ObjectiveTo map and investigate the relationships established on the web between leading health-research institutions around the world.MethodsSample selection was based on the World Health Organization (WHO) Collaborating Centres (CCs). Data on the 768 active CCs in 89 countries were retrieved from the WHO's database. The final sample consisted of 190 institutions devoted to health sciences in 42 countries. Data on each institution's website were retrieved using webometric techniques (interlinking), and an asymmetric matrix was generated for social network analysis.FindingsThe results showed that American and European institutions, such as the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH) and the National Institute of Health and Medical Research (INSERM), are the most highly connected on the web and have a higher capacity to attract hyperlinks. The Karolinska Institute (KI-SE) in Sweden is well placed as an articulation point between several integrants of the network and the component's core but lacks general recognition on the web by hyperlinks. Regarding the north-south divide, Mexico and Brazil appear to be key southern players on the web. The results showed that the hyperlinks exchanged between northern and southern countries present an abysmal gap: 99.49% of the hyperlinks provided by the North are directed toward the North itself, in contrast to 0.51% that are directed toward the South. Regarding the South, its institutions are more connected to its northern partners, with 98.46% of its hyperlinks directed toward the North, and mainly toward the United States, compared with 1.54% toward southern neighbors.ConclusionIt is advisable to strengthen integration policies on the web and to increase web networking through hyperlink exchange. In this way, the web could actually reflect international cooperation in health and help to legitimize and enhance the visibility of the many existing south-south collaboration networks.

The method of co-link was proposed in 1996 and since then it has been applied in many Webometric studies. Its definition refers to ''page co-link analysis'', as links are provided by URLs or pages. This paper presents a new methodological approach, a ''site co-link analysis'', to investigate relations in small networks. The Oswaldo Cruz Foundation institutes were used as a case study. The results indicate that the number of co-links provided by sites led to an increase of 133% in the sample analyzed. In a cluster analysis, three clusters were formed mainly for thematic reasons and four institutes remained isolated.

In order to map Brazilian institutions’ web presence in an international network of health research institutions, a study was conducted in 2009, including 190 institutions from 42 countries. The sample was based on WHO (World Health Organization) collaborating centers, and the methodology used webometric analyses and techniques, especially interlinks, and social network analysis. The results showed the presence of five Brazilian institutions, featuring the Oswaldo Cruz Foundation (Fiocruz), showing links to 20 countries and 42 institutions. Through the interface between the health field and the web, the study aims to contribute to future analyses and a plan for strategic repositioning of these institutions in the virtual world, as well as to the elaboration of public policies and recognition of webometrics as an area to be explored and applied to various other fields of knowledge.