An outbreak of multi-resistant Shigella sonnei in a long-stay geriatric nursing centre.

We report on an outbreak of Shigella sonnei infections involving ten cases notified through the laboratory surveillance system in Denmark in April and May. The likely source was consumption of fresh, raw sugar peas (sugar snaps) imported from Africa. This conclusion was based on interviews with cases and on the occurrence of a similar outbreak one month later in Norway. Fresh imported produce may occasionally be contaminated with pathogenic bacteria even when sold as ready-to-eat.

We report a Shigella sonnei outbreak of 46 cases that occurred in Norway during October 2011. Two municipalities were involved. A large cluster (42 cases)was concentrated in north Norway, while a smallcluster (4 cases) occurred in the south-east region.Epidemiological evidence and trace back investigations have linked the outbreak to the consumption of imported fresh basil. The product has been withdrawn from the market. No further cases have been reported since 25 October.

In May 2009, the Norwegian Institute of Public Health (NIPH) identified a possible outbreak of Shigella sonnei infection involving four cases. Additionally, five suspected cases in two separate households were reported. Inspectors from the Norwegian Food Safety Authority (NFSA) visited the two households and found an unopened package of sugar peas imported from Kenya in one of the households. One sample from the sugar peas was positive for Shigella sonnei by two PCR methods. Based on this result and information from patient interviews, the NFSA prohibited all sales of sugar peas imported from Kenya.

Background: Shoulder arthroscopy is well established as a highly effective and safe procedure for the treatment for several shoulder disorders and is associated with an exceedingly low risk of infectious complications. Few data exist regarding risk factors for infection after shoulder arthroscopy, as previous studies were not adequately powered to evaluate for infection. Purpose: To determine patient-related risk factors for infection after shoulder arthroscopy by using a large insurance database. Study Design: Case-control study; Level of evidence, 3. Methods: The PearlDiver patient records database was used to query the 100% Medicare Standard Analytic Files from 2005 to 2014 for patients undergoing shoulder arthroscopy. Patients undergoing shoulder arthroscopy for a diagnosis of infection or with a history of prior infection were excluded. Postoperative infection within 90 days postoperatively was then assessed with International Classification of Diseases, Ninth Revision codes for a diagnosis of postoperative infection or septic shoulder arthritis or a procedure for these indications. A multivariate binomial logistic regression analysis was then utilized to evaluate the use of an intraoperative steroid injection, as well as numerous patient-related risk factors for postoperative infection. Adjusted odds ratios (ORs) and 95% CIs were calculated for each risk factor, with P < .05 considered statistically significant. Results: A total of 530,754 patients met all inclusion and exclusion criteria. There were 1409 infections within 90 days postoperatively (0.26%). Revision shoulder arthroscopy was the most significant risk factor for infection (OR, 3.25; 95% CI, 2.7-4.0; P < .0001). Intraoperative steroid injection was also an independent risk factor for postoperative infection (OR, 1.46; 95% CI, 1.2-1.9; P = .002). There were also numerous independent patient-related risk factors for infection, the most significant of which were chronic anemia (OR, 1.58; 95% CI, 1.4-1.8; P < .0001), malnutrition (OR, 1.42; 95% CI, 1.2-1.7; P = .001), male sex (OR, 2.71; 95% CI, 2.4-3.1; P < .0001), morbid obesity (OR, 1.41; 95% CI, 1.2-1.6; P < .0001), and depression (OR, 1.36; 95% CI, 1.2-1.5; P < .0001). Conclusion: Intraoperative steroid injection was a significant independent risk factor for postoperative infection after shoulder arthroscopy. There were also numerous significant patient-related risk factors for postoperative infection, including revision surgery, obesity, male sex, chronic anemia, malnutrition, depression, and alcohol use, among others.

To describe the clinical features of infection, and the antibiotic susceptibility of epidemic strains, and investigate plasmid maps and integrons of the isolates from an outbreak of Shigella sonnei infection at an elementary school in southwest China. Cross-sectional study. An elementary school and five hospitals in Chengdu in southwest China. There were 1,134 students in the school. 937 (82.6%) students had signs and symptoms. Of the 568 (60.6%, 568/937) hospitalized students, 93.3% 86.8%, 72.4%, and 28.9% of the hospitalized patients had diarrhea, fever, abdominal pain, and vomiting, respectively. S. sonnei strains were isolated from the stool samples of 36.0% (337/937) students. All of the outbreak isolates had the same high-level antimicrobial resistance and plasmid profiles, which were different from that of sporadic strains. All the outbreak S. sonnei isolates were positive for the integrin gene and contained class 2 integron; however, two outbreak isolates contained class 1 and class 2 integrons. Diarrhea, fever, and abdominal pain were the three most common clinical manifestations observed in patients infected with S. sonnei. High-level antibiotic resistance was observed among Shigella species.

Intraventricular hemorrhage in premature infants often leads to progressive ventricular dilation and the need for ventricular reservoir placement. Unfortunately, these reservoirs have a higher rate of infection than ventriculoperitoneal shunts in premature babies. The authors analyzed the risk factors for infection in this population and studied whether the implementation of an institutional protocol for shunt placement had a corollary effect on ventricular access device (VAD) infection rates in premature neonates with intraventricular hemorrhage. The authors conducted a retrospective cohort review of consecutive premature neonates in whom VADs were inserted in the operating room at Primary Children's Hospital between June 2003 and June 2011 to identify risk factors for infection. Medical records were reviewed for information on infection (culture proven or eroded hardware at 90 days), gestational age at birth, weight, gestational age at surgery, intrathecal antibiotics, hemorrhage, death, and surgeon. The institution used a pilot protocol for shunt infection reduction in 2006-2007, and then the full Hydrocephalus Clinical Research Network protocol from June 2007 to 2011, and the rates of infection during these periods were analyzed. Confounding factors such as sepsis, necrotizing enterocolitis, and a history of meningitis were also analyzed. The overall infection rate was 10.5% (11 patients) in the 105 patients identified. Gestational age at procedure was a significant risk factor for infection (p=0.05). Meningitis was significantly associated with infection, with 63% of the infected group having had prior meningitis compared with 7% for the noninfected group (p<0.001). Concurrent with the implementation of the protocol to reduce shunt infection, the VAD infection rate decreased from 14.7% to 5.4% (p=0.2). Gestational age at procedure and previous meningitis were significant risk factors for VAD infections. In addition, the implementation of an institutional standardized shunt protocol for ventriculoperitoneal shunts may have altered the operating room team's behavior, indicated by a nonmandated use of intrathecal antibiotics in VAD surgeries, contributing to a reduced VAD infection rate. Although the observed difference was not statistically significant with the small sample size, the authors believe that these findings deserve further study.

Background/Aims:It has been shown that circulating tumor necrosis factor α (TNF-α) is elevated in end stage renal disease patients; however, the relationship between TNF-α and the development of infection in these patients is unknown. In this study, we investigated the association of plasma TNF-α and interleukin 6 (IL-6) with infection in peritoneal dialysis (PD) patients. We also evaluated the association of their plasma levels with the production by peripheral blood mononuclear cells (PBMC), and with various clinical parameters.Methods:We enrolled 32 patients on maintenance PD and 10 healthy controls. Plasma and PBMC were isolated from blood. PBMC were stimulated with lipopolysaccharide in vitro.Results:Mean follow-up duration was 775 days. Six patients developed organ infections (five pneumonia and one liver abscess), and six patients developed PD peritonitis and eight developed exit site infection. Plasma TNF-α and IL-6 levels were significantly elevated in organ infections but not in peritonitis or in exit site infection. Plasma TNF-α was the only significant risk factor for organ infections and pneumonia in multivariate regression analysis. Patients with high plasma TNF-α levels showed a significantly greater cumulative hazard rate for organ infections compared to those with low TNF-α levels. Plasma TNF-α levels correlated with TNF-α production by PBMC and showed an inverse association with Kt/V.Conclusions:This is the first study showing that plasma TNF-α is a significant risk factor for infection in PD patients.

Background: To prevent the spread of infectious diseases, several state armies implemented obligatory vaccination programs also practiced in the former Yugoslav National Army (YNA). Iatrogenic hepatitis B virus (HBV) transmissions during vaccinations in the armies were well documented, but to the best of our knowledge, no such study has been performed in the former Yugoslavia. Objectives: In the present study, we determined risk factors for acquiring chronic hepatitis B (CHB) infection in patients in Slovenia. This study focused on the detection of a statistically significant risk factor in males, namely “vaccination in the YNA”. Methods: One thousand seven hundred and twenty-nine patients from all Slovenian regions who tested positive for HBV surface antigen (HBsAg) at the national referential laboratory for viral hepatitis diagnostics between January 1997 and December 2010 were included retrospectively. Accordingly, demographic, epidemiological, virological, and clinical data were extracted from the medical documentation and were statistically analyzed. Results: For 1,122 (64.9%) out of 1,729 patients, data regarding risk factors for acquiring HBV infection were available. The risk factor for infection of almost 60% of HBV chronically infected individuals with available data, followed by “HBV infection in the family” (19.8%) and “blood/blood products transfusion before the nineties” (8%) was unknown. Seven males (0.6%) (mean age ± SD, 53.7 ± 4.50 years) reported “vaccination in the YNA” as a risk factor for acquiring chronic HBV infection. “Vaccination in the YNA” was a significant risk factor for CHB infection in men over 46 years of age (P = 0.006). Conclusions: A significant risk factor for infection in Slovenian men over 46 years of age was identified as “vaccination in the YNA”, which is specific to this geographic region and, to the best of our knowledge, has not been previously described in the peer-reviewed literature.

Surgical site infections increase the incidence of morbidity and mortality as well as health-care expenses. The cost of care increases threefold to fourfold as a consequence of surgical site infection after spinal surgery. The aim of the present study was to determine the role of subcutaneous fat thickness in the development of surgical site infection following cervical spine fusion surgery. We performed a retrospective review of a consecutive cohort of 213 adult patients who underwent posterior cervical spine fusion between 2006 and 2008 at Duke University Medical Center. The horizontal distance from the lamina to the skin surface at the C5 level and the thickness of subcutaneous fat were measured, and the ratio of the fat thickness to the total distance at the surgical site was determined. Previously identified risk factors for the development of surgical site infection were also recorded. Twenty-two of the 213 patients developed a postoperative infection. Obesity (body mass index ≥ 30 kg/m2) was not a significant risk factor for surgical site infection; the body mass index (and 95% confidence interval) was 29.4 ± 1.2 kg/m2 in the patients who developed a surgical site infection compared with 28.9 ± 0.94 kg/m2 in the patients without an infection. However, the thickness of subcutaneous fat and the ratio of the fat thickness to the lamina-to-skin distance were both significant risk factors for infection. The thickness of subcutaneous fat was 27.0 ± 2.5 mm in the patients who developed a surgical site infection group compared with 21.4 ± 0.88 mm in the patients without an infection (p = 0.042). The ratio of fat thickness to total thickness was 0.42 ± 0.019 in the patients who developed a surgical site infection compared with 0.35 ± 0.01 in the patients without an infection (p = 0.020). Multivariate analysis revealed this ratio to be an independent risk factor for developing a postoperative infection (odds ratio, 3.18; 95% confidence interval, 1.02 to 9.97). The study demonstrated that the thickness of subcutaneous fat at the surgical site is a factor in the development of surgical site infection following cervical spine fusion and deserves assessment in the preoperative evaluation.

Osteoarthritis is associated with a strong biomechanical component. Persistent pain in the index knee after total knee arthroplasty could lead to pain in the contralateral knee. The purpose of the present study was to examine whether a change in the natural history of pain in the contralateral knee was related to postoperative pain in the index knee. Seven hundred and seventy-two patients undergoing primary unilateral total knee arthroplasty with use of the Kinemax prosthesis for the treatment of osteoarthritis comprised the cohort (Kinemax Outcomes Study cohort). Patients were assessed preoperatively and were followed for twenty-four months after surgery with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). We collected separate WOMAC pain scores for the index knee and the contralateral knee. Our primary outcome measure was the WOMAC pain score (rescaled to 100, with 100 being the best score) for the contralateral knee at three, twelve, and twenty-four months. We examined whether within-subject changes in the WOMAC pain score for the contralateral knee were predicted by the WOMAC pain score for the index knee at three months with use of linear regression and multilevel models after adjustment for sex, age, country, body mass index, income, and mental well-being. Improvement in terms of pain was observed in both the index and contralateral knees between baseline and three months. Subsequently, there was a modest deterioration of 3.5 units per year (standard deviation, 9.8 units per year) in the contralateral knee (p < 0.001), which was not predicted by pain in the index knee shortly after surgery (p > 0.6). Pain in the index knee at three months after total knee arthroplasty did not appear to predict a symptomatic increase in pain in the contralateral knee over two years of follow-up in our cohort. The contralateral knee did not require any additional clinical surveillance over and above the patients' reports on their symptoms.

During 1994-1996, Shigella sonnei outbreaks occurred in 8 North American traditionally observant Jewish communities. These communities remain relatively separate from neighboring populations while maintaining close contact by travel with coreligionists in other cities. Epidemiologic investigations suggested community-to-community transmission via travel. Outbreak-related and control isolates of S. sonnei from each city were subtyped by pulsed-field gel electrophoresis (PFGE) to confirm an epidemiologic linkage between outbreaks. Forty-three (94%) of 46 outbreak-related isolates had closely related PFGE patterns, constituting a single subtype; 33 (94%) of 35 control isolates demonstrated unrelated PFGE patterns. Several patterns differing by < or = 3 bands were identified within the outbreak subtype; one of these accounted for 65% of outbreak isolates. Hence, a single subtype of S. sonnei caused an international outbreak involving 8 traditionally observant Jewish communities, but not neighboring populations, over a 2-year period, suggesting sustained propagation of the epidemic strain between communities.

In early September 2006, the Norwegian Institute of Public Health was alerted to an outbreak of Shigella sonnei infections (shigellosis) among 23 Norwegian passengers who had taken a bus tour from Kirkenes, Norway to Murmansk, Russia. The trip lasted from 27 to 31 August, and the group stayed in various hotels and visited several restaurants in both Kirkenes and Murmansk during this period. Stool samples from three ill passengers yielded S. sonnei; an additional 10 passengers had gastrointestinal symptoms with diarrhoea or loose stools with abdominal pain. An investigation was initiated in collaboration with the department of epidemiological surveillance in Murmansk. We sent a questionnaire to the work e-mail addresses of all passengers asking about symptoms and exposures. Two restaurants and a hotel visited by the Norwegian tourists in Murmansk were inspected and sampled. Of all the food and beverage items mentioned in the questionnaire, only cured meat consumed in restaurant A in Murmansk on 28 August was associated with the risk of developing illness. Inspections of the restaurants in Murmansk identified some hygienic shortcomings and inadequate routines. However, S. sonnei could not be isolated from food samples or the personnel. Improved routines were implemented.

Smoking as a Significant Risk Factor for Infections After Orthognathic Surgery

Pathogenesis of Shigellosis

An outbreak of Shigella sonnei infection associated with consumption of iceberg lettuce.