Do the eyes have it? Performance of molecular detection of tuberculosis on fresh and paraffin embedded tissues, including those with no visible tissue.

BACKGROUND: Little has been published on the performance of tuberculosis PCR with respect to the quality of tissue specimens. Laboratories often receive liquid samples from fine-needle aspirates with no visible tissue for testing. The sensitivity of tuberculosis (TB) PCR on these specimens is unknown. METHODS: TB PCR was compared to culture or a combination of clinical and histopathological evidence of tuberculosis; a separate analysis excluded patients with current or previous treatment. RESULTS: Sixty-five patients had 81 positive samples; 69 by PCR and 43 by culture. Excluding those on treatment, 51 of 57 (89%) were PCR positive versus 43 of 61 (70%) by culture. 44 samples had 'no visible tissue' noted. Five were PCR positive; only one was culture positive. At least two samples were falsely negative. CONCLUSIONS: Sensitivity of TB PCR is superior to culture on tissue. Five of seven TB cases with no visible tissue were PCR positive. The quality of the specimen deserves comment, as the two (5%) known false negatives are of concern.

Prevalence and predictors of lymphogranuloma venereum among men who have sex with men at a Sydney metropolitan sexual health clinic.

During an 18-month period to June 2012, 1732 anal chlamydia (Chlamydia trachomatis) tests were performed among men who have sex with men (MSM) at RPA Sexual Health in Sydney's inner west. Positive anal chlamydia samples were subsequently tested for lymphogranuloma venereum (LGV). Seventy-five (4.3%) anal samples were positive for chlamydia among 67 men during the study period. Anal symptoms were reported for 16 out of 75 (21.3%) of anal chlamydia episodes overall. Three episodes of LGV (all serovar L2b) were identified, all three of whom reported anal symptoms (100%, 95% confidence interval (CI): 29.2-100%). In contrast, only 13/72 (18.1%, 95% CI: 10.0-28.9%) of those with non-LGV anal chlamydia reported anal symptoms. LGV was not identified in any of 59 episodes of asymptomatic anal chlamydia (0%, 95% CI: 0-6.1%). Of those with LGV, two were known to be HIV-positive and one subsequently seroconverted to HIV within a year of the LGV diagnosis. Our findings suggest that routine LGV testing among MSM is not warranted, except among those with anal symptoms.