Early in the previous millennium the Islamic south of Spain, Al-Andalus, was the centre of scientific and medical knowledge in Europe. In addition, the first universities in Christian Spain (including the present day University of Salamanca), were founded in the 13th C, well before the 15th C completion of the Spanish Reconquest. The beginnings of the study of public health in Spain were seen during the Renaissance under the sponsorship of Philip II 4, in the same era as enormous wealth was flowing into Spain from the Americas. Despite all this, as the 19th C drew to a close, Spain was, in Western European terms, an underdeveloped country characterised by poverty and life expectancy in 1901 of a mere 40 years 5. Also, despite its colonial history, and unlike Belgium, Germany and the UK, in Spain there had been little development in the area of tropical medicine 6. However, it was this epoch at the turn of the 20th C that saw the laying down of the foundations of an effective public health system. The Instituto Nacional de Higiene "Alfonso XIII" (INH) had its origin in this period 6, and a National School of Health (Escuela Nacional de Sanidad, ENS) was founded in 1924 7. Until the INH and ENS merged in 1934 as the Instituto Nacional de Sanidad (INS), the place of the teaching of 'hygiene' in the Universities had been precarious, being far below the levels seen in other European countries 8. Unfortunately, the 1936–39 Spanish civil war interrupted this development of the study of epidemiology and public health for some years, and it was not before 1986 that this work began to be revitalised with the reinvention of the INS through the founding of the Instituto de Salud Carlos III 6. Since then, in recent years (1995–2005) authors based in Spain have accounted for some 2,000 of the papers relating to infectious disease identified in the PubMed database 9. However a study in 1999 had also identified a further 3,000 papers relating to public health and health policy in Spanish journals indexed in the Spanish Medical Index (Índice Médico Español, IME) 10, and a similar study one year earlier found that 2–3% of the papers indexed in IME related to epidemiology or public health, with only 0.2% published in English 11.

Pre-dating independence from Spain by nearly three centuries, the early dates of foundation of the first universities in what are now the Spanish-speaking nations of Latin America and the Caribbean, may not be well recognised in the Anglophone world. Claims to be the oldest university in Latin America are controversial, but in 1538 the Universidad Autónoma de Santo Domingo 12 was founded in what is now the Dominican Republic, although not officially recognised until two decades later. In the meantime were founded in 1551 the Universidad Nacional Mayor de San Marcos (UNMSM), Perú 13 and also the Real y Pontificia Universidad de México (RPUM) which, after an interrupted history in the 19th C was to become the Universidad Nacional Autónoma de México (UNAM) 14. These were followed by the foundation of the Universidad Nacional de Córdoba (Argentina) 15 and the Universidad de Chile 16 in 1622. The oldest medical school in the USA is the University of Pennsylvania School of Medicine, founded in 1765, but the faculties of medicine of UNMSM and UNAM both lay claim to earlier beginnings. Two chairs in medicine were established at UNMSM in 1571, with a functioning faculty by the 17th C, although not formally constituted until 1856. At RPUM the first course on medicine began in 1579 17 (and, despite the 19th C closures of RPUM, the medical school continued in being until absorbed into the refounded university which became UNAM). In 1676 the Universidad San Carlos de Guatemala also officially opened its doors, incorporating the study of medicine along with theology and law 18.

This long history perhaps reflects the fact that in contrast to the colonisation of Africa and the English Caribbean, primarily focused on trade and the exploitation of resources, in Latin America the plundering of wealth was accompanied by a parallel focus on establishing and peopling a (Catholic) civilisation and conversion of the many indigenous populations 19. In many aspects this latter focus was a reflection – perhaps even, in a sense, a continuation – of the methods of the Reconquista, i.e. the reconquest of the Iberian peninsula by the Christians after eight centuries of Islamic rule by the Moors, a process that proved a training ground for the conquests in the Americas and which was completed with the fall of Granada in 1492, the very year that Christopher Columbus made his first encounter with the 'New World' 19.

The medical science and epidemiology that grew from this environment in Latin America was faced with the challenge of both autochthonous and imported infections. A surprisingly early record of a correctly made, but overlooked association between biting insects and disease dates back to 1764 and comes from Peru, where the Spanish-born physician Cosme Bueno described both bartonellosis (Carrion's disease) and cutaneous leishmaniasis and attributed it to the bite of small flies called 'uta' (a term still used in the Peruvian highlands to refer to the disease and the sandfly vectors) 20. The accurate deduction of this relationship preceded the formulation of the 'germ theory' by Pasteur in 1877. From the late 19th C important figures emerge in Latin America, perhaps one of the most prominent being Carlos Finlay in Cuba, who proposed and tried to demonstrate in 1880, while conducting important work on cholera, that mosquitoes transmit yellow fever. In the early 20th C Carlos Chagas in Brazil discovered the presence of Trypanosoma cruzi in human blood (the causative agent of what came to be known as Chagas disease) and in 1909 unravelled its transmission by triatomines 2122. Rodolfo Robles in Guatemala was the first to hypothesise in 1915 the role of blackflies as vectors of human onchocerciasis (called Enfermedad de Robles or Robles disease in Guatemala) and link the infection to blindness, predating by nearly 10 years the work of Blacklock incriminating Simulium damnosum as the vector of river blindness in Africa 23.

Nevertheless, as late as 1960, as Director of the Pan American Health Organization (PAHO), Dr Abraham Horwitz 24 was still able to concur with the observation that in Latin America epidemiology was the "Cinderella of the medical sciences" 25. Since then epidemiology in Latin America has made substantial advances although in many countries an "epidemiological polarisation" prevails, where communicable diseases persist but chronic diseases occupy a critically important and increasing place 2627.

Spain, since arrival of democracy following the end of the Franco dictatorship in the 1970s, has rapidly achieved a Western European standard of living with research in public health and epidemiology becoming associated with the European tradition 928. In contrast, globally, Brazil and Hispanic Latin America exhibit the highest national levels of health inequality 29303132 reflected in a tradition of research and literature on health inequalities 33 and which is associated with the social medicine movement, a movement having a historical role in attempting to resist both colonialism and post-independence military dictatorships 3435. Regrettably there appears to be little knowledge in the English-speaking world of the fruits of this research in the field of social medicine 36. With regard to this, although Almeida-Filho et al. 33 identified a relative neglect of gender, race, and ethnicity issues in health inequity research in the Latin American literature, they also highlighted, at the methodological level, a remarkable diversity of epidemiological research designs and a refined ecological tradition, with consideration of aggregate and ethnographic methods not evident in other research traditions.

In public health and epidemiology, Falagas and colleagues 37 reported that between 1995 and 2003, 686 articles (1.4% of the global total) originating from Latin America and the Caribbean were published in Thomson-ISI indexed journals, a number of the same order as for Eastern Europe but far below that of Western Europe or the United States of America. The mean impact factor of 1.7 however was comparable, exceeding that of W Europe (1.5) and approaching that of the USA (2.0). In parasitology, Falagas et al. 38 reported that in the PubMed database over the same period, 17%, of journal articles originated from Latin America and the Caribbean (LAC), comparable with the production from the USA (20%), and that since 2001 increasing production in the former had resulted in LAC displacing the USA from second place behind W Europe (with 35% of the articles). Falagas et al. 39 subsequently reported that LAC assumed third place behind W Europe and Africa in production of articles in the field of tropical medicine with 21% of articles published, ahead of the USA with 11%. However as with parasitology, the mean impact factors were lower -in tropical medicine 0.90 for LAC compared with 1.65 for USA and 1.21 for W Europe. In the fields of microbiology 40 and infectious diseases 41 1995–2002 productivity in terms of PubMed indexed journals was much lower with just over 2% of articles in both fields although the mean impact factor, 2.89, just exceeded that of W Europe with 2.82, with 3.42 for articles originating in the USA. The latter study also noted that, together with Africa and E Europe, the rate of increase in production in Latin America exceeded that of W Europe and the USA, and that if existing rates of increase were maintained their production would exceed that of the USA within 20 years or so.

A recent bibliometric study 33 using both PubMed and the Literatura Latinoamericana en Ciencias de la Salud (LILACS) 42 database noted that observed differences in research production between SSLAC countries could be misleading, e.g. the searching of indexed journals favours Mexico as, for reasons of geography, Mexican researchers engage in relatively more scientific exchange with North American universities. In fact, Hermes Lima et al. 43 point out that in the field of biomedicine, the predominant pattern of collaborations is South-North, favouring North America, rather than strengthening South-South links between countries within Latin America. However it is clear that among dominant factors influencing levels of research publication in public health are, of course, national expenditure on health research and, by implication, the level of economic wealth, an illustration of which is provided in Figure 1.

The LILACS database is a key resource for the identification of publications originating in Latin America and the Caribbean, whether written in English, Spanish or Portuguese. It includes theses, books and proceedings as well as journal papers. Clark and Castro 1 observed that "LILACS is an under-explored and unique source of articles whose use can improve the quality of systematic reviews" (for a succinct description of LILACS and how to access it see the article by Barreto and Barata in this thematic series 44). Of 64 systematic reviews published in five high impact factor medical journals, only 2 had used LILACS whereas, of the remaining 62 reviews, 23 restricted their search to English language articles with only 18 clearly specifying no language restriction; for 44 of the reviews a subsequent LILACS search revealed articles which had been omitted but which were suitable for inclusion 1, evidence of the "lost science" highlighted by Gibbs 3. Between 1980 and 2002, of the 98,000 publications relating to public health indexed in LILACS, Brazil and a group of seven countries of SSLAC (in descending order of production: Chile, Mexico, Argentina, Venezuela, Colombia, Peru and Cuba) each accounted for 42–43% 45. In these 7 countries of SSLAC the majority (57–89%) of publications were in the form of journal articles with the exception of Peru where 69% was in the form of monographs 45. Between 94% and > 99% of publications from the SSLAC group, depending on country, were written in Spanish with the majority of the rest in English; Venezuela, with 4%, lead the production of publications in English 45. Many of the publications in Spanish, however, also had abstracts in English. These publications were to be found in some 400 journals based in Brazil and over 500 journals in SSLAC, although 47% of the articles were located in just 91 journals, of which those publishing the largest number of articles in Spanish were Revista Médica de Chile (Chile), Archivos Latinoamericanos de Nutrición (Venezuela), Salud Pública de México (México), Gaceta Médica de México (México), Revista Chilena de Pediatría (Chile) and Revista Médica del IMSS (México) (see Macias Chapula 45 for the full list of 91 journals and their specialisms).

The LILACS database is nested within the Virtual Health Library (VHL) 46 of the Pan-American Health Organization's (PAHO) Latin American and Caribbean Center on Health Sciences Information (BIREME) (Figure 2). The VHL (or BVS, Biblioteca Virtual en Salud 47/Biblioteca Virtual em Saúde 48) also encompasses a number of other relevant databases, ADOLEC (Literature on Adolescence Health) and HISA (Latin American and Caribbean History of Public Health) being just two examples. The VHL portal also provides for searches of MEDLINE and the Cochrane database.

Whilst LILACS provides a comprehensive database of Latin American literature, both peer-reviewed and "grey", on public health and epidemiology, the Scientific Electronic Library Online (SciELO) 49, a collaboration between a number or organisations, including BIREME, offers a portal providing free access to many journals from Latin America and the Iberian Peninsula (Spain and Portugal) (see Barreto and Barata 44 in this thematic series for a succinct introduction to this also).

VHL/LILACS is not the only database which specialises in journals emanating from Latin America and/or Spain; see Figure 2. For example, LATINDEX 50 offers a directory of a large number of Spanish and SSLAC journals in all the sciences, a proportion of which appear in a catalogue selected according to international quality standards. There are several others resulting from national or multinational initiatives (e.g. IMBIOMED 51; LASM (Latin American Social Medicine) 52) and focusing on medicine and health or with a wider remit (e.g. E-REVISTAS 53; CLASE 54, PERIÓDICA 54; REDALYC 55). Both PERIÓDICA and CLASE were created by UNAM's Centro de Información Científica y Humanística (CICH) in the 1970s and constitute relevant regional sources of information. Regional full text access to articles appearing in the better quality health sciences journals published in Mexico is also available using the CD-ROM based ARTEMISA (Artículos Editados en México de Información en Salud) database or online since 2006 at Medigraphic Literatura Biomédica 56. Table 3 provides a list of such databases together with the addresses of the relevant websites.

VHL however provides the best starting point for investigating the rich range of Spanish language literature in the field as well as providing a number of other tools such as its "Evidence Portal" and "Health Information Locator". In addition there are many links to national VHL sites which, whilst there is a substantial degree of overlap with the main VHL web site, also provide additional resources – national SciELO sites for example may include journals not featured on the main SciELO site. In fact the wealth of resources is such that it would not be surprising if first-time users experienced a certain degree of bewilderment in navigating their way through this network and, in truth a full description of what is available would stretch to many pages (such a description would also quickly become obsolete as development and consolidation continue to proceed hand in hand).

Focusing now on the Spanish and Latin American Spanish-language journals themselves, Tables 1 and 2 provide a summary of many of those which we feel may be of use to those working in the field of public health or epidemiology (we should emphasise that this list is by no means exhaustive). Amongst other things Tables 1 and 2 indicate the general area of interest for each journal, frequency of publication and addresses of the web pages, many within the SciELO database, where further details and/or online copies of journal articles may be available (a number of these journals are indexed in widely used databases such as MEDLINE, EMBASE or Ulrich's and links for some are also provided from the websites of the International Committee of Medical Journal Editors 57 or World Association of Medical Editors 58). While the number of journals specifically focused on public health and epidemiology is not great, many others may potentially be of interest to workers in the field. A significant number of these journals provide an abstract in English and some also in Portuguese (see Tables 1 and 2). Of those focussed on public health, it is worth mentioning a few that have greater visibility (see Table 4). The Revista de Salud Pública, published by the Universidad Nacional de Colombia since 1999, treats a wide range of subjects relevant to national as well as international public health. It is indexed in MEDLINE, SciELO, LILACS, LATINDEX as well as in two Colombian databases: the National Index of Scientific and Technological Colombian Journals and LILOCS (Literatura Colombiana de la Salud). In 2006 it had an impact factor on a two year basis of 0.18 and a citation half life of 3.25 years in the SciELO database (Table 4). Two Cuban journals, Revista Cubana de Higiene y Epidemiología and Revista Cubana de Salud Pública offer slightly different approaches to public health. The first is more empirical and reports findings of studies in environmental hygiene, food-related infections and occupational medicine while the second mainly publishes essay-type articles on historical, controversial or novel issues relevant to public health involving professionals from other fields. The SciELO 2006 impact factor for these journals are 0.1591 and 0.0395 respectively while the half lives are 5.17 and 2.25 years respectively, suggesting that the Revista Cubana de Higiene y Epidemiología has more visibility. Salud Pública de México, the official journal of the National Institute of Public Health addresses a broad scope of subjects, publishing original articles resulting from research in parasitic diseases' epidemiology to health economics. Its SciELO impact factor for 2006 was 0.2747 and its half life was 4.86 years which reveals its importance in the field. All the articles are available in Spanish and English. Of the Spanish journals, Gaceta Sanitaria, Revista Española de Salud Pública, and Anales del Sistema Sanitario de Navarra provide a robust assortment of information. Gaceta Sanitaria is published by the Spanish Society of Public Health and Sanitary Administration (SESPAS) and it has recently been indexed in the Thomson database with an ISI impact factor of 0.825 in 2007 (note the contrast in scale between ISI and SciELO impact factors, reflecting differences in their corresponding bibliometric algorithms; aside from the issue of scale, Figure 3 illustrates disparities between rankings for a selection of journals). Revista Española de Salud Pública had an impact factor of 0.0417 and a citation half life of 4.14 years in SciELO in 2006. Although Anales del Sistema Sanitario de Navarra is indexed in SciELO, bibliometric information is not provided, however it does have a SCIMago Journal Rank (SJR) of 0.044 (a measure of impact in the SCImago – Science Visualisation – database), while Gaceta Sanitaria has an SJR of 0.068 and Revista Española de Salud Pública has an SJR of 0.052 in this database. An important source of information of public health in Latin America is the Revista Panamericana de Salud Pública/Pan American Journal of Public Health (previously the separate journals: Boletín de la Oficina Sanitaria Panamericana and Bulletin of the Pan American Health Organization) publishing in Spanish, English, and Portuguese by PAHO since 1997. This publishes original research and analysis, with a focus on health promotion and the evolution of the programmes with which PAHO is involved. Its 2006 SciELO's impact factor was 0.2030 with a citation half life of 4.52 years.