehmann and Neumann would include the leprosy and tuberculosis bacilli in the genus Mycobacterium. Neumann had begun his medical studies late in life, graduating from Würzburg only in 1899. He had then obtained a doctorate in Kiel. His autobiography mentions various important institutes at which he worked: Heidelberg, Paris (Pasteur Institute), Liverpool, Cairo (Kasr El-Aini School of Medicine), and Hamburg (Hygiene Institute and Institute for Marine and Tropical Diseases). He investigated not only yellow fever but also schistosomiasis, ancylostomiasis, and malaria. When he arrived in Brazil, he was serving as a professor at Heidelberg University and an associate at the same hospital and institute where Otto

worked.136

German authorities were careful to inform Simond and Marchoux in advance of the arrival of the two German doctors, hoping to prevent a possible resurgence in that distant port city of the ceaseless strife that had engaged scientists of both nations since the Franco-Prussian war and the famous animosity between Louis Pasteur and Robert Koch. According to Tran (1998), the missions collaborated cordially, to the point that Otto and Neumann's work was praised in a commentary published in the Bulletin de L'Institut Pasteur.

They first visited Pernambuco, where they did not find any yellow fever. After their stay in Rio de Janeiro (their foremost aim in the trip), they also visited the capital of São Paulo, as well as two other cities – Campinas and Santos – that they considered well known because of the epidemics of ‘American typhus’. Before returning to Germany, they also stopped in Bahia, a state that had remained free of yellow fever in recent years. They published preliminary versions of their results in a few German journals and, in 1906, a full report, over 150 pages long, including 55 maps, sketches, photographs,

layouts, and seven tables printed in color.137

In Rio de Janeiro, where they stayed almost three months (from 6 Mar. to end May), Otto and Neumann's research was also conducted at São Sebastião Hospital, a good part devoted to verifying the results already obtained by the researchers from the Pasteur Institute. Both Germans were very fearful of contracting the disease since they were “highly susceptible” to yellow fever, and they even injured themselves during autopsies. They of course slept under mosquito nets every night.

The sick they examined were isolated in screen-lined compartments called “Marchoux Rooms,” which housed two beds each and were erected inside the oldest pavilions. The German researchers in fact referred to them as “barracks” since the underlying concept used by the hospital to isolate diseases deemed contagious had been borrowed from military campaigns. They consisted of moveable units that could be easily discarded if they became contaminated. At one point, São Sebastião Hospital, inaugurated in 1889 on the eve of the fall of the monarchy, had paper machê pavilions imported from Germany.

All but three of the twenty-four sick patients examined by Otto and Neumann were past the third day of the illness, increasing the difficulty of investigating the pathogenic agent, which disappeared from human blood by the fourth day. But the high mortality rate (60%) favored autopsy studies.

They verified that yellow fever was an acute infectious disease displaying the characteristics of quickly evolving hemorrhagic septicemia. Anatomical-pathological examination did not reveal any specific characteristic, except for the absence of splenomegalia, which helped distinguish yellow fever from malaria. The prognosis was always serious, and could only be made with any degree of certainty in the second period. Diagnosis was not difficult in serious cases; differential diagnosis was important because of similarities to the hemoglobinuria form of malaria, to bilious typhoid fever, and phosphorous intoxication. The main yellow fever symptoms recorded by Otto and Neumann were redness of the face; body odor (“similar to that of flesh from a recently slaughtered animal”); severe epigastric distress; and the appearance of albumin in the urine from the first days of the disease. In yellow fever (as with typhus), the pulse rate did not adjust to the temperature of the patient. Black vomit, nose bleeds, and bloody stools sometimes did not occur in cases that were less hemorrhagic or might retreat given signs of a kidney dysfunction. The patient's clinical status would then become less precise, and an inexperienced doctor might take it for uremia when hemorrhaging was imperceptible and only the jaundice was intense.

The interior of a yellow fever infirmary, equipped with booths lined

with metal screens, São Sebastião Hospital, 1901-1905 (Musée de

l'Institut Pasteur, MP31340).

Stegomyia fasciata was Otto and Neumann's main object of study. They left Brazil convinced that it was the transmitter of yellow fever, but not that it was the only form of transmission possible. In Hamburg they would continue their experiments. “The initial material came from Santos, Rio, and Bahia, altogether from 30 to 40 mosquitoes, and a good quantity of larvae.” They were transported by ship in a heated compartment, and transferred to the “mosquito room” at the Institute for Tropical and Marine Diseases, a spacious room kept at a constant temperature of 27°C; it contained cages and a large aquarium with a mosquito-proof metal mesh. There they were able to follow twelve generations that were raised in the space of six months. “Regrettably, the Culex fatigans and Anopheles argyrotarsus, which had been brought together, did not reproduce.”

They had used “catching glasses” developed by Nocht to collect the mosquitoes in Rio de Janeiro, but on walls and harder-to-reach places they had used a device suggested by Adolpho Lutz. “It is a simple glass tube, somewhat curved, with a rubber tube and some cotton at one end. One places the tube easily over the mosquito and then draws it through the rubber tube until it reaches the cotton.”

A few problems had been encountered in growing Stegomyia in the Brazilian capital, especially the tiny ants that proved to be avid mosquito eaters.

The glasses where we raised our mosquitoes always had to be

carefully placed in a dish of water. Even so, from time to time,

the ants would somehow find their way into the glasses at night,

passing through the thin piece of gauze and eating our

Stegomyia. We finally greased the sides of the dishes with a

sticky substance that trapped the ants.

To feed the insects in captivity they dipped wet cotton in sugar, honey, bananas, and water. Blood was needed to raise them. In the lab and during the trip from Brazil to Germany, they put canaries and white mice in the mosquito cages. “One hardly needs to mention that Stegomyia fasciata prefers human blood to any animal blood, and that it tries to obtain it every possible way.” Their experiments had provided “imperative” proof that only the females bit. Moreover, they observed that the mosquitoes seemed to prefer “white, delicate skin” to that of people of color.

Cages and apparatus to catch mosquitos. Figure 5 shows an

aspiration tube invented by Lutz (Otto & Neumann, 1906, p.28). In their first report, dated November 1903, Simond, Marchoux, and Salimeni had presented a detailed analysis of Stegomyia fasciata. They cited Adolpho Lutz's research and also Finlay's and the Reed commission's, but the mosquito's habits and biological make-up were nevertheless still not fully understood. It was not even possible to state that this was the only species able to serve as an intermediary host to the still undiscovered yellow fever germ. It was essential to clear the issue up, for the Stegomyia had become the focus of a heated controversy and the cornerstone of the sanitary campaign already underway in Rio de Janeiro.

French doctors investigated all the mosquitoes they were able to capture there, among them Anopheles albitarsis and Culex fatigans, singulatus, and confirmatus (these no longer exist as Culex). They verified that Stegomyia fasciata was the only yellow fever vector.

The insect's geographical distribution (in principle, all regions falling between 40 degrees latitude North and 40 degrees latitude South) and the observations made in Rio de Janeiro by Simond, Marchoux, and Salimbeni pointed up its sensitivity to temperature: between 27° and 30°C was ideal for their development; below 25°C, the species lost a good share of its capacities. This could explain why Petrópolis was immune to yellow fever even when epidemics were sweeping through areas not so far away (less than 100 km today), and despite the intense daily traffic between the city in the hills and the capital.

Many researchers thought that Stegomyia was an insect of daytime habits. This characteristic contradicted the existing idea that yellow fever was a disease that could only be contracted at night. There were no well-known cases of ‘contagion’ in the heart of the throng that descended the mountains every day, coming from Petrópolis to Rio at nine in the morning and going back up at four in the afternoon. On the other hand, there were frequent cases of people falling ill among those who chose to spend a night in Rio, even if it was for a simple soirée. Being in Rio after sunset in order to catch yellow fever “is a requirement that seems almost absolute,” wrote Simond in one of his notebooks (cited in Tran, 1998, p.65).

Simond in his laboratory in the Pasteur mission building. São

 

Sebastião Hospital, 1901-1905 (Musée de l'Institut Pasteur, PLS33).

Building used for Pasteur's mission in São Sebastião Hospital, with

Paul-Louis Simond in the foreground, 1901-1905 (Musée de l'Institut

Pasteur, D2808).

This common-sense notion was justified when the French verified that females indeed bit above all at night; young, recently impregnated insects might do so in the day but they were not yet able to transmit the disease since it took twelve days from the time they drew contaminated blood for them to become infectious.

Otto and Neumann's report reveals the intensity of the controversies surrounding the question.

According to Dr. Lutz's data,138 Stegomyia usually bite during

the daytime. According to George Gray, most of the bites occur

between one and three o'clock in the afternoon. In Durham's

report on … yellow fever in the state of Pará, the lunch hour is

also indicated as the prime time for bites … Lastly, Finlay

observed that Stegomyia bite by day, and Bandi, as we did, had

the opportunity in São Sebastião, in Rio de Janeiro, to capture

during the day mosquitoes that had just bitten.

…

According to the description above, one could be tempted to

declare that Stegomyia is simply a daytime mosquito, although it

can also bite in the evening and during the night … On many

occasions we were able to capture female Stegomyia under

mosquito nets at night after they had drawn blood. They likewise

bit us in our chalet at Hotel Internacional when we were still

seated at the table late at night, wearing only light clothing.

Ribas also observes bites without distinguishing day and night

… It is indeed strange that all those who stay in Rio during the

day and travel back to Petrópolis only in the early evening …

should be spared from yellow fever.

…

Marchoux, Salimbeni, and Simond … think … that once

Stegomyia has drawn blood, it will not bite again during the day,

but will do so at night. Bandi disagrees with this notion, saying

there is no motive to stop mosquitoes from biting right away

once they have finished a previous bite … Thus, Marchoux,

Salimbeni, and Simond's opinion can not be cited as proof of the

mosquito theory.

For Otto and Neumann, infections took place principally at night due to a notable characteristic of Stegomyia fasciata, both in its winged form and as larva and nymph: its aversion to light. These mosquitoes had a preference for dark corners or objects. In the laboratory they were seen or captured almost always on black trousers or on the fabric that covered the photographic equipment. “Their behavior is so marked that they will not bite an arm that is placed in the cage that is suddenly illuminated by a strong electric light, but will readily attack with the lights out.”

From left to right, Paretti de la Roca, Carlos Seidl (director of São

 

Sebastião Hospital, Simond and, standing behind them, Salimbeni

and two other unidentified people (Musée de l'Institut Pasteur,

PLS40).

People who lived or worked in Rio de Janeiro had not been so exposed to mosquito attacks during the day because they usually found themselves out on the street or in well-lit rooms. Outside homes, Stegomyia liked to lay their eggs in open-air channels, tanks, barrels used to capture rainwater, puddles, bottles, boxes of preserved food, and broken glass. Inside homes they sought out dark corners and would lay their eggs in the outlets of washbasins and tanks, in toilet water, in plates beneath potted plants, and in spittoons and similar objects. They had a predilection for humid, muggy places, such as warehouses, bars, basements, and brothels. Because of their attraction to sweet foods, they could be found in great concentrations in beer halls, bakeries, sugar refineries, and restaurants.

They did not like drafts but could rise to heights of hundreds of meters. They did not undertake major migrations but did travel great distances in trains, streetcars, automobiles, and ships, especially in cargoes of sugar, molasses, and fruit and in damp packages. Otto and Neumann put Stegomyia inside suitcases of dry and damp clothing, and saw that the sturdiest females would survive up to fifteen days.

According to Tran (1998), in a retrospective view, the French missions most original feat was to demonstrate that these mosquitoes could transmit the yellow fever ‘virus’ to descendents through heredity (vertical or transovarian). This line of investigation was prompted by the puzzling appearance of sporadic cases, sometimes spaced out, between epidemics. The theories held back then explained that the disease was ‘imported’ to stricken areas by travelers or objects that had been infected by microbes, and these sporadic resurgences were attributed to the transformation that the germ underwent in the ground, responding to climate-related or telluric factors. The ‘Havana theory’ could not explain this adequately, since the mosquito only had a limited lifetime.

Writing a paper for the general public (1903), Lutz stated that Stegomyia fasciata could live “for two or three summer months as long as they were fed.” He went on:

it is well known that not only among us but even in colder

nations, they can last through an entire winter. At lower

temperatures, Stegomyia do not bite, which halts the

appearance of new infections until the heat returns. If the

temperature does rise significantly in the winter, they can leave

their hiding places and bite again, explaining the cases we have

observed in this season.

Both sporadic cases and outbreaks that occurred independently of any outside imports were given a new explanation in 1932 when Soper's team discovered jungle yellow fever and then demonstrated the existence of a sylvatic cycle dependent on non-human receptacles of the yellow fever virus, more especially forest-dwelling primates. At the beginning of the 20 th century, in the absence of any proven animal models, suspicion could not fall on any vertebrate hosts other than humans. Walter Reed's team had tried to verify the hypothesis of an autonomous mosquito-based circuit of transmission, but their results had been negative.

French researchers in Rio de Janeiro conducted experiments in which eggs laid by females who had bitten sick patients were raised from the larvae stage to the adult stage, but to prove that they and their descendents were infectious meant resorting to human volunteers. Attempts in 1903 were unsuccessful, but in 1905 the researchers managed to reproduce symptoms of the disease in a volunteer (Tran, 1998, p.66). Simond and Marchoux (1905) hurried to publish these observations, even before the release of the third report the next year.

The newspaper article “Mystère de la Fièvre Jaune. Les découvertes des docteurs Marchoux et Simond expliquent l’ épidemia inexplicable de Panama,” published in Le Matin (1 Aug. 1905, p.1-2), raised doubts about the anti-Culex measures put into practice in Cuba and Brazil. This was because in Panama these measures did not prevent the disease from proliferating at twice its previous intensity from May to June of 1905, despite the previous year's mosquito-fighting measures. An outbreak of the epidemic in New Orleans also led the newspaper to ask Marchoux and Simond whether yellow fever might not have a way of propagating in those places which was unlike the means used in Havana and Rio de Janeiro.

Authorized by the Minister of the Colonies, the two French doctors went public with information that would be included in their reports. They vehemently rejected the suspicions that had been raised. Their studies had ratified Finlay's theory, but in the Brazilian capital they verified that the incriminated mosquito had two new sources of infection. One consisted of the mild cases of yellow fever that would pass unnoticed by doctors yet would still provide mosquitoes with what they needed to keep the epidemic going. The main fuel, however, was provided by babies still being breast-fed: these recent arrivals to infected regions were as susceptible as any immigrant, but they were remarkably resistant to the yellow fever ‘poison’. The other source of invisible infection was the hereditary transmission of the yellow fever ‘virus’ to the descendents of the female Stegomyia fasciata that had drawn blood from sick patients. “This fact will certainly cause great sensation in the scientific field,” the paper noted. “Its verification was based on direct experience … It was impossible for the French mission to find another volunteer in Rio to continue the experiment, but one hopes that it will be taken up again in Panama by the American doctors.”

A newspaper article published at about the same time in Le Journal (2 Jul. 1905) by Fernand Hauser, also drew attention to that “frightening [thing], the microbial infection of yellow fever, which

extends to the eggs of the infected mosquito.” 139

 

The etiological enigma

In spite of the Reed commission's efforts to demonstrate that the yellow fever agent was a “filterable virus,” recent papers on paludism had disseminated the supposition that it was perhaps a parasite whose characteristics were analogous to the Laveran plasmodium.

In an article published in the Revista de Medicina Tropical (Havana, Apr. 1903), Finlay himself defended the hypothesis: this parasite would be an ultra-microscopic protozoan whose stages of development were more or less similar to those of the malaria parasite. He supposed that its sexual reproduction took place inside humans (its definitive host), while schizogony occurred in the mosquito. This inference was based on the observation that the infection of Stegomyia lasted indefinitely, while in humans it was short. On the other hand, in the case of malaria, infection in man was of indefinite duration while in Anopheles it was apparently limited.

It was during this period that the first report by Parker, Beyer, and Pothier was released (1903; also Parker, 1903). The doctors from the U.S. Navy commission did not find any specific organism in the blood of yellow fever patients or in their tissues after death. Observation of Stegomyia fasciata, however, proved promising. After feeding on a patient, the insect's ovaries at first underwent hypertrophy, as would normally occur after a feeding of normal blood; they would then undergo complete atrophy. The salivary glands also displayed excessive enlargement. Three or four days after the absorption of contaminated blood a “small fusiform protozoan” (whose development was analogous to that of coccidia) would be found in the salivary glands and stomach. In future experiments, the authors expected to better determine the life cycle and etiological role of the organism they named Myxococcidium stegomyiae.

Parker, Beyer, and Pothier considered it a definitive scientific fact that the disease's medium of transference was Stegomyia fasciata. But they could not yet tell if it was “its sole medium of transference.” They believed that “to prove this negative affirmation, appropriate conditions must be afforded for producing the disease at will, or under constant conditions” – an indirect allusion to experimentation

on human subjects. 140

Influenced by those ideas and by work he had already done on coccidia, (1897), Simond, in Rio de Janeiro, turned enthusiastically to a microsporidium of the genus Nosema, which was similar to Myxococcidium stegomyiae and which he had found in the Stegomyia digestive tract in March 1902. The discovery generated great expectations in the French legation, which confidentially informed Théophile Delcassé, Frances Minister of Foreign Affairs:

 

Image of nosema. Source:

www.tc.umn.edu/~reute001/images/disease/F6-nosema-guts.jpg,

acesso em 22.6.2005.

Drs. Marchoux, Simond, and Salimbeni … confided in me the

fortunate result of their initial research: they would like us to

maintain utmost confidentiality with respect to their experiments

until the director of the Pasteur Institute has made a statement.

(cited in Tran, 1998, p.56)

The director, however, dampened that enthusiasm in a letter dated 28 March 1902: The mosquito that had bitten a victim of the disease did indeed have a coccidian, but the preparations he had been sent were not convincing; Roux had not seen anything, either in the blood

or in the liver, suggestive of the etiological agent of yellow fever. 141

The three French researchers would eventually recognize that the parasite was frequently found in Stegomyia, even in those that had not bitten yellow fever sufferers.

Émile Roux, who one year later would publish “Sur les microbes dits invisibles,” thought the cause of the disease might be a microorganism of this still enigmatic group, but he considered the hypothesis of bacterial etiology more likely. He wrote to Simond: