Review of the epidemiology and infection control aspects of nosocomial Salmonella infections in hospitalised horses

Outbreaks of nosocomial Salmonella infections in hospitalised horses can occur when surveillance and infection control protocols are not in place, or not well structured and enforced. The aim of this article is to present a review of published studies that have contributed to the literature of the epidemiology and infection control aspects of nosocomial Salmonella infections in hospitalised horses. The review highlights important elements that must be taken into consideration during the formulation, implementation and evaluation of a hospital surveillance and infection control programme designed to reduce the risk of an outbreak of nosocomial Salmonella infection in hospitalised horses.     

Surveillance for nosocomial infections in veterinary hospitals.

Surveillance for nosocomial infection and disease is a critical component in an integrated and highly effective infection control program. Surveillance activities provide a sensory role to guide ongoing control practices so that they are focused and efficient. Without input from surveillance results, infection control practices are likely to be guided more by emotion and opinion than by data and evidence. This article discusses issues to be considered when developing effective nosocomial infection surveillance programs as well as the historical perspective of surveillance efforts for nosocomial infection in human health care settings.     

Risk factors for nosocomial Salmonella infection among hospitalized horses.

OBJECTIVE: To identify risk factors for nosocomial Salmonella infections among hospitalized horses. DESIGN: Longitudinal study. ANIMALS: 1,583 horses hospitalized in an intensive care unit between January 1992 and June 1996. PROCEDURE: Survivor functions were used to estimate time to shedding salmonellae for various Salmonella serotypes. Survival analysis was then used to determine how variables associated with patient management, environmental conditions, hospital conditions, and other disease processes affected the risk of nosocomial Salmonella infection. RESULTS: 78 horses shed Salmonella organisms: 35 shed Salmonella krefeld, 26 shed S typhimurium, and 17 shed other Salmonella serotypes. Mean time from admission to shedding was significantly longer for horses shedding S krefeld or S typhimurium than for horses shedding other Salmonella serotypes. Therefore, infection with S krefeld or S typhimurium was considered nosocomial. Seven variables were found to be significantly associated with risk of nosocomial Salmonella infection: mean number of horses in the hospital shedding S krefeld during the 4 days prior to and the day of admission, mean number of horses shedding S typhimurium during this period, a diagnosis of large colon impaction, withholding feed, number of days fed bran mash, duration of treatment with potassium penicillin G, and mean daily ambient temperature. CLINICAL IMPLICATIONS: Results suggest that risk of nosocomial Salmonella infections is greater for horses with large colon impactions. In addition to implementing hospital protocols that minimize cross contamination between patients, strategies to reduce the risk of nosocomial Salmonella infection should include minimizing use of potassium penicillin G and regulation of environmental temperature in the hospital.     

Salmonella infections in neonatal dairy calves.

To estimate herd prevalence of Salmonella spp, fecal specimens were obtained for culture from neonatal calves of 47 Ohio dairy herds. Of the 452 calves tested, 10 calves from 7 farms were culture-positive. Salmonella serotypes isolated were S dublin, S typhimurium, S enteritidis, S agona, S mbandaka, and S montevideo. Bulk tank milk filters from these dairies were also submitted for culture. Salmonella sp was isolated from 1 of the 50 filters, and 2 calves from this herd were found to be shedding Salmonella sp of the same serotype.     

如何降低家禽沙门氏菌感染的风险(续完)

3预防沙门氏菌传播的措施3.1卫生和消毒在引进新一批鸡群前,所有鸡舍和器具必须进行清洁消毒,特别是在前一批鸡群为沙门氏菌阳性的情况下,清洁消毒就更有必要。卫生措施的有效性可通过严格的细菌学定量检测验证,要求肠道细     

Reducing risks of Salmonella infections in poultry

3预防沙门氏菌传播的措施 3.1卫生和消毒 在引进新一批鸡群前,所有鸡舍和器具必须进行清洁消毒,特别是在前一批鸡群为沙门氏菌阳性的情况下,清洁消毒就更有必要.卫生措施的有效性可通过严格的细菌学定量检测验证,要求肠道细菌计数小于103个/25 m2.     

Host response to various treatments to reduce Salmonella infections in swine.

Host response was evaluated following the administration of various treatments, such as probiotics, prebiotics, and vaccination, to reduce Salmonella in swine. Response to the treatments were studied by the evaluation of phagocytosis rates by flow cytometry, by studying the activation of whole-blood phagocytes by bioluminescence, the production of IgA against S. Typhimurium, and by histopathology. Significant differences were observed in the activation of whole-blood phagocytes in all groups of treated pigs (P = 0.0001). In SC54 vaccinated pigs, a significant reduction of Salmonella in the ileum was observed (P < 0.05) and the production of IgA against S. Typhimurium was higher in this group in comparison to uninfected control pigs (P = 0.0007). Furthermore, significant histopathological (P < 0.05) changes were observed in SC54 vaccinated pigs. Villus height and mucus and goblet cells density in the small intestine were reduced in vaccinated pigs in comparison to infected control pigs. Taken together, these findings suggest that SC54 vaccine can stimulate local immunity and reduce the presence of Salmonella in the ileum in swine. Use of SC54 vaccine should thus be considered in further field experiments.     

Salmonella enterica infections in Spanish swine fattening units

The present study is the first conducted in Spain to estimate the bacteriological herd prevalence of Salmonella enterica in fattening units and to describe the Salmonella serovar diversity on these farms using a sample representative of the entire swine population. For this purpose, 10 faecal samples were collected from 10 different pens containing pigs close to market weight in a total of 232 fattening units. Total sample size was proportionally distributed according to the fattener census in each of the regions of the country and all the samples were examined by culture of 25 g of faecal material. One hundred (43.1%) farms had at least one Salmonella-positive sample (95% CI: 37-49.1%). Salmonella enterica was detected in 290 (12.5%) pooled faecal floor samples (95% CI: 11.2-13.8%). The apparent herd prevalence of salmonellosis was similar among multi-site, finishing and farrow to finish farms. Overall, 24 different serovars were identified, with S. Typhimurium, S. Rissen and S. Derby being the most common both at herd and sample level. Results of phage typing were available for the 91 isolates of S. Typhimurium. A total number of 10 different phage types were identified, with DT 193 being the most frequent. Phage types DT 104, DT 104b and DT U302, which have been associated with several multi-resistant patterns, accounted for 23% and 29% of the Typhimurium total isolates or Typhimurium infected farms respectively.     

Prevalence and antimicrobial susceptibility of Salmonella infections in free-range pigs

The prevalence of Salmonella spp. infection was determined in 67 free-range pig herds in southern Spain. Microbiological assessment was performed on ileocolic lymph nodes collected at slaughter according to ISO 6579:2002 procedures. Overall, 33% of herds were infected and the prevalence of infection was 5.3%. Salmonella spp. serovars most frequently isolated were Anatum and Typhimurium, although uncommon serovars such as Hessarek and Mikawasima were also detected. Isolates were tested against 16 antimicrobial agents and exhibited resistance to streptomycin (46%), tetracycline (30%), sulphonamides (25%) and ampicillin (23%) by the break-point method. Multi-drug resistance, defined as resistance to ≥ 4 antimicrobials, was 36%.