Nosocomial nontyphoidal salmonellosis after antineoplastic chemotherapy: reactivation of asymptomatic colonization?

Abstract

An increased frequency of nontyphoidal salmonellosis is well established in cancer patients, but it is unclear whether this represents increased susceptibility to exogenous infection or opportunistic, endogenous reactivation of asymptomatic carriage. In a retrospective study, a simple case definition was used to identify the probable presence of reactivation salmonellosis in five cancer patients between 1996 and 2002. Reactivation salmonellosis was defined as the development of nosocomial diarrhea >72 h after admission and following the administration of antineoplastic chemotherapy in an HIV-seronegative cancer patient who was asymptomatic on admission, in the absence of epidemiological evidence of a nosocomial outbreak. Primary salmonellosis associated with unrecognized nosocomial transmission or community acquisition and an unusually prolonged incubation period could not entirely be ruled out. During the same time period, another opportunistic infection, Pneumocystis pneumonia, was diagnosed in six cancer patients. Presumably, asymptomatic intestinal Salmonella colonization was converted to invasive infection by chemotherapy-associated intestinal mucosal damage and altered innate immune mechanisms. According to published guidelines, stool specimens from patients hospitalized for longer than 72 h should be rejected unless the patient is neutropenic or >or=65 years old with significant comorbidity. However, in this study neutropenia was present in only one patient, and four patients were <65 years old. Guidelines should thus be revised in order not to reject stool culture specimens from such patients. In cancer patients, nosocomial salmonellosis can occur as a chemotherapy-triggered opportunistic reactivation infection that may be similar in frequency to Pneumocystis pneumonia.

Diagnosis and Treatment of Acute or Persistent Diarrhea

“…Cases have been linked to contaminated food, 69 infected food handlers, 70 person-toperson spread, 71 enteral nutrition or baby formula, 72,73 and chemotherapy-induced reactivation. 74 Alarm has been raised by a number of hospital outbreaks of Salmonella strains that have developed resistance by acquiring an extended-spectrum ␤-lactamase. 75,76 Other implicated bacterial pathogens that have been reported to cause nosocomial infections or outbreaks include Shigella, E coli O157, EPEC, K oxytoca, and S aureus.…”

Performance of stool cultures before and after a 3-day hospitalization: fewer cultures, better for patients and for money

“…Among the 13 clinically relevant cases of nosocomial diarrhoea, 7 received chemotherapy. Asymptomatic colonization with enteropathogenic bacteria can lead to invasive disease triggered by cancer chemotherapy, as previously reported for Salmonella (Delaloye et al, 2004), probably due to mucositis and immunosuppression. In our study, 4 patients developed nosocomial Campylobacter diarrhoea (2 Campylobacter coli, 2 Campylobacter jejuni), and 3 developed S. enterica diarrhoea after receiving chemotherapy.…”

Emergence and serovar profiling of non-typhoidal Salmonellae (NTS) isolated from gastroenteritis cases–A study from South India

“…[18] NTS infection in cancer patients could also be termed as nosocomial NTS diarrhoea due to the following reasons: (i) primary community-acquired Salmonella infection associated with an unusually long incubation period, often because of secondary transmission or microbiologically undocumented diarrhoeal illness; (ii) eating contaminated food from outside sources that is brought to the hospital; or (iii) truly nosocomially acquired infection (eating hospital food). [19] In the present study, Salmonella ser. Oslo was the prevalent serovar isolated from patients with malignancy.…”