Case Control Study On Association Between Passive Smoking And Childhood Tuberculosis In Surat City Jayesh Rana1, Gaurang Parmar2, Prakash Patel3, Rachna Prasad4, R K Bansal5 1PG Student, 3Assistant professor , 4Associate professor, 5Professor and Head, Department of Community Medicine, SMIMER, Surat, 2Medical Officer, Govt. of Gujarat

BACKGROUND Tuberculosis cases occurring in children (0-14 years) varies from developed countries to developing & underdeveloped countries (Seth, 2012). 5% to 15% In India during 2012, about 81,482 TB cases were notified. 7% TB cases Gujarat had reported under RNTCP in paediatric age-group. 6% Surat Municipal Corporation had diagnosed approximately 300 TB cases (TB Gujarat, 2013). 7.4%

BACKGROUND More than 20% of TB cases worldwide are attributable to smoking (WHO, 2013). In India, 40% children were exposed to passive smoking (WHO atlas 10). This study attempts to determine the risk factors, including passive smoking, for paediatric tuberculosis (0-14 years) in Surat city.

OBJECTIVES To know the association between passive smoking and tuberculosis in pediatric age- group (0-14 years). To determine other risk factors for childhood tuberculosis.

METHODOLOGY Study Type : Case Control Study Study Setting: Study was conducted at DMC (Designated Microscopy Centre) of Surat Municipal Institute of Medical Education & Research (SMIMER), a tertiary care hospital of Surat city. Study Period: From August 2013 to November 2013. Sample size: 195 (cases-65, controls-130). Calculated by Epi. Info software using the prevalence of passive smoking among control 15.8% and odds ratio 2.68 from the previous Indian studies [Ramchandran R, et al (2011), Singh M, et al (2005)]

METHODOLOGY Sampling : Simple random sampling method, after preparing a line-listing of paediatric TB patients registered at DMC, SMIMER within last 6 months (February 2013 to July 2013). Two controls were recruited for each case from neighbourhood of case with matching to maintain the ratio of case to control 1:2. Study Tools: After obtaining permission from IEC, SMIMER pre-designed semi-structured questionnaire was developed which was filled up by oral interview technique. The children fulfilled the inclusion criteria were visited at their home.

METHODOLOGY Informed written consent was obtained from parents who were willing to participate in the study ensuring them about the strict confidentiality during whole study. The questionnaire consisted of questions pertaining to socio-demographic profile, biological factors, indoor air pollution, smoking history of family members, exposure to passive smoke etc. The same questionnaire was used for both Case and Control.

OPERATIONAL DEFINITIONS Case: Incident case of TB in child (0-14 years) residing in Surat city diagnosed at DMC, SMIMER and registered under RNTCP. Control: Child (0-14 years) without any symptoms suggestive of TB immediate weeks before the data collection (persistent fever, cough >2 weeks, loss of weight, h/o contact with infectious TB case) or diagnosed as TB or any other respiratory condition. Any other symptoms or signs suggestive of extra-pulmonary TB like lymph node enlargement or pyrexia of unknown origin were excluded from control selection. Passive smoking: Inhalation of cigarette, bidi, cigar or pipe smoke produced by another individual, composed of second hand smoke (exhaled by smoker) and side stream smoke. Contact: Any person with a suspected or diagnosed case of active TB disease within the last two years.

RESULTS Mean age of tuberculosis cases was 9.5 years with SD of 3.5 years. Table 1: Association between Socio-demographic Factors of children and childhood tuberculosis (n=195) Variable Case (%) Control (%) P value OR 95% CI Age of child (10-14 years) 37 (56.9) 19 (14.6) <0.001 7.72 3.87-15.41 Male Child 34 (52.3) 73 (56.2) 0.611 0.86 0.47-1.56 Nuclear Family 46 (70.8) 55 (42.3) 3.30 1.75-6.25 Migrant Community 19 (29.2) 0.015 2.41 1.17-4.97 Illiterate Mother 23 (36.5) 36 (27.7) 0.212 1.50 0.75-2.99 Illiterate Father 12 (19.7) 31 (24.2) 0.519 0.78 0.34-1.75 Working Mother 17 (27.0) 8 (6.2) 5.64 2.11-15.42 Working Father 35 (59.3) 94 (75.2) 0.017 0.45 0.23-0.88 Modified Prasad's class (III, IV, V) 63 (96.9) 125 (96.2) 1.000 1.26 0.21 – 9.67

RESULTS Table 2: Association between Biological Factors of children and childhood tuberculosis (n=195) Variable Case (%) Control (%) P value OR 95% CI Low birth weight 9 (25.7) 29 (27.6) 0.826 0.91 0.38-2.17 Underweight 58 ( 90.6) 123 (94.6) 0.452 1.81 0.48 – 6.61 No BCG Vaccine 17 (26.2) 14 (10.8) 0.006 2.93 1.25-6.90 No DPT Vaccine 20 (30.8) 27 (20.8) 0.124 0.59 0.30-1.16 No Measles Vaccine 22 (33.8) 26 (20.0) 0.034 0.49 0.25-0.96 Family history of TB 25 (38.5) 35 (26.9) 0.100 0.31-1.11 Frequency of illness (≥ once a month) 12 (9.3) 0.001 3.48 1.44-8.47 H/o Steroid treatment 5 (7.7) 0 (0.0) 0.003 Undefined HIV Infection 8 (12.3) <0.001 Past history of TB

RESULTS Table 3: Association between Environmental Factors of children and childhood tuberculosis (n=195) Variable Case (%) Control (%) P value OR 95% CI Pucca House 60 (92.3) 111 (85.4) 0.165 2.05 0.73-5.78 Inadequate Sunlight penetration 27 (41.5) 55 (42.3) 0.918 1.03 0.56-1.89 Inadequate Ventilation of house 29 (44.6) 53 (40.8) 0.608 0.85 0.47-1.56 Absent Cross Ventilation 49 (75.4) 97 (74.6) 0.907 0.96 0.48-1.91 Overcrowding 57 (87.7) 121 (93.1) 0.209 1.89 0.69-5.15 Indoor Air Pollution 47 (36.2) 0.253 1.42 0.78-2.61 > 5 years of exposure to indoor smoke 23 (79.3) 16 (34.0) <0.001 0.14 0.05-0.40 Gas as cooking fuel 80 (61.5) 0.054 1.91 0.97-3.73 Coal as cooking fuel 10 (15.4) 5 (3.8) 0.004 4.55 1.48-13.92

RESULTS Table 4: Association between Family History of Smoking and childhood tuberculosis (n=195) Variable Case (%) Control (%) P value OR 95% CI Smoking by any family member 13 (20.0) 25 (19.2) 0.894 1.05 0.47-2.22 Smoking by Father 10 (15.4) 19 (14.6) 0.887 1.06 0.46-2.44 Indoor smoking by father 5 (50.0) 13 (68.4) 0.5659 0.46 0.10-2.22 Child Exposed to Passive smoking 7(53.8) 19 (73.0) 0.290 0.43 0.08-2.12

RESULTS Table 5: Multiple Logistic Regression Variables B S.E. Wald Df Sig. Exp(B) 95% CI for EXP(B) Lower Upper Age group 1.420 1.000 2.016 1 .156 4.137 .583 29.371 Gender .030 .902 .001 .973 1.031 .176 6.039 Type of family -1.572 .853 3.397 .065 .208 .039 1.105 Type of community -1.729 .996 3.015 .083 .178 .025 1.249 Maternal Occupation 2.655 1.367 3.768 .052 14.219 .975 207.426 Father’s Occupation .305 .858 .127 .722 1.357 .253 7.292 Frequency of illness -1.270 3.504 .131 .717 .281 .000 269.661 No BCG vaccination 2.633 1.308 4.050 .044 13.915 1.071 180.767 No Measles vaccination -1.329 1.072 1.535 .215 .265 .032 2.166 Coal as fuel of cooking -0.050 1.107 .002 .964 .951 .109 8.330 Duration of indoor smoke exposure 2.001 .957 4.375 .036 7.398 1.134 48.250 Constant -3.843 1.748 4.831 .028 .021  

CONCLUSION Age of more than 10 year, nuclear family, migrant community, working mother, father working as laborer are socio-demographic factors which significantly associated with cases of childhood TB compare to non TB children. Biological variables like no immunization with BCG or measles, frequency of illness (≥ once a month) within last year, HIV infection, h/o steroid treatment and past history of TB were found significantly associated with cases of childhood TB compare to non TB children.

CONCLUSION The present study could not found association between passive smoking and childhood TB. However, environmental factors found associated with childhood TB were duration of indoor air pollution (>5 years) and coal used as fuel for cooking. On multivariate analysis, no immunization with BCG and duration of indoor air pollution were found to be the independent predictors for childhood tuberculosis.

RECOMMENDATIONS Immunization of children with BCG should be more strengthen. Children with HIV, steroid treatment, not immunized against measles and with history of frequent illnesses are vulnerable groups for TB which should be screened with available resources and carefully watched to identify tuberculosis at early stage. Children with past history of TB should be looked carefully for relapse of tuberculosis.  

RECOMMENDATIONS Children belonged to migrant group, nuclear family & with working mother are also risk groups and should be included into target population to increase the notification of hidden cases of childhood TB.   Usage of coal for cooking and indoor air pollution make children at risk of TB. So parents should be educated regarding their harmful effects on their children. Majority of the children were suffering from extra- pulmonary form of TB which was mainly diagnosed by lymph node enlargement. Thus any lymph node found enlarged should be carefully watched for TB diagnosis.

Thank you

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