**2. Social networking**

68 Current Topics in Tropical Medicine

various manifestations according to the affected organ. Prognosis and time to develop

Disease can ranges a spectrum that can begin from a latent infection or reactivation slowly evolving into a focal or whole spread and involvement of multiple organs, which makes it difficult to diagnosis by clinicians and health care workers, who many times could not identify it timely (Castañeda-Hernández et al. 2012a). One of the most severe forms of extrapulmonary TB is the meningitis (TB meningitis), which occurs as a result of hematogenous spread of bacilli into the subarachnoid space. This is known as a complication of primary TB and may occur years later as an endogenous reactivation of a latent tuberculosis or as a result of exogenous reinfection (Glaziou et al. 2009, Hoek et al.

Tuberculosis is a complex disease in terms of the multiple factors that are involved in its occurrence and persistence in the human societies. In first place there are factors associated with the bacillus (viability, transmissibility and virulence), with the host as a biological individual (immune status, genetic susceptibility, duration and intensity of exposure) as

At a second, clinical level, the occurrence of pulmonary tuberculosis undiagnosed or untreated, overcrowding, malnutrition, immunosuppresion from any cause (HIV infection, use of immunosuppressive drugs, diabetes, cancer, chronic renal failure, silicosis, alcoholism

At community public health interventional level, protective factors include the BCG (Bacille Calmette Guerin) vaccine, applied in developing countries, which provides protection before exposure and prevent severe infection forms, especially in infants and young children, reaching up to 80% of protection against the development of forms of the disease such as meningeal and miliary TB (Garcia-Rodriguez et al. 2011, Garg 2010, Black et al. 2003,

Additional to those clinical implications, changes in the susceptibility of the etiological agent to the therapy used drugs has imposed more challenges in the management of TB. The magnitude of problem with TB now lies in the fact that one third of the world population is infected by *Mycobacterium tuberculosis*. Even in the 21st century, TB kills more people than any other infective agent. This, then, occurs in part as a result of a progressive decrease in its susceptibility to anti-TB drugs or resistance emergence. Cases of resistant TB, defined by the recommendations of the World Health Organization (WHO) as primary, initial, acquired multidrug resistant (MDR-TB) or extensively drug resistant TB (XDR-TB) are emerging in

The development of resistance TB may result from the administration of mono-therapy or inadequate combinations of anti-TB drugs. A possible role of health care workers in the development of multi drug-resistant TB is very important. Actually, multi drug-resistant TB is a direct consequence of mistakes in prescribing chemotherapy, provision of antituberculosis drugs, surveillance of the patient and decision-making regarding further treatment as well as in a wrong way of administration of anti-TB drugs. The problem of XDR-TB in the world has become very alarming. Only adequate treatment according to directly supervised short regiment for correctly categorized cases of TB can stop the escalation of MDR-TB or XDR-TB, which is actually, in large magnitude, a global threat in the 21st century (Torres et al. 2011, Solari et al. 2011, Chadha et al. 2011, Arenas-Suarez et al.

Another important issue in TB is the social component, related to a complex background and multiple interacting factors that internally and externally affect individuals affected by

well, at the bacillus-host interaction (place of affection, severity of illness).

disease also can vary according to the affected organ.

2011, Galimi 2011, Garcia-Rodriguez et al. 2011).

and drug addiction), are also important factors.

different areas of the World.

2010, Ferro et al. 2011, Martins 2011).

Francis et al. 2002, Arbelaez et al. 2000, Ginsberg 2000).

Human societies can be regarded as large numbers of locally interacting agents, connected by a broad range of social and economic relationships. These relational ties are highly diverse in nature and can represent, e.g., the feeling a person has for another (friendship, enmity, love), communication, exchange of goods (trade), or behavioral interactions (cooperation or punishment). Each type of relation spans a social network of its own. A systemic understanding of a whole society can only be achieved by understanding these individual networks and how they influence and co-construct each other. The shape of one network influences the topologies of the others, as networks of one type may act as a constraint, an inhibitor, or a catalyst on networks of another type of relation.

For instance, the network of communications poses constraints on the network of friendships, trading networks are usually constrained to positively connoted interactions such as trust, and networks representing hostile actions may serve as a catalyst for the network of punishments. A society is therefore characterized by the superposition of its constitutive socioeconomic networks, all defined on the same set of nodes. This superposition is usually called multiplex, multirelational, multimodal, or multivariate network (Szell et al. 2010). Summarizing, a social network is a social structure made up of individuals (or organizations) called "nodes", which are tied (connected) by one or more specific types of interdependency, such as friendship, kinship, common interest, financial exchange, dislike, sexual relationships, or relationships of beliefs, knowledge or prestige (Palinkas et al. 2011, Szell et al. 2010).

Understanding and modeling network structures have been a focus of attention in a number of diverse fields, including physics, biology, computer science, statistics, and social sciences. Applications of network analysis include friendship and social networks, marketing and recommender systems, the World Wide Web, disease models, and food webs, among others (Zhao et al. 2011). Social network analysis (SNA) is the study of structure. It involves relational datasets. That is, structure is derived from the regularities in the patterning of relationships among social entities, which might be people, groups, or organizations. Social network analysis is quantitative, but qualitative interpretation also its necessary. It has a long history in sociology and mathematics and it is creeping into health research as its analytical methods become more accessible with user friendly software (Hawe et al. 2004). SNA views social relationships in terms of network theory consisting of nodes and ties (also called edges, links, or connections).

Social Networking in Tuberculosis: Experience in Colombia 71

populations to prevent, control, and potentially eliminate poverty diseases, such as TB. Improving the health of these forgotten populations will place them in an environment more conducive to development and will likely contribute significantly to the achievement of the Millennium Development Goals in this area of the globe (Franco-Paredes et al. 2007). For example in Colombia, TB is still a significant public health problem. Figure 1 shows the

Multiple studies have evidenced links between social, economic and biologic determinants to TB, recently using modeling approaches (Guzzetta et al. 2011, Drewe et al. 2011, Wilson et al. 2011, Bohm et al. 2008, Cook et al. 2007, Cohen et al. 2007, Ayala & Kroeger 2002). Tuberculosis is the archetypal disease of poverty, and social inequalities undermine TB control (Rocha et al. 2011, Lonnroth et al. 2010). Poverty predisposes individuals to TB through multiple mechanisms, such as malnutrition (Rocha et al. 2011, Lonnroth et al. 2010, Cegielski & McMurray 2004), and TB worsens poverty as it increases expenses and reduces income (Rocha et al. 2011, Pantoja et al. 2009, Pantoja et al. 2009, Kemp et al. 2007, Lonnroth

Furthermore, poor TB-affected households often experience stigmatization; adding barriers to TB control (Rocha et al. 2011, Atre et al. 2011, Dhingra & Khan 2010, Pungrassami et al. 2010, Jittimanee et al. 2009). Poor people at the greatest risk of TB are therefore, in many settings, also the least able to access TB care (Rocha et al. 2011). Then, socio-economic interventions adapted to the needs of TB-affected households living in impoverished peri-

The socio-economic interventions can successfully engaged most TB-affected households in an active civil society that was associated with marked improvements in uptake of TB prevention, diagnosis and treatment, resulting in strengthened TB control (Rocha et al. 2011). The development of social networks and SNA, however, has been mostly approached only for investigation of TB outbreaks (Fitzpatrick et al. 2001, Sterling et al. 2000) and fewly in the support with the strategies of the WHO for TB Control (World

The WHO Stop TB Strategy, recently revised (World Health Organization 2011), stated a vision for a TB-free world, with a goal of to dramatically reduce the global burden of TB by 2015 in line with the Stop TB Partnership targets and the Millennium Development Goals (MDGs) which pursue the significant reduction in endemic diseases, such as TB and others, even regional diseases (e.g. Chagas disease), that can represent an impediment in achieving the MDGs (Franco-Paredes et al. 2007). In their components, it is included Empower people with TB, and communities through partnership through: a. Pursue advocacy, communication and social mobilization; b. Foster community participation in TB care, prevention and health promotion; and c. Promote use of the Patients' Charter for

In Brazil, one of the countries in Latin America where TB is a major public health problem, recent experiences suggest the importance of networking and civil society participation for TB control (Santos Filho & Santos Gomes 2007). In that country, until 2003, the presence of civil society in the fight against TB took place by means of several initiatives from researchers, healthcare professionals and medicine students, especially from the Sociedade Brasileira de Pneumologia e Tisiologia (Brazilian Thoracic and Tuberculosis Society), Rede

WHO profile for TB in Colombia for 2010.

**4. Social networks in tuberculosis** 

et al. 2007, Rajeswari et al. 1999).

Health Organization 2011).

urban shantytowns and other demographical settings.

Tuberculosis Care (World Health Organization 2011).

Nodes are the individual actors within the networks, and ties are the relationships between the actors. The resulting graph-based structures are often very complex. There can be many kinds of ties between the nodes. Research in a number of academic fields has shown that social networks operate on many levels, from families up to the level of nations, and play a critical role in determining the way problems are solved, organizations are run, and the degree to which individuals succeed in achieving their goals (McGrath 1988, Palinkas et al. 2011, Szell et al. 2010, Zhao et al. 2011, Hawe et al. 2004).

In its simplest form, a social network is a map of specified ties, such as friendship, between the nodes being studied. The nodes to which an individual is thus connected are the social contacts of that individual. The network can also be used to measure social capital – the value that an individual gets from the social network. These concepts are often displayed in a social network diagram, where nodes are the points and ties are the lines.

Its use in health (Bhardwaj et al. 2010, Lawrence & Fudge 2009), and more on in infectious diseases (Klovdahl et al. 2002), has been recently highlighted, including sexually transmitted infections (Perisse & Costa Nery 2007), as well in TB (Boffa et al. 2011, Waisbord 2007, Curto et al. 2010, Burlandy & Labra 2007, Santos Filho & Santos Gomes 2007, Freudenberg 1995, Murray et al. 2011).

#### **3. Tuberculosis as a social issue**

Multiple studies have evidenced links between social, economic and biologic determinants to TB, recently using modeling approaches that have been used to understand their contribution to the epidemic dynamics of TB (Murray et al. 2011). Specifically, different authors have evidence for associations between smoking, indoor air pollution, diabetes mellitus, alcohol, nutritional status, crowding, migration, aging and economic trends, and the occurrence of TB infection and/or disease. We outline some methodological problems inherent to the study of these associations; these include study design issues, reverse causality and misclassification of both exposure and outcomes. From a social perspective, multiple analyses can be useful and approaches to modeling the impact of determinants and the effect of interventions as the follow will help: the population attributable fraction model, which estimates the proportion of the TB burden that would be averted if exposure to a risk factor were eliminated from the population, and deterministic epidemic models that capture transmission dynamics and the indirect effects of interventions. Can be stated that by defining research priorities in both the study of specific determinants and the development of appropriate models to assess the impact of addressing these determinants (Murray et al. 2011, Santin & Navas 2011, Juniarti & Evans 2011).

Although not considered neglected, TB disproportionally affect resource-constrained areas of the World, including Latin America. In tropical and subtropical areas of this region, the vicious cycle of poverty, disease and underdevelopment is widespread, including TB as one of the significant pathologies involved. The burden of disease associated to TB in this region is highly significant in some countries (eg. Bolivia, Haiti, Brazil, among others). TB has burdened Latin America throughout centuries and has directly influenced their ability to develop and become competitive societies in the current climate of globalization.

Therefore, the need for a new paradigm that integrates various public health policies, programs, and a strategy with the collaboration of all responsible sectors is long overdue. In this regard, innovative approaches are required to ensure the availability of low-cost, simple, sustainable, and locally acceptable strategies to improve the health of neglected populations to prevent, control, and potentially eliminate poverty diseases, such as TB. Improving the health of these forgotten populations will place them in an environment more conducive to development and will likely contribute significantly to the achievement of the Millennium Development Goals in this area of the globe (Franco-Paredes et al. 2007). For example in Colombia, TB is still a significant public health problem. Figure 1 shows the WHO profile for TB in Colombia for 2010.
