Factors That Affect Legionella Positivity in Healthcare Building Water Systems from a Large, National Environmental Surveillance Initiative.

Legionella growth in healthcare building water systems can result in legionellosis, making water management programs (WMPs) important for patient safety. However, knowledge is limited on Legionella prevalence in healthcare buildings. A dataset of quarterly water testing in Veterans Health Administration (VHA) healthcare buildings was used to examine national environmental Legionella prevalence from 2015 to 2018. Bayesian hierarchical logistic regression modeling assessed factors influencing Legionella positivity. The master dataset included 201,146 water samples from 814 buildings at 168 VHA campuses. Overall Legionella positivity over the 4 years decreased from 7.2 to 5.1%, with the odds of a Legionella-positive sample being 0.94 (0.90-0.97) times the odds of a positive sample in the previous quarter for the 16 quarters of the 4 year period. Positivity varied considerably more at the medical center campus level compared to regional levels or to the building level where controls are typically applied. We found higher odds of Legionella detection in older buildings (OR 0.92 [0.86-0.98] for each more recent decade of construction), in taller buildings (OR 1.20 [1.13-1.27] for each additional floor), in hot water samples (O.R. 1.21 [1.16-1.27]), and in samples with lower residual biocide concentrations. This comprehensive healthcare building review showed reduced Legionella detection in the VHA healthcare system over time. Insights into factors associated with Legionella positivity provide information for healthcare systems implementing WMPs and for organizations setting standards and regulations.

A novel ergonomic wheelchair reduces bacterial hand contamination.

OBJECTIVE: To determine whether bacterial contamination of rider's hands is less with a novel ergonomic wheelchair (EW) than a standard wheelchair (SW). EXPERIMENTAL DESIGN: After wheelchair hand rims were disinfected, volunteers wearing nitrile gloves propelled each wheelchair through a standardised "run" in hospital. Post-run cultures were obtained from riders' gloved hands. Bacterial hand counts were compared between runs matched by rider (same rider, different chairs) or time (different riders in each chair, running concurrently), and overall. SETTING: Minneapolis Veterans Affairs Health Care System (MVAHCS), a large tertiary care facility. PARTICIPANTS: Eleven employee volunteers. INTERVENTION: EW, as compared with SW. With SW, co-location of hand rims and tyres potentially exposes the user's hands to tyres, which risks contaminating the user's hands with ground-source bacteria. Our novel ergonomic wheelchair (EW) separates drive wheel and hand rims, potentially reducing hand contamination. MAIN OUTCOME MEASURE: Bacterial hand counts. RESULTS: Post-run bacterial hand counts were over 10-fold lower with the EW than the SW. This was true (i) when the same rider tested both chairs sequentially (n = 8 pairs) (median counts, 40 vs. 1030; p = 0.008), (ii) when different riders tested the two chairs concurrently (n = 9 pairs) (median counts, 40 vs. 660; p = 0.004), and (iii) overall (median counts, 40 [n = 9 runs] vs. 550 [n = 10 runs]; p < 0.001). CONCLUSION: Separation of wheelchair hand rims from tyres significantly reduces bacterial hand contamination. Reduced hand contamination could decrease bacterial infections and dissemination of resistant bacteria, warranting further study.Implications for rehabilitationThe novel design of the ergonomic wheelchair, removing the push rim from proximity to the wheelchair tyre, keeps the hands of wheelchair users cleaner.The re-design of the standard manual wheelchair was implemented initially to improve shoulder ergonomics during manual wheelchair propulsion and has the added benefit of reduction in the transfer of bacteria from floors to hands for manual wheelchair users.Since the ergonomic wheelchair has the potential to decrease rates of bacterial infection in manual wheelchair users, further testing is warranted.

Risk of surgical site infection after carpal tunnel release performed in an operating room versus a clinic-based procedure room within a Veterans Affairs medical center.

BACKGROUND: Carpal tunnel release (CTR) is increasingly performed in a clinic-based procedure room (PR) environment, which is less restrictive than traditional operating rooms (ORs). It is unknown if there is an impact on surgical site infection (SSI) rates. METHODS: Records of patients who underwent clean, elective CTR from October 2014 to April 2017 at a single site were identified using Current Procedural Terminology codes and charts reviewed using National Healthcare Safety Network SSI criteria. Procedure type and patient characteristics were assessed with multivariate logistic regression and costs compared using administrative data. RESULTS: A total of 312 procedures were included: 221 in OR and 91 in PR. SSI rate, including revisions, was 2.88% (nonrevision rate was 2.30%). Unadjusted SSI rate was 3.2% in OR and 2.2% in PR (P = .64). After adjusting for underlying risk factors, procedure setting was not associated with risk of SSI (P = .53; odds ratio, 0.43; 95% confidence interval, 0.03-5.94). Revision CTR was a predictor of SSI (P = .02; odds ratio, 28.21; 95% confidence interval, 1.84-434.57). The mean total cost of CTR in the OR was $4,254.21 and PR was $416.93. CONCLUSIONS: There was no significant difference in SSI rates for CTR performed in OR and PR environments. CTRs performed in a PR led to a 10-fold cost savings. Based on our findings of PRs as both safe and cost-effective, we recommend that more facilities explore the use of PRs for CTR.

Immunohistochemistry and electrophysiological findings in swine abattoir workers with immune-mediated polyradiculoneuropathy.

IMPORTANCE: Workers exposed to aerosolized brain in a swine-processing plant developed immune-mediated polyradiculoneuropathy (IP) possibly triggered by an immune response. OBJECTIVE: Immunohistochemistry results were correlated with electrophysiological variables to examine the immunopathogenesis of this disorder. DESIGN/SETTING: Laboratory studies used normal nerve tissue that was exposed to sera from 12 IP patients; 10 exposed controls; and 10 unexposed controls. Clinical and electrophysiological data from IP patients were obtained from medical record reviews. MAIN OUTCOME MEASURES: Analysis included electromyography results of IP patients and nerve conduction studies examining CMAP amplitude, distal motor latency, motor conduction velocity, F-wave latency, sensory nerve action potential amplitude, and sensory nerve conduction velocity. Case and control results were compared relative to distance from exposure. RESULTS: Electrodiagnostic findings revealed prolongation of the distal and f-wave latencies suggestive of demyelination at the level of the nerve root and distal nerve terminals. Immunohistochemical results identified an antibody to the peripheral nerve, with staining at the level of the axolemma. Thus, IP may be a primary axonopathy with secondary paranodal demyelination causing the conduction changes. Staining of the distal and proximal portions of the nerve appears consistent with easier access through the blood-nerve barrier. CONCLUSIONS AND RELEVANCE: IP is an immune-mediated neuropathy related to antibodies to an axon-based antigen on peripheral nerves. Secondary paranodal demyelination is likely. Further studies to identify the primary axonal antigenic target would be useful.

An outbreak of measles in an undervaccinated community.

Measles is readily spread to susceptible individuals, but is no longer endemic in the United States. In March 2011, measles was confirmed in a Minnesota child without travel abroad. This was the first identified case-patient of an outbreak. An investigation was initiated to determine the source, prevent transmission, and examine measles-mumps-rubella (MMR) vaccine coverage in the affected community. Investigation and response included case-patient follow-up, post-exposure prophylaxis, voluntary isolation and quarantine, and early MMR vaccine for non-immune shelter residents >6 months and <12 months of age. Vaccine coverage was assessed by using immunization information system records. Outreach to the affected community included education and support from public health, health care, and community and spiritual leaders. Twenty-one measles cases were identified. The median age was 12 months (range, 4 months to 51 years) and 14 (67%) were hospitalized (range of stay, 2-7 days). The source was a 30-month-old US-born child of Somali descent infected while visiting Kenya. Measles spread in several settings, and over 3000 individuals were exposed. Sixteen case-patients were unvaccinated; 9 of the 16 were age-eligible: 7 of the 9 had safety concerns and 6 were of Somali descent. MMR vaccine coverage among Somali children declined significantly from 2004 through 2010 starting at 91.1% in 2004 and reaching 54.0% in 2010 (χ(2) for linear trend 553.79; P < .001). This was the largest measles outbreak in Minnesota in 20 years, and aggressive response likely prevented additional transmission. Measles outbreaks can occur if undervaccinated subpopulations exist. Misunderstandings about vaccine safety must be effectively addressed.

Two concurrent enteric disease outbreaks among men who have sex with men, minneapolis-st paul area.

Between 1 November 2013 and 31 March 2014, concurrent shigellosis and cryptosporidiosis outbreaks occurred among men who have sex with men in the Minneapolis-St. Paul area, 75% of whom were HIV-infected. Current HIV/AIDS strategy emphasizing treatment as prevention may effectively decrease HIV transmission, but raises concerns about other diseases if safer sex messages are de-emphasized.

Foodborne outbreak of group a streptococcus pharyngitis associated with a high school dance team banquet--Minnesota, 2012.

BACKGROUND: On 20 March 2012, the Minnesota Department of Health (MDH) was notified of multiple Facebook postings suggestive of a foodborne outbreak of Group A Streptococcus (GAS) pharyngitis occurring among attendees of a high school dance team banquet. An investigation was initiated. METHODS: Associations between GAS pharyngitis and specific food items were assessed among banquet attendees. Pharyngeal swabs were performed on attendees, household contacts, and food workers. Patient GAS isolates from clinical laboratories were also obtained. Pharyngeal and food specimens were cultured for GAS by the MDH Public Health Laboratory. Isolates were further characterized by pulsed-field gel electrophoresis (PFGE) and emm typing. RESULTS: Among 63 persons who consumed banquet food, 18 primary illnesses occurred, yielding an attack rate of 29%. Although no food or beverage items were significantly associated with illness, pasta consumption yielded the highest relative risk (risk ratio, 3.56; 95% confidence interval, .25-50.6). GAS colonies with indistinguishable PFGE patterns corresponding to emm subtype 1.0 were isolated from 5 patients and from leftover pasta. The pasta was prepared at home by a dance team member parent; both parent and child reported GAS pharyngitis episodes 3 weeks before the banquet. CONCLUSIONS: In this foodborne outbreak of GAS pharyngitis, pasta was implicated as the vehicle. Recognition of foodborne GAS illness is challenging because transmission is typically assumed to occur by respiratory spread; foodborne transmission should be considered when clusters of GAS pharyngitis patients are encountered. DNA-based typing can reveal potentially epidemiologically related isolates during GAS disease outbreaks and facilitate understanding and control of GAS disease.

Satisfaction and public health cost of a statewide influenza nurse triage line in response to pandemic H1N1 influenza.

BACKGROUND: The 2009 H1N1 pandemic strained healthcare systems. There was a need for supportive services, rapid antiviral access, and minimization of unnecessary healthcare contacts particularly face-to-face interactions. In response, the Minnesota Department of Health (MDH) launched a telephone-based nurse triage line (NTL) called the Minnesota FluLine coordinating all major MN healthcare systems with NTLs to form a single toll-free number triage service. Callers were evaluated for symptoms of influenza-like illness (ILI) and were prescribed an antiviral if indicated, using nurse administered protocols. METHODS: To determine caller outcomes, associated healthcare seeking, and satisfaction a telephone survey of Minnesota FluLine callers was conducted using a 5% random sample of those who completed the protocol and those who did not. RESULTS: Of 6,122 callers with ILI who began the nurse protocol administered by the contract NTL, 1,221 people were contacted for the survey and 325 agreed to participate; response rate was 26%. Of those who completed the nurse protocol 73% said they would have sought healthcare without the Minnesota FluLine, 89% reported the service was moderately or very helpful, and 91% reported being satisfied or very satisfied. Of those not completing the protocol, 50% reported the service was moderately or very helpful and 50% reported being satisfied or very satisfied. 72% of qualitative responses to open-ended questions were positive regarding the MN FluLine. Cost to MDH for operating the Minnesota FluLine service was $331,226 to service 27,391 callers ($12.09/call). DISCUSSION: The Minnesota FluLine diverted patients with mild ILI symptoms away from acute care visits at low cost and had a high rate of satisfaction among callers. Early intervention likely prevented morbidity and possibly additional cases. NTLs are powerful and flexible tools for pandemic response and should be considered as an important tool for future emergency responses.

Allocating resources during a crisis: you can't always get what you want.

During a disaster or disease outbreak, health care providers may have to make difficult decisions about how to allocate scarce resources. A committee convened by the Minnesota Department of Health has recently focused on this issue as part of statewide disaster preparedness planning. This article presents the group's recommendation that health care facilities need to plan for shortages and introduces resources and strategies that can be used in planning. It also discusses ethical considerations that must be taken into account when shortages occur and decisions must be made about how to distribute equipment, supplies, or medications in short supply.

Impact of USA300 methicillin-resistant Staphylococcus aureus on clinical outcomes of patients with pneumonia or central line-associated bloodstream infections.

BACKGROUND: The USA300 methicillin-resistant Staphylococcus aureus (MRSA) strain, which initially emerged as a cause of community-associated infections, has recently become an important pathogen in healthcare-associated infections (HAIs). However, its impact on patient outcomes has not been well studied. We evaluated patients with invasive MRSA infections to assess differences in outcomes between infections caused by USA100 and those caused by USA300. METHODS: Population-based data for invasive MRSA infections were used to identify 2 cohorts: (1) nondialysis patients with central line-associated bloodstream infections (CLABSIs) and (2) patients with community-onset pneumonia (PNEUMO) during 2005-2007 from 6 US metropolitan areas. Medical records of patients with confirmed MRSA USA100 or USA300 infection were reviewed. Logistic regression and, when appropriate, survival analysis was performed to evaluate mortality, early and late complications, and length of stay. RESULTS: A total of 236 and 100 patients were included in the CLABSI and PNEUMO cohorts, respectively. USA300 was the only independent predictor of early complications for PNEUMO patients (odds ratio [OR], 2.6; P = .02). Independent predictors of CLABSI late complications included intensive care unit (ICU) admission before MRSA culture (adjusted OR [AOR], 2.1; P= .01) and Charlson comorbidity index (AOR, 2.6; P = .003), but not strain type. PNEUMO patients were significantly more likely to die if they were older (P = .02), black (P < .001), or infected with USA100 strain (P = .02), whereas those with CLABSI were more likely to die if they were older (P < .001), had comorbidities (P < .001), or had an ICU admission before MRSA culture (P = .001). CONCLUSIONS: USA300 was associated with early complications in PNEUMO patients. However, it was not associated with mortality for either PNEUMO or CLABSI patients. Concerns regarding higher mortality from HAIs caused by USA300 may not be warranted.

Fatal Naegleria fowleri infection acquired in Minnesota: possible expanded range of a deadly thermophilic organism.

BACKGROUND: Primary amebic meningoencephalitis (PAM), caused by the free-living ameba Naegleria fowleri, has historically been associated with warm freshwater exposures at lower latitudes of the United States. In August 2010, a Minnesota resident, aged 7 years, died of rapidly progressive meningoencephalitis after local freshwater exposures, with no history of travel outside the state. PAM was suspected on the basis of amebae observed in cerebrospinal fluid. METHODS: Water and sediment samples were collected at locations where the patient swam during the 2 weeks preceding illness onset. Patient and environmental samples were tested for N. fowleri with use of culture and real-time polymerase chain reaction (PCR); isolates were genotyped. Historic local ambient temperature data were obtained. RESULTS: N. fowleri isolated from a specimen of the patient's brain and from water and sediment samples was confirmed using PCR as N. fowleri genotype 3. Surface water temperatures at the times of collection of the positive environmental samples ranged from 22.1°C to 24.5°C. August 2010 average air temperature near the exposure site was 25°C, 3.6°C above normal and the third warmest for August in the Minneapolis area since 1891. CONCLUSIONS: This first reported case of PAM acquired in Minnesota occurred 550 miles north of the previously reported northernmost case in the Americas. Clinicians should be aware that N. fowleri-associated PAM can occur in areas at much higher latitude than previously described. Local weather patterns and long-term climate change could impact the frequency of PAM.

Staphylococcal toxic shock syndrome 2000-2006: epidemiology, clinical features, and molecular characteristics.

INTRODUCTION: Circulating strains of Staphylococcus aureus (SA) have changed in the last 30 years including the emergence of community-associated methicillin-resistant SA (MRSA). A report suggested staphylococcal toxic shock syndrome (TSS) was increasing over 2000-2003. The last population-based assessment of TSS was 1986. METHODS: Population-based active surveillance for TSS meeting the CDC definition using ICD-9 codes was conducted in the Minneapolis-St. Paul area (population 2,642,056) from 2000-2006. Medical records of potential cases were reviewed for case criteria, antimicrobial susceptibility, risk factors, and outcome. Superantigen PCR testing and PFGE were performed on available isolates from probable and confirmed cases. RESULTS: Of 7,491 hospitalizations that received one of the ICD-9 study codes, 61 TSS cases (33 menstrual, 28 non-menstrual) were identified. The average annual incidence per 100,000 of all, menstrual, and non-menstrual TSS was 0.52 (95% CI, 0.32-0.77), 0.69 (0.39-1.16), and 0.32 (0.12-0.67), respectively. Women 13-24 years had the highest incidence at 1.41 (0.63-2.61). No increase in incidence was observed from 2000-2006. MRSA was isolated in 1 menstrual and 3 non-menstrual cases (7% of TSS cases); 1 isolate was USA400. The superantigen gene tst-1 was identified in 20 (80%) of isolates and was more common in menstrual compared to non-menstrual isolates (89% vs. 50%, p = 0.07). Superantigen genes sea, seb and sec were found more frequently among non-menstrual compared to menstrual isolates [100% vs 25% (p = 0.4), 60% vs 0% (p<0.01), and 25% vs 13% (p = 0.5), respectively]. DISCUSSION: TSS incidence remained stable across our surveillance period of 2000-2006 and compared to past population-based estimates in the 1980s. MRSA accounted for a small percentage of TSS cases. tst-1 continues to be the superantigen associated with the majority of menstrual cases. The CDC case definition identifies the most severe cases and has been consistently used but likely results in a substantial underestimation of the total TSS disease burden.

Vaccine-derived poliomyelitis 12 years after infection in Minnesota.

A 44-year-old woman with long-standing common variable immunodeficiency who was receiving intravenous immune globulin suddenly had paralysis of all four limbs and the respiratory muscles, resulting in death. Type 2 vaccine-derived poliovirus was isolated from stool. The viral capsid protein VP1 region had diverged from the vaccine strain at 12.3% of nucleotide positions, and the two attenuating substitutions had reverted to the wild-type sequence. Infection probably occurred 11.9 years earlier (95% confidence interval [CI], 10.9 to 13.2), when her child received the oral poliovirus vaccine. No secondary cases were identified among close contacts or 2038 screened health care workers. Patients with common variable immunodeficiency can be chronically infected with poliovirus, and poliomyelitis can develop despite treatment with intravenous immune globulin.

Attitudes toward and uptake of H1N1 vaccine among health care workers during the 2009 H1N1 pandemic.

BACKGROUND: Though recommended by many and mandated by some, influenza vaccination rates among health care workers, even in pandemics, remain below optimal levels. The objective of this study was to assess vaccination uptake, attitudes, and distinguishing characteristics (including doctor-nurse differences) of health care workers who did and did not receive the pandemic H1N1 influenza vaccine in late 2009. METHODOLOGY/PRINCIPAL FINDINGS: In early 2010 we mailed a self-administered survey to 800 physicians and 800 nurses currently licensed and practicing in Minnesota. 1,073 individuals responded (cooperation rate: 69%). 85% and 62% of Minnesota physicians and nurses, respectively, reported being vaccinated. Accurately estimating the risk of vaccine side effects (OR 2.0; 95% CI 1.5-2.7), agreeing with a professional obligation to be vaccinated (OR 10.1; 95% CI 7.1-14.2), an ethical obligation to follow public health authorities' recommendations (OR 9.9; 95% CI 6.6-14.9), and laws mandating pandemic vaccination (OR 3.1; 95% CI 2.3-4.1) were all independently associated with receiving the H1N1 influenza vaccine. CONCLUSIONS/SIGNIFICANCE: While a majority of health care workers in one midwestern state reported receiving the pandemic H1N1 vaccine, physicians and nurses differed significantly in vaccination uptake. Several key attitudes and perceptions may influence health care workers' decisions regarding vaccination. These data inform how states might optimally enlist health care workers' support in achieving vaccination goals during a pandemic.

Epidemiologic investigation of immune-mediated polyradiculoneuropathy among abattoir workers exposed to porcine brain.

BACKGROUND: In October 2007, a cluster of patients experiencing a novel polyradiculoneuropathy was identified at a pork abattoir (Plant A). Patients worked in the primary carcass processing area (warm room); the majority processed severed heads (head-table). An investigation was initiated to determine risk factors for illness. METHODS AND RESULTS: Symptoms of the reported patients were unlike previously described occupational associated illnesses. A case-control study was conducted at Plant A. A case was defined as evidence of symptoms of peripheral neuropathy and compatible electrodiagnostic testing in a pork abattoir worker. Two control groups were used - randomly selected non-ill warm-room workers (n = 49), and all non-ill head-table workers (n = 56). Consenting cases and controls were interviewed and blood and throat swabs were collected. The 26 largest U.S. pork abattoirs were surveyed to identify additional cases. Fifteen cases were identified at Plant A; illness onsets occurred during May 2004-November 2007. Median age was 32 years (range, 21-55 years). Cases were more likely than warm-room controls to have ever worked at the head-table (adjusted odds ratio [AOR], 6.6; 95% confidence interval [CI], 1.6-26.7), removed brains or removed muscle from the backs of heads (AOR, 10.3; 95% CI, 1.5-68.5), and worked within 0-10 feet of the brain removal operation (AOR, 9.9; 95% CI, 1.2-80.0). Associations remained when comparing head-table cases and head-table controls. Workers removed brains by using compressed air that liquefied brain and generated aerosolized droplets, exposing themselves and nearby workers. Eight additional cases were identified in the only two other abattoirs using this technique. The three abattoirs that used this technique have stopped brain removal, and no new cases have been reported after 24 months of follow up. Cases compared to controls had higher median interferon-gamma (IFNgamma) levels (21.7 pg/ml; vs 14.8 pg/ml, P<0.001). DISCUSSION: This novel polyradiculoneuropathy was associated with removing porcine brains with compressed air. An autoimmune mechanism is supported by higher levels of IFNgamma in cases than in controls consistent with other immune mediated illnesses occurring in association with neural tissue exposure. Abattoirs should not use compressed air to remove brains and should avoid procedures that aerosolize CNS tissue. This outbreak highlights the potential for respiratory or mucosal exposure to cause an immune-mediated illness in an occupational setting.

An outbreak of neurological autoimmunity with polyradiculoneuropathy in workers exposed to aerosolised porcine neural tissue: a descriptive study.

BACKGROUND: Between November, 2006, and May, 2008, a subacute neurological syndrome affected workers from two swine abattoirs in Minnesota and Indiana who had occupational exposure to aerosolised porcine brain. We aimed to describe the pathogenic and immunological characteristics of this illness. METHODS: All patients from two abattoirs who presented or were referred to the Mayo Clinic (Rochester, MN, USA) with neurological symptoms were included. We recorded details of exposure to aerosolised brain tissue and did comprehensive neurological, laboratory, neuroimaging, electrophysiological, pathological, and autoimmune serological assessments. Healthy controls were recruited from the community and from workers at the plant in Minnesota. FINDINGS: 24 patients were identified (21 from Minnesota, three from Indiana). The shortest duration from first exposure to symptom onset was 4 weeks. No infectious agent that could trigger disease was identified. All patients developed polyradiculoneuropathy, which was usually sensory predominant and painful. Two patients had initial CNS manifestations: transverse myelitis and meningoencephalitis. Nerve conduction studies localised abnormalities to the most proximal and distal nerve segments. Quantitative sensory and autonomic testing revealed involvement of large and small sensory fibres and sweat fibres. MRI showed prominent abnormalities of roots and ganglia. Nerve biopsies identified mild demyelination, axonal degeneration, and perivascular inflammation. Protein concentrations were high in the CSF of 18 (86%) of 21 patients. Sera from all patients and 29 (34%) of 85 unaffected workplace controls (but none of 178 community controls) had a distinctive neural-reactive IgG; 75% of patients' sera contained an IgG specific to myelin basic protein. Seropositivity correlated directly with exposure risk in patients and controls. 17 patients required immunomodulatory therapies, six improved spontaneously, and one was lost to follow-up after exposure stopped. INTERPRETATION: The neurological disorder described is autoimmune in origin and is related to occupational exposure to multiple aerosolised porcine brain tissue antigens. The pattern of nerve involvement suggests vulnerability of nerve roots and terminals where the blood-nerve barrier is most permeable. FUNDING: Mayo Clinic Foundation; Minnesota Department of Health; Centers for Disease Control and Prevention.