Nursery Salmonellosis Delayed Recognition Due to Unusually Long Incubation Period

Abstract

A nursery outbreak of diarrheal illness caused by Salmonella nienstedten initially involved seven infants cared for in one nursery; secondary infection subsequently affected one infant cared for in the same nursery as well as four other infants. Recognition of the outbreak was delayed due to an unusually long incubation period. The period from last known exposure to onset of diarrhea ranged from two to 18 days, with a median of ten days. The prolonged incubation period may have resulted from a low inoculum of the organism, from a previously unknown characteristic of Salmonella nienstedten, or may be an age-specific response. Hospital infection control personnel should be aware that nosocomial cases of salmonellosis may have a longer incubation period than has been previously recognized.

Non-typhoidal Salmonella in Children: Microbiology, Epidemiology and Treatment

“…The incubation for NTS gastroenteritis depends on the host and the inoculum. It is usually 12-36 h, although incubation periods of up to nearly 2 weeks have been reported with certain strains [12][13][14].…”

An Outbreak ofSalmonellaSerotype Typhimurium Infections with an Unusually Long Incubation Period

“…Although this is the longest incubation period reported to the CDC for a Typhimurium-related foodborne outbreak, outbreaks of illnesses with unusually long incubation periods have been previously described for this (Seals et al, 1983) and other non-typhoidal Salmonella serotypes (Ethelberg et al, 2004;Matsui et al, 2004;Nagai et al, 1999;O'Mahony et al, 1990). In some other studies, incubation periods for enteric infections with non-typhoidal Salmonella have been correlated with the dose of bacteria consumed (Abe et al, 2004;Blaser and Newman, 1982;Glynn and Palmer, 1992;Mintz et al, 1994).…”

A Multischool Outbreak Due to Salmonella enterica serovar Napoli Associated with Elevated Rates of Hospitalizations and Bacteremia, Milan, Italy, 2014

“…Although the incubation period for nontyphoidal salmonellosis is generally 6-72 h, nontyphoidal salmonellosis outbreaks with similar prolonged incubation periods have been reported (Seals et al, 1983;Nagai et al, 1999), also in a Japanese school (Matsui et al, 2004). Overall, it appears that the ingestion of low bacterial doses usually entails long incubation periods (Abe et al, 2004) and low attack rates (Matsui et al, 2004).…”