Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 13, Number 10—October 2007
Global Poverty and Human Development

Public Transportation and Pulmonary Tuberculosis, Lima, Peru

Olivia J. Horna-Campos*Comments to Author , Héctor J. Sánchez-Pérez†, Inma Sánchez*, Alfredo Bedoya‡, and Miguel Martín*
Author affiliations: *Universidad Autónoma de Barcelona, Barcelona, Spain; †Colegia de la Frontera Sur, Chiapas, Mexico; ‡Dirección de Salud IV Lima Este, Lima, Peru;

Cite This Article


The association between public transportation for commuting and pulmonary tuberculosis (TB) was analyzed in workers in Lima, Peru. Traveling in minibuses was a risk factor for pulmonary TB. Preventive measures need to be taken by health services to prevent spread of this disease.

Tuberculosis (TB) continues to be an important public health problem in impoverished areas (14). It is spread through the air by patients with pulmonary TB (5). Because those most affected by pulmonary TB are persons 15–50 years of age, employment-related characteristics of these persons must be taken into account when studying this disease. In Lima, Peru, residents of peripheral neighborhoods generally use minibuses to travel to work or school and have long commute times. Because public transportation in Latin America routinely carries more passengers than permitted by law, it is plausible to assume that in areas with endemic pulmonary TB, daily use of public transportation may be a risk factor for acquiring TB (69).

The greatest amount of expectoration (productive coughing) occurs during the morning commute (6:00 am–7:00 am) because of accumulation of bronchial secretions at night (10). Given the conditions in which persons travel to work in Lima (long travel times and overcrowding on minibuses with closed windows), we analyzed whether use of minibuses was associated with the spread of pulmonary TB as part of a larger study to assess pulmonary TB in the Ate-Vitarte District of this city.

The Study

The study was conducted in the Ate-Vitarte district (population 365,473), which is located ≈12 km from the center of Lima. It is a marginal urban area that receives immigrants who come to Lima with high rates of TB. The study was reviewed and approved by the ethics committee of the East Lima Health Directorate IV.

During July–August 2004, interviews were conducted with a random sample of 150 commuters >15 years of age who had productive coughs for >15 days and who came to health services for treatment. A total of 142 persons agreed to participate: 96 were treated at hospitals and 46 were treated at health centers. Informed consent was obtained from all participants. Interviews were conducted in the health services that persons visited. We obtained demographic and socioeconomic information, as well as information on perceived health, and means of transportation used in commuting.

All persons with productive coughs were requested to provide 3 sputum samples (the first immediately after the interview and the other 2 on 2 consecutive days) for smear testing. Samples were tested by using the Ziehl-Neelsen method, which is used in all epidemiologic surveillance in Peru (11). Study participants were considered positive for pulmonary TB if >1 acid-fast bacilli (AFB) were found (11).

Results were analyzed by using bivariate and multivariate logistic models with SPSS version 12 software (SPSS Inc., Chicago, IL, USA). Statistical significance was defined as p<0.05.

Demographic and socioeconomic characteristics of the study group are shown in Table 1. Variables analyzed for persons tested for pulmonary TB are shown in Table 2. Seventeen (11.9%) of 142 study participants were smear positive (29.6% 1 cross, 41.0% 2 crosses, and 29.4% 3 crosses). Two persons had been discharged from a TB treatment program <6 months earlier.

None of the demographic and socioeconomic indicators analyzed (Table 1) were associated with pulmonary TB. Table 2 shows crude associations between variables and pulmonary TB. The use of a minibus and a commuting time >1 hour had the highest associations with pulmonary TB. Adjusted relationships obtained by logistic regression that controlled for all variables shown in Table 2 confirmed that commuting to work by minibus was associated with a positive test result for pulmonary TB (adjusted odds ratio 4.90, 95% confidence interval 1.04–23.04).


We observed a pulmonary TB prevalence rate of 12% in persons with chronic productive coughs who came to health services in the study area. This rate was similar to a prevalence of 11% reported in a similar study conducted in an area of poor socioeconomic status in Chiapas, Mexico (12).

The proportion of persons 15–44 years of age with pulmonary TB in our study was consistent with data of the World Health Organization and the Peruvian Ministry of Health, which show that this age group has the highest prevalence of this disease (5,13,14). Our results also showed that there were no sex-related differences in the frequency of pulmonary TB (13, 14).

Socioeconomic variables showed no association with pulmonary TB. However, this finding should be interpreted cautiously because of the small sample size, particularly the number of persons who lived in extreme poverty. Another factor that could limit our conclusions is accessibility of persons in areas of extreme poverty to public transportation. The fact that the field work phase of our study could not be increased because of shortages of resources and health center personnel time is also a limitation.

The relationship of having pulmonary TB with working at home or away from home showed a positive prevalence ratio of 6.06. Among persons working outside the home, commuting by minibus increased the risk of having pulmonary TB by a factor of 4.09 compared with persons who used individual forms of transportation. A commuting time >1 hour on a minibus also increased the risk for pulmonary TB by a factor of 2.07 (Table 2).

Minibuses in Lima increase the risk for pulmonary TB because they are usually overloaded (capacity is often doubled) in the early morning and late evening. Overcrowding, exposure to persons with productive coughs while commuting 2 times a day 5 days a week, and closed windows on minibuses, combined with a high prevalence of pulmonary TB in Lima, increase the risk of acquiring this disease. Because persons with cases of pulmonary TB have more productive coughs in the morning (when more bacilli are released because of their accumulation at night), there is increased risk for transmission of TB to other passengers (15), as has already been suggested by other studies in developing and industrialized countries (69). The findings that 41% of persons tested were positive with 2 crosses and 29.4% were positive with 3 crosses indicate poor TB prevention and control programs in the study area and higher probabilities of transmission (15).

Despite the limitations of our study, commuting in minibuses was a risk factor for pulmonary TB. Consequently, preventive measures need to be taken by health services to encourage persons with productive coughs to avoid this type of public transportation and to come to health services for diagnosis and treatment. Health services should also be more accessible to persons with pulmonary TB who, for whatever reason, cannot use other forms of transportation. This increased accessibility would include home treatment during the infectious phase of this disease.

Ms Horna-Campos is completing her PhD in public health at the Universidad Autónoma de Barcelona, Spain. Her primary research interest is pulmonary tuberculosis health services in impoverished areas.



This study was supported by the Dirección de Salud IV Lima Este and the Grups de Recerca d’América I Africa Llatines–Universidad Autónoma de Barcelona (



  1. Beggs  CB, Noakes  CJ, Sleigh  PA, Fletcher  LA, Siddiqi  K. The transmission of tuberculosis in confined spaces: an analytical review of alternative epidemiological models. Int J Tuberc Lung Dis. 2003;7:101526.PubMedGoogle Scholar
  2. Weissenbacher  M, Salvatella  R, Hortal  M. Desafío de las enfermedades emergentes y reemergentes. Revista Medica del Uruguay. 1998;14:3448.
  3. Jansá  JM, García de Olalla  P. Salud e inmigración: nuevas realidades y nuevos retos. Gac Sanit. 2004;18:20713. DOIPubMedGoogle Scholar
  4. García-Sánchez  I, Pérez de Oteyza  C, Gilsanz Fernández  C. Estudio epidemiológico de la tuberculosis en un hospital de tercer nivel en el año 2001. Anales de Medicina Interna (Madrid). 2005;22:2226.
  5. American Thoracic Society. Diagnostic standards and classification of tuberculosis in Bissau: incidence in adults and children. Am J Respir Crit Care Med. 2000;161:137695.PubMedGoogle Scholar
  6. Tuberculosis spreads through crowded city buses, Cornell researcher reports. Science Daily. February 1, 1999. [cited 2006 May 7]. Available from
  7. Rodrigues  C, Debanne  S, Boffi  L, Aparicio  J, Pilheu  J. Transmisión de la tuberculosis en medios de transporte en el área metropolitana de Buenos Aires. [cited 2006 May 5]. Available from
  8. Brotes de tuberculosis en niños que usaban autobus escolar. 200SISIB. [cited 2006 May 7]. Available from
  9. Caylá  JA. Estudis en poblacions marginals amb alta prevalencia en països desenvolupats: El cas de Barcelona. In: Primer seminari GRAAL 2005: pobresa, marginació i salut. Barcelona (Spain): Universidad Autónoma de Barcelona, May 22–25, 2005. [cited 2006 May 5]. Available from
  10. Ministerio de Salud (MINSA). Norma técnica de salud para el control de la tuberculosis en el Perú. Estrategia Nacional de Prevención y Control de la Tuberculosis (ESN-PCT). [cited 2006 May 15]. Available from
  11. Ministerio de Salud del Perú (MINSA). Dirección de salud de las personas. Programa Nacional de Control de las Enfermedades Transmisibles/Control de la Tuberculosis. Actualización de la doctrina, normas y procedimientos para el control de la tuberculosis en el Perú. Lima (Peru): Le Ministerio; 2001.
  12. Sánchez Pérez  HJ, Prat-Monterde  D, Jansá  JM, Martín-Mateo  M. Tuberculosis pulmonar y uso de servicios del primer nivel de atención en zonas de alta y muy alta marginación socioeconómica de Chiapas, México. Gac Sanit. 2000;14:26876.PubMedGoogle Scholar
  13. Bishai  WR, Graham  NM, Harrington  S, Pope  DS, Hooper  N, Astemborski  J, Molecular and geographic patterns of tuberculosis transmission after 15 years of directly observed therapy. JAMA. 1998;280:167984. DOIPubMedGoogle Scholar
  14. Godoy  P, Nogués  A, Alsedà  M, Manonelles  A, Artigues  A, García  M. Factores de riesgo asociados a pacientes con TB con microscopia de esputo positiva. Gac Sanit. 2001;15:50612.PubMedGoogle Scholar
  15. Beggs  CB, Noakes  CJ, Sleigh  PA, Fletcher  LA, Siddiqi  K. The transmission of tuberculosis in confined spaces and analytical review of alternative epidemiological models. Int J Tuberc Lung Dis. 2003;7:101526.PubMedGoogle Scholar




Cite This Article

DOI: 10.3201/eid1310.060793

Table of Contents – Volume 13, Number 10—October 2007

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.



Please use the form below to submit correspondence to the authors or contact them at the following address:

Olivia J. Horna-Campos, Unidad de Bioestadística, Facultad de Medicina, Universidad Autónoma de Barcelona, Edificio M, Cerdanyola del Vallés, 08193 Bellaterra, Barcelona, Spain;

Send To

10000 character(s) remaining.


Page created: July 02, 2010
Page updated: July 02, 2010
Page reviewed: July 02, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.