Skip to main content
NCBI home page
Epidemiology and Infection logoLink to Epidemiology and Infection
. 1995 Aug;115(1):31–38. doi: 10.1017/s095026880005809x

A pseudo-outbreak of salmonellosis.

R E Joce 1, F Murphy 1, M H Robertson 1
PMCID: PMC2271565  PMID: 7641836

Abstract

during July 1991, a single laboratory reported an increased number of an unusual salmonella isolate. An outbreak control team was convened. A case was defined as an individual with diarrhoea from whose faecal sample Salmonella hadar was isolated after 1 July 1991. By 30 July, 90 isolates had been identified and 57 persons interviewed including 39 primary cases. Interviews failed to identify any common features among the cases. A review of the laboratory procedures revealed that the selenite enrichment medium was inoculated using the spoon from the stool collection kit after it was used to emulsify the faecal sample with saline for microscopy. Salmonella hadar was isolated from this saline. Once this practice was stopped, no further isolates of S. hadar were made. This pseudo-outbreak is a powerful reminder to verify the existence of an outbreak, especially when epidemiological data are inconsistent.

Full text

PDF
31

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Armstrong C. W., Hackler R. L., Miller G. B., Jr Two pseudo-outbreaks of infectious mononucleosis. Pediatr Infect Dis. 1986 May-Jun;5(3):325–327. doi: 10.1097/00006454-198605000-00010. [DOI] [PubMed] [Google Scholar]
  2. Centers for Disease Control (CDC) Pseudo-outbreak of intestinal amebiasis--California. MMWR Morb Mortal Wkly Rep. 1985 Mar 8;34(9):125–126. [PubMed] [Google Scholar]
  3. Fitch L. E., Uttley A. H., Honeywell K. M., Yates M. D., Simpson R. A. Cross contamination of bronchial washings. J Hosp Infect. 1991 Apr;17(4):322–324. doi: 10.1016/0195-6701(91)90287-i. [DOI] [PubMed] [Google Scholar]
  4. Goldstein B., Abrutyn E. Pseudo-outbreak of Bacillus species: related to fibreoptic bronchoscopy. J Hosp Infect. 1985 Jun;6(2):194–200. [PubMed] [Google Scholar]
  5. Graham D. R., Wu E., Highsmith A. K., Ginsburg M. L. An outbreak of pseudobacteremia caused by Enterobacter cloacae from a phlebotomist's vial of thrombin. Ann Intern Med. 1981 Nov;95(5):585–588. doi: 10.7326/0003-4819-95-5-585. [DOI] [PubMed] [Google Scholar]
  6. Haji T. C., Sanderson P. J., Sangam A., Willmot I. C. Blood culture procedure and contamination with Serratia. J Hosp Infect. 1982 Sep;3(3):312–313. doi: 10.1016/0195-6701(82)90053-6. [DOI] [PubMed] [Google Scholar]
  7. Lettau L. A., Benjamin D., Cantrell H. F., Potts D. W., Boggs J. M. Bacillus species pseudomeningitis. Infect Control Hosp Epidemiol. 1988 Sep;9(9):394–397. doi: 10.1086/645897. [DOI] [PubMed] [Google Scholar]
  8. Maki D. G. Through a glass darkly. Nosocomial pseudoepidemics and pseudobacteremias. Arch Intern Med. 1980 Jan;140(1):26–28. [PubMed] [Google Scholar]
  9. Nye K., Chadha D. K., Hodgkin P., Bradley C., Hancox J., Wise R. Mycobacterium chelonei isolation from broncho-alveolar lavage fluid and its practical implications. J Hosp Infect. 1990 Oct;16(3):257–261. doi: 10.1016/0195-6701(90)90114-4. [DOI] [PubMed] [Google Scholar]
  11. Pitt T. L., Gaston M. A. Pseudobacteraemia and ESR bottles. J Hosp Infect. 1982 Dec;3(4):395–397. doi: 10.1016/0195-6701(82)90074-3. [DOI] [PubMed] [Google Scholar]
  12. Robertson M. H. Pseudobacteraemia yet again. J Hosp Infect. 1983 Dec;4(4):413–413. doi: 10.1016/0195-6701(83)90015-4. [DOI] [PubMed] [Google Scholar]
  13. Stine T. M., Harris A. A., Levin S., Rivera N., Kaplan R. L. A pseudoepidemic due to atypical mycobacteria in a hospital water supply. JAMA. 1987 Aug 14;258(6):809–811. [PubMed] [Google Scholar]
  14. Willson P. A., Baker S. L., Petts D. N. Blood culture procedure and contamination with Klebsiella. J Hosp Infect. 1983 Mar;4(1):89–90. doi: 10.1016/0195-6701(83)90072-5. [DOI] [PubMed] [Google Scholar]

Articles from Epidemiology and Infection are provided here courtesy of Cambridge University Press

RESOURCES