Hog Operations Research Articles

Relating Antimicrobial Resistance and Virulence in Surface-Water E. coli.

The role of the environment in the emergence and spread of antimicrobial resistance (AMR) is being increasingly recognized, raising questions about the public health risks associated with environmental AMR. Yet, little is known about pathogenicity among resistant bacteria in environmental systems. Existing studies on the association between AMR and virulence are contradictory, as fitness costs and genetic co-occurrence can be opposing influences. Using Escherichia coli isolated from surface waters in eastern North Carolina, we compared virulence gene prevalence between isolates resistant and susceptible to antibiotics. We also compared the prevalence of isolates from sub-watersheds with or without commercial hog operations (CHOs). Isolates that had previously been evaluated for phenotypic AMR were paired by matching isolates resistant to any tested antibiotic with fully susceptible isolates from the same sample date and site, forming 87 pairs. These 174 isolates were evaluated by conventional PCR for seven virulence genes (bfp, fimH, cnf-1, STa (estA), EAST-1 (astA), eae, and hlyA). One gene, fimH, was found in 93.1% of isolates. Excluding fimH, at least one virulence gene was detected in 24.7% of isolates. Significant negative associations were found between resistance to at least one antibiotic and presence of at least one virulence gene, tetracycline resistance and presence of a virulence gene, resistance and STa presence, and tetracycline resistance and STa presence. No significant associations were found between CHO presence and virulence, though some sub-significant associations merit further study. This work builds our understanding of factors controlling AMR dissemination through the environment and potential health risks.

Hurricanes, Industrial Hog Operations, and Acute Gastrointestinal Illness in North Carolina, USA

Background and aim: North Carolina (NC) is the third most hurricane-prone state and second leading hog producer. NC’s hogs are housed in industrial hog operations (IHOs) in its eastern, hurricane-prone region. Hurricanes can inundate hog waste lagoons, transporting fecal bacteria that may cause diarrhea, vomiting, and/or nausea, collectively known as acute gastrointestinal illness (AGI). Hurricanes Matthew (2016) and Florence (2018) were NC's most recent deadliest hurricanes. We aim to understand the association between hurricanes and AGI in areas with and without IHOs. Methods: We used NC ZIP code-level surveillance data to calculate rates of AGI emergency department (ED) visits during 2016-2019. Using gridded PRISM precipitation data and swine permit data, we assessed the increase in AGI rate during the three weeks after Hurricanes Matthew and Florence in ZIP codes with heavy rain (>75th percentile of storm precipitation) and ≥10 IHOs and in ZIP codes with heavy rain but no IHOs by comparing AGI rates in these areas to their AGI rates during comparable non-hurricane time periods (2017, 2019). Results: The AGI rate in ZIP codes with heavy rain and ≥10 IHOs increased 13% (RR=1.13, 95% CI: 1.00, 1.29) after Hurricane Florence and 8% (RR=1.08, 95% CI: 0.87, 1.33) after Hurricane Matthew, while the AGI rates in ZIP codes with heavy rain and no IHOs experienced no increase (Florence: RR=0.99, 95% CI: 0.88, 1.12; Matthew: RR=0.98, 95% CI: 0.82, 1.16). ZIP codes with heavy precipitation and IHOs also had a higher proportion of Black, American Indian, and Hispanic residents than the state average. Conclusions: Heavy rain from hurricanes in areas with IHOs may increase AGI rates, disproportionately harming people of color in NC. Keywords: Climate change, extreme weather, hurricane, disaster, flooding, industrial animal operations

Exposure to industrial hog and poultry operations and urinary tract infections in North Carolina, USA

An increasing share of urinary tract infections (UTIs) are caused by extraintestinal pathogenic Escherichia coli (ExPEC) lineages that have also been identified in poultry and hogs with high genetic similarity to human clinical isolates. We investigated industrial food animal production as a source of uropathogen transmission by examining relationships of hog and poultry density with emergency department (ED) visits for UTIs in North Carolina (NC). ED visits for UTI in 2016–2019 were identified by ICD-10 code from NC's ZIP code-level syndromic surveillance system and livestock counts were obtained from permit data and aerial imagery. We calculated separate hog and poultry spatial densities (animals/km2) by Census block with a 5 km buffer on the block perimeter and weighted by block population to estimate mean ZIP code densities. Associations between livestock density and UTI incidence were estimated using a reparameterized Besag-York-Mollié (BYM2) model with ZIP code population offsets to account for spatial autocorrelation. We excluded metropolitan and offshore ZIP codes and assessed effect measure modification by calendar year, ZIP code rurality, and patient sex, age, race/ethnicity, and health insurance status. In single-animal models, hog exposure was associated with increased UTI incidence (rate ratio [RR]: 1.21, 95 % CI: 1.07–1.37 in the highest hog-density tertile), but poultry exposure was associated with reduced UTI rates (RR: 0.86, 95 % CI: 0.81–0.91). However, the reference group for single-animal poultry models included ZIP codes with only hogs, which had some of the highest UTI rates; when compared with ZIP codes without any hogs or poultry, there was no association between poultry exposure and UTI incidence. Hog exposure was associated with increased UTI incidence in areas that also had medium to high poultry density, but not in areas with low poultry density, suggesting that intense hog production may contribute to increased UTI incidence in neighboring communities.

A watershed study assessing effects of commercial hog operations on microbial water quality in North Carolina, USA

Commercial Hog Operations (CHOs) produce large amounts of fecal waste, which is often treated in lagoons and sprayed onto fields as fertilizer. The effects of these systems on proximal water quality compared to ambient conditions have not been well-studied, and are particularly important for understanding the dissemination of fecal bacteria and antimicrobial resistance. A longitudinal, case-control watershed study was designed to study effects of CHOs on microbial water quality among watersheds with similar soil, land use, human population, and area. We compared watersheds with (n = 13) and without (n = 9) CHOs over one year measuring fecal indicator bacteria (FIB), microbial source tracking (MST) fecal markers, and antimicrobial resistance in isolated Escherichia coli. E. coli concentrations were higher (p < 0.001) at sites downstream of CHOs (1284 CFU/100 mL, n = 103) compared to background sites (687 CFU/100 mL, n = 74). The human MST marker HF183 was detected at similarly low concentrations (PR = 1.3 (0.91, 1.8), p = 0.30). However, the swine MST marker pig-2-bac was found at more sites downstream of CHOs (PR = 3.5 (0.98, 12), p = 0.035) and at a significantly higher (p = 0.003) mean concentration at sites downstream of CHOs (283 copies/mL) compared to background sites (0.76 copies/mL). The presence of any antimicrobial resistance was observed more often for E. coli isolated downstream from CHOs (19%, n = 556) than background sites (6%, n = 356), with tetracycline resistance observed most often. Nine isolates from four sites downstream of CHOs and one isolate from a background site were confirmed β-lactamase-producing E. coli. Overall, these results show that fecal microbes and antimicrobial resistance from CHOs may be transported off-site, however more research is needed to characterize timing and conditions of off-site transport. Mitigation strategies such as optimizeation of waste treatment, buffers, and antibiotic stewardship could help reduce the contributions of microbial contaminants to surface water.

Exposure to industrial hog operations and gastrointestinal illness in North Carolina, USA

With 9 million hogs, North Carolina (NC) is the second leading hog producer in the United States. Most hogs are housed at concentrated animal feeding operations (CAFOs), where millions of tons of hog waste can pollute air and water with fecal pathogens that can cause diarrhea, vomiting, and/or nausea (known as acute gastrointestinal illness (AGI)). We used NC's ZIP code-level emergency department (ED) data to calculate rates of AGI ED visits (2016–2019) and swine permit data to estimate hog exposure. Case exposure was estimated as the inverse distances from each hog CAFO to census block centroids, weighting with Gaussian decay and by manure amount per CAFO, then aggregated to ZIP code using population weights. We compared ZIP codes in the upper quartile of hog exposure (“high hog exposed”) to those without hog exposure. Using inverse probability of treatment weighting, we created a control with similar demographics to the high hog exposed population and calculated rate ratios using quasi-Poisson models. We examined effect measure modification of rurality and race using adjusted models. In high hog exposed areas compared to areas without hog exposure, we observed a 11% increase (95% CI: 1.06, 1.17) in AGI rate and 21% increase specifically in rural areas (95% CI: 0.98, 1.43). When restricted to rural areas, we found an increased AGI rate among American Indian (RR = 4.29, 95% CI: 3.69, 4.88) and Black (RR = 1.45, 95% CI: 0.98, 1.91) residents. The association was stronger during the week after heavy rain (RR = 1.41, 95% CI: 1.19, 1.62) and in areas with both poultry and swine CAFOs (RR = 1.52, 95% CI: 1.48, 1.57). Residing near CAFOs may increase rates of AGI ED visits. Hog CAFOs are disproportionally built near rural Black and American Indian communities in NC and are associated with increased AGI most strongly in these populations.

Assessing Residential Exposure to Microbes from Industrial Hog Operations in Rural North Carolina: Methods and Lessons Learned.

Recent advances in molecular source tracking make answering questions from residents regarding their exposure to microbial contaminants from industrial hog operations (IHOs) possible. Associations between residential distance to IHOs and exposure can be addressed by measuring livestock-associated (Staphylococcus aureus) and pig-specific bacteria in the air, on household surfaces, and in participants' nasal and saliva swabs. Here we assess the mechanics, feasibility, capacity-building, and lessons learned during a pilot study employing this novel technology in community-based participatory research of bacterial exposure and human health. Together, our team of academics and community members designed a field- and laboratory-based pilot study. Air samples, surface and human swabs, and questionnaires from households at varying distances from IHOs were collected. Data were assessed for completeness and quality by two independent reviewers. These metrics were defined as: missingness (completeness), incorrect data type (validity), out of range (validity), and outliers (accuracy). While critical field equipment was obtained, and knowledge exchange occurred, leading to an increased capacity for future work, after review, 38 of 49 households were deemed eligible for inclusion in the study. Of eligible participants, 98% of required electronic survey questions were complete and 100% were valid; an improvement over prior work which employed paper surveys. While all human microbial and air samples were collected from eligible households (n = 231), (5%) of environmental swabs were reported missing. Using community-appropriate sampling protocols, a pilot study of residential exposure to bacteria from IHOs was completed. While high-quality data was collected from those eligible, we learned the necessity of early and continual data review.

Application of Markov models to predict changes in nasal carriage of Staphylococcus aureus among industrial hog operations workers

Industrial hog operation (IHO) workers can be occupationally exposed to Staphylococcus aureus and may carry the bacteria in their nares. Workers may persistently carry S. aureus or transition between different states of nasal carriage over time: no nasal carriage, nasal carriage of a human-associated strain, and nasal carriage of a livestock-associated strain. We developed a mathematical model to predict the proportion of IHO workers in each nasal carriage state over time, accounting for IHO worker mask use. We also examined data sufficiency requirements to inform development of models that produce reliable predictions. We used nasal carriage data from a cohort of 101 IHO workers in North Carolina, sampled every 2 weeks for 4 months, to develop a three-state Markov model that describes the transition dynamics of IHO worker nasal carriage status over the study period and at steady state. We also stratified models by mask use to examine their impact on worker transition dynamics. If conditions remain the same, our models predicted that 49.1% of workers will have no nasal carriage of S. aureus, 28.2% will carry livestock-associated S. aureus, and 22.7% will carry human-associated S. aureus at steady state. In stratified models, at steady state, workers who reported only occasional mask (<80% of the time) use had a higher predicted proportion of individuals with livestock-associated S. aureus nasal carriage (39.2%) compared to workers who consistently (≥80% of the time) wore a mask (15.5%). We evaluated the amount of longitudinal data that is sufficient to create a Markov model that accurately predicts future nasal carriage states by creating multiple models that withheld portions of the collected data and compared the model predictions to observed data. Our data sufficiency analysis indicated that models created with a small subset of the dataset (approximately 1/3 of observed data) perform similarly to models created using all observed data points. Markov models may have utility in predicting worker health status over time, even when limited longitudinal data are available.

Emissions of H2S from Hog Finisher Farm Anaerobic Manure Treatment Lagoons: Physical, Chemical and Biological Influence

Hydrogen sulfide (H2S) from hog operations contributes to noxious odors in the surrounding environment and can be life-threatening. There is, however, limited understanding of what influences H2S emissions from these farms. Emissions of H2S were measured periodically over the course of two years at hog finisher farms in humid mesothermal (North Carolina, NC, USA) and semi-arid (Oklahoma, OK, USA) climates. Emissions were determined using an inverse dispersion backward Lagrangian stochastic model in conjunction with line-sampled H2S concentrations and measured turbulence. Daily emissions at the two lagoons were characterized by low emissions on most days with occasional days of high emissions. Mean annual area-specific emissions were much lower for the NC lagoon (1.32 µg H2S m−2 s−1 ± 0.07 µg H2S m−2 s−1) than the OK lagoon (6.88 µg H2S m−2 s−1 ± 0.13 µg H2S m−2 s−1). Mean annual hog-specific emissions for the NC lagoon were 0.75 g H2S hd−1 d−1 while those for the OK lagoon were 1.92 g H2S hd−1 d−1. Emissions tended to be higher during the afternoon, likely due to higher mean winds. Daily H2S emissions from both lagoons were greatest during the first half of the year and decreased as the year progressed and a reddish color (indicating high populations of purple sulfur bacteria (PSB)) appeared in the lagoon. The generally low emissions at the NC lagoon and higher emissions at the OK lagoon were likely a result of the influence of wind on mixing the lagoon and not the presence of PSB.

A Watershed Study Assessing Effects of Commercial Hog Operations on Microbial Water Quality in North Carolina, USA

A Watershed Study Assessing Effects of Commercial Hog Operations on Microbial Water Quality in North Carolina, USA

Exposure to Industrial Hog Operations and Gastrointestinal Illness in North Carolina, USA

BACKGROUND AND AIM: With 9 million hogs, North Carolina (NC) is the second leading hog producer in the United States. Most hogs are housed at concentrated animal feeding operations (CAFOs), where millions of tons of hog waste can pollute the air and water with fecal pathogens that can cause diarrhea, vomiting, and/or nausea (known as acute gastrointestinal illness (AGI)). METHODS: We used NC’s ZIP code-level syndromic surveillance system to calculate rates of AGI emergency department (ED) visits during 2016-2019 and swine permit data to estimate hog exposure. Exposure was estimated as the inverse distances from each hog CAFO to census block centroids, weighting with Gaussian decay and by hogs per CAFO, then aggregated to ZIP codes using population weights. We compared ZIP codes in the upper quartile of hog exposure to those without hog exposure. Using inverse probability of treatment weighting, we created a control with similar demographics to the high hog exposed population and calculated rate ratios (RR) using quasi-Poisson models. We examined effect measure modification of rurality and race using adjusted models. RESULTS:Among the 111 high hog exposed ZIP codes, the median number of hogs per ZIP code was 50,022. In high hog exposed areas compared to areas without hog exposure, we observed a 17% increase in AGI rate (95% CI: 1.08, 1.26) and a 24% increase in rural areas (95% CI: 1.04, 1.48). The association was stronger during the weeks after heavy rain (RR=1.54, 95% CI: 1.25, 1.83). When restricted to rural areas, we found an increased AGI rate among American Indian (RR=5.26, 95% CI: 4.60, 5.91) and Black (RR=1.47, 95% CI: 1.04, 1.89) patients. CONCLUSIONS:Residing near hog CAFOs may increase rates of AGI ED visits. Hog CAFOs are disproportionally built near rural Black and American Indian communities in NC and are associated most strongly with increased AGI in these populations. KEYWORDS: Concentrated animal feeding operation (CAFO), animal production, swine, environmental pollution, gastrointestinal illness, waterborne pathogens

Getting ahead of antibiotic-resistant Staphylococcus aureus in U.S. hogs

Antibiotic-resistant strains of Staphylococcus aureus, an opportunistic bacterial pathogen, have emerged in industrial livestock operations and agricultural settings. In the United States, there is limited access to industrial livestock operations and farm-level antibiotic use data. As a result, studies often rely on retail meat as a proxy for direct animal sampling. To move beyond this limitation and assess S. aureus colonization in hogs, we purchased the heads of recently-slaughtered hogs and compared S. aureus populations in those raised on industrial hog operations versus those raised without antibiotics. S. aureus isolates were analyzed for antibiotic resistance and putative genotypic markers of livestock adaptation. Although methicillin-resistant S. aureus (MRSA) was not detected in this study, all of the hogs from industrial hog operations (n = 9/9) carried multidrug-resistant S. aureus (MDRSA) with two livestock-adaptation markers (scn-negative and clonal complex (CC) 9 or 398) compared to 11% of hogs raised without antibiotics (n = 1/9). Hogs from industrial operations were 9.0 times (95% confidence interval (CI): 1.4–57.1) as likely to carry livestock-adapted S. aureus and 4.5 times (95% CI: 1.3–15.3) as likely to carry MDRSA as hogs raised without antibiotics. In contrast, the majority of antibiotic-free hogs (67%, n = 6/9) contained human-adapted S. aureus (i.e. scn-positive, CC1) compared to 11% (n = 1/9) of IHO hogs. These results indicate that antibiotic use in IHO hogs may make them more conducive hosts to antibiotic-resistant, livestock-adapted S. aureus strains when compared to hogs raised without antibiotics. Our results are important, as they provide strong evidence that antibiotic use practices influence the S. aureus populations carried by U.S. hogs, supporting the need for increased access to routine monitoring of hog operations for antibiotic resistance management using a One Health framework.

Transmission of Antimicrobial-Resistant Staphylococcus aureus Clonal Complex 9 between Pigs and Humans, United States.

Transmission of livestock-associated Staphylococcus aureus clonal complex 9 (LA-SA CC9) between pigs raised on industrial hog operations (IHOs) and humans in the United States is poorly understood. We analyzed whole-genome sequences from 32 international S. aureus CC9 isolates and 49 LA-SA CC9 isolates from IHO pigs and humans who work on or live near IHOs in 10 pig-producing counties in North Carolina, USA. Bioinformatic analysis of sequence data from the 81 isolates demonstrated 3 major LA-SA CC9 clades. North Carolina isolates all fell within a single clade (C3). High-resolution phylogenetic analysis of C3 revealed 2 subclades of intermingled IHO pig and human isolates differing by 0–34 single-nucleotide polymorphisms. Our findings suggest that LA-SA CC9 from pigs and humans share a common source and provide evidence of transmission of antimicrobial-resistant LA-SA CC9 between IHO pigs and humans who work on or live near IHOs in North Carolina.

Benefit-cost analysis of near-infrared spectroscopy technology adoption by Alberta hog producers

Feed cost is a significant component of livestock production costs, accounting for over half of total operating costs for hog producers. This provides an incentive to minimize feed costs while meeting dietary requirements. However, producers may not know the nutritional content of their feed grains with certainty. Near-infrared reflectance spectroscopy (NIRS) imaging technology can quickly and accurately estimate the nutritional content of different types of feed grain. Although the technology has been available for almost five decades, producer adoption has been slow due to issues with cost and usability. The objectives of this study are to estimate feed cost savings resulting from the adoption of NIRS on a representative Alberta hog farm and to conduct a benefit-cost analysis to investigate the potential viability of NIRS adoption. A joint mathematical programming-simulation approach is used to estimate the cost savings generated by adoption of NIRS technology. Results suggest mean annual savings of up to $4 per hog and benefit-cost results suggest that adopting NIRS technology may be viable, particularly for larger Alberta hog operations. However, initial investment requirements, uncertainty in the magnitude of benefits, and access to the technology from feed mills will likely continue to limit adoption.

Risk of Antibiotic-Resistant Staphylococcus aureus Dispersion from Hog Farms: A Critical Review.

The World Health Organization has declared antibiotic resistance "one of the biggest threats to global health." Mounting evidence suggests that antibiotic use in industrial-scale hog farming is contributing to the spread of antibiotic-resistant Staphylococcus aureus. To capture available evidence on these risks, we searched peer-reviewed studies published before June 2017 and conducted a meta-analysis of these studies' estimates of the prevalence of swine-associated, antibiotic-resistant S. aureus in animals, humans, and the environment. The 166 relevant studies revealed consistent evidence of livestock-associated methicillin-resistant S. aureus (MRSA) in hog herds (55.3%) raised with antibiotics. MRSA prevalence was also substantial in slaughterhouse pigs (30.4%), industrial hog operation workers (24.4%), and veterinarians (16.8%). The prevalence of swine-associated, multidrug-resistant S. aureus (MDRSA)-with resistance to three or more antibiotics-is not as well documented. Nonetheless, sufficient studies were available to estimate MDRSA pooled prevalence in conventional hog operation workers (15.0%), workers' household members (13.0%), and community members (5.37%). Evidence also suggests that antibiotic-resistant S. aureus can be present in air, soil, water, and household surface samples gathered in or near high-intensity hog operations. An important caveat is that prevalence estimates for humans reflect colonization, not active infection, and the health risks of colonization remain poorly understood. In addition, these pooled results may not represent risks in specific locations, due to wide geographic variation. Nonetheless, these results underscore the need for additional preventive action to stem the spread of antibiotic-resistant pathogens from livestock operations and a streamlined reporting system to track this risk.

P1.10 Inflammatory Signature Difference in Rural Urban and Regional Occupational Exposure in Lung Cancer

Lung Cancer remains the major cause of cancer related mortality in the state of North Carolina. Hog and poultry farming is an important part of agriculture in Eastern NC, where more than 2/3rd of the counties fall under rural distribution per US Census data. There is a growing body of evidence that implicates inflammation as a mechanism of disease progression and reduced survival in patients with advanced cancer (Laird et al, Oncologist 2013). Smoldering inflammation in the tumor microenvironment regulates and escalates cancer invasion, angiogenesis and immune surveillance escape (Balkwill and Mantovani, Lancet 2001). Modified Glasgow Progonostic Score (mGPS) is a composite inflammatory score based on CRP and serum albumin with proven prognostic and predictive value in various tumor types (Simmons et al, Lung Cancer 2017). A prospective observational single institutional study was conducted whereby serum albumin and CRP were drawn at baseline for 333 patients with diagnosis of cancer regardless of stage from 30 counties in Eastern North Carolina. The mGPS score was compared according to rural urban divide and regional occupational exposure of various counties stratified per US Census Data. Lung cancer was the predominant cancer type in 93% of patients. The median age was 65 years with equal distribution of males and females. The racial distribution was: White (52%), Black (26%), other (22%). The mGPS of zero was seen in 96(29%), mGPS of one in 124 (37%), mGPS of two in 118 patients (35%). The mGPS of zero in Urban and Rural counties was noted in 50% patients. The mGPS score of two in Urban vs Rural counties was noted in 32.2% and 67.7% respectively. The mGPS of two in areas of hog farming, cattle farming and wet waste lands was seen in 41%, 38% and 43% (p = 0.0019). The mGPS of zero was seen in 24%, 20% and 27% respectively (p = 0.0008). This study suggests a strikingly unfavorable inflammatory signature in rural population as well as areas of hog farm, cattle farm and wet waste lands. The hog and poultry operations heighten the harmful effect on waterways and can adversely affect the inflammatory signature, hence the tumor biology. This underscores additional interventions in these high risk populations that can have significant implications for quality of life and survival, especially in the era of immunotherapy.

Piloting the use of mobile devices in community-driven research to assess occupational and environmental exposures from industrial hog operations in rural eastern North Carolina, USA

Piloting the use of mobile devices in community-driven research to assess occupational and environmental exposures from industrial hog operations in rural eastern North Carolina, USA

Demographic stratification of inflammatory signature in lung cancer patients in North Carolina: A prospective cohort study.

e14200 Background: Lung Cancer remains the major cause of cancer related mortality in the state of North Carolina. There is a growing body of evidence that implicates inflammation as a mechanism of disease progression and reduced survival in patients with advanced cancer (Laird et al, Oncologist 2013). Smoldering inflammation in the tumor microenvironment regulates and escalates cancer invasion, angiogenesis and immune surveillance escape (Balkwill and Mantovani, Lancet 2001). We investigated the predictive value of inflammatory signature according to social stratification of cancer patients using Modified Glasgow Prognostic Score (mGPS). mGPS is a composite inflammatory score based on CRP and serum albumin with proven prognostic and predictive value in various tumor types. Methods: A prospective observational single institutional study was conducted whereby serum albumin and CRP were drawn at baseline for 333 patients with diagnosis of cancer regardless of stage from 30 counties in Eastern North Carolina. The mGPS score was compared according to rural urban divide and occupational regional exposure of various counties stratified per US Census Data. Results: Lung cancer was the predominant cancer type in 93% of patients. The mGPS of zero in Urban vs Rural counties was noted in 36% and 24% patients respectively. The mGPS score of two in Urban vs Rural counties was noted in 26% and 41% respectively. The mGPS of two in areas of hog farming, cattle farming and wet waste lands was seen in 41%, 38% and 43% respectively (p = 0.0019). The mGPS of zero was seen in 24%, 20% and 27% respectively (p = 0.0008). Conclusions: This study suggests a strikingly unfavorable inflammatory signature in rural population as well as areas of hog farm, cattle farm and wet waste lands. The hog and poultry operations heighten the harmful effect on waterways and can adversely affect the inflammatory signature, hence the tumor biology. This underscores additional interventions in these high risk populations that can have significant implications for quality of life and survival, especially in the era of immunotherapy.

Connecting Environmental Justice and Community Health: Effects of Hog Production in North Carolina.

Environmental justice means equal access to a healthful environment for all. In North Carolina, many sources of pollution disproportionately affect low-income communities and communities of color. Clinicians who recognize effects of environmental injustices can improve patient care and community health. As an example, we present the effects of industrial-scale hog operations in North Carolina.

Occurrence of Staphylococcus aureus in swine and swine workplace environments on industrial and antibiotic-free hog operations in North Carolina, USA: A One Health pilot study

Occupational exposure to swine has been associated with increased Staphylococcus aureus carriage, including antimicrobial-resistant strains, and increased risk of infections. To characterize animal and environmental routes of worker exposure, we optimized methods to identify S. aureus on operations that raise swine in confinement with antibiotics (industrial hog operation: IHO) versus on pasture without antibiotics (antibiotic-free hog operation: AFHO). We associated findings from tested swine and environmental samples with those from personal inhalable air samplers on worker surrogates at one IHO and three AFHOs in North Carolina using a new One Health approach. We determined swine S. aureus carriage status by collecting swab samples from multiple anatomical sites, and we determined environmental positivity for airborne bioaerosols with inhalable and impinger samplers and a single-stage impactor (ambient air) cross-sectionally. All samples were analyzed for S. aureus, and isolates were tested for antimicrobial susceptibility, absence of scn (livestock marker), and spa type. Seventeen of twenty (85%) swine sampled at the one IHO carried S. aureus at >1 anatomical sites compared to none of 30 (0%) swine sampled at the three AFHOs. All S. aureus isolates recovered from IHO swine and air samples were scn negative and spa type t337; almost all isolates (62/63) were multidrug resistant. S. aureus was recovered from eight of 14 (67%) ambient air and two (100%) worker surrogate personal air samples at the one IHO, whereas no S. aureus isolates were recovered from 19 ambient and six personal air samples at the three AFHOs. Personal worker surrogate inhalable sample findings were consistent with both swine and ambient air data, indicating the potential for workplace exposure. IHO swine and the one IHO environment could be a source of potential pathogen exposure to workers, as supported by the detection of multidrug-resistant S. aureus (MDRSA) with livestock-associated spa type t337 among swine, worker surrogate personal air samplers and environmental air samples at the one IHO but none of the three AFHOs sampled in this study. Concurrent sampling of swine, personal swine worker surrogate air, and ambient airborne dust demonstrated that IHO workers may be exposed through both direct (animal contact) and indirect (airborne) routes of transmission. Investigation of the effectiveness of contact and respiratory protections is warranted to prevent IHO worker exposure to multidrug-resistant livestock-associated S. aureus and other pathogens.

Work Activities, Self-Reported Symptoms, and Diminished Lung Function in a Population of Predominantly Hispanic Industrial Hog Operation Workers in North Carolina, United States

Background/Aim: Although swine worker respiratory disease is established, evidence is mainly from predominantly Caucasian farm-owner-operator cohorts whose work exposures may differ from laborers hired to perform day-to-day intensive swine production jobs in confinement barns. The Rural Empowerment Association for Community Help (REACH) has initiated community-based participatory research (CBPR) with Hispanic laborers hired to work in industrial hog operations (IHOs) in eastern North Carolina. Together with REACH, we investigated whether such IHO workers’ occupational exposures were related to respiratory health outcomes. Methods: During 2013-14, we completed a 4-month CBPR panel study, involving baseline and 8 bi-weekly visits to collect demographic, personal, and work exposure data and spirometry measurements. We assessed the relation of IHO work activities with respiratory outcomes at baseline (linear regression) and longitudinally (fixed-effects ordinal logistic regression), adjusting for potential confounders. Results: One hundred and three IHO workers were enrolled (88% Hispanic; 46% male; age mean[±SD] 38±11 years) and completed 782 bi-weekly visits. Asthma prevalence was 8.7% and 92.6% were non-smokers. At baseline, total number of years of IHO work was negatively associated with forced expiratory volume (L) in the first second (FEV1) (ß=-0.031; 95% confidence interval [CI]: -0.060, -0.001). Longitudinally, positive associations were observed between pressure washing barns and coughing (odds ratio [OR]=3.8; 95%CI: 1.2, 12.3), herd changes and nasal congestion (OR=7.4; 95%CI: 1.2, 44.6) and confinement barn ventilation fans turned off and difficulty breathing (OR=11.2; 95% CI: 2.8, 44.4), eye irritation (OR=5.8; 95%CI: 1.1, 30.7), and chills (OR=5.1; 95%CI: 3.0, 8.9). Conclusions: In a predominantly Hispanic cohort of IHO workers, we observed relations between IHO work activities and adverse respiratory outcomes, particularly prolonged IHO employment and activities that aerosolize and keep waste in-barn. Challenges in exposure assessment from lack of on-IHO access and worker reluctance to enroll in cohorts can be mitigated using an empowering CBPR approach.