Dhritiman V. Mukherjee

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.

Survival of influenza virus on hands and fomites in community and laboratory settings

BACKGROUND Transmission dynamics modeling provides a practical method for virtual evaluation of the impact of public health interventions in response to prospective influenza pandemics and also may help determine the relative contribution of different modes of transmission to overall infection rates. Accurate estimates of longevity for all forms of viral particles are needed for such models to be useful. METHODS We conducted a time course study to determine the viability and longevity of H1N1 virus on naturally contaminated hands and household surfaces of 20 individuals with laboratory-confirmed infection. Participants coughed or sneezed into their hands, which were sampled immediately and again after 5, 10, and 30 minutes. Samples also were obtained from household surfaces handled by the participants immediately after coughing/sneezing. Clinically obtained H1N1 isolates were used to assess the viability and longevity of the virus on various artificially inoculated common household surfaces and human hands in a controlled laboratory setting. Viral detection was achieved by culture and real-time reverse-transcriptase polymerase chain reaction. RESULTS The results suggest that H1N1 does not survive long on naturally contaminated skin and fomites, and that secretions deposited on hands by coughing or sneezing have a concentration of <2.15 × 10 to 2.94 × 10 TCID(50)/mL. CONCLUSIONS These data can be used to estimate the relative contribution of direct and indirect contact transmission on overall infection rates.

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.

Obesity as a Determinant of Staphylococcus aureus Colonization Among Inmates in Maximum-Security Prisons in New York State

Obesity increases a persons susceptibility to a variety of infections, including Staphylococcus aureus infections, which is an important cause of morbidity in correctional settings. Using a cross-sectional design, we assessed the association between obesity and S. aureus colonization, a risk factor for subsequent infection, in New York State maximum-security prisons (2011-2013). Anterior nares and oropharyngeal cultures were collected. Structured interviews and medical records were used to collect demographic, behavioral, and medical data. Body mass index (BMI; weight (kg)/height (m(2))) was categorized as 18.5-24.9, 25-29.9, 30-34.9, or ≥35. The association between BMI and S. aureus colonization was assessed using log-binomial regression. Thirty-eight percent of 638 female inmates and 26% of 794 male inmates had a BMI of 30 or higher. More than 40% of inmates were colonized. Female inmates with a BMI of 25-29.9 (prevalence ratio (PR) = 1.37, 95% confidence interval (CI): 1.06, 1.76), 30-34.9 (PR = 1.52, 95% CI: 1.17, 1.98), or ≥35 (PR = 1.49, 95% CI: 1.13, 1.96) had a higher likelihood of colonization than did those with a BMI of 18.5-24.9 after we controlled for age, educational level, smoking status, diabetes status, and presence of human immunodeficiency virus. Colonization was higher among male inmates with a BMI of 30-34.9 (PR = 1.27, 95% CI: 1.01, 1.61). Our findings demonstrate an association between BMI and S. aureus colonization among female prisoners. Potential contributory biologic and behavioral factors should be explored.

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.

Correspondence analysis to evaluate the transmission of Staphylococcus aureus strains in two New York State maximum-security prisons

Prisons/jails are thought to amplify the transmission of Staphylococcus aureus (SA) particularly methicillin-resistant SA infection and colonisation. Two independently pooled cross-sectional samples of detainees being admitted or discharged from two New York State maximum-security prisons were used to explore this concept. Private interviews of participants were conducted, during which the anterior nares and oropharynx were sampled and assessed for SA colonisation. Log-binomial regression and correspondence analysis (CA) were used to evaluate the prevalence of colonisation at entry as compared with discharge. Approximately 51% of admitted (N = 404) and 41% of discharged (N = 439) female detainees were colonised with SA. Among males, 59% of those admitted (N = 427) and 49% of those discharged (N = 393) were colonised. Females had a statistically significant higher prevalence (1·26: P = 0·003) whereas males showed no significant difference (1·06; P = 0·003) in SA prevalence between entry and discharge. CA demonstrated that some strains, such as spa types t571 and t002, might have an affinity for certain mucosal sites. Contrary to our hypothesis, the prison setting did not amplify SA transmission, and CA proved to be a useful tool in describing the population structure of strains according to time and/or mucosal site.

Predictors of Illicit Drug Use Among Prisoners.

ABSTRACT Background: The United States of America currently has the highest incarceration rate in the world, and approximately 80% of incarcerated individuals have a history of illicit drug use. Despite institutional prohibitions, drug use continues in prison, and is associated with a range of negative outcomes. Objectives: To assess the relationship between prison drug use, duration of incarceration, and a range of covariates. Results: Most participants self-reported a history of illicit drug use (77.5%). Seven percent reportedly used drugs during the previous six months of incarceration (n = 100). Participants who had been incarcerated for more than a year were less likely than those incarcerated for longer than a year to report using drugs (OR = 0.50; 95% CI = 0.26–0.98). Participants aged 37–89 were less likely than younger prisoners to use drugs (OR = 0.39; 95% CI = 0.19–0.80). Heroin users were twice as likely as nonheroin users to use drugs (OR = 2.28; 95% CI = 1.04–5.03); crack cocaine users were also twice as likely as participants with no history of crack cocaine usage to report drug use (OR = 2.53; 95% CI = 1.13–5.69). Conclusions: Correctional institutions should be used as a resource to offer evidence-based services to curb drug usage. Drug treatment programs for younger prisoners, heroin and crack cocaine users, and at the beginning of a prisoners sentence should be considered for this population.

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.