The utility of routine tuberculosis screening in county hospital patients with uveitis.
OBJECTIVE
To evaluate the utility of tuberculosis (TB) screening in diagnosing ocular TB in uveitis patients in a government-funded hospital.


METHODS
The charts of 142 consecutive patients seen during August 2011-July 2012 at the Los Angeles County Hospital uveitis clinic were reviewed for manifestation/laterality of uveitis, purified protein derivative (PPD) test results, interferon γ release assay, chest x-ray, birthplace, treatment history and diagnosis. 'Presumed TB-uveitis' was diagnosed when patients had positive TB screening and favourable response to anti-TB therapy, and definite ocular TB when Mycobacterium tuberculosis' presence was demonstrated. Post-test probabilities were determined.


RESULTS
TB screening was positive in 21.1%. Six patients were diagnosed with TB-related uveitis: one definite, four presumed and one systemic TB with uveitis. With regard to PPD positivity, being foreign-born was the only statistically significant factor with OR of 2.26 (95% CI 1.01 to 5.13; p<0.01) if born in Mexico and 4.90 (95% CI 1.74 to 13.83; p<0.01) if born in other foreign countries. The post-test probabilities of a positive PPD in a uveitis patient showed a 17.2% (overall) or 30.3% (foreign-born patients) chance of ocular TB.


CONCLUSIONS
PPD skin test plays an important role in the diagnosis of TB-associated uveitis in high-risk groups, such as immigrants from TB endemic regions.
Doheny Eye Institute, Los Angeles, California, USA Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.
Bryan Kun
BK
Hong
Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.
Hossein Nazari
HN
Khanamiri
Doheny Eye Institute, Los Angeles, California, USA Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.
Simon R
SR
Bababeygy
Doheny Eye Institute, Los Angeles, California, USA Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.
Narsing A
NA
Rao
D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use; D003941:Diagnostic Techniques, Ophthalmological / Q000706:statistics & numerical data; D005260:Female; D006766:Hospitals, County / Q000706:statistics & numerical data; D006801:Humans; D015141:Los Angeles; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D014374:Tuberculin Test / Q000379:methods; D014392:Tuberculosis, Ocular / Q000175:diagnosis* / Q000188:drug therapy; D014605:Uveitis / Q000175:diagnosis* / Q000382:microbiology
D000995:Antitubercular Agents
Diagnostic tests/Investigation; Infection; Public health