[Invasive Campylobacter jejuni/coli Infections: 9 Case Reports at a Single Center between 2000 and 2015, and a Review of Literature Describing Japanese Patients].

There have been few coherent reports on extraintestinal infection or bacteremia caused by Campylobacter jejuni (C. jejuni) or C. coli in Japan. To clarify the clinical and microbiological characteristics of invasive infections caused by these two species, we retrospectively analyzed the records of patients from whom these pathogens had been isolated from sterile sites between 2000 and 2015. During this study period, we identified 9 patients. The clinical syndrome of all of these patients was bacteremia. Three patients had underlying diseases with both liver cirrhosis and malignant neoplasm, and all of these patients were aged 60 years or older. The remaining 6 patients were immunocompetent and younger than 40 years of age. All 9 patients had a fever of 38.5 degrees C or higher. The proportion of patients with gastrointestinal symptoms was lower for the 3 patients with underlying diseases, compared with the 6 patients without underlying diseases (1/3 cases vs, 4/6 cases). Of the 8 strains evaluated for antimicrobial susceptibility, all were susceptible to imipenem/cilastatin, kanamycin and erythromycin, and 2 were resistant to levofloxacin. Antimicrobial treatment was administered to 8 patients, but one spontaneously recovered without any treatment. We were able to follow the outcomes of 8 patients, and all of these patients completely recovered without relapses. We also reviewed 14 Japanese patients reported in the Japanese and English literature and found similar clinical features consisting of a high-grade fever and an association with underlying diseases and gastrointestinal symptoms. Of note, 3 agammaglobulinemic patients presented with bacteremia and extraintestinal infections and had multiple relapses. Based on the findings of our 9 cases and previous reports, the affected patients were divided into two groups according to clinical syndrome and therapeutic intervention. One group consisted of previously healthy children or young adults showing bacteremia. Most of them had enterocolitis complications but had a good prognosis. The other group consisted of patients with underlying diseases or elderly patients who presented with bacteremia alone or bacteremia with extraintestinal infections. The latter group, especially among those with humoral immunodeficiency, should be parentally treated with antimicrobial agents and requires careful monitoring for relapse. This is the largest case series study to examine invasive C. jejuni/coli infections in Japan, and it provides important epidemiological information on this rare infection.