Tara Smith

Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is associated with increased infection risk, yet colonization and infection isolates are rarely compared within the same study. The objectives of this study were to compare colonization and infection isolates from a Veterans Administration hospital in Iowa, and to determine the prevalence of livestock-associated MRSA (LA-MRSA) colonization and infection in a state with high livestock density. All patients with available MRSA isolates collected through routine nasal screening (73%; n = 397) and from infections (27%; n = 148) between December 2010 and August 2012 were included and tested for spa type and presence of PVL and mecA genes. Clinical isolates were tested for antibiotic resistance patterns. Paired colonization and infection isolates were compared for genetic and phenotypic congruity. The most common spa types were t002 (and other CC5-associated strains; 65%) and t008 (and other CC8-associated strains;...

Background
Methicillin-resistant S. aureus (MRSA) pneumonia is associated with poor clinical outcomes. This study examined the association between microbial characteristics and poor outcomes among patients with methicillin-resistant Staphylococcus aureus pneumonia.

Findings
This retrospective cohort study included 75 patients with MRSA pneumonia who were admitted to two large tertiary care medical centers during 2003–2010. Multivariable models were created using Cox proportional hazards regression and ordinal logistic regression to identify predictors of mortality or increased length of stay (LOS). None of the microbial characteristics (PFGE type, agr dysfunction, SCCmec type, and detection of PVL, ACME, and TSST-1) were significantly associated with 30-day mortality or post-infection hospital length of stay, after adjusting for gender, age, previous hospital admission within 12 months, previous MRSA infection or colonization, positive influenza test, Charlson Comorbidity Index score, and treatment (linezolid or vancomycin).

Conclusion
Large prospective studies are needed to examine the impact of microbial characteristics on the risk of death and other adverse outcomes among patients with MRSA pneumonia.

The most recent epidemic of Ebola virus disease (EVD), beginning in Guinea in December 2013 and still underway as of September 2015, has claimed almost 11 300 lives and resulted in almost 28 000 cases. The first EVD epidemic in history to span multiple countries at once; the outbreak caught the world unprepared, undoubtedly leading to higher illness and death counts that may have occurred in areas with solid medical infrastructure. An analysis of the many facets of the epidemic touches on many important topics covered in an introductory global health course, including issues of economics, ethics, culture, infectious disease, policy, preparedness and technology. However, in contrast to many global health offerings, a study of Ebola provides a unifying narrative throughout the course.

The most recent epidemic of Ebola virus disease (EVD), beginning in Guinea in December 2013 and still underway as of September 2015, has claimed almost 11 300 lives and resulted in almost 28 000 cases. The first EVD epidemic in history to span multiple countries at once; the outbreak caught the world unprepared, undoubtedly leading to higher illness and death counts that may have occurred in areas with solid medical infrastructure. An analysis of the many facets of the epidemic touches on many important topics covered in an introductory global health course, including issues of economics, ethics, culture, infectious disease, policy, preparedness and technology. However, in contrast to many global health offerings, a study of Ebola provides a unifying narrative throughout the course.

The most recent epidemic of Ebola virus disease (EVD), beginning in Guinea in December 2013 and still underway as of September 2015, has claimed almost 11 300 lives and resulted in almost 28 000 cases. The first EVD epidemic in history to span multiple countries at once; the outbreak caught the world unprepared, undoubtedly leading to higher illness and death counts that may have occurred in areas with solid medical infrastructure. An analysis of the many facets of the epidemic touches on many important topics covered in an introductory global health course, including issues of economics, ethics, culture, infectious disease, policy, preparedness and technology. However, in contrast to many global health offerings, a study of Ebola provides a unifying narrative throughout the course.

Aerosolized methicillin-resistant Staphylococcus aureus (MRSA) was sampled inside and downwind of a swine facility. Animal feed was sampled before and after entry into the swine facility. Aerosolized particles were detected using an optical particle counter for real time measurement and with an Andersen Sampler to detect viable MRSA. Molecular typing and antimicrobial susceptibility testing were performed on samples collected. Viable MRSA organisms isolated inside the swine facility were primarily associated with particles > 5µm, and those isolated downwind from the swine facility were associated with particles <5µm. MRSA isolates included spa types t008, t034, and t5706 and were resistant to methicillin, tetracycline, clindamycin, and erythromycin. Animal feed both before and after entry into the swine facility tested positive for viable MRSA. These isolates were of similar spa types as the airborne MRSA organisms. Air samples collected after power washing with a biocide inside the swine facility resulted in no viable MRSA organisms detected. Our pilot study showed that the ecology of MRSA is complex. Additional studies are warranted on the maximum distance that viable MRSA can be emitted outside the facility, and the possibility that animal feed may be a source of contamination.

Background. Livestock-associated Staphylococcus aureus (LA-SA) has been documented worldwide. However, much remains unknown about LA-SA colonization and infection, especially in rural environments.

Methods. We conducted a large-scale prospective study of 1342 Iowans, including individuals with livestock contact and a community-based comparison group. Nasal and throat swabs were collected to determine colonization at enrollment, and skin infection swabs over 17 months were assessed for S. aureus. Outcomes included carriage of S. aureus, methicillin-resistant S. aureus (MRSA), tetracycline-resistant S. aureus (TRSA), multidrug-resistant S. aureus (MDRSA), and LA-SA.

Results. Of 1342 participants, 351 (26.2%; 95% confidence interval [CI], 23.8%–28.6%) carried S. aureus. MRSA was isolated from 34 (2.5%; 95% CI, 1.8%–3.5%) and LA-SA from 131 (9.8%; 95% CI, 8.3%–11.5%) of the 1342 participants. Individuals with current swine exposure were significantly more likely to carry S. aureus (prevalence ratio [PR], 1.8; 95% CI, 1.4–2.2), TRSA (PR, 8.4; 95% CI, 5.6–12.6), MDRSA (PR, 6.1; 95% CI, 3.8–10.0), and LA-SA (PR, 5.8; 95% CI, 3.9–8.4) than those lacking exposure. Skin infections (n = 103) were reported from 67 individuals, yielding an incidence rate of 6.6 (95% CI, 4.9–8.9) per 1000 person-months.

Conclusions. Current swine workers are 6 times more likely to carry MDRSA than those without current swine exposure. We observed active infections caused by LA-SA. This finding suggests that individuals with livestock contact may have a high prevalence of exposure to, and potentially infection with, antibiotic-resistant S. aureus strains, including LA-SA strains.

Background. Previous studies indicated that vancomycin is inferior to beta-lactams for treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections. However, it is unclear if this association is true for both empiric and definitive therapy. This study compared beta-lactams with vancomycin for empiric and definitive therapy of MSSA bloodstream infections among patients admitted to 122 hospitals.

Methods. This retrospective cohort study included all patients admitted to Veteran's Affairs hospitals from 2003 to 2010 who had positive blood cultures for MSSA. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression. Empiric therapy was defined as starting treatment 2 days before until 4 days after the first MSSA blood culture was collected. Definitive therapy was defined as starting treatment between 4 to 14 days after the first positive blood culture was collected.

Results. Patients who received empiric therapy with a beta-lactam had similar mortality compared with vancomycin (HR: 1.03; 95% CI: 0.89-1.20) after adjusting for other factors. However, patients who received definitive therapy with a beta-lactam had 35% lower mortality compared with patients receiving vancomycin (HR: 0.65; CI: 0.52-0.80) after controlling for other factors. The hazard of mortality decreased further for patients who received cefazolin or an antistaphylococcal penicillin compared with vancomycin (HR: 0.57; CI: 0.46-0.71).

Conclusions. For patients with MSSA bloodstream infections, beta-lactams are superior to vancomycin for definitive therapy but not for empiric treatment. Patients should receive a beta-lactam for definitive therapy, specifically an antistaphylococcal penicillin or cefazolin.

The present study was performed to characterize the epidemiology of necrotizing soft tissue infection caused by Streptococcus pyogenes (n = 14) and Staphylococcus aureus (n = 14) isolates collected at the University of Iowa Hospitals and Clinics. An additional 9 S. pyogenes isolates were collected from patients being treated for mild respiratory infections and served as a comparison sample in the analysis. Patient data corresponding to the isolates (n = 37) were also collected in order to identify risk factors or comorbid conditions possibly correlated with necrotizing fasciitis (NF). The prevalence of methicillin-resistant S. aureus among the study isolates was 35.7% (5/14), and the prevalence of the Panton–Valentine leukocidin (PVL) gene was 57% (8/14). The S. pyogenes NF (wound) isolates (n = 14) belonged to 10 different emm types, none of which appeared to be associated with more severe disease when compared to the milder infection (throat) samples (n = 9). Comorbid conditions such as diabetes and cardiovascular disease were significantly associated with NF. The results indicate that there may be a high prevalence of the PVL virulence factor in NF infections and that spa type t008 may be responsible for the increasing incidence of S. aureus NF infections in Iowa.

Background
Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is associated with increased infection risk, yet colonization and infection isolates are rarely compared within the same study. The objectives of this study were to compare colonization and infection isolates from a Veterans Administration hospital in Iowa, and to determine the prevalence of livestock-associated MRSA (LA-MRSA) colonization and infection in a state with high livestock density.

Methods
All patients with available MRSA isolates collected through routine nasal screening (73%; n = 397) and from infections (27%; n = 148) between December 2010 and August 2012 were included and tested for spa type and presence of PVL and mecA genes. Clinical isolates were tested for antibiotic resistance patterns. Paired colonization and infection isolates were compared for genetic and phenotypic congruity.

Results
The most common spa types were t002 (and other CC5-associated strains; 65%) and t008 (and other CC8-associated strains; 20%). No classic LA-MRSA spa types were identified. CC5-associated strains were less likely to be associated with infections (22%; 77/353) compared with CC8-associated strains (49%; 53/109). MRSA colonization was more common among patients with infections (71%) compared with the general screening population (7%). In most cases (82%; 28/34), paired colonization and infection isolates were genetically and phenotypically indistinguishable.

Conclusions
Our data demonstrate a direct link between antecedent nasal colonization and subsequent MRSA infection. Further, our data indicate variability in colonization and infection efficiency among MRSA genotypes, which points to the need to define the molecular determinants underlying emergence of S. aureus strains in the community and nosocomial setting.

Background
Methicillin-resistant Staphylococcus aureus (MRSA) is a devastating pathogen that is associated with high morbidity and mortality worldwide. Livestock are a well-known reservoir for this pathogen, which poses substantial health risks for livestock workers. Little is known about the epidemiology of livestock-associated MRSA (LA-MRSA) among livestock workers in Eastern Europe.

Methods
To study the epidemiology of LA-MRSA among swine workers in Romania, we collected and characterized nasal and oropharygneal samples from swine workers on commercial pig farms. A survey that included questions about work-related tasks, biosafety practices, contact with animals, and health status was used to assess the risk factors that were potentially associated with LA-MRSA colonization.

Results
The prevalence of MRSA colonization among swine workers was 6.8%. Two LA-MRSA strains with the spa types t034 and t011 and one likely community-associated MRSA strain with the spa type t321 were isolated from workers on five farms. Interestingly, all MRSA carriers worked on farms that imported animals from other production facilities.

Conclusion
This is the first study to confirm the presence of LA-MRSA among swine workers in Romania and suggests the need to minimize the risk of LA-MRSA-related infections in swine workers and their community contacts. The findings also suggest a link between the commercial movement of swine and the introduction of LA-MRSA.

Despite numerous cases of human infection with Streptococcus suis worldwide, human disease is rarely diagnosed in North America. We studied 73 swine-exposed and 67 non-swine-exposed US adults for antibodies to S. suis serotype 2. Serologic data suggest that human infection with S. suis occurs more frequently than currently documented.

SUMMARY Asymptomatic carriage of Staphylococcus aureus is an important risk factor for developing infection, as well as a key contributor to transmission. Despite the fact that childcare workers are at known risk for infections, little research has focused on bacterial carriage in this occupational group. We conducted a cross-sectional study comparing the prevalence of S. aureus in 110 childcare employees with the prevalence in 111 unexposed participants.

Recent studies have shown that livestock can carry Staphylococcus aureus and transmit it to human caretakers. We conducted a pilot study to determine the prevalence and molecular epidemiology of S. aureus among rural Iowans, including individuals with livestock contact. Nasal and throat swabs were collected and plated onto selective media to isolate methicillin-susceptible and methicillin-resistant S. aureus (MRSA), followed by antibiotic resistance testing and molecular analysis of the isolates.

Abstract In the last decade livestock-associated methicillin-resistant S. aureus (LA-MRSA) has become a public health concern in many parts of the world. Sequence type 398 (ST398) has been the most commonly reported type of LA-MRSA. While many studies have focused on long-term exposure experienced by swine workers, this study focuses on short-term exposures experienced by veterinary students conducting diagnostic investigations.

Fairs and petting zoos have been associated with outbreaks of zoonotic disease. Previously, the presence of meticillin-resistant Staphylococcus aureus (MRSA) was documented in commercial pigs; therefore, it was hypothesised that antibiotic-resistant S aureus may also occur in pigs exhibited at agricultural fairs. To test this hypothesis, 157 pigs were swabbed at two state fairs in 2008 to 2009. Both nares were sampled and cultures were grown in enrichment broth, then plated onto selective MRSA plates and blood plates. S aureus was confirmed using phenotypic and molecular methods, and was analysed using spa typing, gene-specific polymerase chain reaction and antibiotic susceptibility testing. The presence of S aureus was confirmed in samples collected from pigs exhibited at USA pig shows. Twenty-five of 157 (15.9 per cent) samples were positive for S aureus. Two isolates (8 per cent) were resistant to meticillin; 23/25 (92 per cent), 14/25 (56 per cent) and 15/25 (60 per cent) were resistant to tetracycline, erythromycin and clindamycin, respectively. spa typing revealed multiple isolates of spa type t034 (9/25, 36 per cent) and t337 (7/25, 28 per cent) and singletons of t002, t209, t526, t1236, t1334, t1683, t3075, t5784 and t5883. These results verify the presence of antibiotic-resistant S aureus in pigs exhibited at USA fairs, suggesting that pigs are a potential reservoir for S aureus within this environment.

Clinical infections with livestock-associated Staphylococcus aureus sequence type (ST) 398 have been reported in Europe, Canada, and the People’s Republic of China (1), as well as the Caribbean (2,3), and Colombia (4). Most reports describe infection with methicillin-resistant S. aureus; relatively few describe infection with methicillin-susceptible S. aureus (MSSA). In the United States, colonization of healthy adults by ST398 has been reported in Iowa (5) and in New York, New York (2); MSSA infections have been anecdotally reported in St. Louis, Missouri (6), and The Bronx, New York (7). We describe 8 infections with MSSA ST398 in the New York City area during a 7-year period (2004–2010). Five infections with a related ST (ST291) from clonal complex (CC) 398 also were identified. These findings highlight the emergence of clinical infections with 2 distinct CC398 sequence types in the New York City area.

Background

The anterior naris has been considered the most consistent location of asymptomatic Staphylococcus aureus colonization. However, recent studies have shown that a substantial number of individuals, ranging from 7% to 32% of colonized individuals, are exclusive throat carriers. Most of these studies have been carried out in a health care setting, limiting their generalizability to nonhospitalized populations.
Methods

To evaluate anatomic carriage sites of S aureus in individuals outside of a health care setting, we combined the results of 2 cross-sectional studies conducted in Iowa.
Results

S aureus was carried by 103 of 340 individuals (30.3%), including 31 (30.1%) exclusive throat carriers, 44 (42.7%) exclusive nose carriers, and 28 (27.2%) colonized in both sites. Nonwhite race (adjusted odds ratio [OR], 4.91; 95% confidence interval [CI], 1.26-18.3) and younger age (≥30 years: OR, 0.23; 95% CI, 0.10-0.54) were associated with increased odds of exclusive throat carriage, whereas nonwhite race (OR, 5.14; 95% CI, 1.62-16.3) and spring or summer sampling season (OR, 2.62; 95% CI, 1.32-5.18) were associated with increased odds of exclusive nasal carriage.
Conclusions

These findings suggest that including a throat swab in addition to a nasal swab could play an important role in the success of surveillance programs, particularly among younger adults.

Since its discovery in the early 2000s, methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) has become a rapidly emerging cause of human infections, most often associated with livestock exposure. We applied whole-genome sequence typing to characterize a diverse collection of CC398 isolates (n = 89), including MRSA and methicillin-susceptible S. aureus (MSSA) from animals and humans spanning 19 countries and four continents. We identified 4,238 single nucleotide polymorphisms (SNPs) among the 89 core genomes. Minimal homoplasy (consistency index = 0.9591) was detected among parsimony-informative SNPs, allowing for the generation of a highly accurate phylogenetic reconstruction of the CC398 clonal lineage. Phylogenetic analyses revealed that MSSA from humans formed the most ancestral clades. The most derived lineages were composed predominantly of livestock-associated MRSA possessing three different staphylococcal cassette chromosome mec element (SCCmec) types (IV, V, and VII-like) including nine subtypes. The human-associated isolates from the basal clades carried phages encoding human innate immune modulators that were largely missing among the livestock-associated isolates. Our results strongly suggest that livestock-associated MRSA CC398 originated in humans as MSSA. The lineage appears to have undergone a rapid radiation in conjunction with the jump from humans to livestock, where it subsequently acquired tetracycline and methicillin resistance. Further analyses are required to estimate the number of independent genetic events leading to the methicillin-resistant sublineages, but the diversity of SCCmec subtypes is suggestive of strong and diverse antimicrobial selection associated with food animal production.

IMPORTANCE Modern food animal production is characterized by densely concentrated animals and routine antibiotic use, which may facilitate the emergence of novel antibiotic-resistant zoonotic pathogens. Our findings strongly support the idea that livestock-associated MRSA CC398 originated as MSSA in humans. The jump of CC398 from humans to livestock was accompanied by the loss of phage-carried human virulence genes, which likely attenuated its zoonotic potential, but it was also accompanied by the acquisition of tetracycline and methicillin resistance. Our findings exemplify a bidirectional zoonotic exchange and underscore the potential public health risks of widespread antibiotic use in food animal production.

Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization has been documented in swine and swine workers. MRSA has also been found in the shower facilities of conventional swine farms. We previously conducted a review of the literature to identify measures used to reduce MRSA prevalence in athletic facilities. In this study, we evaluated those measures for adaptability to the pork production environment.
A best practices protocol was developed to reduce MRSA levels in pork production shower facilities and implemented in two conventional swine production systems.

In order to examine the prevalence of Staphylococcus aureus on retail pork, three hundred ninety-five pork samples were collected from a total of 36 stores in Iowa, Minnesota, and New Jersey. S. aureus was isolated from 256 samples (64.8%, 95% confidence interval [CI] 59.9%–69.5%). S. aureus was isolated from 67.3% (202/300) of conventional pork samples and from 56.8% (54/95) of alternative pork samples (labeled “raised without antibiotics” or “raised without antibiotic growth promotants”). Two hundred and thirty samples (58.2%, 95% CI 53.2%–63.1%) were found to carry methicillin-sensitive S. aureus (MSSA). MSSA was isolated from 61.0% (183/300) of conventional samples and from 49.5% (47/95) of alternative samples. Twenty-six pork samples (6.6%, 95% CI 4.3%–9.5%) carried methicillin-resistant S. aureus (MRSA). No statistically significant differences were observed for the prevalence of S. aureus in general, or MSSA or MRSA specifically, when comparing pork products from conventionally raised swine and swine raised without antibiotics, a finding that contrasts with a prior study from the Netherlands examining both conventional and “biologic” meat products. In our study spa types associated with “livestock-associated” ST398 (t034, t011) were found in 26.9% of the MRSA isolates, while 46.2% were spa types t002 and t008—common human types of MRSA that also have been found in live swine. The study represents the largest sampling of raw meat products for MRSA contamination to date in the U.S. MRSA prevalence on pork products was higher than in previous U.S.-conducted studies, although similar to that in Canadian studies.

Several recent studies have indicated a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in retail-available meat. However, few studies have investigated MRSA in meat in the United States. The aim of this study was to determine the presence of Staphylococcus aureus (S. aureus) on meat samples available at retail stores. Samples of fresh raw pork, chicken, beef, and turkey were purchased from 22 food stores throughout Iowa. S. aureus strains were isolated from 27 of 165 samples, giving an overall prevalence of 16.4%. Turkey, pork, chicken, and beef had individual S. aureus prevalence rates of 19.4%, 18.2%, 17.8%, and 6.9%, respectively. Two isolates of MRSA were isolated from pork, giving an overall prevalence of 1.2%. One MRSA isolate was positive for the PVL gene. Common spa types included t034, t337, t008, and t002. These results suggest that MRSA is present on low numbers of retail meat in Iowa.

Context: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is a major pathogen among skin and soft tissue infections (SSTIs). Most CA-MRSA infections are managed initially on an outpatient basis. It is critical that primary care clinicians recognize and appropriately treat patients suspected of having such infections.

Objective: To identify and evaluate best methods and procedures for primary care clinicians to manage skin and soft tissue infections.

Design, Setting, and Patients: Preintervention/postintervention study in eight Iowa Research Network offices conducted between October 2007 and August 2010. We reviewed medical records of 216 patients with SSTI before a set of interventions (preintervention) and 118 patients after the intervention (postintervention).

Interventions: Included a focus group meeting at each office, distribution of a modified Centers for Disease Control and Prevention (CDC) algorithm, "Outpatient Management of MRSA Skin and Soft Tissue Infections," education handouts, and an office policy for patients with skin infections.

Main Outcome Measures: Proportion of subjects who were prescribed an antibiotic that would cover MRSA at the initial visit and proportion who were prescribed an antibiotic that would cover MRSA at any time.

Results: Three hundred sixty-eight forms (244 preintervention and 124 postintervention) were returned; 216 (89%) preintervention forms and 118 (95%) postintervention forms were usable. Multivariable logistic regression models found statistically significant and independent factors associated with MRSA coverage at the initial visit included being in the postintervention rather than the preintervention group, having an abscess component compared with cellulitis alone, having a culture sent, being prescribed two or fewer antibiotics, and not being hospitalized.

Conclusions: The CDC algorithm was feasible for offices to use. Following a discussion of SSTI management in the outpatient setting, use of MRSA coverage increased both initially and overall. Thus, involving clinicians in a discussion about guidelines rather than simply providing guidelines or a didactic session may be a useful way to change physician practices.

We report a novel vga(A) detected in 3 methicillin-resistant Staphylococcus aureus ST398 recovered from swine and a swine caretaker in the United States. Strains were wild type for L3 and L4, but positive for vga(A) and tet(M). vga(A) was plasmid-located (ca. 24-kb) and demonstrated mobilization genes upstream and a transposase belonging to the IS3 family located downstream.

An estimated 95,000 people developed methicillin-resistant Staphylococcus aureus (MRSA) infections during 2005 of which 14% were community-associated and 85% were hospital or other health setting associated, and 19,000 Americans died from these infections that year.

Purpose: To explore health care providers’ perspectives on management of skin and soft tissue infections to gain a better understanding of the problems faced by busy providers in primary care settings.

Methods: Focus group meetings were held at 9 family physician offices in the Iowa Research Network. Seventy-eight clinicians including physicians, nurses, nurse practitioners, and house officers attended. Meeting audiotapes were transcribed and coded by 3 investigators, and a MRSA-management taxonomy was developed.

Findings: The main themes that emerged from the focus groups included epidemiology, diagnosis, treatment, management, prevention, special populations, and public relations. The incidence of MRSA infections was perceived to have increased over the past decade. However, diagnosis and treatment protocols for physicians in the outpatient setting have lagged behind, and no well-accepted diagnostic or treatment algorithms were used by physicians attending the focus groups.

Conclusion: The clinicians in this study noted considerable confusion and inconsistency in the management of skin and soft tissue infections, particularly those due to MRSA.

Pork producers selected from the National Pork Board`s producer database were surveyed. Five (3.7%) reported being diagnosed with a MRSA infection. Risk factors related to swine farm biosecurity were examined. None were statistically significant predictors of MRSA infection.

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) has changed dramatically over the past 15 years. Initially a nosocomial pathogen, newly emergent strains of MRSA have become increasingly common in the community among individuals lacking contact with healthcare. More recently, a third group of MRSA strains have been identified in association with livestock, particularly swine. These strains, termed livestock-associated MRSA, have now been identified in Europe, North America, and Asia in humans and animals. One molecular type, ST398, has been the dominant strain of livestock-associated MRSA identified to date. The emergence of this strain in animals and humans will be described in this review, including colonization and clinical infections caused by this strain. We also discuss lingering research questions and implications for controlling spread of this bacterium in an agricultural environment and beyond.

The majority of emerging infectious diseases are zoonotic in origin. Swine represent a potential reservoir for many novel pathogens and may transmit these to humans via direct contact with live animals (such as swine farmers and large animal veterinarians), or to the general human population via contaminated meat. We review recent emerging microbes associated with swine and discuss public health implications.

As methicillin-resistant Staphylococcus aureus (MRSA) has been found in pigs, we sought to determine if MRSA is present in pork production shower facilities. In two production systems tested, 3% and 26% of shower samples were positive for MRSA. spa types identified included t034, t189, t753, and t1746.

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) has become a leading cause of infectious disease morbidity and mortality in the United States. The epidemiology of the organism has changed, with novel strains emerging in the community among individuals lacking any healthcare contact. Although direct human-to-human transmission via skin contact is one way for this organism to spread, transmission via environmental contamination of fomites or through air are other potential ways that the organism can be acquired. As such, an improved understanding of MRSA transmission is needed to implement maximally effective control and prevention interventions. We review the research documenting the role of the environment in MRSA spread.

BACKGROUND: Recent research has demonstrated that many swine and swine farmers in the Netherlands and Canada are colonized with MRSA. However, no studies to date have investigated carriage of MRSA among swine and swine farmers in the United States (U.S.).

METHODS: We sampled the nares of 299 swine and 20 workers from two different production systems in Iowa and Illinois, comprising approximately 87,000 live animals. MRSA isolates were typed by pulsed field gel electrophoresis (PFGE) using SmaI and EagI restriction enzymes, and by multi locus sequence typing (MLST). PCR was used to determine SCCmec type and presence of the pvl gene.

RESULTS: In this pilot study, overall MRSA prevalence in swine was 49% (147/299) and 45% (9/20) in workers. The prevalence of MRSA carriage among production system A's swine varied by age, ranging from 36% (11/30) in adult swine to 100% (60/60) of animals aged 9 and 12 weeks. The prevalence among production system A's workers was 64% (9/14). MRSA was not isolated from production system B's swine or workers. Isolates examined were not typeable by PFGE when SmaI was used, but digestion with EagI revealed that the isolates were clonal and were not related to common human types in Iowa (USA100, USA300, and USA400). MLST documented that the isolates were ST398.

CONCLUSIONS: These results show that colonization of swine by MRSA was very common on one swine production system in the midwestern U.S., suggesting that agricultural animals could become an important reservoir for this bacterium. MRSA strain ST398 was the only strain documented on this farm. Further studies are examining carriage rates on additional farms.

Evolution is the unifying theory in all of biology, but is frequently missing from curricula in medicine and public health. Yet evolution has shaped the burden of disease in the modern world in which we practice medicine and educate for public health, and understanding the interface between evolutionary biology and the biomedical sciences may lead to improved medical therapies and public health practices. This course, appropriate for undergraduates in Biology, Anthropology, Public Health, and Nursing, among others, will examine what has been termed “evolutionary medicine” or “Darwinian medicine,” examining connections between evolution and biomedicine including infectious diseases, cancer, aging, and human genetic diseases.

Infectious disease affects us all, but many areas within the field are controversial. Should I treat my child’s ear infection with antibiotics? Should I vaccinate my child (or myself?) How do infectious diseases contribute to other “chronic” diseases? How does culture and social standing affect outcomes of infectious disease outbreaks?  This course is appropriate both for humanities  majors looking for an introduction to infectious diseases as well as science majors looking to better understand infectious diseases in their historical and cultural context, and the way these diseases have (and continue to) shape history, including the questions above. Ultimately, students should be able to understand the basics of infectious disease epidemiology and disease control within a wide cultural context. The course will encompass various topics in the history of microbiology and infectious disease, using primarily popular non-fiction books on these subjects as sources.

This course is designed to provide students with an advanced understanding of the epidemiology of infectious diseases.  In this course, the history, principles, methods, and practice of infectious disease epidemiology will be surveyed.  Epidemiologic surveillance, disease outbreak investigation, and other methods used to elucidate the epidemiology of infectious diseases will be reviewed.  The descriptive epidemiology of important infectious diseases of humans will be considered and the implications of this epidemiology for prevention and control discussed.  While the focus of this course is on epidemiology of infectious diseases, the readings and discussions will incorporate relevant aspects of the microbiology of infectious agents of disease.

Ebola has been known to humankind for almost 40 years, but the recent outbreak in West Africa has brought it to the public consciousness like no time before. However, many people don’t know the story of the Ebola virus. What is its history? Why did this outbreak happen? How did it jump to the United States? How and why did the West African outbreak begin in the first place? This course will cover the history of the virus, and the biological, social, and political aspects that have made this outbreak into the largest Ebola outbreak on record by far.