Zoltan L. Apa

Staphylococcus aureus Oropharyngeal Carriage in a Prison Population

Throat carriage (42.7%) of Staphylococcus aureus exceeded nasal carriage (35.0%) in 2 New York prisons. Methicillin resistance, primarily due to USA300, was high at both sites; 25% of dually colonized inmates had different strains. Strategies to reduce S. aureus transmission will need to consider the high frequency of throat colonization.

Challenges and Strategies for Research in Prisons

In this article, we discuss some of the challenges encountered while conducting research in two maximum security prisons and approaches we found helpful to facilitate the research process through the development of collaborative relationships, the establishment of prison contacts, and the implementation of rigorous research methods. As a result of our experiences, we have been successful at maintaining a high rate of inmate participation (>80%) and a well-functioning multidisciplinary team. The approaches described may be useful to other investigators planning to conduct research in a challenging setting such as prisons.

Prevalence and risk factors for Staphylococcus aureus colonization in individuals entering maximum-security prisons

To assess the prevalence and risk factors for colonization with Staphylococcus aureus in inmates entering two maximum-security prisons in New York State, USA, inmates (N=830) were interviewed and anterior nares and oropharyngeal samples collected. Isolates were characterized using spa typing. Overall, 50·5% of women and 58·3% of men were colonized with S. aureus and 10·6% of women and 5·9% of men were colonized with MRSA at either or both body sites. Of MSSA isolates, the major subtypes were spa type 008 and 002. Overall, risk factors for S. aureus colonization varied by gender and were only found in women and included younger age, fair/poor self-reported general health, and longer length of prior incarceration. Prevalence of MRSA colonization was 8·2%, nearly 10 times greater than in the general population. Control of epidemic S. aureus in prisons should consider the constant introduction of strains by new inmates.

Task Demand Influences Relationships Among Sex, Clustering Strategy, and Recall: 16-Word Versus 9-Word List Learning Tests

Objective:We compared the relationships among sex, clustering strategy, and recall across different task demands using the 16-word California Verbal Learning Test-Second Edition (CVLT-II) and the 9-word Philadelphia (repeatable) Verbal Learning Test (PrVLT). Background:Women generally score higher than men on verbal memory tasks, possibly because women tend to use semantic clustering. This sex difference has been established via word-list learning tests such as the CVLT-II. Methods:In a retrospective between-group study, we compared how 2 separate groups of cognitively healthy older adults performed on a longer and a shorter verbal learning test. The group completing the CVLT-II had 36 women and 26 men; the group completing the PrVLT had 27 women and 21 men. Results:Overall, multiple regression analyses revealed that semantic clustering was significantly associated with total recall on both tests’ lists (P<0.001). Sex differences in recall and semantic clustering diminished with the shorter PrVLT word list. Conclusions:Semantic clustering uniquely influenced recall on both the longer and shorter word lists. However, serial clustering and sex influenced recall depending on the length of the word list (ie, the task demand). These findings suggest a complex nonlinear relationship among verbal memory, clustering strategies, and task demand.

Epidemiological and Biological Determinants of Staphylococcus aureus Clinical Infection in New York State Maximum Security Prisons

BACKGROUND Large outbreaks of Staphylococcus aureus (SA) infections have occurred in correctional facilities across the country. We aimed to define the epidemiological and microbiological determinants of SA infection in prisons to facilitate development of prevention strategies for this underserved population. METHODS We conducted a case-control study of SA infection at 2 New York State maximum security prisons. SA-infected inmates were matched with 3 uninfected controls. Subjects had cultures taken from sites of infection and colonization (nose and throat) and were interviewed via structured questionnaire. SA isolates were characterized by spa typing. Bivariate and multivariable analyses were conducted using conditional logistic regression. RESULTS Between March 2011 and January 2013, 82 cases were enrolled and matched with 246 controls. On bivariate analysis, the use of oral and topical antibiotics over the preceding 6 months was strongly associated with clinical infection (OR, 2.52; P < .001 and 4.38, P < .001, respectively). Inmates with clinical infection had 3.16 times the odds of being diabetic compared with inmates who did not have clinical infection (P < .001). Concurrent nasal and/or oropharyngeal colonization was also associated with an increased odds of infection (OR, 1.46; P = .002). Among colonized inmates, cases were significantly more likely to carry the SA clone spa t008 (usually representing the epidemic strain USA300) compared to controls (OR, 2.52; P = .01). CONCLUSIONS Several inmate characteristics were strongly associated with SA infection in the prison setting. Although many of these factors were likely present prior to incarceration, they may help medical staff identify prisoners for targeted prevention strategies.

Is Environmental Contamination Associated with Staphylococcus aureus Clinical Infection in Maximum Security Prisons

Over the past decade, large outbreaks of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have occurred in correctional facilities across the country.1,2 Although many have been managed with aggressive interventions, response to standard infection control procedures has been variable, highlighting our incomplete understanding of staphylococcal transmission in this setting.2 Environmental contamination has recently emerged as a possible target for novel prevention and control strategies.3,4 This study sought to characterize the relationship between environmental contamination and clinical infection in this vulnerable population. We conducted a case-control study of S. aureus environmental contamination at 2 New York State (NYS) maximum security prisons: Sing Sing (men) and Bedford Hills (women). Prisoners with documented S. aureus skin infections were identified by medical personnel at each prison. For every case, 2 uninfected controls—1 nasally and/or oropharyngeally colonized with S. aureus and 1 noncolonized—were selected from the same prison in a contemporaneous fashion. These were identified through our research group’s ongoing study of S. aureus colonization in NYS prisons.5 Consenting study participants had a standardized set of environmental surfaces cultured within 1 week of infection diagnosis (cases) or selection (controls). These included bed sheets, sink handles, toilet flushes, toilet seats, cell bars, light switches, soap dishes, window handles, locker handles, and radios but varied on the basis of the prisoner’s cell contents. Cultures were also obtained from shared gymnasiums in each prison at study initiation. All samples were collected using premoistened rayon-tipped swabs and qualitatively cultured as described else-where.5 S. aureus isolates were typed by polymerase chain reaction sequencing of the spa (staphylococcal protein A) gene.6 SAS (ver. 9.2; SAS Institute) was utilized for data analysis. The study was approved by the Columbia University and NYS Department of Corrections Institutional Review Boards. Ten cases were enrolled in this study. Twenty controls were selected, but 2 did not meet inclusion criteria. There were no significant associations between case status and the demographic and exposure variables assessed (sex, age, race/ ethnicity, self-perceived health, shower frequency, and gym use). The proportion of subjects with S. aureus contamination on 1 or more surfaces did not vary appreciably on the basis of infection status (3/10 cases [30%] vs 6/18 controls overall [33.3%]; Table 1). Despite this, environmental contamination of controls varied depending on their colonization status. Surface contamination, when present, was more frequent among cases than among controls (13/18 surfaces from 3 cases [72.2%] vs 20/43 surfaces from 6 controls [46.5%]; P = .07). Six clonal types were identified on surfaces of the 9 contaminated cells; only 1 cell had more than 1 clone present. None of the infectious, colonization, or personal environmental isolates were methicillin resistant. TABLE 1 Environmental Contamination of Cases and Controls Of the 20 items sampled in the Sing Sing gymnasium, 8 (40%) were positive for S. aureus. These included the gym door handle, boxing gloves, basketballs, abdominal crunch machine, seated and upright leg presses, and hand sanitizer dispenser. Among these surfaces, 6 clonal types were found (spa t002, t008, t334, t701, t1510, and t2334), and all were methicillin susceptible. The Bedford Hills gymnasium was not heavily contaminated; 2 (7.7%) of 26 surfaces were positive, 1 with methicillin-resistant spa t008. Few studies have assessed the prevalence and significance of bacterial surface contamination in jails or prisons. In 2009, Felkner et al7 cultured 132 surfaces from a Texas jail in a nonoutbreak setting. S. aureus was recovered from 10 surfaces (7.6%), with the majority of isolates (8/10) resistant to methicillin. A subset of isolates (6/10) underwent pulsed-field gel electrophoresis, and two-thirds were found to be identical to the USA300 epidemic strain (spa t008). Inmates at Sing Sing and Bedford Hills are known to have high rates of asymptomatic colonization with MRSA (11.2% and 11.1%, respectively) and USA300 (10% and 12.4%, respectively).5 Although this study documented a high prevalence of staphylococcal contamination, only 1 (0.4%) of the 283 environmental cultures was positive for MRSA. The etiology of this discrepancy is unclear. As previous studies have shown effective survival of USA300 and MRSA in the environment,6, 8 the comparatively low prevalence of surface contamination with these clones may be related to infection control strategies within the prison. Since USA300 is a common cause of skin abscesses, systemic antibiotics administered to those with active infection may reduce asymptomatic carriage and subsequent environmental contamination with this clone. Similarly, aggressive environmental hygiene may be differentially applied to locations highly contaminated with this strain if they are associated with purulent skin infections. Prisoners are responsible for disinfecting their own environments using quaternary ammonium products on a weekly basis. Despite this, the true frequency and intensity of cleaning may vary on the basis of prisoner preferences. Our finding of increased environmental contamination among colonized controls compared with that among noncolonized controls suggests that asymptomatic nasal and/or oropharyngeal carriage correlates with environmental reservoirs. Although every effort was made to culture cases’ cells immediately after an infection was identified, antimicrobials and disinfection administered immediately after ascertainment may have limited our ability to capture environmental contamination. Our study is further impaired by its small sample size, limited largely by a low incidence of infections over our study period. It is possible that investigations of environmental contamination during prison-based outbreaks could yield different results. Prospective studies with larger enrollments may be more effective in demonstrating small but significant trends in environmental colonization. While mounting evidence suggests a linkage between S. aureus surface contamination and clinical infection, data remain conflicting.3,4,6 Further research into prison-based infectious reservoirs will be essential to effectively protect this important population and the communities in which they reside.

Obesity as a Determinant of Staphylococcus Aureus Colonization Among Maximum Security Prisoners in New York State

ISSUE: Corynebacteria are aerobic gram-positive rods which are one of normal microbiota in human skin and mucous membranes. Corynebacteria are also widely distributed in the environment and have highly intrinstic antimicrobial resistance. We have encountered the outbreak of multi-drug resistant (MDR) Corynebacterium striatum in Japanese university hospital. PROJECT: MDR C. striatum was defined as resistant against over three classes of antimicrobial agents. Thirty-three strains of MDR C. striatumwere isolated from January 2013 to March 2013 in 13 units of Aichi Medical University Hospital. We performed epidemiological analysis from the aspects of clinical features and also performed using pulsed-field gel electrophoresis (PFGE). RESULTS: Thirty-three strains of MDRC. striatumwere isolated from sputum, pus, central venous (CV)-catheter and urine with 76%, 8%, 6.5% and 4%, respectively. Twenty-four patients among 33 patients (72.7%) needed critical care at medical intensive care unit (ICU) or high care unit (HCU). We could divide C. striatum isolates into 6 different groups using PFGE analysis, which have judged as nosocomial spread of MDR C. striatum. There have been no infectious patients by MDR C. striatum to treat with antimicrobial agents. LESSON LEARNED: There have been a few reports on nosocomial spread of MDR C. striatum. Since there are also several reports on infections by C. striatum in immunocompromised hosts although C. striatum consists of normal flora in humans, C. striatum should be considered as one of important nosocomial pathogens and also might be one of good benchmarker for nococomial infection control.

Regional distribution of white matter hyperintensities in mild cognitive impairment

Background: Small vessel cerebrovascular disease, visualized as white matter hyperintensities (WMH) on MRI, has been linked to age-associated cognitive dysfunction, but whether it is related to Alzheimer’s disease (AD) is unclear. This study examined the regional distribution of WMH among older adults at high risk for developing AD drawn from a cohort of community-dwelling older adults. Because hippocampal atrophy, a putative marker for neurodegeneration, is typically increased among patients with AD, we also compared the ability of regional WMH volume with hippocampus volume to classify individuals as at-risk for AD (i.e., those with amnestic mild cognitive impairment) and as controls. Methods: Highresolution MRI was acquired in 717 non-demented, older (80.0+/5.5.8) and ethnically diverse adults from upper Manhattan. Participants were evaluated medically and neuropsychologically, and classified as normal controls (n 1⁄4 508); non-amnestic mild cognitive impairment (naMCI; n 1⁄4 74); and amnestic MCI (aMCI single/multiple domain; n 1⁄4 97), previously shown to be up to 4.3 times more likely to progress to AD than controls. Lobar (frontal, temporal, parietal, occipital) WMH volumes were quantified on T2-weighted FLAIR MRI scans. Hippocampal volumes were derived and normalized for head size, and presence/absence of infarct was recorded. Controlling for relevant demographic factors and infarct, we compared the regional distribution of WMH among the three groups with a mixed-design general linear model. We predicted group membership (aMCI vs. control) with regional WMH volume and hippocampus volume with logistic regression. Results: The aMCI group had significantly more overall WMH volume than controls. A Group by Region interaction revealed that both MCI groups had greater WMH volume in the frontal lobes than controls, but only the aMCI group had greater WMH in the parietal lobes. Parietal lobe WMH volume, but not hippocampus volume, reliably classified participants as aMCI or controls. Conclusions: While increased WMH volume in frontal lobes is related to cognitive dysfunction in aging, WMH volume in parietal lobes is elevated among those at greatest risk for developing AD specifically. Posterior WMH distribution reflects early vascular pathology that may precede neurodegeneration marked by hippocampal atrophy. Mechanistic links between small vessel cerebrovascular disease, particularly in posterior areas, and AD should continue to be evaluated.