Volume 80, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


This cross-sectional study sought to identify household contextual determinants that might be associated with infection as assessed by tuberculin skin test (TST) positivity among familial contacts of index patients of infectious pulmonary tuberculosis (TB) while controlling for the effects of individual-level factors. We analyzed data on TST results on 359 household contacts of 77 index cases of acid-fast bacilli (AFB) sputum smear-positive pulmonary TB using multilevel logistic regression analysis with characteristics of household contacts at the first level and that of households at the second level. The prevalence of infection as assessed by TST positivity among household contacts of index TB patients was 49.9% (179/359). After taking into account the individual-level risk factors, household-level contextual determinants significantly associated with contact’s TST positivity were gender of index TB patient (adjusted odds ratio [OR] = 2.2; 95% confidence interval [CI]: 1.3–3.9%) and density of AFB sputum smear (adjusted OR = 3.2; 95% CI: 1.9–5.5%). Household variances in multilevel models indicated significant inter-household heterogeneity in TST positivity among contacts. This study provided the evidence for substantive effects of household-level contextual variables on the TST positivity among contacts of index TB patients. Thus, both individual-level and household-level characteristics need to be taken into account while prioritizing contacts for investigations to improve TB control and prevention in resource-constrained countries such as Pakistan.


Article metrics loading...

Loading full text...

Full text loading...



  1. WHO, The World Health Report 2004: Changing History. Geneva: World Health Organization.
  2. Maartens G, Wilkinson RJ, 2007. Tuberculosis. Lancet 370 : 2030–2043.
  3. WHO, 2006. Global Tuberculosis Control: Surveillance, Planning, Financing. Geneva, 2006: WHO/HTM/TB/362.
  4. Dye C, Scheele S, Dolin P, Pathania V, Raviglione MC, 1999. Global burden of tuberculosis: estimated incidence, prevalence, and mortality by country. JAMA 282 : 677–686.
  5. Corbett EL, Watt CJ, Walker N, Maher D, Williams BG, Raviglione MC, Dye C, 2003. The growing burden of tuberculosis: global trends and interactions with HIV epidemic. Arch Intern Med 163 : 1009–1021.
  6. Dye C, 2006. Global epidemiology of tuberculosis. Lancet 367 : 938–940.
  7. Morrison J, Pai M, Hopewell PC, 2008. Tuberculosis and latent tuberculosis infection in close contacts of people with pulmonary tuberculosis in low-income and middle-income countries: a systematic review and meta-analysis. Lancet Infect Dis 8 : 359–368.
  8. Liippo KK, Kulmala K, Tala EO, 1993. Focusing tuberculosis contact tracing by smear grading of index cases. Am Rev Respir Dis 148 : 235–236.
  9. Chapman JS, Dyerly MD, 1964. Social and other factors in intrafamilial transmission of tuberculosis. Am Rev Respir Dis 90 : 48–60.
  10. Rubel AJ, Garro LC, 1992. Social and cultural factors in the successful control of tuberculosis. Public Health Rep 107 : 626–636.
  11. Lomnitz L, 1977. Networks and Marginality: Life in a Mexican Shanty Town. New York: Academic Press.
  12. Verver S, Warren RM, Munch Z, Richardson M, van der Spuy GD, Borgdorff MW, Behr MA, Beyers N, van Helden PD, 2004. Proportion of tuberculosis transmission that takes place in households in a high-incidence area. Lancet 363 : 212–214.
  13. Reichler MR, Reves R, Bur S, Thompson V, Mangura BT, Ford J, Valway SE, Onorato IM; Contact Investigation Study Group, 2002. Evaluation of investigations conducted to detect and prevent transmission of tuberculosis. JAMA 287 : 991–995.
  14. Van Geuns HA, Meijer J, Styblo K, 1975. Results of contact examination in Rotterdam, 1975–1969. Bull Int Union Tuberc 50 : 107–124.
  15. Rathi SK, Akhtar S, Rahbar MH, Azam SI, 2002. Prevalence and risk factors associated with tuberculin skin test positivity among household contacts of smear-positive pulmonary tuberculosis cases in Umerkot, Pakistan. Int J Tuberc Lung Dis 6 : 651–657.
  16. Guwatudde D, Nakakeeto M, Jones-Lopez EC, Maganda A, Chiunda A, Mugerwa RD, Ellner JJ, Bukenya G, Whalen CC, 2003. Tuberculosis in household contacts of infectious cases in Kampala, Uganda. Am J Epidemiol 158 : 887–898.
  17. District Census Report 1998. Census Publication No. 617. Population Census Organization, Statistics Division. Islamabad: Government of Pakistan.
  18. Datta M, Radhamani MP, Selvaraj R, Paramasivan CN, Gopalan BN, Sudeendra CR, Prabhakar R, 1993. Critical assessment of smear positive pulmonary tuberculosis programme. Tuber Lung Dis 74 : 180–186.
  19. Kamat SR, Dawson JJY, Devadatta DS, Fox W, Janardhanam B, Radhakrishna S, Ramakrishnan CV, Somasundararam PR, Stott H, Velu S, 1998. A controlled study of the influence of segregation of tuberculosis patients for year on the attack rate of tuberculosis in a 5 year period in close family contacts in South India. Bull World Health Organ 76 : 109–124.
  20. Ott L, An Introduction to Statistical Methods and Data Analysis. PWS-Kent Publishing Company, Boston, 1988, 229.
  21. Schlesselman JJ, Stolley PD, Case-Control Studies: Design, Conduct, Analysis. Oxford University Press, New York, 1982.
  22. International Union against Tuberculosis and Lung Disease, 1986. Technical guide for sputum examination for tuberculosis by direct microscopy. Bull Int Union Tuberc Lung Dis 6 : 1–16.
  23. Pereira SM, Dourado I, Barreto ML, Cunha SS, Ichiara MY, Hijjar MA, Goes JC, Rodrigues LC, 2001. Sensitivity and specificity of BCG scar reading in Brazil. Int J Tuberc Lung Dis 5 : 1067–1070.
  24. Alcaide J, Altet MN, Plans P, Parrón I, Folguera L, Saltó E, Domínguez A, Pardell H, Salleras L, 1996. Cigarette smoking as a risk factor for tuberculosis in young adults: a case-control study. Tuber Lung Dis 77 : 112–116.
  25. al-Kassimi FA, Abdullah AK, al-Orainey IO, Benar AB, al-Hajjaj MS, al-Majed S, 1991. The significance of positive Mantoux reactions in BCG-vaccinated children. Tubercle 72 : 101–104.
  26. Falk A, O’Connor JB, Pratt C, 1969. Classification of pulmonary tuberculosis, in Diagnostic Standards and Classification of Tuberculosis. New York, NY: National Tuberculosis and Respiratory Disease Association’s Manual, 68–76.
  27. Leyland AH, Goldstein H, 2001. Multilevel Modeling of Health Statistics. Chichester, UK: Wiley.
  28. Larsen K, Petersen JH, Budtz-Jorgensen E, Endahl L, 2000. Interpreting parameters in the logistic regression model with random effects. Biometrics 56 : 909–914.
  29. Larsen K, Merlo J, 2005. Appropriate assessment of neighbor-hood effects on individual health: integrating random and fixed effects in multilevel logistic regression. Am J Epidemiol 161 : 81–88.
  30. Tabachnick BG, Fiddel LS, 2001. Using Multivariate Statistics, (Fourth edition). Boston: Allyn & Bacon.
  31. Klebanoff MA, Cole SR, 2008. Use of multiple imputation in the epidemiologic literature. Am J Epidemiol 168 : 355–357.
  32. CDC, 2005. Guidelines for the investigation of contacts of persons with infectious tuberculosis: recommendations from the National Tuberculosis Controllers Association and CDC. MMWR 54 (RR-15):1–37.
  33. Brosch R, Vincent V, 2007. Cutting-edge science and the future of tuberculosis control. Bull World Health Organ 85 : 410–412.
  34. Vidal R, Miravitlles M, Caylà JA, Torrella M, de Gracia J, Morell F, 1997. Increased risk of tuberculosis transmission in families with microepidemics. Eur Respir J 10 : 1327–1331.
  35. Lemos AC, Matos ED, Pedral-Sampaio DB, Netto EM, 2004. Risk of tuberculosis among household contacts in Salvador, Bahia. Braz J Infect Dis 8 : 424–430.
  36. Whalen CC, Johnson JL, Okwera A, Hom DL, Huebner R, Mugyenyi P, Mugerwa RD, Ellner JJ, 1997. A trial of three regimens to prevent tuberculosis in Ugandan adults infected with the human immunodeficiency virus. N Engl J Med 337 : 801–808.
  37. Beyers N, Gie RP, Schaaf HS, Van Zyl S, Talent JM, Nel ED, Donald PR, 1997. A prospective evaluation of children under the age of 5 years living in the same household as adult with recently diagnosed pulmonary tuberculosis. Int J Tuberc Lung Dis 1 : 38–43.
  38. CDC, 2008. Workplace-based investigation of contacts of a patient with highly infectious tuberculosis in Maryland, District of Columbia, and Virginia. MMWR 57 : 94–98.
  39. Ferebee SH, 1970. Controlled chemoprophylaxis trials in tuberculosis: a general review. Adv Tuberc Res 17 : 28–106.
  40. Comstock GW, Livesay VT, Woolpert SF, 1974. The prognosis of a positive tuberculin reaction in childhood and adolescence. Am J Epidemiol 99 : 131–138.
  41. Colditz GA, Brewer TF, Berkey CS, Wilson ME, Burdick E, Fineberg HV, Mosteller F, 1994. Efficacy of BCG vaccine in the prevention of tuberculosis. JAMA 271 : 698–702.
  42. O’Brien RJ, Perriens JH, 1995. Preventive therapy for tuberculosis in HIV infection: the promise and the reality. AIDS 9 : 665–673.
  43. Bellamy RJ, Hill AV, 1998. Host genetic susceptibility to human tuberculosis. Novartis Found Symp 217 : 3–13.
  44. Comstock G, 1982. Epidemiology of tuberculosis. Am Rev Respir Dis 125 : 8–15.
  45. Bailey WC, Gerald LB, Kimerling ME, Redden D, Brook N, Bruce F, Tang S, Duncan S, Brooks CM, Dunlap NE, 2002. Predictive model to identify positive tuberculosis skin test results during contact investigations. JAMA 287 : 996–1002.
  46. Becerra MC, Pachao-Torreblanca IF, Bayona J, Celi R, Shin SS, Kim JY, Farmer PE, Murray M, 2005. Expanding tuberculosis case detection by screening household contacts. Public Health 120 : 271–272.
  47. Gustafson P, Lisse I, Gomes V, Vieira CS, Lienhardt C, Nauclér A, Jensen H, Aaby P, 2007. Risk factors for positive tuberculin skin test in Guinea-Bissau. Epidemiology 18 : 340–347.
  48. Wang L, Turner MO, Elwood RK, Schulzer M, FitzGerald JM, 2002. A meta-analysis of the effect of Bacille Calmette Guérin vaccination on tuberculin skin test measurements. Thorax 57 : 804–809.
  49. WHO, 2004. BCG vaccine. Wkly Epidemiol Rec 79 : 27–40.
  50. Teo SS, Shingadia DV, 2006. Does BCG have a role in tuberculosis control and prevention in the United Kingdom? Arch Dis Child 6 : 529–531.
  51. Liippo KK, Kulmala K, Tala EO, 1993. Focusing tuberculosis contact tracing by smear grading of index cases. Am Rev Respir Dis 148 : 235–236.
  52. EI-Sony A, Enarson O, Khamis A, Baraka O, Bjune G, 2002. Relation of grading of sputum smears with clinical features of tuberculosis patients in routine practice in Sudan. Int J Tuberc Lung Dis 6 : 91–97.
  53. Sepkowitz KA, 1996. How contagious is tuberculosis? Clin Infect Dis 23 : 954–962.
  54. Wares DF, Akhtar M, Singh S, Luitel H, 2000. Is TB contact screening relevant in a developing country setting? Experiences from eastern Nepal, 1996–1998. Int J Tuberc Lung Dis 4 : 920–924.
  55. Carvalho AC, DeRiemer K, Nunes ZB, Martins M, Comelli M, Marinoni A, Kritski AL, 2001. Transmission of Mycobacterium tuberculosis to contacts of HIV-infected tuberculosis patients. Am J Respir Crit Care Med 164 : 2166–2171.
  56. WHO, Forty-fourth World Health Assembly, Resolutions and Decisions. Resolution WHA 44.8 Report no. WHA44/1991/REC/I. Geneva: World Health Organization, 1991.

Data & Media loading...

  • Received : 30 Jun 2008
  • Accepted : 01 Dec 2008

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error