The Brazilian congresses of epidemiology

: This paper deals with the first ten epidemiology conferences held by ABRASCO between 1990 and 2017. Objective : To provide historical records of these events, highlighting the context in which they were conceived, the chosen themes and their role in the national and international epidemiological landscape, the venues, and the presidents of the different editions. Methods : Data were extracted from printed and electronic proceedings, with some data gaps that could not be filled. Results : The numbers and characteristics of different activities are also presented, with emphasis on conferences and roundtables, lectures, panels and debates, and the collaboration of the academic and professional community for coordinated communications and posters outlining a wide range of themes and approaches. This paper keeps record of most of the activities carried out. Conclusions : The authors are aware that the record presented is a pale picture of the real meaning of these meetings in which the development of epidemiology was being built, in an articulation between scholars and health services and as a cooperation between national researchers and our companions and friends who work in foreign institutions all around the world.

REV BRAS EPIDEMIOL 2022; 25: E220008 The conceptual foundations were then created and the conditions to promote the Brazilian congresses of epidemiology were matured. This picture was strengthened by the creation of the National Epidemiology Center under the Ministry of Health, later absorbed, in 2003, by the Health Surveillance Secretariat. With the support of the Ministry of Health and PAHO, which invested human and financial efforts, the congress, now in its 11th version, took place and was consolidated. Recognized by the scientific community, the event could count on the financial support of state and municipal health departments, state research support foundations, and federal agencies National Council for Scientific and Technological Development (CNPq), which funds studies and projects, and Coordination for the Improvement of Higher Education Personnel (CAPES). The funding for the tenth edition was very limited, but the academic community paid for part of the costs using resources from projects and productivity grants.
One of the most outstanding features of epidemiology events, as well as other Abrasco's congresses, is the weighty participation of health professionals, graduate students and, more recently, undergraduate students, professors and researchers in the field.

GENERAL FEATURES
The Brazilian congresses of epidemiology, promoted by Abrasco and organized by the association's epidemiology committees, aimed to create a space for sharing knowledge produced by professors, academic researchers and health professionals.
Although Abrasco was created as a scientific association for postgraduate studies in collective health, its founders and partners were aware of the need to maintain an articulation between the policy of training human resources, research and health policies, fundamentally expressed in the consolidation and improvement of the Unified Health System (SUS).
This concern was reflected not only in the composition of congressmen, evenly divided between academic participants and health professionals, but also in the very conception of such events.
Chart 1 shows the dates and locations of congresses, their presidents and themes chosen. The presidents were always professors from the promoting institutions and/or members of the Epidemiology Commission 2-11 .
The III Brazilian Congress of Epidemiology took place in association with the II Ibero-American Congress of Epidemiology (Ibero-American Society of Epidemiology) and the I Latin American Congress of Epidemiology. In 2008, the VII Brazilian Congress of Epidemiology happened along with the XVIII World Congress of International Epidemiological Association. These partnerships show the development achieved by Brazilian epidemiology and Abrasco's level of articulation to the international extent.
The themes chosen for each edition represent the concerns of the community at each moment, as interpreted by the epidemiology commissions. Thus, for the first congress, held in 1990, the core theme was social inequality and its repercussions on health 2 .
The issue of social inequalities in health became increasingly present in the scientific literature from late 1960s onwards. The increase in economic and social disparities across all Western countries drawn the interest of epidemiologists both in developed and underdeveloped countries. Brazil, as one of the most unequal countries in the American continent, could not be left out of this movement, and the theme was naturally chosen when the first epidemiology congress was idealized.
In addition to addressing an academically relevant issue, the discussion on social inequalities in health extended the dialogue in epidemiology to other disciplines in the theoretical field of collective health, linking it to political commitments when it comes to collective health practices. The theme of the second congress was quality of life 3 . This matter gained momentum during the 1970s and reflected two sets of concerns: the need for a positive formulation of the concept of health, overcoming its traditional approach of "absence of disease"; the impact of epidemiological knowledge on health promotion and risk exposure control activities.
The third congress revisited the theme of social inequalities, emphasizing the aspect of equity as one of the constitutional principles of SUS 4 . In 1995, issues related to the implementation of the health system were the order of the day. The scientific literature began to take the issue of equity as a topic of investigation shortly before. In the database of the US National Library of Medicine, the first articles addressing the subject were published in 1970, and by 1995 they had surpassed only one hundred publications.
The fourth congress, for the first time, addressed a theme that reflected a specific methodological issue of the discipline: descriptive epidemiology 5 . There were a few reasons behind this choice. The first is the need to reinforce the importance of studying the distribution of diseases, not restricting the role of epidemiology to the study of risk factors or occurrence functions, as proposed in manuals published in the last decades of the 20th century.
The second reason was the revision of the paradigm of epidemiological transition under the impact of the AIDS epidemic and the worsening of the epidemiological situation of tuberculosis, in part associated with the AIDS epidemic itself, in part with the worsening of poverty in large urban centers. Contrary to what many theorists assumed, communicable diseases were not disappearing and giving way to so-called chronic diseases. The epidemiological profile was proven more complex, and the tools of descriptive epidemiology were still useful in guiding control practices 12 .
The third reason that contributed to reaffirming the place of descriptive epidemiology was the appearance of so-called emerging or reemerging diseases. All investigations of these situations that were putting at risk the overcoming of infectious diseases as populational problems were based on descriptive epidemiology 13 .
Obviously, the topic did not imply a simple revisit to or a continuation of well-established knowledge; it proposed, instead, updating numerous analysis techniques and brought new concepts applicable to studies of disease distributions between populations.
The fifth congress' theme was health promotion 6 , an issue very much spoken of around the world in international conferences sponsored by the World Health Organization (WHO). The first one took place in Ottawa, in 1986, and served as a beacon for initiatives by public health associations worldwide. In the academic world, the number of articles dedicated to this topic began to gain volume in late 1990s, after four other conferences were held. In 2002, the year of the V Brazilian Congress of Epidemiology, the WHO's annual report was entitled "Reducing risks, promoting health life" 14 .
The congress aimed to go beyond the approach chosen by the WHO. It was not just about reducing risks in order to promote a healthy life, but also understanding macrostructural determining factors of health conditions and acting on them.
The sixth congress addressed the urban matter and repercussions on health in the life in large cities 7 . The quick urbanization process experienced by poor and middle-income countries has brought a set of new public health problems, bearing new theoretical, methodological and practical challenges for epidemiology. Problems such as urban violence, drug trafficking, consumerism, mental disorders, rapid population aging and loneliness in large urban centers occupy a relevant place in the early 21st century.
The seventh congress, held in association with the International Congress of Epidemiology, drew more attention to the practical commitments of this branch of medicine, placing it as a tool in the field of collective health to achieve "health for all", the theme formulated by the WHO at the International Conference on Primary Health Care, in Alma-Ata 15 . The theme reaffirmed the belonging of epidemiology to the field of collective health and the commitment of epidemiologists to the production of new knowledge and, especially, to the translation of this knowledge into tools able to change the health situation of the world population 8 .
The anniversary of the Alma-Ata Declaration certainly influenced the choice of theme for WHO's annual report: "Primary Health Care (now more than ever)" 16 . Again, the global themes and those taken by epidemiologists to guide the activities of their meetings were in sync.
In the eighth congress, the chosen theme continued the line of thought of the seventh, creating a place for epidemiological knowledge to formulate, implement and evaluate public health policies 9 .
The ninth congress, in 2014, highlighted the importance of transforming scientific knowledge into action, articulating the academic character of the discipline and its practical applications 10 . Once again, the theme was in line with that of the WHO annual report: "Research for Universal Health Coverage" 17 .
The tenth congress linked epidemiology to the defense of SUS through its activities of training of professors and professionals, technical-scientific research and direct actions in health policy and services. The necessity to reaffirm the principles and commitments of the discipline was well noted in the scenario of uncertainties and setbacks represented by the interruption of efforts to strengthen social policies driven by the objective of reducing poverty and social inequalities, resulting from the removal of president Dilma Rousseff through a parliamentary coup in the previous year.
The following congress, held in 2021, addressed the links between democracy and health and the role of epidemiology in the struggle to preserve such values. Once again, the event was intended to bring the broader political situation into question. The far-right government installed in the country, with deleterious effects on all aspects of national life, has had extremely negative impacts on population health not only by the negligence in the conduct of national health policies in the face of the enormous challenge posed by the covid-19 pandemic, but also by the systematic dismantling of all social protection policies. In the face of all troubles, however, the greater evil is the constant challenge to the rule of law and the maintenance of democracy in the Brazilian society.
The themes of the Brazilian congresses of epidemiology are characterized by broad questions, generally with macrostructural scope, that articulate the scientific and pragmatic nature of the discipline and its belonging to the field of public health. In none of the congresses did the theme emphasize epidemiology only as a scientific method applicable to certain sets of biomedical phenomena. Until now, Brazilian epidemiologists have sought to bring about matters that are relevant for the health-disease process, promoting theoretical, conceptual, methodological and technical development of the discipline without neglecting the transformation of this knowledge into concrete practices of intervention through policies, programs and health services, with a view to improving population health.

THE CORE AGENDA OF CONGRESSES: CONFERENCES AND ROUND TABLES
Conferences are one-off events in specific presentation times intended to all participants. The number of conferences varied from three to seven in each congress, with the exception of the VII Brazilian Congress of Epidemiology, in which conferences were replaced by 22 lectures in order to accommodate themes and guests for the international congress.
Just over half of the invitees in the 61 conferences were researchers working in Brazil, followed by eight speakers from the United States and nine from the United Kingdom. The other 11 speakers worked in countries such as South Africa, Saudi Arabia, Canada, Colombia, Ecuador, Spain, France and Switzerland 2-10 .
Invited lecturers, from 35 national or foreign institutions, worked as professors/ researchers in higher education institutions, research institutes, international organizations or health bodies 2-10 .
Without detracting from the important contribution of lecturers, there were some memorable moments such as the lecture by Mervyn Susser at the third congress, by Richard Doll at the fourth, by John Lynch at the fifth, by George Davey-Smith and Alfredo Morabia in the seventh, by Michael Marmot in the eighth, and by Arthur Reingold in the tenth.
In total, there were 30 roundtables sessions in the first five congresses, being two presented simultaneously on each day. On the sixth and eighth editions, three sessions were held simultaneously, and on the seventh, eight sessions. This number has yet grown in the last two congresses: 10 daily sessions in the ninth and 15 daily sessions in the tenth [2][3][4][5][6][7][8][9][10] .
In the roundtables, participants operating in Brazil were predominant (74%), followed by guests operating in the United States (9%), the United Kingdom (5%), Switzerland (1%) and Spain (1%). The other participants came from 17 countries distributed: 21 from Latin American countries, seven from other European countries, three from African countries and six from Oceania. REV BRAS EPIDEMIOL 2022; 25: E220008

COMPLEMENTARY AGENDA: LECTURES, PANELS AND DEBATES
The lectures, panels and debates were designed, in part, by the epidemiology commissions, with exhibitors invited by the organization. A significant portion was selected from the works submitted by the community.
There were 502 exhibitions, 300 of which (65.1%) were made by professors, researchers or professionals working in Brazil, and 161 (34.9%) working abroad.
These sessions were dedicated to discussing specific diseases, groups of diseases or health problems (53%), complementing the core agenda. Methodological themes were addressed in 14% of them and epidemiological practices in health services in 10%. Theoretical themes and subjects placed between epidemiology and other scientific disciplines corresponded to 8 and 7% of sessions, respectively. Finally, health information systems or science and technology topics were the focus in 3 and 4% of sessions, respectively.

AGENDA BY SPECIFIC THEMES: WORKS SUBMITTED BY THE COMMUNITY
The coordinated communication sessions are formed by the works selected for oral presentation, grouped by themes or methodology and analysis techniques used.
In the first two congresses, around 40 coordinated communications were presented. In the third, fourth and fifth congresses, this number increased to 90 or 95. A further increase was observed in the following three congresses, with about 110 coordinated communications. In the last two, 37 and 55 sessions were held, respectively. In addition to the increase in number of sessions, papers presented increased from 3 to 4 in each session. Thus, from 145 works in 1990, there were 514 in 2008 and 238 in the last one. Table 1 shows the main themes and the proportion of each in the congress editions. Epidemiology of communicable diseases was the most common topic, except for the second and ninth congresses, remaining among the five most common in all editions, as well as epidemiology in health services. The epidemiology of chronic diseases was mentioned in the fourth congress and remained among the five most frequent topics until the ninth.
Analysis methods and techniques were among the most frequent topics from the first to the eighth congress. The issue of social determinants and inequalities was highlighted in the first, third and eighth congresses. Health and work was among the most frequent topics in the first four congresses, being emphasized again in the tenth.
The biggest change occurred in the tenth congress, which focused on epidemiology of infectious diseases, child and adolescent health, nutritional epidemiology, reproductive health, oral health, environmental health, and health and work.
Eight of the topics showed a downward trend in the period: epidemiology of communicable diseases, health and work, theory and concepts, mortality studies, population surveys, teaching, methods and techniques, and epidemiology in health services.

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Nine topics, on the other hand, showed a marked upward trend in the 20-year time frame: epidemiology of chronic diseases, nutrition and health, oral health, aging, reproductive health, indigenous health, gender studies, pharmacoepidemiology, and science and technology.   Four themes showed fluctuations in the period, with neither a downward or upward trend: violence and accidents, environmental health, health status and risk exposures, and mental health. Mental health studies drew increasingly more attention in the last two congresses.
Two topics-health information systems and evaluation of policies, programs and services-had a similar behavior, with an increase in number of sessions until the sixth congress and a decrease in the others. Child and adolescent grew until the fourth congress, declined slightly afterwards, and grew again in the last two editions.
These variations between themes reflect the epidemiological profile and the expansion of researchers' interests beyond more traditional subjects. Some were introduced later, such as indigenous health and science and technology. The inception of determining factors and social inequalities in health coincided with the production on Latin American social medicine and the choice of the theme for the first congresses. Then, it retracted and gain importance again in the first decade of the 21st century, under the impact of the WHO Commission on Social Determinants and the strengthening of the theme in Europe and the United States.
Abstracts submitted by the community could also be selected for poster-like presentation. Graph 1 shows the growth in number of posters in the first 18 years and reduction in the last three congresses. The numbers of the seventh congress can be seen as a detour thanks to international participation. The eighth edition had the same number as the sixth and the tenth, suggesting a levelling. Table 2 shows the distribution of themes in eight of the ten congresses, corresponding to two thirds of the total. It was not possible to obtain the thematic classification of posters in the fourth and seventh congresses. Of 13,000 posters, around 24% focused on communicable or chronic diseases, and 30% on epidemiology in health services or the evaluation of programs and services.
The themes presented in posters grew in line with the increase in submitted abstracts. There were, however, some themes that behaved differently. Posters focusing on theory and concepts have remained constant for 27 years. Some themes showed a decreasing trend in the period: health diagnoses, mortality studies, morbidity studies, population surveys and surveys. This reduction may reflect the maturing of the field, as traditional descriptive studies have become less frequent among selected works. On the other hand, some topics have grown over time-health and work, environmental health, oral health, nutrition and pharmacoepidemiology-with the expansion of training in epidemiology among health professionals such as dentists, pharmacists and nutritionists.
The significant increase both in number of participants and of abstracts submitted can be attributed to three movements that converge towards greater recognition and appreciation of Brazilian epidemiology: first, the growth of graduate programs, increasing the number of researchers trained whether academically or working in health services; the creation of undergraduate courses in public health, renewing practitioners in this area and expanding the audience for congresses; and finally, the recognition of quality added and maintained in the organization of congresses, ensuring a diversity of themes and theoretical approaches, focusing on global, national and local problems and bringing together professors, researchers, students and health professionals.

CONCLUSION
The Brazilian Congresses of Epidemiology emerged in the context of three main events: