Abebe et al. BMC Public Health 2012, 12:504 http://www.biomedcentral.com/1471-2458/12/504 Table 1 Distribution of TB lymphadenitis cases in the study Kebeles of Gilgel Gibe Field Research Center, Southwest Ethiopia Kebele Siba Asandabo Burka Kajelo Koticha Ayino Enkure Bore Danaba CI Confidence interval. Total population surveyed 2893 4493 3539 3409 2342 3382 2048 2065 3426 TB lymphadenitis n (prevalence per 100,000 people) 1 (34.6) 0 (0) 1 (28.3) 2 (58.7) 1 (42.7) 2 (59.1) 3 (146.5) 0 (0) 6 (175.1) Page 4 of 7 95% CI 6.1-195.5 0-85.4 5.0-159.9 16.1-213.7 7.5-241.5 16.2-215.4 49.8-429.8 0-185.7 80.3-381.6 Epidemiological factors associated with TB lymphadenitis TB lymphadenitis was more frequent in females (86.5 per 100,000) and age group 35–44 (90.4 per 100,000 people) followed by 45 years or older (71.9 per 100,000 people). The differences in the prevalence of TB lymph- adenitis with respect to sex and age group were not statistically significant (Table 2). Other personal charac- teristics associated with TB lymphadenitis are described in Table 3. Only contact with a person with chronic cough was significantly associated with TB lymphadenitis (OR 5.58, 95% CI 1.23-25.43). Characteristics of the lymph nodes associated with TB lymphadenitis Lypmh node characteristics affecting positivity for tuber- culous lymphadenitis are described in Table 4. Among the lymph nodes characteristics only caseous FNA sam- ples were more likely to be from persons with TB lymphadenitis (OR 5.46, 95% CI 1.69-17.61). Discussion Extrapulmonary TB is a significant health problem worldwide because of difficulties in its diagnosis and in monitoring its treatment. The proportion of extrapul- monary TB among all TB cases varies from country to country. Of the 22 high burden countries the highest proportion was reported from Cambodia (34.2%) and the lowest from China (0.69%) [5]. The extrapulmonary manifestation of TB is prevalent in 10-34% of non-HIV cases while it occurs in 50-70% of patients co-infected with HIV [11]. Ethiopia reports the third highest number of extrapulmonary TB globally (50,417) [5]. In the current study, we assessed TB lymphadenitis, the major form of extrapulmonary TB, in a rural community in Ethiopia. In this study the diagnosis of TB lymphadenitis was established when FNA smear microscopy for AFB, cul- ture and/or cytology reported positive. In fact cytology suffers from low number of cells that are all in disper- sion rather than organized tissue as in biopsies. Never- theless, cytology is specific when compared against combined criteria [3]. The prevalence of pulmonary TB was 76.1 per 100,000 people in the same study population during the same study period [12]. It is higher than the prevalence of TB lymphadenitis as reported here. TB lymphadenitis Table 2 Prevalence of lymphadenopathy and tuberculous lymphadenitis per 100,000 people by sex and age in Gilegl Gibe, south west Ethiopia Total population Lymphadenopathy n(prevalence) TB Lymphadenitis n (prevalence) OR [95% CI] Variable Sex Male Female Age 15-24 25-34 35-44 > = 45 OR Odds ratio, CI Confidence interval. 13718 13879 10482 7129 4423 5563 24 (174.9) 63 (453.9) 16 (152.6) 30 (420.8) 28 (633.1) 13 (233.7) 4 (29.2) 12 (86.5) 3 (28.6) 5 (70.1) 4 (90.4) 4 (71.9) 1 1 2.97 [0.97- 9.20] 3.43 [0.89- 13.28] 2.37 [0.48- 11.75] 1.89 [0.38- 9.34]