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In 1923, Doctor Sebastião Barroso, head of the Rural Sanitation and Prophylaxis Service of Bahia, submitted a report on the previous year's activities. The document contains information on initiatives coordinated by the entity on rural epidemics and prophylaxis, accompanied by a compilation of the reports by the professionals responsible for the rural prophylaxis units and tables containing data on the different regions in the state, notifications received, and expenses. The section of this document presented here enables us to investigate the state's role in addressing public health issues in a context marked by recurring outbreaks of epidemics, especially yellow fever.

In 1958, the Pan American Health Organization declared that Brazil had successfully eradicated the mosquito Aedes aegypti, responsible for the transmission of yellow fever, dengue fever, chikungunya, and Zika virus. Yet in 2016 the Brazilian minister of health described the situation of dengue fever as "catastrophic." Discussing the recent epidemic of Zika virus, which amplified the crisis produced by the persistence of dengue fever, Brazil's president declared in January 2016 that "we are in the process of losing the war against the mosquito Aedes aegypti." I discuss the reasons for the failure to contain Aedes in Brazil and the consequences of this failure. A longue durée perspective favors a view of the Zika epidemic that does not present it as a health crisis to be contained with a technical solution alone but as a pathology that has the persistence of deeply entrenched structural problems and vulnerabilities.

In the 19th century, yellow fever thrived in the tropical, urban trade centers along the American Gulf Coast. Industrializing and populated, New Orleans and Memphis made excellent habitats for the yellow fever-carrying Aedes aegypti mosquitoes and the virulence they imparted on their victims. Known for its jaundice and black, blood-filled vomit, the malady terrorized the region for decades, sometimes claiming tens of thousands of lives during the near annual summertime outbreaks. In response to the failing medical community, a small, pronounced population of sick and healthy laypeople openly criticized the efforts to rid the Gulf region of yellow jack. Utilizing newspapers and cartoons to vocalize their opinions, these critics doubted and mocked the medical community, contributing to the regional and seasonal dilemma yellow fever posed for the American South. These sentient expressions prove to be an early example of patient distrust toward caregivers, a current problem in clinical heath care.

Background: The last outbreak of yellow fever in the city of Barcelona, Spain, was caused by a ship arriving from Cuba. The objective of this study was to describe and analyze the epidemic of 1870 by using the available mortality data., Methods: The information on 1,235 deaths identified in the parochial registries was analyzed, using statistical and epidemiological procedures for epidemic outbreaks., Results: Mortality due to yellow fever was 549.7 per 100,000 inhabitants. The temporal distribution of the deaths showed two peaks at the end of September and October with the last fatalities occurring in December 1870. The distribution of the fatalities in the city's neighborhoods was unequal. In La Barceloneta, in particular, more fatalities were found in the streets adjacent to the port than in the most remote streets (r=0.83; p<0.0001)., Conclusions: This study reveals a temporal bimodal mortality distribution for yellow fever during the outbreak, with a high impact in adult men and in the La Barceloneta neighborhood.

After the discovery of the New World, yellow fever proved to be an important risk factor of morbidity and mortality for Caribbean populations. In the following centuries epidemic risk, expanded by sea trade and travel, progressively reached the settlements in North America and Brazil as well as the Atlantic seaboard of tropical and equatorial Africa. In the eighteenth century and the first half of the nineteenth century epidemics of yellow fever were reported in some coastal towns in the Iberian peninsula, French coast, Great Britain and Italy, where, in 1804 at Leghorn, only one epidemic was documented. Prevention and control programs against yellow fever, developed at the beginning of the twentieth century in Cuba and in Panama, were a major breakthrough in understanding definitively its aetiology and pathogenesis. Subsequently, further advances in knowledge of yellow fever epidemiology were obtained when French scientists, working in West and Central Africa, showed that monkeys were major hosts of the yellow fever virus (the wild yellow fever virus), besides man. In addition, advances in research, contributing to the development of vaccines against the yellow fever virus in the first half of the nineteenth century, are reported in this paper.

In 1861, a brief epidemic of Yellow Fever made 26 dead among 44 sick persons. Because of the lack of knowledge in bacteriological origins it was impossible to link the illness to the role in the transmission of the virus by insects. Chiefly it was impossible to understand why the people on the shore were hit while some sailors leaving the boat were not? Why some people living to leeward of the ship were touched? Thus Melier championed the concept of transmission by an agent carried by the atmosphere. Without scientific epidemiological knowledge he was able to bring out some wise pre-emptive measures.

This article briefly details the history of the 1905 yellow fever epidemic in New Orleans and the successful and permanent eradication of The Pestilence. First the authors will give some medical and historical background regarding Bronze Jack from its transmission from West Africa by the Spanish slave trade to the New World, through the Caribbean to New Orleans, the great port city which became the Necropolis of the South. We will then focus on the summer of 1905 when New Orleans experienced what proved to be the last epidemic in the history of New Orleans and the United States, and the methods employed to combat it. This year, 2005, marks the centennial of one of the truly remarkable and critical accomplishments of medicine and public health.

The scientific discoveries of the U.S. Army Yellow Fever Board of 1900 are well known as are the Army physicians who led the board. Walter Reed, of course, is the best known, but James Carroll, Aristides Agramonte, and Jesse Lazear are also known, if not nationally, to their local communities. This article deals not with the known but with the unknown, meaning the volunteers who subjected themselves to the ravages of yellow fever and the real possibility of death. The year 1900 was known as a "yellow fever year" among the locals in Cuba because in the preceding year the epidemics had been relatively mild. Beginning its work in June 1900 in the midst of a deadly epidemic, the board conducted a truly remarkable set of experiments that set a benchmark for controlled clinical trials and informed consent. Because no animal model was known to be susceptible to yellow fever, they used human volunteers for their experiments. These volunteers were recruited from among Spanish immigrants and were accepted from soldiers and two civilians who volunteered. Over 30 men participated in the experiments, and 22 developed yellow fever. With expected death rates of 20% to 40%, it is incredible that none of these volunteers died. In 1929, the U.S. government honored the Americans who volunteered by placing their names on a Roll of Honor published annually in the Army Register. The successes of the 1900 U.S. Army Yellow Fever Board were truly remarkable, and many of the successes were made possible by the men who volunteered, some repeatedly, to risk their lives "in the interest of humanity and the cause of science."

The year 2000 marked the centennial of the discovery of the mode of transmission of yellow fever. Informed consent was systematically used for the first time in research. This process was the result of a complex social phenomenon involving the American Public Health Association, the US and Spanish Governments, American and Cuban scientists, the media, and civilian and military volunteers. The public health and medical communities face the AIDS pandemic at the beginning of the 21st Century, as they faced the yellow fever epidemic at the beginning of the 20th Century. Current medical research dilemmas have fueled the debate about the ethical conduct of research in human subjects. The AIDS pandemic is imposing enormous new ethical challenges on the conduct of medical research, especially in the developing world. Reflecting on the yellow fever experiments of 1900, lessons can be learned and applied to the current ethical challenges faced by the international public health research community. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

We have carried out a meticulous time-space-analysis of the incidence of yellow fever in humans in Brazil from 1954 to 1972 and especially from 1973 to 1999. This study has added to our knowledge of the epidemiology of yellow fever and enabled us to redefine epidemiological zones and determine their geographical limits. The endemic area is located within the Amazon basin; here cases are scattered and generally limited in number. However, there are also "foci of endemic emergence" within this area, where cases are less rare, although occurrence remains irregular. The epidemic area is for the most part situated outside the Amazon basin, to the north east and particularly to the south. It has been divided into two parts according to whether the occurrence of yellow fever is cyclic or sporadic. The epidemics, which are all sylvatic, follow either a circular path (in the forest area) or a linear path (in forest-galleries of the savannah area). The study of the development of the 3 main epidemics (1972-74; 1979-82; 1986-92) in the cyclic emergence area showed that, on each occasion, the yellow fever virus appeared at a particularly active outbreak site located in the "serra dos Carajás", and from there, it followed the courses of the Tocantins and Araguaia rivers upstream, moving southwards during the "pre-epidemic phase" which may be visible due to the occurrence of a few cases, or may remain invisible. Subsequently the virus reached the emergence area, where it appeared in the form of epidemics. In this zone, it also followed privileged south-western pathways, moving from one hydraulic basin to another along the upstream courses of the rivers. Almost exactly the same pathways have been identified for each of the 3 epidemics studied. The distances travelled by the virus over a period of one year--when it goes rapidly--can reach several hundred kilometers. On the other hand, it may be stationary for a period of one or two consecutive years, occasionally three, remaining present in the area but infecting humans only rarely if at all. The virus occasionally leaves the cyclic emergence area and appears in the sporadic emergence area to the east, in the states of Bahia, Minas Gerais and São Paulo, and, as a consequence, moving onto other hydraulic basins. The small river basins in Maranhão and NorthWest states, as well as in the northern part of the state of Roraima also form part of the sporadic emergence area. The epidemics that occur here are directly linked to the endemic area and are only preceded by sometimes indiscernible epizootics and can consequently not be foreseen. Again the virus appears to use privileged pathways to reach the sporadic emergence areas where human and monkey populations are generally only partially immunised against yellow fever and where contact with mosquitoes is intense despite the fact it is limited in space and time, being restricted to the often narrow strip of trees along the water courses. Other routes used by the virus may be the Madeira, Xingu and Tapajós rivers, the scene of outbreaks observed in the state of Rondônia and in the north of Mato Grosso, where ongoing environmental changes are likely to result in an increasing number of outbreaks in the coming years. Since the discovery of the sylvatic cycle of yellow fever in 1933, not only the extent of the epidemiological areas has changed, but also their limits. Ecological modifications that are currently taking place in the Amazon basin, which is an endemic reservoir of the virus, will inevitably facilitate an increase the contact between humans and vectors. While more and more urban areas harbour populations of Aedes aegypti, the domestic and urban vector of yellow fever, it is particularly important to try to protect human populations living in emergence zones and epidemic areas and thus to prevent the arrival of the virus in towns via humans with viremia--in other words the much feared urbanisation of yellow fever in Brazil.

The outbreak of yellow fever that struck Barcelona in 1821 followed a typical pattern for the times: a brick from Cuba introduced the disease in the port docks; the epidemic first reached the poor suburbs, and finally the center of the city. It was assumed that at least 20,000 inhabitants died from the scourge, that is a sixth of the total population of the city estimated 120,000. French authorities promptly took emergency measures at land and maritime borders by locking French ports to Catalan vessels and defining a quarantine line along the Pyrenean border controlled by an army 15,000 strong. French medical team including six physicians and two nuns was sent to Barcelona to provide assistance. Long after the epidemic had receded, the Pyrenean quarantine line was maintained by the French authorities for a hidden political purpose: Paris wished to contain Spanish Liberalism, a "revolutionary pest". French troops engaged in the so-called quarantine line were used in 1823 for invading the Spanish kingdom, while French physicians returning to Paris were celebrated as heroes and benefactors of the mankind although they had not provided any serious contribution to the therapeutics or the epidemiology of yellow fever. They were glorified in publications of the time without reserve. This unexpected manifestation of nationalism was welcomed and encouraged by the government of Louis XVIII who felt himself threatened by the liberal opposition.

P.L. Simond participated in the Pasteur Institute mission sent to Rio de Janeiro from 1901 to 1905 to investigate yellow fever and was to make an important contribution to the knowledge of the disease. At that time, the aetiologic agent of yellow fever was still unknown, and its transmission by mosquitoes was controversial. Several authors had observed apparent differences in the susceptibility to the illness between African and European populations. Otherwise, the soundness of epidemic control measures then being administered was often called into question. As such, many points needed to be definitely clarified. During the four years they spent in Brazil, the Pasteur Institute scientists--and particularly Simond--achieved important results. They confirmed the viral aetiology of yellow fever, were able to define several pathological aspects of the disease and conduct various serotherapeutic tests. The role of Aedes aegypti (known at the time as Stegomyia fasciata) was also confirmed and the bionomics of the mosquito began to be studied. This research laid the ground for classical measures of controlling the vector and preventing outbreaks of the disease. Furthermore, Marchoux and Simond observed the vertical transmission of yellow fever virus in Ae. aegypti; this phenomenon of major epidemiological importance remained controversial until it was confirmed in the field as recently as 1997. The French scientists were also able to specify many aspects of the epidemiology of yellow fever, particularly its apparent low pathogenicity in young children--a possible explanation for the fact that local residents of endemic zones often had a certain level of immunity as a result of benign infection contracted in childhood. P.L. Simond later spent several months in Martinique where he set up a successful yellow fever vector control programme. Clearly Simond, who had already acquired much expertise in the epidemiology of vector-borne diseases, played a key role in the success of the mission sent by Institute Pasteur to Brazil, and, more generally, in the scientific advances of yellow fever prevention.

During the summer of 1849-50, a yellow fever epidemic hit the city of Rio de Janeeiro. In analyzing the epidemic's impact on local funeral customs, the article asked to what extent the subsequent high mortality rate was a catalyst that changed people's attitudes towards death and the deceased. The central hypothesis is that the epidemic was the final argument physicians needed to convince the imperial government and the population to implement these doctors' project, one which would medicalize death and standardize funeral customs.

Yellow fever (YF) has remained a disease of public health importance since it was first described in the fifteenth century. At different periods in human history, YF has caused untold hardship and indescribable misery among populations in the Americas, Europe, and Africa. It brought economic disaster in its wake, constituting a stumbling block to development. Yellow fever is an arboviral infection with three epidemiological transmission cycles between monkeys, mosquitoes, and humans. It is an acute infectious disease characterized by sudden onset, with two phases of development separated by a short period of remission. The clinical spectrum of YF varies from a very mild, nonspecific, febrile illness to a fulminating, sometimes fatal disease with pathognomonic features. In severe cases, jaundice and bleeding diathesis with hepatorenal involvement are common. The fatality rate of severe YF is 50% or higher. Despite landmark achievements in the understanding of the epidemiology of YF and the availability of a safe, efficacious vaccine, YF remains a major public health problem in both Africa and South America, where annually the disease affects an estimated 200,000 persons, causing an estimated 30,000 deaths. Since the 1980s epidemics of YF in Africa have affected predominantly children under the age of 15 years. The failure to control YF arises from a misapplication of public health strategies and insufficient political commitment by governments in YF endemic areas, especially in Africa, to control the disease.

The Kingdom of Hawaii suffered a disastrous series of epidemics starting from the first contact with Captain Cook's crew and continuing to the present. Despite the huge volume of shipping to and through Hawaii, one plague failed to appear. Yellow Jack (yellow fever) engendered more fear in sailors of the 19th century than any other disease. By 1910 the details of transmission were well-known and Hawaii met all the requirements for an epidemic. On October 30, 1910, the first case of shipboard yellow fever arrived at Honolulu but quarantine averted the threat. On October 28, 1911, a Hawaiian man, employed as a quarantine guard, was reported to have yellow fever and efforts were initiated to control a possible epidemic. This was the only occurrence of yellow fever in Hawaii.

Throughout the 19th century, yellow fever was the scourge of southern coastal cities. Because of primitive diagnostic tools, differential diagnosis during epidemics was often difficult. Many patients were diagnosed with "malarial fever," breakbone fever, "the prevailing fever," and "mild yellow fever," to name a few. Dr. Manning Simon's opportunity to study an almost "pure" epidemic of yellow fever among an "unacclimated" population was a breakthrough in diagnostic medicine. Fortunately, his findings were not to be needed again in South Carolina, since this was the last outbreak of yellow fever in the state.

The history of yellow fever is discussed with relevance to the Lisbon epidemic of 1857. Robert S.D. Lyons, professor of medicine at the Catholic University Medical School in Dublin, was given leave by the rector to investigate its pathology and set off for Portugal in November. He performed autopsies and studied possible environmental factors, with negative results. The professor's "prolonged absence" began to worry the rector in January but, before long, Dr Lyons returned to his duties and published a report.