Occurrence of tuberculosis cases in Crato, Ceará, from 2002 to 2011: a spatial analisys of specific standards

Mayrla Lima Pinto Talina Carla da Silva Lidiane Cristina Félix Gomes Maria Rita Bertolozzi Lourdes Milagros Mendoza Villavicencio Kleane Maria da Fonseca Araújo Azevedo Tânia Maria Ribeiro Monteiro de Figueiredo About the authors

Abstracts

OBJECTIVE:

to analyze the spatial distribution of tuberculosis in Crato, Ceará, Brazil, from 2002 to 2011, aiming to check for a point pattern.

METHODS:

This is an ecological, temporal trend and hybrid design study, with a quantitative approach. A total of 261 cases of tuberculosis were geo-referenced and 20 (7.1%) were considered as losses due to the lack of address. The profile of patients in 10 years of study was in accordance with the following pattern: men aged between 20 and 59 years, with low schooling, affected by the pulmonary form of tuberculosis and who were cured from the disease.

RESULTS:

The analysis of the spatial distribution of tuberculosis points out that in the period of study, new cases of the disease were not distributed on a regular basis, indicating a clustered spatial pattern, confirmed by the L-function. The map with the density of new cases estimated by the Kernel method showed that the "hot" areas are more concentrated in the vicinity of the central urban area.

CONCLUSION:

The study allowed pointing out areas of higher and lower concentration of tuberculosis, identifying the spatial pattern, but it also recognized that the disease has not reached all of the population groups with the same intensity. Those who were most vulnerable were the ones who lived in regions with higher population densities, precarious living conditions, and with intense flow of people.

Tuberculosis; Spatial analysis; Medical Geography; Uses of epidemiology; Epidemiological surveillance; Public health


INTRODUCTION

Despite being an old disease, tuberculosis (TB) still requires special attention because its control remains to be a challenge for public health in global terms. The control of this condition has been difficult, especially in developing countries, which concentrate about 95% of the TB cases; 22% of these are responsible for 80% of the global load of the disease11. Bowkalowski C, Bertolozzi MR. Vulnerabilidades em pacientes com tuberculose no distrito sanitário de Santa Felicidade, Curitiba, PR. Cogitare Enferm 2010; 15(1): 92-9.

2. World Health Organization (WHO). Global tuberculosis report 2013. Geneva: WHO; 2013.
- 33. Brasil. Ministério da Saúde. Sistema de Informação de Agravos de Notificação (SINAN). Tuberculose: casos confirmados notificados no Sistema de Informação de Agravos de Notificação - SINAN Net, 2012 [Internet]. Disponível em: http://dtr2004.saude.gov.br/sinanweb/tabnet/dh?sinannet/tuberculose/bases/tubercbrnet.def (Acessado em 06 de dezembro de 2013).
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. In this ranking, which includes countries such as China, India, and South Africa, in 2012 Brazil had the 15th position in number of registered cases. In terms of disease incidence, in that same year, Brazil was at the 111th position22. World Health Organization (WHO). Global tuberculosis report 2013. Geneva: WHO; 2013..

Currently, it is estimated that one of three people in the world is infected with Mycobacterium tuberculosis, biological agent that causes TB2; however, generally, a relatively small proportion of these individuals is likely to have the disease. The probability of getting sick is higher among people with compromised immunity, living in worse life conditions. TB is also more common among men, affecting mainly adults at economically productive age22. World Health Organization (WHO). Global tuberculosis report 2013. Geneva: WHO; 2013..

In 2012, approximately 8.6 million people had TB, and 1.3 million died of it. The high number of deaths caused by TB is unacceptable, once most of them can be prevented by early diagnosis and if people underwent the therapy, which is provided for free22. World Health Organization (WHO). Global tuberculosis report 2013. Geneva: WHO; 2013..

In 2012, the Notifiable Diseases Information System (SINAN) registered 71,189 new cases of the disease, corresponding to the incidence of 36.7 per 100 thousand inhabitants. In comparison to the previous year, the numbers went up again; in 2011 70,731 new cases were notified, however, the incidence remained practically stable (36.8 per 100 thousand inhabitants)44. Brasil. Ministério da Saúde. Secretaria de Vigilância Epidemiológica em Saúde. Departamento de Vigilância Epidemiológica. Programa Nacional de Controle da Tuberculose. Brasília: Ministério da Saúde; 2013. Disponível em: portalsaude.saude.gov.br/images/pdf/2014/abril/09/taxa-incidencia-tuberculose-1990-2012-base-DEZ-2013.pdf. (Acessado em10 de maio de 2014).
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In the country, according to information about the Mortality Information System, in 2011 about 4.6 thousand deaths were caused by TB, with a mortality rate of 2.4/100 thousand inhabitants; therefore, TB became the fourth cause of death for infectious and parasitic diseases, after septicemia, acquired immune deficiency syndrome (AIDS), and Chagas' disease; for those living with human immunodeficiency virus (HIV), TB is the main cause of death3.

In Ceará, in 2012, about 3,483 new cases of TB were registered; of which, 36 took place in the city of Crato, which corresponds to the incidence of 29.0 per 100,000 inhabitants; even though it is below the national incidence, it is a matter of concern for health managers and professionals. By analyzing the results of the closure situation of the city in the same year, it is observed that the percentage of cure (47.2%) and abandonment (19.4%) of the cases is not in accordance with the goals recommended by the World Health Organization (WHO), which is to heal 85% cases and reduce abandonment to 5%, at most45. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011..

Some of the factors that contribute with the non-control of TB are social inequities, such as poverty, low schooling, and unemployment, because these situations do not allow the individual to access the minimum conditions that are essential to health. Internal and external migration movements also collaborate with the transmission of the disease due to their influence on the circulation of the etiological agent among people; besides, there are no restrictions for migration in some countries. Also, the lack of new investments in research for the development of new drugs and vaccines, the high prevalence of multidrug resistance, and the association with the HIV and deficient health systems make it more difficult to control the disease22. World Health Organization (WHO). Global tuberculosis report 2013. Geneva: WHO; 2013. , 55. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011..

With this epidemiological scenario, it is necessary to include the use of new instruments that can provide subsidies to national, state, and local administrator, thus subsidizing the decision-making, the organization, and the planning of actions addressed to the occurrence of health problems, especially infectious conditions such as TB.

Geoprocessing is a tool that enables the conduction of spatial analysis. It can be defined as a set of techniques of collection, treatment, manipulation, and presentation of spatial data; when used in health, it allows the mapping of diseases, risk assessment, planning of actions, and evaluation of care networks55. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011. , 66. Druck S, Carvalho MS, Câmara G, Monteiro AMV. Análise Espacial de Dados Geográficos. Brasília: EMBRAPA; 2004. Disponível em: http://www.dpi.inpe.br/gilberto/livro/analise/index.html. (Acessado em 30 de agosto de 2012).
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The use of geoprocessing techniques applied to public health can contribute to the understanding of the current sanitary situation and its tendencies, by building approaches addressed to health surveillance practices, such as identification of critical areas, concentration of population groups, and prioritizing actions and resources, besides enabling the verification of possible associations with local characteristics of the social environment in which patients live77. Barcellos CC, Sabroza PC, Peiter P, Rojas LI. Organização espacial: saúde e qualidade de vida: análise espacial e uso de indicadores na avaliação de situações de saúde. In: Ministério da Saúde. Fundação Nacional de Saúde. Informe Epidemiológico do SUS. Brasília: Ministério da Saúde; 2002. p. 129-38..

Spatial distribution allows identifying the occurrence of events in one territory, thus providing information about the diffusion of diseases, such as TB, which is directly associated with the demographic conditions and the socioeconomic aspects, as well as with its infecto-contagious aspect, which favors its propagation in the environment8 8. HinoP.. Distribuição espacial dos casos de tuberculose no município de Ribeirão Preto, nos anos de 1998 a 2002 dissertação Ribeirão Preto: Escola de Enfermagem de Ribeirão Preto, Universidade de São Paulo; 2004 ..

In this sense, this study aimed at studying the spatial distribution of TB in the city of Crato, from 2002 to 2011, to verify if there is a point pattern.

METHODS

This is a hybrid, ecological temporal trend study with a quantitative approach, conducted in Crato, in the state of Ceará. It was chosen for being one of the priority locations by the Ministry of Health regarding TB control.

The study population comprised 365 new cases of TB, notified in SINAN under all clinical forms, from 2002 to 2011. The following cases were included: records with full address (street, number, and neighborhood) and people living in the urban zone of Crato, Ceará. Therefore, the sample accounted for 281 cases; of which, 261 were geo-referenced and 20 (7.1%) were excluded for being losses, due to the non-location of the address.

Data were collected from December 2012 to February 2013, in subsequent stages. At first, the digital net of the city was captured in the Secretary of Planning, as well as secondary data from patients in SINAN, provided by the Coordination of the Tuberculosis Control Program. Afterwards, they were organized regarding duplicity, lack of information, and exclusion of cases of inhabitants of the rural zone. Finally, the households of the patient were manually geo-referenced with the Global Positioning System (GPS) by two previously trained researchers.

The territorial unit of data analysis was the census sectors, chosen for presenting the advantage of being the most disaggregated level of population and socioeconomic groups, which are composed of a set of blocks with clear limits; there is an average of 300 houses in a population of about 1,500 inhabitants, national standards99. Instituto Brasileiro de Geografia e Estatística (IBGE). Base de informações do Censo Demográfico 2010: resultados do universo por setor censitário. Rio de Janeiro: IBGE; 2011. Disponível em: http://www.ipea.gov.br/redeipea/images/pdfs/base_de_informacoess_por_setor_censitario_universo_censo_2010.pdf. (Acessado em 12 de fevereiro de 2012).
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, 1010. Hino P, Villa TCS, Cunha TN, Santos CB. Padrões espaciais da tuberculose e sua associação à condição de vida no município de Ribeirão Preto. Ciênc Saúde Coletiva 2011; 16(12): 4795-4802..

The elaboration of maps and spatial analyses was conducted using the software ArcGis, version 9, by Esri. The R software was used for the characterization of study subjects, and data were submitted to calculations of absolute and relative frequency, considering the sociodemographic variables (sex, age group, and schooling), clinical form of the disease, and situation of case conclusion (cure, death, abandonment, change in diagnosis, and transfer to another health service or city).

The spatial distribution of points was used to assess the behavior of the point pattern. Afterwards, to observe the concentration of cases and map "hot areas", the Kernel density estimator was used, with an influence ray of 500 meters and flattening surface of 20 meters. This function counts all of the points inside a region of influence by weighing them according to distance from the location of interest66. Druck S, Carvalho MS, Câmara G, Monteiro AMV. Análise Espacial de Dados Geográficos. Brasília: EMBRAPA; 2004. Disponível em: http://www.dpi.inpe.br/gilberto/livro/analise/index.html. (Acessado em 30 de agosto de 2012).
http://www.dpi.inpe.br/gilberto/livro/an...
. Despite being useful, because it provides a general view of the distribution of the disease, this estimator is not a method to detect cluster, but instead a technique that allows exploring the point pattern of health data66. Druck S, Carvalho MS, Câmara G, Monteiro AMV. Análise Espacial de Dados Geográficos. Brasília: EMBRAPA; 2004. Disponível em: http://www.dpi.inpe.br/gilberto/livro/analise/index.html. (Acessado em 30 de agosto de 2012).
http://www.dpi.inpe.br/gilberto/livro/an...
, 77. Barcellos CC, Sabroza PC, Peiter P, Rojas LI. Organização espacial: saúde e qualidade de vida: análise espacial e uso de indicadores na avaliação de situações de saúde. In: Ministério da Saúde. Fundação Nacional de Saúde. Informe Epidemiológico do SUS. Brasília: Ministério da Saúde; 2002. p. 129-38.. Besides, the interpretation of the obtained results is subjective and depends on the previous knowledge of the study area66. Druck S, Carvalho MS, Câmara G, Monteiro AMV. Análise Espacial de Dados Geográficos. Brasília: EMBRAPA; 2004. Disponível em: http://www.dpi.inpe.br/gilberto/livro/analise/index.html. (Acessado em 30 de agosto de 2012).
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Therefore, the K-function method was applied and used as a tool to compare the empirical estimation and the resulting estimation of a pattern process of random spatial points. To compare the K estimation of a set of data, the L function was plotted with simulation by using the parameters: minimum distance, 0; maximum distance, 5,000; interval, 50; and simulation, 50. The L graph in function of the h distance indicates that positive peaks above the superior envelope show clusters in the scale, whereas negative depressions below the inferior envelope show regularity in all scales66. Druck S, Carvalho MS, Câmara G, Monteiro AMV. Análise Espacial de Dados Geográficos. Brasília: EMBRAPA; 2004. Disponível em: http://www.dpi.inpe.br/gilberto/livro/analise/index.html. (Acessado em 30 de agosto de 2012).
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The research project was approved by the Ethics Committee of Universidade Estadual da Paraíba (UEPB), CAAE number 0176.0.133.000-11, meeting the recommendations in Resolution 466/12, from the National Health Council.

RESULTS

Two hundred and sixty-one new cases of TB were geo-referenced, corresponding to approximately 93% of all patients living in the urban zone of the city. In Table 1, it is possible to see that the profile of patients in the 10 years of the study followed this pattern: male individuals aged between 20 and 59 years old, with low schooling, affected by the pulmonary form of TB. It is also observed that a considerable number of elderly people developed the condition and, in the schooling variable, some information was ignored and was not filled out.

Table 1.
Distribution of the new cases of tuberculosis according to gender, age group, schooling, clinical form, and case conclusion, Crato, CE, 2002 to 2011.

As to the situation of case conclusions, most of the analyzed patients were cured; however, the obtained percentage was lower to that recommended by the Ministry of Health55. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011. (85%), as well as the proportion of treatment abandonment, which is much higher than the acceptable level (5%). Regarding the proportion of deaths, the categories death by TB (1.1%) and death by other causes (3.4%) were grouped to obtain this indicator.

With the distribution of TB points in the city of Crato, it was possible to visualize that new cases of TB were not distributed regularly, once some points are very close to each other, thus indicating a clustered spatial pattern, especially in the north, northeast, northwest, and southwest regions of the central area of the map. This shows that these events were not random; therefore, they did not follow a random pattern. After applying the L function, shown in Figure 1, the results confirmed that the distribution of points is not random, but clustered.

Figure 1.
K-function with simulation for new cases of tuberculosis from 2002 to 2011, in the urban zone of Crato, CE.

The peak distances for each graph corresponded to the mean dimensions of these clusters. By assessing the distribution of points in the space, it is possible to notice the presence of lines or regularities between the points, which can be a reflex of occurrences in the same street or block. These data indicate that in these places, there is a predisposition to the onset of new cases and that information can be useful both for the disease surveillance and to work on TB determinants.

Figure 2 presents the map with the density of cases by the Kernel method, and it is possible to observe that the "hot" areas were concentrated in the vicinities of the central region of the map. Besides, the gradient of colors shows that the further from the center of the map, the lower the concentration of cases. The maximum area of concentration is located in the central-northeast and central-northwest regions, that is, neighborhoods São Miguel and Seminário, respectively. Intermediate density was identified in TB cases in the census sectors composing the neighborhoods Parque Recreio, Vila Alta, Centro, Pinto Madeira, Alto da Penha, Pimenta, and Novo Crato. Low density was found especially in neighborhoods Gizélia Pinheiro, São Gonçalo, Lameiro, Granjeiro, Coqueiro, Lobo, Barro Branco, São José, Muriti, and São Bento.

Figure 2.
Kernel density in cases of tuberculosis in the urban zone of Crato, CE, 2002 to 2011.

DISCUSSION

The profile of patients identified in the study is not different from that found in other analyses conducted in Brazil1010. Hino P, Villa TCS, Cunha TN, Santos CB. Padrões espaciais da tuberculose e sua associação à condição de vida no município de Ribeirão Preto. Ciênc Saúde Coletiva 2011; 16(12): 4795-4802.

11. Cavalcante EFO, Silva DMGV. Perfil de pessoas acometidas por tuberculose. Rev Rene 2013; 14(4): 720-9.
- 1212. Araújo KMFA, Figueiredo TMRM, Gomes LCF, Pinto ML, Silva TC, Bertolozzi MR. Evolução da distribuição espacial dos casos novos de tuberculose no município de Patos (PB), 2001-2010. Cad Saúde Colet 2013; 21(3): 296-302.. The national incidence by gender in 2012 showed that approximately twice as many men (48.8/100 thousand inhabitants) had TB in comparison to women (23.1/100 thousand inhabitants)44. Brasil. Ministério da Saúde. Secretaria de Vigilância Epidemiológica em Saúde. Departamento de Vigilância Epidemiológica. Programa Nacional de Controle da Tuberculose. Brasília: Ministério da Saúde; 2013. Disponível em: portalsaude.saude.gov.br/images/pdf/2014/abril/09/taxa-incidencia-tuberculose-1990-2012-base-DEZ-2013.pdf. (Acessado em10 de maio de 2014).
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Despite the space earned by women throughout the years, in some societies and families men are still the only or the main providers of the house, which could lead to the higher exposure to Mycobacterium tuberculosis outside the household (industries, fairs, commerce, construction sites). This fact would also lead to late diagnosis, once primary care and medium complexity services have restricted working hours, which are the same as the working hours of these individuals. So, they do not look for care for fear of losing their job, in case they miss or arrive late due to the disease1313. Belo MTCT, Luiz RR, Hanson C, Selig L, Teixeira EG, Chalfoun T, Trajman A. Tuberculose e gênero em um município prioritário no estado do Rio de Janeiro. J Bras Pneumol 2010; 36(5): 621-5.

14. Schraiber LB, Figueiredo WS, Gomes R, Couto MT, Pinheiro TF, Machin R, et al. Necessidades de saúde e masculinidades: atenção primária no cuidado aos homens. Cad Saúde Pública 2010; 26(5): 961-70.
- 1515. Hino P, Takahashi RF, Bertolozzi MR, Egry EY. Coinfecção de Tb/HIV em um distrito administrativo do município de São Paulo. Acta Paul Enferm 2012; 25(5): 755-61.. Even though most cases and deaths caused by TB occur among men, the disease load among women is also high. In 2012, the global estimation was of 2.9 million new cases and 410 thousand deaths by TB among women22. World Health Organization (WHO). Global tuberculosis report 2013. Geneva: WHO; 2013..

TB affects the poorer parts of the population; therefore, the fact that people at the economically active age group are becoming sick is worrisome, and influences the socioeconomic condition of the sick person. The disease wears out the strength of the individual, leading this person to progressive malnutrition, debility, and inanition. The person feels weak and unable to perform daily activities, thus generating unemployment and problems given the financial situation of the person and relatives.

The high incidence in this gender and age group is also justified by particular life habits of this group, such as the use of alcohol, smoking, illicit drugs, irregular meal hours, less interest in health self-care, and more exposure to crowds in places of work and leisure11. Bowkalowski C, Bertolozzi MR. Vulnerabilidades em pacientes com tuberculose no distrito sanitário de Santa Felicidade, Curitiba, PR. Cogitare Enferm 2010; 15(1): 92-9. , 1616. Figueiredo TMRM, Pinto ML, Cardoso MAA, Silva VA. Desempenho no estabelecimento do vínculo nos serviços de atenção à tuberculose. Rev Rene 2011; 12(n. esp.): 1028-35. , 1717. Souza KMJ, Sá LD, Palha PF, Nogueira JA, Villa TCS, Figueiredo DA. Abandono do tratamento de tuberculose e relações de vínculo com a equipe de saúde da família. Rev Esc Enferm USP 2010; 44(4): 904-11..

TB among the elderly is more common in developed countries1818. Powell KE, Farer LS. The rising age of the tuberculosis patient: a sign of success and failure. J Infect Dis 1980; 142(6): 946-8.. However, a relevant number of people aged 60 years old or more has been identified in our results. This situation can be explained by the growing number of elderly in the country, generated by the increasing life expectancy, which would lead to the development of the disease due to immunological deficiencies caused by aging. Additional factors, such as the difficulty to access health services, confinement in care homes, and delay to look for a doctor for confusing the symptoms of this disease with those of others must also be considered19.

The low schooling of the patients may have a negative effect on the acquisition of information, once schooling favors the understanding the knowledge about living with the disease or being sick11. Bowkalowski C, Bertolozzi MR. Vulnerabilidades em pacientes com tuberculose no distrito sanitário de Santa Felicidade, Curitiba, PR. Cogitare Enferm 2010; 15(1): 92-9. , 1111. Cavalcante EFO, Silva DMGV. Perfil de pessoas acometidas por tuberculose. Rev Rene 2013; 14(4): 720-9. , 1616. Figueiredo TMRM, Pinto ML, Cardoso MAA, Silva VA. Desempenho no estabelecimento do vínculo nos serviços de atenção à tuberculose. Rev Rene 2011; 12(n. esp.): 1028-35.. Also, the low schooling could increase the vulnerability to TB by reflecting individual and uneven access to information, goods, and the health service itself, so it works as a marker of the poor life conditions and higher vulnerability to TB.

The sick person who has the pulmonary clinical form, whose sputum bacilloscopy is positive, is considered to be the main source of infection and the main transmitter of the disease. After diagnostic confirmation, the treatment must begin as early as possible, which would reduce the transmission because the positive bacilli, if untreated, can infect around 10 to 15 people in a year55. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011. , 2020. Brasil. Ministério da Saúde. Secretaria de Vigilância em Saúde. Guia de vigilância epidemiológica. 6 ed. Brasília: Ministério da Saúde; 2005..

High healing percentages are a consequence of the effectiveness of treatment, working as an indicator of the result of actions to control TB and as a marker for the quality of the service provided, because it translated the fulfillment of the protocol and the level of competence of health teams2121. Souza MSPL, Pereira SM, Marinho JM, Barreto ML. Características dos serviços de saúde associadas à adesão ao tratamento da tuberculose. Rev Saúde Pública 2009; 43(6): 998-1005.. The decreasing proportion of healed cases consequently increases the levels of abandonment, thus presenting a direct relationship with the dissemination of the disease and the onset of multiresistant strains2.

Mortality also shows the effects of the institutional component, being considered as a good indicator of the efficiency of the work to control the disease and its operation2222. Vicentin G, Santo AH, Carvalho MS. Mortalidade por tuberculose e indicadores sociais no município do Rio de Janeiro. Ciênc Saúde Coletiva 2002; 7(2): 253-63.. Characteristics related to the previous treatment, such as abandonment of treatment, multiresistance, and coinfection TB/HIV, have been associated with deaths in cases of TB2323. Lindoso AABP, Waldman EA, Komatsu NK, Figueiredo SM, Taniguchi M, Rodrigues LC. Per?l de pacientes que evoluem para óbito por tuberculose no município de São Paulo, 2002. Rev Saúde Pública 2008; 42(5): 805-12.. A study carried out in 2008 in Recife, Pernambuco, showed that the previous abandonment was a risk factor for the occurrence of death among patients with TB2424. Domingos MP, Caiaffa WT, Colosimo EA. Mortality, TB/HIV co-infection, and treatment dropout: predictors of tuberculosis prognosis in Recife, Pernambuco State, Brazil. Cad Saúde Pública 2008; 24(4): 887-96.. Therefore, to obtain good results regarding adherence to treatment, the Ministry of Health recommends the sensitization and the formation of professionals to work in the perspective of the directly observed treatment; organization of the flow of patients and one place in the unit to supervise the daily intake of medication; control the absences, household visits, and provision of social incentives for the patients5.

It was possible to identify that the space, object of study in geography, was essential in the investigation and understanding of the occurrence and distribution of TB in the groups because data on health and disease have a spatial dimension and can be expressed in this context, in which space is the place of circulation of the infectious agent, which, under specific conditions, causes the disease.

The spatial distribution of new cases of TB showed the presence of different points in the random pattern, and the presence of clusters was confirmed by the L function. These data suggest that, in these regions, there may be a common source of exposure or that individuals living in these locations are more prone to getting sick, and that can be related to the TB health/disease process involving conditions of the geographic space inhabited by the patient, difficulties to access health services, as well as intrinsic and extrinsic factors of the individual.

As aforementioned, the predominant clinical form was the pulmonary one, the transmissible form of the disease and treatment abandonment were high, which may have contributed to infect individuals living close to these sick people. A study showed that sick people that cough have 11 times more chances to look for care late2525. Sreeramareddy CT, Panduru KV, Menten J, Van den Ende J. Time delays in diagnosis of pulmonary tuberculosis: a systematic review of literature. BMC Infect Dis 2009; 9: 91-101., that is, for some people, coughing does not mean being sick; so, it leads to the delay in the search for a health service2626. Nogueira JA, Ruffino Netto A, Monroe AA, Gonzales RIC, Villa TCS. Busca ativa de sintomáticos respiratórios no controle da tuberculose na percepção do Agente Comunitário de Saúde. Rev Eletrônica Enferm 2007; 9(1): 106-18..

The untreated and undiagnosed person with TB also walks around other places in the city, especially the central region, which concentrates activities of exchange and social interaction. It facilitates the transmissibility of the condition to other places other than the household. This fact reinforces the concept of space defended by Santos2727. Santos M. A natureza do espaço: técnica e tempo, razão e emoção. São Paulo: Hucitec; 1996.. For him, it should be a system of objects and actions a set of establishments and flows.

The intense movement of people favors the circulation of the bacillus causing TB, therefore, "hot areas" were identified in the census sectors involving neighborhoods that are close to downtown, as shown in the Kernel density map (Figure 2). The neighborhood Seminário, in the center-northwest region, is one of the most populous ones, and its residents have poor life conditions. São Miguel, located in the central-northeast region, is a commercial neighborhood concentrating supermarkets, colleges, and technical school, so, the flow of people coming of many locations is large.

Crato is located approximately 13 km away from Juazeiro do Norte, which welcomes pilgrims from all over the country, who are often visiting Horto do Padre Cícero. Some of them also visit the Church of Sé, located in the urban center of the city. There are many students, and all of them are considered to be strong agents of disease dispersion. In other studies that analyze the spatial distribution of TB, a concentration of cases was shown close to the central region of the city1212. Araújo KMFA, Figueiredo TMRM, Gomes LCF, Pinto ML, Silva TC, Bertolozzi MR. Evolução da distribuição espacial dos casos novos de tuberculose no município de Patos (PB), 2001-2010. Cad Saúde Colet 2013; 21(3): 296-302. , 2828. Queiroga RPF, Sá LD, Nogueira JA, Lima ERV, Silva ACO, Pinheiro PGOD, et al. Distribuição espacial da tuberculose e a relação com condições de vida na área urbana do município de Campina Grande - 2004 a 2007. Rev Bras Epidemiol 2012; 15(1): 222-32..

The reference service of the city is also located near the analyzed neighborhood, which makes it easier for users living in the region to access the service. However, this access is difficult for those living in the suburbs, where a few cases were notified throughout the 10 years of study. In general, the suburbs are considered to have little infrastructure; these are developing neighborhoods, which are crowded due to irregular occupation of land, precarious settlements, or slums. Most patients who live in these places have lower purchasing power and need transportation to get to the reference service2828. Queiroga RPF, Sá LD, Nogueira JA, Lima ERV, Silva ACO, Pinheiro PGOD, et al. Distribuição espacial da tuberculose e a relação com condições de vida na área urbana do município de Campina Grande - 2004 a 2007. Rev Bras Epidemiol 2012; 15(1): 222-32..

Most of the interviewed people with TB, in a study conducted in Ribeirão Preto, São Paulo2929. Beraldo AA, Arakawa T, Pinto ESG, Andrade RLP, Wysocki AD, Silva Sobrinho RA, et al. Atraso na busca por serviço de saúde para o diagnóstico da tuberculose em Ribeirão Preto (SP). Ciênc Saúde Coletiva 2012; 17(11): 3079-86., looked for public services that were closer to their houses, so there were no costs of care and transportation. In this sense, it is important to reinforce activities regarding the contact with individuals with TB and the active search for respiratory symptomatic patients in the regions indicated in the map with higher concentration of cases, besides other people who attends health services, regardless of motive to do so55. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011.. The activities of active search must also be conducted, especially in the suburbs of the city, because the results showed there were no cases notified during the period of the study, to understand why no patients appeared in those regions.

The results of this study enabled to assume that the patterns of TB transmissibility are also conditioned by transformations in the space. This is the result of the action of society over nature because its configuration gathers social structure and its dynamics. The geographic space shows the symbolic dimension of social relations, which express the factors associated with the development and the dissemination of diseases, besides their distribution among the several social groups3030. Barcellos C, Lammerhirt CB, Almeida MAB, Santos E. Distribuição espacial da leptospirose no Rio Grande do Sul, Brasil: recuperando a ecologia dos estudos ecológicos. Cad Saúde Pública 2003; 19(5): 1283-92. , 3131. Castellanos PL. Epidemiologia, saúde pública, situação de saúde e condições de vida. Considerações conceituais. In: Barata RB, org. Condições de vida e situação de saúde. Rio de Janeiro: Abrasco; 1997. p. 31-75..

Barcellos et al.77. Barcellos CC, Sabroza PC, Peiter P, Rojas LI. Organização espacial: saúde e qualidade de vida: análise espacial e uso de indicadores na avaliação de situações de saúde. In: Ministério da Saúde. Fundação Nacional de Saúde. Informe Epidemiológico do SUS. Brasília: Ministério da Saúde; 2002. p. 129-38. stated that if the disease is considered to be a manifestation of the individual, then the life conditions are the expression of the place where this person lives because these places are the result of historical, environmental, and social situations that generate particular conditions for the production of diseases. Therefore, the health status can not only be understood in its individual dimension, it should also be contemplated in its social and collective dimension55. Brasil. Ministério da Saúde. Manual de recomendações para o controle da tuberculose no Brasil. Brasília: Ministério da Saúde; 2011. , 66. Druck S, Carvalho MS, Câmara G, Monteiro AMV. Análise Espacial de Dados Geográficos. Brasília: EMBRAPA; 2004. Disponível em: http://www.dpi.inpe.br/gilberto/livro/analise/index.html. (Acessado em 30 de agosto de 2012).
http://www.dpi.inpe.br/gilberto/livro/an...
.

CONCLUSIONS

This study enabled to point out areas of higher and lower concentration of TB cases by identifying the spatial pattern, as well as to recognize that the disease did not affect all of the population groups with the same severity. Those who were more vulnerable lived in regions with higher population densities, poor life conditions, and with an intense flow of people.

The methodology used confirmed that the geoprocessing techniques allow visualizing the cases of the diseases distributed by territory, so it is possible to identify vulnerable population groups, besides providing visibility regarding the rates of disease detection per neighborhood and/or region. Therefore, it is possible to contribute with the epidemiological surveillance service.

By assessing the individual characteristics of the patients, it is possible to observe that the sociodemographic profile of people with TB is in accordance with the global and national reality. This is relevant because it identified groups that need more surveillance. It was also possible to assess health care by indicators of cure, abandonment, and death, which make significant contributions for redirecting basic care actions, and generally guide the formulation of public health policies.

It is expected that knowing the distribution of TB cases in an individual and collective level can collaborate with the Tuberculosis Control Program because it makes information available about the spatial pattern of TB and the identification of vulnerable areas; these must be a priority both regarding the need for social improvement and the understanding of the social geographic space and the conduction of concentrated control actions.

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  • Financial support: none.

Publication Dates

  • Publication in this collection
    Apr-Jun 2015

History

  • Received
    24 Mar 2014
  • Reviewed
    23 Aug 2014
  • Accepted
    30 Sept 2014
Associação Brasileira de Pós -Graduação em Saúde Coletiva São Paulo - SP - Brazil
E-mail: revbrepi@usp.br