Detection of Measles Virus RNA in Air and Surface Specimens in a Hospital Setting.

Measles virus (MeV) is known to be highly contagious, with an infectious period lasting from 4 days before to 4 days after rash onset. An unvaccinated, young, female patient with measles confirmed by direct epidemiologic link was hospitalized on day 5 after rash onset. Environmental samples were collected over the 4-day period of hospitalization in a single room. MeV RNA was detectable in air specimens, on surface specimens, and on respirators on days 5-8 after rash onset. This is the first report of environmental surveillance for MeV, and the results suggest that MeV-infected fomites may be present in healthcare settings.

Exposure to influenza virus aerosols during routine patient care.

BACKGROUND: Defining dispersal of influenza virus via aerosol is essential for the development of prevention measures. METHODS: During the 2010-2011 influenza season, subjects with influenza-like illness were enrolled in an emergency department and throughout a tertiary care hospital, nasopharyngeal swab specimens were obtained, and symptom severity, treatment, and medical history were recorded. Quantitative impaction air samples were taken not ≤0.305 m (1 foot), 0.914 m (3 feet), and 1.829 m (6 feet) from the patient's head during routine care. Influenza virus was detected by rapid test and polymerase chain reaction. RESULTS: Sixty-one of 94 subjects (65%) tested positive for influenza virus. Twenty-six patients (43%) released influenza virus into room air, with 5 (19%) emitting up to 32 times more virus than others. Emitters surpassed the airborne 50% human infectious dose of influenza virus at all sample locations. Healthcare professionals (HCPs) were exposed to mainly small influenza virus particles (diameter, <4.7 µm), with concentrations decreasing with increasing distance from the patient's head (P < .05). Influenza virus release was associated with high viral loads in nasopharyngeal samples (shedding), coughing, and sneezing (P < .05). Patients who reported severe illness and major interference with daily life also emitted more influenza virus (P < .05). CONCLUSIONS: HCPs within 1.829 m of patients with influenza could be exposed to infectious doses of influenza virus, primarily in small-particle aerosols. This finding questions the current paradigm of localized droplet transmission during non-aerosol-generating procedures.

Heat index in migrant farmworker housing: implications for rest and recovery from work-related heat stress.

Although the health risk to farmworkers of working in hot conditions is recognized, potential for excessive heat exposure in housing affecting rest and recovery has been ignored. We assessed heat index in common and sleeping rooms in 170 North Carolina farmworker camps across a summer and examined associations with time of summer and air conditioning use. We recorded dangerous heat indexes in most rooms, regardless of time or air conditioning. Policies to reduce heat indexes in farmworker housing should be developed.

Cooking and eating facilities in migrant farmworker housing in North Carolina.

OBJECTIVES: We sought to (1) describe observed cooking and eating facilities in migrant farmworker camps, (2) compare observed conditions with existing farmworker housing regulations, and (3) examine associations of violations with camp characteristics. METHODS: We collected data in 182 farmworker camps in eastern North Carolina during the 2010 agricultural season. We compared our observations with 15 kitchen-related housing regulations specified by federal and state housing standards. RESULTS: We observed violations of 8 regulations in at least 10% of camps: improper refrigerator temperature (65.5%), cockroach infestation (45.9%), contaminated water (34.4%), rodent infestation (28.9%), improper flooring (25.8%), unsanitary conditions (21.2%), improper fire extinguisher (19.9%), and holes or leaks in walls (12.1%). Logistic regression showed that violations were related to the time of the agricultural season, housing type, number of dwellings and residents, and presence of workers with H-2A visas. CONCLUSIONS: Cooking and eating facilities for migrant farmworkers fail to comply with regulations in a substantial number of camps. Greater enforcement of regulations, particularly during occupancy during the agricultural season, is needed to protect farmworkers.

The quality of drinking water in North Carolina farmworker camps.

OBJECTIVES: The purpose of this study was to assess water quality in migrant farmworker camps in North Carolina and determine associations of water quality with migrant farmworker housing characteristics. METHODS: We collected data from 181 farmworker camps in eastern North Carolina during the 2010 agricultural season. Water samples were tested using the Total Coliform Rule (TCR) and housing characteristics were assessed using North Carolina Department of Labor standards. RESULTS: A total of 61 (34%) of 181 camps failed the TCR. Total coliform bacteria were found in all 61 camps, with Escherichia coli also being detected in 2. Water quality was not associated with farmworker housing characteristics or with access to registered public water supplies. Multiple official violations of water quality standards had been reported for the registered public water supplies. CONCLUSIONS: Water supplied to farmworker camps often does not comply with current standards and poses a great risk to the physical health of farmworkers and surrounding communities. Expansion of water monitoring to more camps and changes to the regulations such as testing during occupancy and stronger enforcement are needed to secure water safety.

Migrant farmworker housing regulation violations in North Carolina.

BACKGROUND: The quality of housing provided to migrant farmworkers is often criticized, but few studies have investigated these housing conditions. This analysis examines housing regulation violations experienced by migrant farmworkers in North Carolina, and the associations of camp characteristics with the presence of housing violations. METHODS: Data were collected in183 eastern North Carolina migrant farmworker camps in 2010. Housing regulation violations for the domains of camp, sleeping room, bathroom, kitchen, laundry room, and general housing, as well as total violations were assessed using North Carolina Department of Labor standards. RESULTS: Violations of housing regulations were common, ranging from 4 to 22 per camp. Housing regulation violations were common in all domains; the mean number of camp violations was 1.6, of sleeping room violations was 3.8, of bathroom violations was 4.5, of kitchen violations was 2.3, of laundry room violations was 1.2, and of general housing violations was 3.1. The mean number of total housing violations was 11.4. Several camp characteristics were consistently associated with the number of violations; camps with workers having H-2A visas, with North Carolina Department of Labor Certificates of Inspection posted, and assessed early in the season had fewer violations. CONCLUSIONS: These results argue for regulatory changes to improve the quality of housing provided to migrant farmworkers, including stronger regulations and the more vigorous enforcement of existing regulations.

Transocular entry of seasonal influenza-attenuated virus aerosols and the efficacy of n95 respirators, surgical masks, and eye protection in humans.

BACKGROUND: The efficacy of barrier precautions to prevent influenza transmission is unknown. METHODS: Twenty-eight participants were exposed to monodispersed live attenuated influenza vaccine (LAIV) particles (4.9 µm) in 6 groups: group 1, no precautions; group 2, ocular exposure only; group 3, surgical mask without eye protection; group 4, surgical mask with eye protection; group 5, fit-tested N95 respirator without eye protection; and group 6, fit-tested N95 respirator with eye protection. Influenza was detected by reverse-transcription polymerase chain reaction (RT-PCR) and culture in nasal washes. Exact 95% confidence intervals (CIs) were calculated. RESULTS: Influenza was detected in 4 of 4 participants in group 1 (95% CI, 0-.60), 3 of 4 in group 2 (95% CI, .006-.806]), 5 of 5 in group 3 (95% CI, 0-.522), 5 of 5 in group 4, (95% CI, 0-.522), 3 of 5 in group 5 (95% CI, .053-.853), and 1 of 5 in group 6 (95% CI, .05-.72). RT-PCR revealed significant differences between group 1 and all other groups except group 3. CONCLUSIONS: Transocular transmission of LAIV occured in most participants suggesting the necessity of eye protection. An N95 respirator provided the best guard further enhanced by eye protection.

Long-term impact of contact precautions cessation for Methicillin-Resistant Staphylococcus Aureus (MRSA).

BACKGROUND: Methicillin-Resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections (HAI). Contact isolation has been traditionally implemented to stop transmission but its impact is increasingly questioned. METHODS: A single center, retrospective, nonrandomized, observational, quasi-experimental study compared MRSA HAI rates between pre-/postdiscontinuation of MRSA contact isolation in a tertiary university hospital over 68 months. Data on primary outcomes, Central line-associated bloodstream infections and MRSA LabID bacteremia events, were analyzed by interrupted time series design using segmented Poisson regression modeling. As secondary outcomes catheter-associated urinary tract infections , ventilator-associated pneumonia , surgical site infections and hospital-associated pneumonia were compared using Fisher's exact tests. Current savings due to discontinuation were calculated based on gown use. RESULTS: Two hundred and ninty-five patients developed 399 HAIs. Infection rates between pre- and postinterventions were as follows: Central line-associated bloodstream infections: (0.02% vs 0.02%; P-value = .64), MRSA LabID events: (0.01% vs 0.02%; P-value = .32), hospital-associated pneumonia: (0.01% vs 0.01%; P-value = .64), catheter-associated urinary tract infections: (0% vs 0.01%; P-value = .56), ventilator-associated pneumonia: (0.01% vs 0.01%; P-value = .32), surgical site infections (0.55% vs 0.15%; P-value = .03). Savings amount to $139,228 annually. CONCLUSIONS: Discontinuing CP did not negatively impact endemic MRSA HAI rates between pre-postdiscontinuation periods and saved costs for isolation materials.

Coronavirus disease 2019 (COVID-19) research agenda for healthcare epidemiology.

This SHEA white paper identifies knowledge gaps and challenges in healthcare epidemiology research related to coronavirus disease 2019 (COVID-19) with a focus on core principles of healthcare epidemiology. These gaps, revealed during the worst phases of the COVID-19 pandemic, are described in 10 sections: epidemiology, outbreak investigation, surveillance, isolation precaution practices, personal protective equipment (PPE), environmental contamination and disinfection, drug and supply shortages, antimicrobial stewardship, healthcare personnel (HCP) occupational safety, and return to work policies. Each section highlights three critical healthcare epidemiology research questions with detailed description provided in supplementary materials. This research agenda calls for translational studies from laboratory-based basic science research to well-designed, large-scale studies and health outcomes research. Research gaps and challenges related to nursing homes and social disparities are included. Collaborations across various disciplines, expertise and across diverse geographic locations will be critical.

Removal of SARS-CoV-2 bioaerosols using ultraviolet air filtration.

Engineering controls play an important role in reducing the spread of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).1 Established technologies such as air filtration, and novel approaches such as ultraviolet (UV)-C light or plasma air ionization, have the potential to support the fight against the coronavirus disease 2019 (COVID-19) pandemic.2 We tested the efficacy of an air purification system (APS) combining UV-C light and high-efficiency particulate air (HEPA) filtration in a controlled environment using SARS-CoV-2 as test organism. The APS successfully removed the virus from the air using UV-C light by itself and in combination with HEPA air filtration.

Detection of Environmental Spread of SARS-CoV-2 and Associated Patient Characteristics.

Understanding transmission of severe acute respiratory syndrome coronavirus 2 informs infection prevention practices. Air sampling devices were placed in patient hospital rooms for consecutive collections with and without masks. With patient mask use, no virus was detected in the room. High viral load and fewer days from symptom onset were associated with viral particulate dispersion.

HIV and sexually transmitted disease risk among male Hispanic/Latino migrant farmworkers in the Southeast: Findings from a pilot CBPR study.

BACKGROUND: Little is known about the HIV and sexually transmitted disease (STD) risk behaviors of Hispanic/Latino farmworkers. This study was designed to describe risk factors for HIV and STD infection, explore personal characteristics associated with condom use, and evaluate the feasibility of collecting self-report and biomarker data from farmworkers. METHODS: Self-report and biomarker data were collected from a sample of male farmworkers living in 29 camps in North Carolina during the 2008 growing season. RESULTS: Over half of the 100 male workers, mean age 37.1 (range 19-68) years, reported binge drinking during the past 12 months. Forty percent of those who reported having had sex during the past 3 months indicated that they were under the influence of alcohol. Knowledge of HIV and STD transmission and prevention was low. Among the 25 workers who reported having had sex during the past 3 months, 16 and 2 reported using a condom consistently during vaginal and anal sex, respectively, and nearly 1 out of 6 workers reported paying a woman to have sex. Two workers tested positive for syphilis. CONCLUSIONS: Farmworkers in this sample demonstrated significant HIV and STD risks; however, when exploring potential bivariate associations with consistent condom use no statistically significant associations were identified perhaps due to the small sample size. Because it was feasible to collect self-report and biomarker data related to HIV and STDs from Hispanic/Latino farmworkers, research needed to further explore risks and develop interventions to reduce disease exposure and transmission among this vulnerable population.

How well do N95 respirators protect healthcare providers against aerosolized influenza virus?

N95 respirator masks are recommended for protection against respiratory viruses. Despite passing fit-testing 10% of N95 respirator users encountered breakthroughs with exposure to influenza virus compared to full protection provided by a powered air purifying respirator. The current recommendation of N95 respirators should be evaluated for endemic and emerging scenarios.

Successful control of a methicillin-resistant Staphylococcus aureus outbreak in a burn intensive care unit by addition of universal decolonization with intranasal mupirocin to basic infection prevention measures.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is frequently implicated in health care-associated outbreaks in burn intensive care units, incurring substantial morbidity and mortality to these high-risk patients and excess costs to health care systems. METHODS: MRSA health care-associated infections (HAIs) were noted before and after the implementation of basic infection prevention measures and the subsequent implementation of universal decolonization with intranasal mupirocin. Pulsed-field gel electrophoresis was used to determine the relatedness of clinical isolates. A case-control study was conducted to characterize the risk factors for MRSA HAIs. RESULTS: Basic interventions failed to decrease the rate of MRSA HAIs, although compliance with these interventions was high throughout the study. MRSA HAIs decreased from 8.53 HAIs per 1,000 patient days before the implementation of intranasal mupirocin to 3.61 HAIs per 1,000 patient days after the implementation of intranasal mupirocin (P = .033). Pulsed-field gel electrophoresis disclosed 10 unique clones with no large clusters. The case-control study revealed a significant association between MRSA HAIs and lengths of stay, body surface area burned, intubation, pressor requirement, leukocytosis, lactic acidosis, development of pneumonia, MRSA colonization, and death. CONCLUSIONS: Basic environmental and behavioral interventions fell short of controlling a low-count, sporadic, and multiclonal MRSA outbreak in the burn intensive care unit of a tertiary medical center. However, the added implementation of universal decolonization with intranasal mupirocin was effective. Burn victims with greater disease severity were at higher risk for MRSA HAIs.

Preventing the airborne spread of Staphylococcus aureus by persons with the common cold: effect of surgical scrubs, gowns, and masks.

OBJECTIVE: Transmission of Staphylococcus aureus via air may play an important role in healthcare settings. This study investigates the impact of barrier precautions on the spread of airborne S. aureus by volunteers with experimentally induced rhinovirus infection (ie, the common cold). DESIGN: Prospective nonrandomized study. SETTING: Wake Forest University School of Medicine (Winston-Salem, NC).Participants. A convenience sample of 10 individuals with nasal S. aureus carriage selected from 593 students screened for carriage. INTERVENTION: Airborne S. aureus dispersal was studied in the 10 participants under the following clothing conditions: street clothes, surgical scrubs, surgical scrubs and a gown, and the latter plus a face mask. After a 4-day baseline period, volunteers were exposed to a rhinovirus, and their clinical course was followed for 12 days. Daily swabs of nasal specimens, pharynx specimens, and skin specimens were obtained for quantitative culture, and cold symptoms were documented. Data were analyzed by random-effects negative binomial models. RESULTS: All participants developed a common cold. Incidence rate ratios (IRRs) indicated that, compared with airborne levels of S. aureus during sessions in which street clothes were worn, airborne levels decreased by 75% when surgical scrubs were worn (P<.001), by 80% when scrubs and a surgical gown were worn (P<.001), and by 82% when scrubs, a gown, and a face mask were worn (P<.001). The addition of a mask to the surgical scrubs and gown did not reduce the airborne dispersal significantly (IRR, 0.92; P>.05). Male volunteers shed twice as much S. aureus as females (incidence rate ratio, 2.04; P=.013). The cold did not alter the efficacy of the barrier precautions. CONCLUSIONS: Scrubs reduced the spread of airborne S. aureus, independent of the presence of a rhinovirus-induced cold. Airborne dispersal of S. aureus during sessions in which participants wore surgical scrubs was not significantly different from that during sessions in which gowns and gowns plus masks were also worn.

Dispersal of Staphylococcus aureus into the air associated with a rhinovirus infection.

OBJECTIVE: To determine whether healthy adult nasal carriers of Staphylococcus aureus can disperse S. aureus into the air after rhinovirus infection. DESIGN: We investigated the "cloud" phenomenon among adult nasal carriers of S. aureus experimentally infected with a rhinovirus. Eleven volunteers were studied for 16 days in an airtight chamber wearing street clothes, sterile garb, or sterile garb plus surgical mask; rhinovirus inoculation occurred on day 2. Daily quantitative air, nasal, and skin cultures for S. aureus; cold symptom assessment; and nasal rhinovirus cultures were performed. SETTING: Wake Forest University School of Medicine, Winston-Salem, North Carolina. PARTICIPANTS: Wake Forest University undergraduate or graduate students who had persistent nasal carriage of S. aureus for 4 or 8 weeks. RESULTS: After rhinovirus inoculation, dispersal of S. aureus into the air increased 2-fold with peak increases up to 34-fold. Independent predictors of S. aureus dispersal included the time period after rhinovirus infection and wearing street clothes (P < .05). Wearing barrier garb but not a mask decreased dispersal of S. aureus into the air (P < .05). CONCLUSION: Virus-induced dispersal of S. aureus into the air may have an important role in the transmission of S. aureus and other bacteria.

Infrequent air contamination with Acinetobacter baumannii of air surrounding known colonized or infected patients.

Using a validated air sampling method we found Acinetobacter baumannii in the air surrounding only 1 of 12 patients known to be colonized or infected with A. baumannii. Patients' closed-circuit ventilator status, frequent air exchanges in patient rooms, and short sampling time may have contributed to this low burden.

Staphylococcus aureus nasal carriage in a student community: prevalence, clonal relationships, and risk factors.

OBJECTIVE: To evaluate the prevalence and risk factors of nasal Staphylococcus aureus (SA) in the community. DESIGN: Cross-sectional study. SETTING: Wake Forest University, Winston-Salem, North Carolina. PARTICIPANTS: Four hundred fifty students were screened for nasal SA carriage during the fall of 2000, 2001, and 2002. METHODS: Students were screened by nose swabs. A self-administered questionnaire collected information on demographics and medical history. Antibiotic testing and PFGE were performed on isolates. Risk factors were determined by logistic regression analysis. RESULTS: Of 450 volunteers, 131 (29%) were SA carriers. Antibiotic resistance was high for azithromycin (26%) and low for ciprofloxacin (1%), tetracycline (5%), mupirocin (1%), and methicillin (2%). PFGE patterns were not associated with carriage. Age, male gender, white race, medical student, allergen injection therapy, chronic sinusitis, rheumatoid arthritis, hospitalization for 6 months or less, and use of antibiotics were associated with carrier status by univariate analysis. Stepwise multivariate logistic regression led to a best fitting model with older age (OR, 1.04; CI95, 1.005-1.079), male gender (OR, 1.50; CI95, 0.982-2.296), and chronic sinusitis (OR, 2.71; CI95, 0.897-8.195) as risk factors. Antibiotic use (< 4 weeks) (OR, 0.41; CI95, 0.152-1.095) and allergen injection therapy (OR, 0.41; CI95, 0.133-1.238) were protective. Analyses of carriers revealed candidate factors for persistent carriage to be nasal SA colonization rate and male gender. Factors for azithromycin resistance were non-medical students and antibiotic use in the past 6 months. CONCLUSION: Older male volunteers suffering from chronic sinusitis and not taking antibiotics were at higher risk for carrying SA.

Airborne dispersal as a novel transmission route of coagulase-negative staphylococci: interaction between coagulase-negative staphylococci and rhinovirus infection.

OBJECTIVE: To investigate whether rhinovirus infection leads to increased airborne dispersal of coagulase-negative staphylococci (CoNS). DESIGN: Prospective nonrandomized intervention trial. SETTING: Wake Forest University School of Medicine, Winston-Salem, North Carolina. PARTICIPANTS: Twelve nasal Staphylococcus aureus-CoNS carriers among 685 students screened for S. aureus nasal carriage. INTERVENTIONS: Participants were studied for airborne dispersal of CoNS in a chamber under three conditions (street clothes, sterile gown with a mask, and sterile gown without a mask). After 2 days of pre-exposure measurements, volunteers were inoculated with a rhinovirus and observed for 14 days. Daily quantitative nasal and skin cultures for CoNS and nasal cultures for rhinovirus were performed. In addition, assessment of cold symptoms was performed daily, mucous samples were collected, and serum titers before and after rhinovirus inoculation were obtained. Sneezing, coughing, and talking events were recorded during chamber sessions. RESULTS: All participants had at least one nasal wash positive for rhinovirus and 10 developed a symptomatic cold. Postexposure, there was a twofold increase in airborne CoNS (P = .0004), peaking at day 12. CoNS dispersal was reduced by wearing a gown (57% reduction, P < .0001), but not a mask (P = .7). Nasal and skin CoNS colonization increased after rhinovirus infection (P < .05). CONCLUSIONS: We believe this is the first demonstration that a viral pathogen in the upper airways can increase airborne dispersal of CoNS in nasal S. aureus carriers. Gowns, gloves, and caps had a protective effect, whereas wearing a mask did not further reduce airborne spread.