1. Prevalence of HIV Infection and Risk Factors of Tuberculin Skin Test Results among Household Contacts in a HIV Epidemic Area: Chiang Rai Province, Thailand by Pornnapa Suggaravetsiri , Ph.D.(Epidemiology) Faculty of Public Health, Khon Kaen University, Thailand Juthatip Putthasorn , M.D. Chiang Rai Prachanukraow Hospital, Thailand
13. Participation of subjects Participate 526 TB cases Pool of TB index cases 530 cases Participate and TST 12 11 contacts Participate and TST 12 40 contacts – 29 anergy skin test
14. Prevalence of HIV +ve among household contacts 7.74% (72 / 930 of contacts who did agree for HIV testing) Results
15. Prevalence of TST +ve among household contacts 56.98% (690 / 1211 of contacts who did agree for TST)
16. Table 1 Rate and OR of TST positive and characteristics of household contacts <0.01 1.36-2.98 2.01 93/194 (47.94) ≥ 60 <0.01 2.69-6.77 4.27 82/124 (66.13) 50-59 <0.01 3.21-7.80 5.01 103/148 (69.59) 40-49 <0.01 3.27-7.66 5.00 119/171 (69.59) 30-39 <0.01 3.80-9.48 6.00 107/146 (73.29) 20-29 <0.01 2.09-4.63 3.11 111/189 (58.73) 10-19 1.00 75/239 (31.38) <10 Age (years) <0.01 0.40-0.65 0.51 363/683 (53.15) Female 1.00 327/528 (61.93) Male Sex p-value 95% CI Crude OR Number and Prevalence (%) of TST-positive Characteristic
17. Table 1 Rate and OR of TST positive and characteristics of household contacts ( cont.) 0.02 1.05-1.91 1.42 187/325 (57.54) Parent 0.64 0.78-1.50 1.08 121/238 (50.84) Children <0.01 1.93-3.74 2.68 203/282 (71.99) Spouse 1.00 179/366 (48.91) Relative Relationship to Index case <0.01 1.15-2.43 1.67 88/145 (60.69) Divorced <0.01 1.52-2.48 1.94 358/558 (64.16) Married 1.00 244/508 (48.03) Single Marital status 0.56 0.73-1.79 1.14 51/ 85 (60.00) Hill tribe 1.00 639/1126 (56.75) Thai Race / Ethnicity p-value 95% CI Crude OR Number and Prevalence (%) of TST-positive Characteristic
18. Table 2 Univariate analysis of risk factors associated with TB infectious among household contacts 0.17 0.83-2.87 1.55 316 539 Negative 1.00 20 22 Positive HIV status <0.01 0.60-0.95 0.75 247 279 Negative 1.00 274 411 Positive BCG scar present <0.01 1.13-1.85 1.45 141 241 Yes 1.00 380 449 No Cigarette smoking <0.01 1.50-3.16 2.18 43 113 Yes 1.00 478 577 No Alcohol drinking p-value 95 % CI OR TST - TST+ Variable
19. Table 2 Univariate analysis of risk factors associated with TB infectious among household contacts ( cont.) <0.01 1.31-2.18 1.69 126 242 Yes 1.00 395 448 No Sleeping in the same bed as the TB patient <0.01 1.47-2.37 1.87 159 311 Yes 1.00 362 379 No Sleeping in the same bedroom as the TB patient <0.01 2.83-3.81 2.95 115 314 Yes 1.00 406 376 No Care giver to the TB patient p-value 95 % CI OR TST - TST + Variable
20. Table 3 Multivariate analysis of risk factors associated with TB infectious among hhc Variables entered in the Multiple Logistic Regression Analysis were sex, age, BCG scar present, HIV status, Care giver to the TB patient, and Sleeping in the same bedroom as the TB patient <0.01 2.56 (1.29-5.08) ≥ 60 <0.01 6.26 (2.99-12.87) 50-59 <0.01 5.55 (2.79-11.05) 40-49 <0.01 5.34 (2.70-10.57) 30-39 <0.01 6.45 (3.21-12.96) 20-29 <0.01 3.70 (1.89-7.25) 10-19 1.00 <10 Age (years) <0.01 0.45 (0.33-0.61) Female 1.00 Male Sex p-value Adj.OR (95 % CI) Variable in model
21. Table 3 Multivariate analysis of risk factors associated with TB infectious among household contacts (cont) <0.01 1.99 (1.44-2.74) Yes 1.00 No Sleeping in the same bedroom as the TB patient <0.01 2.04 (1.48-2.81) Yes 1.00 No Care giver to the TB patient <0.01 3.15 (1.57-6.33) Negative 1.00 Positive HIV status 0.08 0.74 (0.53-1.04) Negative 1.00 Positive BCG scar present p-value Adj.OR (95 % CI) Variable in model
Slide 2 Rationale of the study were both HIVor AIDS and TB are increasing in Thailand, especially in the Northern region, and knowledge on the extent to which HIV+TB contributes to transmission of the disease will be useful for further planning of intervention.
Slide 3 Objective of this study is to compare prevalence of TB infection (as measured by PPD skin test) between among household contacts of HIV positive active TB patients and HIV negative active TB patients.
This is a cross-sectional study, carried out on household contact tracing of TB index cases who were a mixture of HIV-positive and HIV-negative.
Sample size This study expecting 48 % of PPD test positive among contacts of HIV+ TB index cases and 63 % of those HIV-TB. Using 95% confidence level and 80% power the sample size is 182 contact in each group Assuming 3 contact/index case and a design effect of 3, n in each group is 182 /3 x 3 = 182 Another 10% compensation for no contact Final sample size in each group = 200 index cases
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