Non-Typhoidal Salmonella Infections in Cancer Patients
Non-typhoidal Salmonella(NTS) is an important foodborne pathogen resulting in gastroenteritis, bacteremia and subsequent focal infection such as endovascular disease and deep seated infection. Although malignancy is considered as a risk factor of NTS infection, there is limited data describing the clinical characteristics and outcome in cancer patients. The objective of our study is to investigate microbiological, clinical characteristics and outcome of NTS infection among cancer patients.
From January 2000 to December 2007, we retrospectively reviewed charts of patients with NTS clinical isolates at MD Anderson Cancer Center. We investigated demographics, site of infection, serotype, susceptibility, management and outcomes.
We identified 60 isolates in 45 clinical cases. Median age was 55 (23 – 76) with 3:2 male to female ratio. All had underlying malignancy and 64% had hematological malignancy (45% lymphoma). 27% had neutropenia and 42% had lymphopenia. 60% took antacid, 56% steroids, and 67% chemotherapy within 1 month. Among 60 isolates, 48% were from blood, followed by 22% stool, 18% urine, 5% sputum, and others. Among clinically diagnosed UTI, 57% had anatomical abnormality in urinary tract. Serotype C was the leading pathogen in all isolates (38%), whereas B was most common in blood isolates (41%). Most of the isolates were susceptible (90% to ampicillin, 100% to ceftriaxone and 96% to fluoloquinolones). 29% had severe disease (severe sepsis, septic shock or invasive disease) and among them, 85% received steroids and/or chemotherapy. Only 2% had endovascular disease. 89% received initial active antibiotics. Recurrence within 3 months was seen in 7%, infection related mortality was 4%, and overall mortality was 8%.
Our study is one of the largest case series in cancer patients. The most common malignancy was lymphoma and severe infection occurred in patients receiving immunosuppressive agents. Compared with previous reports in cancer patients, our study showed: 1) higher proportion of severe disease and lower endovascular disease, 2) lower mortality (8% vs 30-40%), perhaps due to earlier initiation of active antibiotics, and 3) more frequent UTI, especially in patients with urologic abnormalities.
J. Adachi, None
V. Mulanovich, None