Cat scratch disease. Clinical study of 26 patients. Place and importance of PCR.

Purpose. - Cat scratch disease is a mild pathology but diagnosis often rema in difficult. Methods. - A retrospective study has been conducted by the department of in fectious diseases at the University hospital in Angers. Between January 199 4 and October 1998, 26 observations were recorded providing the presence of three criteria out of four among the following: contact with a cat, clinic al presentation and its favorable course, absence of any other cause notice d, and the presence of either a positive serology or a positive PCR, or the examination of a suggestive pathology. Results. - Fourteen men and 12 women were concerned. From a clinical point of view, the inoculation lesion was observed six times, all patients showed at least one adenopathy during their illness, 12 patients showed only an a denopathy without clinical signs. A surgical biopsy was carried out on nine patients and a diagnosis established. Bartonella henselae serology was don e in all patients. Six presented a significant rate of IgG antibodies as ea rly as the first dosage. A seroconversion was observed in four cases belate dly 1 to 2 months after the beginning of the symptomatology. The method's s ensitivity was approximately 38%. A PCR search was accomplished in the pus obtained from a ganglionic puncture on 12 patients. It was positive seven t imes, which corresponds to a sensitivity of about 58%. In associating these two diagnostic criteria a sensitivity rate of nearly 92% was reached, the diagnosis not having been confirmed only in one case. The outcome proved to be favorable in all cases, with or without an antibiotic treatment. Conclusion. - The association of serology and PCR in the pus permits a cert ain diagnosis in the majority of the cases and avoids the more aggressive b iopsy. (C) 2001 Editions scientifiques et medicales Elsevier SAS.