Cervical lymphadenitis: tuberculosis or tularaemia?

Both tuberculosis cervical lymphadenitis (TCL) and oropharyngeal tularaemia (OT) have similar signs, symptoms and pathological findings. We aimed to investigate the frequency of tularaemia antibodies in patients diagnosed with TCL. Using data from the Tuberculosis Control Dispensaries between the years of 2008 and 2011 in Turkey, all patients diagnosed with TCL were informed about and included in the study. Control group subjects were selected from healthy blood donors who lived in the same region. After informed consent was obtained, the sera obtained from volunteer TCL patients and the control group were tested with a microagglutination technique for Francisella tularensis. Antibodies to Brucella were also investigated with a tube agglutination test for cross-reactivity in sera that were seropositive for tularaemia. Sera were obtained from a total of 1170 individuals in the TCL group and 596 in the control group from 67 of 81 provinces in Turkey. Francisella tularensis-positive antibodies were found in 79 (6.75%) cases in the TCL group and two (0.33%) cases in the control group with a titre of ≥1:80 (p < 0.01). When the presence of antibody of any titre was considered, the ratio became 8.2% (96/1170) in the TCL group and 0.67% (4/596) in the control group (p < 0.001). For the first time, with this study, tularaemia serology was found to be positive in a significant portion (6.75%) of diagnosed cases of TCL. In tularaemia endemic regions, it was concluded that tularaemia serology should be investigated in patients suspected of having TCL.