An increase in animal-related occupational injuries at a veterinary medical center (2008-2022)

OBJECTIVE

To characterize animal-related injuries in veterinary medical center staff at a veterinary medical center.

SAMPLE

706 hospital staff injuries.

METHODS

Deidentified injury reports were submitted to Human Resources from 2008 through 2022. Injury data collected included the injury description, date of injury, occupation, and worker's compensation claim information. Data were summarized by year, cause of injury, total cost associated with injury, and occupation.

RESULTS

There was an increase in injuries reported in recent years when compared to past years, with the plurality of injuries being bite injuries, specifically occurring on the hand, finger, and wrist area. Bite injuries had a higher average total worker's compensation cost paid to staff than striking injuries. There were more injuries reported by staff who had less experience working with animals. More injuries occurred during the summer months (June through September). There was not an unusual trend in the reporting of injuries due to COVID-19. Other injuries (eg, needlesticks and falls) were reported from only 2019 to 2022, but constituted a substantial burden for staff.

CLINICAL RELEVANCE

These findings can help stakeholders at teaching hospitals and veterinary clinics to take steps toward creating a safer workplace environment for employees. It is important to identify work hazards and provide proper training and prevention methods to reduce the risk of injuries, especially among less experienced employees. Proper prevention methods will help reduce worker's compensation costs for the teaching hospital and reduce the number of workdays missed by staff.

Assessing Self-reported Occupational Hazards of Manure Applicators in the Upper Midwest

Manure management on farms presents potential risks to human health and safety, including infectious, chemical, and physical exposures that may result in injury or fatality. Toxic gases and confined spaces are among the most common hazards. These hazards are especially salient for the Upper Midwest of the United States. This study characterizes the occupational health and safety practices and experiences of manure applicators in Minnesota. This cross-sectional study surveyed 162 commercial manure applicators about their work characteristics, safety practices, and health and safety experiences. Respondents reported an average of 17 hours per day applying manure during the busy season, which typically occurs several weeks each year. One hundred and thirty-one (90%) of 145 respondents did not regularly use gas monitors during application. Thirty-three (37%) of 90 respondents reported at least one symptom of gas exposure during manure application work. Those that worked with swine manure were more likely to report symptoms of gas exposure than those who did not work with swine (OR 9.5; CI: 2.0, 89.0). Those that had entered confined spaces were more likely to report symptoms of gas exposure than those who had not entered confined spaces (OR 4.4; CI: 0.1, 1.1). Fourteen (9%) of 150 respondents reported being injured when applying manure. Manure work can be hazardous and may be associated with injury and gas exposure. These findings offer a starting point for future research and intervention to protect and improve the health and safety of applicators.

Occurrence and potential transmission of extended-spectrum beta-lactamase-producing extraintestinal pathogenic and enteropathogenic Escherichia coli in domestic dog faeces from Minnesota

Interactions between humans and pets are increasingly valued in western countries, leading to more extensive contact between humans and their pets within households. Although the magnitude of the risk of transfer of Escherichia coli between humans and their companion animals is undefined, that such transmission occurs has been established and warrants attention. This study examined 186 fresh faecal samples from companion dogs visiting 22 municipal dog parks in the Minneapolis/Saint Paul metropolitan area, Minnesota, USA. Samples were processed to isolate 3rd-generation cephalosporin-resistant E. coli, which were further characterized using PCR-based virulence genotyping, antimicrobial susceptibility profiling and whole-genome sequencing. Of the 186 faecal samples, 29% yielded cephalosporin-resistant E. coli, and 2.2% yielded extended-spectrum beta-lactamase producers. Co-resistance to sulfonamides was typical (77.3% of isolates), and multidrug resistance (i.e. to ≥3 antimicrobial classes), including to combinations of tetracyclines, phenicols, quinolones and aminoglycosides, was substantial (18.9% of isolates). Identified beta-lactamase genes included bla_CMY-2 , bla_TEM-1B , bla_TEM-1 , bla_CTX-M-24 , bla_CTX-M-15 and bla_OXA-1 . Genome sequencing of 14 isolates identified genes typical of extraintestinal pathogenic E. coli or enteropathogenic E. coli. In three instances, closely related isolates were recovered from different dogs, within either the same park-suggesting transfer of E. coli between dogs within the park-or different parks-suggesting that dogs may be pre-disposed to carry certain E. coli types, such as those from serogroups O4, O71 and O157. This study adds to the existing evidence that companion dogs can harbour and share antimicrobial-resistant E. coli with presumed intestinal or extraintestinal pathogenic potential.

Strengthening global health security by improving disease surveillance in remote rural areas of low-income and middle-income countries

The COVID-19 pandemic has underscored the need to strengthen national surveillance systems to protect a globally connected world. In low-income and middle-income countries, zoonotic disease surveillance has advanced considerably in the past two decades. However, surveillance efforts often prioritise urban and adjacent rural communities. Communities in remote rural areas have had far less support despite having routine exposure to zoonotic diseases due to frequent contact with domestic and wild animals, and restricted access to health care. Limited disease surveillance in remote rural areas is a crucial gap in global health security. Although this point has been made in the past, practical solutions on how to implement surveillance efficiently in these resource-limited and logistically challenging settings have yet to be discussed. We highlight why investing in disease surveillance in remote rural areas of low-income and middle-income countries will benefit the global community and review current approaches. Using semi-arid regions in Kenya as a case study, we provide a practical approach by which surveillance in remote rural areas can be strengthened and integrated into existing systems. This Viewpoint represents a transition from simply highlighting the need for a more holistic approach to disease surveillance to a solid plan for how this outcome might be achieved.

Importance of anthropogenic sources at shaping the antimicrobial resistance profile of a peri-urban mesocarnivore

Anthropogenically derived antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARG) have been detected in wildlife. The likelihood of detecting ARB and ARG in wildlife increases with wildlife exposure to anthropogenic sources of antimicrobial resistance (AMR). Whether anthropogenic sources also increase the risk for AMR to spread in bacteria of wildlife is not well understood. The spread of AMR in bacteria of wildlife can be estimated by examining the richness of ARB and ARG, and the prevalence of ARB that have mobilizable ARG (i.e., ARG that can be transferred across bacteria via plasmids). Here, we investigated whether raccoons (Procyon lotor), with different exposures to anthropogenic sources, differed in prevalence and richness of extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli, richness of ARG present in ESC-R E. coli, and prevalence of ESC-R E. coli with plasmid-associated ARG. Sampling took place over the course of 10 months at seven sites in Chicago, USA. ESC-R E. coli were isolated from over half of the 211 raccoons sampled and were more likely to be isolated from urban than suburban raccoons. When examining the whole-genome sequences of ESC-R E. coli, 56 sequence types were identified, most of which were associated with the ARG bla_CMY and bla_CTX-M. A greater richness of ESC-R E. coli sequence types was found at sites with a wastewater treatment plant (WWTP) than without, but no difference was detected based on urban context. ARG richness in ESC-R E. coli did not significantly vary by urban context nor with presence of a WWTP. Importantly, ESC-R E. coli carrying plasmid-associated bla_CTX-M and bla_CMY ARG were more likely to be isolated from raccoons sampled at sites with a WWTP than without. Our findings indicate that anthropogenic sources may shape the AMR profile of wildlife, reinforcing the need to prevent dissemination of AMR into the environment.

Genetic diversity of influenza A viruses circulating in pigs between winter and summer in a Minnesota live animal market

There has been little surveillance of influenza A viruses (IAVs) circulating in swine at live animal markets, particularly in the United States. To address this gap, we conducted active surveillance of IAVs in pigs, the air, and the environment during a summer and winter season in a live animal market in St. Paul, Minnesota, that had been epidemiologically associated with swine-origin influenza cases in humans previously. High rates of IAV were detected by PCR in swine lungs and oral fluids during both summer and winter seasons. Rates of IAV detection by PCR in the air were similar during summer and winter, although rates of successful virus isolation in the air were lower during summer than in winter (26% and 67%, respectively). H3N2 was the most prevalent subtype in both seasons, followed by H1N2. Genetically diverse viruses with multiple gene constellations were isolated from both winter and summer, with a total of 19 distinct genotypes identified. Comparative phylogenetic analysis of all eight segments of 40 virus isolates from summer and 122 isolates from winter revealed that the summer and winter isolates were genetically distinct, indicating IAVs are not maintained in the market, but rather are re-introduced, likely from commercial swine. These findings highlight the extent of IAV genetic diversity circulating in swine in live animal markets, even during summer months, and the ongoing risk to humans.

Factors that enable effective One Health collaborations - A scoping review of the literature

Advocates for a One Health approach recognize that global health challenges require multidisciplinary collaborative efforts. While past publications have looked at interdisciplinary competency training for collaboration, few have identified the factors and conditions that enable operational One Health. Through a scoping review of the literature, a multidisciplinary team of researchers analyzed peer-reviewed publications describing multisectoral collaborations around infectious disease-related health events. The review identified 12 factors that support successful One Health collaborations and a coordinated response to health events across three levels: two individual factors (education & training and prior experience & existing relationships), four organizational factors (organizational structures, culture, human resources and, communication), and six network factors (network structures, relationships, leadership, management, available & accessible resources, political environment). The researchers also identified the stage of collaboration during which these factors were most critical, further organizing into starting condition or process-based factors. The research found that publications on multisectoral collaboration for health events do not uniformly report on successes or challenges of collaboration and rarely identify outputs or outcomes of the collaborative process. This paper proposes a common language and framework to enable more uniform reporting, implementation, and evaluation of future One Health collaborations.

Lead Intoxication in Free-Ranging Bald Eagles (Haliaeetus leucocephalus)

Lead toxicity due to ingestion of spent ammunition is an ongoing cause of mortality in bald eagles. While gross and histologic lesions of lead intoxication have been described in a few individuals of this species, the prevalence of lesions is underreported. A retrospective study of 93 bald eagles with severe lead intoxication was performed to describe the associated lesions and their prevalence and to compare the lesions with blood, liver, kidney, and/or bone lead concentrations. Gross lesions associated with lead toxicity were most frequent within the heart (51/93 birds) and consisted of multifocal myocardial pallor and rounding of the apex. Within the brain, gross lesions included petechiae or hemorrhagic necrosis (13/93 birds). Histologic lesions compatible with lead toxicity occurred within the heart (76/93 birds), brain (59/93 birds), and eyes (24/87 birds). Lead toxicity in bald eagles is characterized by fibrinoid necrosis of small- to medium-caliber arteries, most commonly affecting the heart, brain, and eyes. Gross and histologic lesions are consistent with ischemia caused by a primary vascular injury. A blood lead concentration of greater than 4 ppm and markedly elevated liver lead concentrations were associated with a greater likelihood of lesions in the heart. Severe lead intoxication is frequently associated with lesions that are histologically detectable in bald eagles. The presence of fibrinoid arterial necrosis and parenchymal degeneration, necrosis, and/or hemorrhage within the heart, brain, and/or eyes is suggestive of lead toxicity in bald eagles and warrants evaluation of liver or bone lead concentrations.

Knowledge, Attitudes and Practices Associated with Brucellosis among Small-Scale Goat Farmers in Thailand

OBJECTIVES

This study aimed to identify occupational risk factors for brucellosis among small scale goat farmers in Thailand.

METHODS

To better understand farmers' knowledge, attitudes and practices associated with brucellosis we interviewed 51 farmers and tested 314 goats for Brucella melitensis.

RESULTS

All serological samples tested negative for Brucella infection. Based on previous research and estimates provided from the Thai national brucellosis surveillance system, zero seropositivity was less than expected. Findings from interviews with farmers demonstrate that most respondents were relatively new to goat farming with just over half (53%) reporting owning goats for five or fewer years. The majority of respondents demonstrated important gaps in knowledge on disease transmission in animals and knowledge of human brucellosis was particularly limited with just over half (54%) reporting that humans could become infected. Participants had a very low perceived risk of infection with the majority (91.7%) reporting that they or a member of their household were not at risk of the disease.

CONCLUSION

Overall findings from this study support that brucellosis poses an occupational risk to goat farmers with specific areas of concern including weak awareness of disease transmission to humans and lack of knowledge on specific safe farm practices such as quarantine practices. Findings from this study contribute to a more comprehensive understanding of brucellosis in Thailand by identifying specific occupational risk factors and describing areas where farmer education and training should be strengthened.

Prevalence and Molecular Characteristics of Clostridium difficile in Retail Meats, Food-Producing and Companion Animals, and Humans in Minnesota

Community-associated Clostridium difficile infection (CA-CDI) now accounts for approximately 50% of CDI cases in central Minnesota; animals and meat products are potential sources. From November 2011 to July 2013, we cultured retail meat products and fecal samples from food-producing and companion animals in central Minnesota for C. difficile by using standard methods. The resulting 51 C. difficile isolates, plus 30 archived local veterinary C. difficile isolates and 208 human CA-CDI case isolates from central Minnesota (from 2012) from the Minnesota Department of Health, were characterized molecularly, and source groups were compared using discriminant analysis. C. difficile was recovered from 0 (0%) of 342 retail meat samples and 51 (9%) of 559 animal fecal samples. Overall, the 81 animal source isolates and 208 human source isolates were highly diverse genetically. Molecular traits segregated extensively in relation to animal versus human origin. Discriminant analysis classified 95% of isolates correctly by source group; only five (2.5%) human source isolates were classified as animal source. These data do not support meat products or food-producing and companion animals as important sources of CA-CDI in the central Minnesota study region.

Risk factors associated with highly pathogenic avian influenza subtype H5N8 outbreaks on broiler duck farms in South Korea

Highly Pathogenic Avian Influenza (HPAI) subtype H5N8 outbreaks occurred in poultry farms in South Korea in 2014 resulting in significant damage to the poultry industry. Between 2014 and 2016, the pandemic disease caused significant economic loss and social disruption. To evaluate the risk factors for HPAI infection in broiler duck farms, we conducted a retrospective case-control study on broiler duck farms. Forty-three farms with confirmed laboratories on premises were selected as the case group, and 43 HPAI-negative farms were designated as the control group. Control farms were matched based on farm location and were within a 3-km radius from the case premises. Spatial and environmental factors were characterized by site visit and plotted through a geographic information system (GIS). Univariable and multivariable logistic regression models were developed to assess possible risk factors associated with HPAI broiler duck farm infection. Four final variables were identified as risk factors in a final multivariable logistic model: "Farms with ≥7 flocks" (odds ratio [OR] = 6.99, 95% confidence interval [CI] 1.34-37.04), "Farm owner with ≥15 years of raising poultry career" (OR = 7.91, 95% CI 1.69-37.14), "Presence of any poultry farms located within 500 m of the farm" (OR = 6.30, 95% CI 1.08-36.93) and "Not using a faecal removal service" (OR = 27.78, 95% CI 3.89-198.80). This highlights that the HPAI H5N8 outbreaks in South Korea were associated with farm owner education, number of flocks and facilities and farm biosecurity. Awareness of these factors may help to reduce the spread of HPAI H5N8 across broiler duck farms in Korea during epidemics. Greater understanding of the risk factors for H5N8 may improve farm vulnerability to HPAI and other subtypes and help to establish policies to prevent re-occurrence. These findings are relevant to global prevention recommendations and intervention protocols.

Seroprevalence of brucellosis in goats and sheep in Thailand: Results from the Thai National Brucellosis Surveillance System from 2013 to 2015

In Thailand, brucellosis re-emerged in humans in 2003 and is considered a public health risk to goat farmers as the disease is endemic in small ruminants. The Thai Department of Livestock Development (DLD) established a nationwide surveillance system for brucellosis in goats and sheep in 1997. Using data from this surveillance system, we describe the seroprevalence of brucellosis from 2013 to 2015 in small ruminants and the spatial distribution of the disease throughout Thailand. Surveillance data collected included the number of animals and herds tested, the province of the animal and herd and the laboratory results. Seroprevalence was estimated at both the animal and herd levels. During the 3-year period, 443,561 goats and sheep were tested for brucellosis by the DLD throughout Thailand using the Rose Bengal Plate Test (RBPT) and the enzyme-linked immunosorbent assay test for Brucella. Among the 3 years, 2013 had the highest proportion of herds that tested positive for brucellosis at 13.80% (95% CI, 12.52, 15.16). Overall, this study found that brucellosis seroprevalence in small ruminants is decreasing throughout Thailand. However, there is variability in the spread of the disease with provinces in the eastern and western regions of Thailand having higher proportions of animals and herds testing positive. Overall provinces in the south had the lowest proportion of animals and herds testing positive for brucellosis. Periodic review of surveillance data documents the impact of the current brucellosis control programme and supports a targeted response in higher prevalence regions when there are limited financial resources for control measures.

Serotypes and Antimicrobial Resistance in Salmonella enterica Recovered from Clinical Samples from Cattle and Swine in Minnesota, 2006 to 2015

Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance.

Comparison of Histopathologic Criteria and Skeletal Muscle Fixation Techniques for the Diagnosis of Polysaccharide Storage Myopathy in Horses

The purpose of the study reported here was to determine the effect of three methods of fixation of skeletal muscle biopsy specimens on the histopathologic appearance of muscle sections and to determine criteria that were most consistently associated with a diagnosis of polysaccharide storage myopathy (PSSM) in horses. Surgically excised semimembranosus muscle biopsy specimens were obtained from nine horses previously diagnosed with PSSM and from 15 control horses. Portions of each specimen were fixed in formalin, frozen immediately, and chilled for 24 hours prior to freezing. Sections stained with hematoxylin and eosin (HE), periodic acid-Schiff (PAS), and amylase-PAS were scored for histopathologic criteria by three investigators blinded to the sample origin. The presence of amylase-resistant, abnormal polysaccharide was found to be the most sensitive and specific diagnostic indicator for PSSM, and was readily detected regardless of the fixation technique or investigator. Other less-specific features associated with PSSM included atrophy and cytoplasmic and subsarcolemmal vacuoles; however, their histologic scores varied among fixation technique and investigators. Scores for subsarcolemmal and cytoplasmic amylase-sensitive glycogen in horses with PSSM were similar to those for control horses and varied among fixation techniques. In conclusion, PSSM is most accurately diagnosed in muscle biopsy specimens on the basis of appearance of amylase-resistant, abnormal polysaccharide, not amylase-sensitive glycogen, regardless of fixation technique. In general, frozen sections appeared to be better suited for studying myopathies because many histopathologic features of skeletal muscle were obscured by formalin fixation.

Live Animal Markets in Minnesota: A Potential Source for Emergence of Novel Influenza A Viruses and Interspecies Transmission

BACKGROUND

Live animal markets have been implicated in transmission of influenza A viruses (IAVs) from animals to people. We sought to characterize IAVs at 2 live animal markets in Minnesota to assess potential routes of occupational exposure and risk for interspecies transmission.

METHODS

We implemented surveillance for IAVs among employees, swine, and environment (air and surfaces) during a 12-week period (October 2012-January 2013) at 2 markets epidemiologically associated with persons with swine-origin IAV (variant) infections. Real-time reverse transcription polymerase chain reaction (rRT-PCR), viral culture, and whole-genome sequencing were performed on respiratory and environmental specimens, and serology on sera from employees at beginning and end of surveillance.

RESULTS

Nasal swabs from 11 of 17 (65%) employees tested positive for IAVs by rRT-PCR; 7 employees tested positive on multiple occasions and 1 employee reported influenza-like illness. Eleven of 15 (73%) employees had baseline hemagglutination inhibition antibody titers ≥40 to swine-origin IAVs, but only 1 demonstrated a 4-fold titer increase to both swine-origin and pandemic A/Mexico/4108/2009 IAVs. IAVs were isolated from swine (72/84), air (30/45), and pen railings (5/21). Whole-genome sequencing of 122 IAVs isolated from swine and environmental specimens revealed multiple strains and subtype codetections. Multiple gene segment exchanges among and within subtypes were observed, resulting in new genetic constellations and reassortant viruses. Genetic sequence similarities of 99%-100% among IAVs of 1 market customer and swine indicated interspecies transmission.

CONCLUSIONS

At markets where swine and persons are in close contact, swine-origin IAVs are prevalent and potentially provide conditions for novel IAV emergence.

Evaluation of risk and protective factors for work-related bite injuries to veterinary technicians certified in Minnesota

OBJECTIVE

To identify risk and protective factors for work-related bite injuries among veterinary technicians certified in Minnesota.

DESIGN

Nested case-control study.

SAMPLE

868 certified veterinary technicians (CVTs).

PROCEDURES

A questionnaire was mailed to CVTs who previously participated in a survey regarding work-related injuries and did (cases; 301 surveys sent) or did not (controls; 567) report qualifying work-related animal bite injuries in the preceding 12 months. Descriptive statistics were summarized. Demographic and work-related variables for the month preceding the bite injury (for cases) or a randomly selected month (controls) were assessed with univariate analysis (489 CVTs) and multivariate analysis of a subset of 337 CVTs who worked in small or mixed mostly small animal facilities.

RESULTS

Responses were received from 176 case and 313 control CVTs. For the subset of 337 CVTs, risk of bite injury was higher for those < 25 years of age (OR, 3.82; 95% confidence interval [CI], 1.84 to 7.94) than for those ≥ 35 years of age, for those who had worked < 5 years (OR, 3.24; 95% CI, 1.63 to 6.45) versus ≥ 10 years in any veterinary facility, and for those who handled ≥ 5 species/d (OR, 1.99; 95% CI, 1.06 to 3.74) versus < 3 species/d. Risk was lower for CVTs who handled < 10 versus ≥ 20 animals/d (OR, 0.23; 95% CI, 0.08 to 0.71).

CONCLUSIONS AND CLINICAL RELEVANCE

Several work-related factors were associated with the risk of work-related bite injury to CVTs. These findings may serve as a basis for development of intervention efforts and future research regarding work-related injuries among veterinary staff.

Evaluation of factors associated with work-related injuries to veterinary technicians certified in Minnesota

OBJECTIVE

To evaluate the magnitude and consequences of work-related injuries and associated factors among veterinary technicians certified in Minnesota.

DESIGN

Cross-sectional survey.

SAMPLE

1,427 certified veterinary technicians (CVTs).

PROCEDURES

Surveys were used to collect data on demographics, personal characteristics, injury occurrences in the 12 months prior to survey completion, and injury consequences. Annual injury rates were estimated on the basis of demographic and work-related characteristics. Risk of injury associated with various factors was estimated by calculation of incidence rate ratios, controlling for multiple factors.

RESULTS

465 of 873 eligible CVTs reported 1,827 injury events (total and bite injury rates, 237 and 78 injuries/100 persons/y). Primary injury sources were cats and dogs, and most injuries occurred during animal restraint or treatment. Self-reported most severe injuries involved bites; cuts, lacerations, or scratches; bruises or contusions; and abrasions. Injury consequences included treatment and restricted work activity. Risk of work-related injury was lower for CVTs who worked < 40 h/wk than for those who worked ≥ 40 h/wk. The risk was higher for CVTs working in small animal or mixed mostly small animal facilities and lower for those working in mixed large and small animal facilities, commercial or industry operations, and government or regulatory facilities, compared with CVTs in colleges or universities. Handling 4 to > 6 (vs < 4) animal species during the 12 months prior to the survey and belief that injuries are not preventable were also associated with higher risk of injury.

CONCLUSIONS AND CLINICAL RELEVANCE

Several factors associated with the risk of work-related injury among CVTs were identified. Beyond these risk factors, investigation of additional exposures is integral to relevant intervention strategies.

Reptile-associated salmonellosis in Minnesota, 1996-2011

Reptile-associated salmonellosis (RAS) occurs when Salmonella is transmitted from a reptile to a human. This study describes the epidemiology of RAS in Minnesota during 1996-2011. All Minnesotans with confirmed Salmonella infections are reported to the Minnesota Department of Health (MDH). Case patients are interviewed about illness characteristics and risk factors, including foods eaten, drinking and recreational water exposures, contact with ill people, and animal contact. Willing RAS case patients can submit stool from the reptile for culture. Serotype and pulsed-field gel electrophoresis (PFGE) subtype of Salmonella isolates from reptiles and case patients are compared. Of 8389 sporadic (not associated with an outbreak) non-typhoidal salmonellosis case patients in Minnesotans during 1996-2011, 290 (3.5%) reported reptile exposure. The median age of case patients with reptile exposure was 11 years, 31% were under the age of 5 years and 67% were under the age of 20 years; 50% were female. The median illness duration was 8 days; 23% required hospitalization. The most commonly reported reptile exposures were lizard (47%), snake (20%), turtle (19%) and a combination of reptile types (14%). Eighty-four per cent of isolates from case patients who reported reptile exposure were Salmonella enterica subspecies I. The three most common serotypes were Typhimurium (15%), Enteritidis (7%) and subspecies IV serotypes (7%). Of 60 reptiles testing positive for Salmonella, 36 (60%) yielded the same Salmonella serotype as the human isolate. Twenty-six of 27 reptile isolates that were subtyped by PFGE were indistinguishable from the human isolate. Of these, 88% were subspecies I; the most common serotypes were Enteritidis (12%), Typhimurium (8%), and Bareilly (8%). RAS accounts for approximately 3.5% of salmonellosis cases in Minnesota, primarily affecting children. The majority of isolates from case patients and reptiles belonged to Salmonella subspecies I, suggesting that reptiles are a source of human infection with serotypes not traditionally considered to be reptile-associated.

Using syndromic surveillance to estimate baseline rates for healthcare-associated infections in critical care units of small animal referral hospitals

BACKGROUND

Expected rates of healthcare-associated infections (HCAI) have not been established in veterinary hospitals. Baseline rates are critically needed as benchmarks for quality animal care.

OBJECTIVE

To estimate the occurrence of events related to HCAI identified using a standardized syndromic surveillance system in small animals in critical care cases at referral hospitals.

ANIMALS

Weaned dogs and cats (n = 1,951) that were hospitalized in the critical care unit of referral teaching hospitals during a 12-week period.

METHODS

Multicenter, prospective longitudinal study. A survey was completed for all enrolled animals to record basic demographics, information about procedures and treatments that animals received, and to document the occurrence of defined nosocomial syndromes. Data were analyzed to identify risk factors associated with the occurrence of these nosocomial syndromes.

RESULTS

Controlling for hospital of admission, 16.3% of dogs (95% confidence intervals [CI], 14.3-18.5) and 12% of cats (95% CI, 9.3-15.5) were reported to have had ≥ 1 nosocomial syndrome occur during hospitalization. Risk factors found to have a positive association with the development of a nosocomial syndrome were longer hospital stays, placement of a urinary catheter, surgical procedures being performed, and the administration of antiulcer medications and antimicrobial drugs excluding those given perioperatively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Syndromic surveillance systems can be successfully standardized for use across multiple hospitals to effectively collect data pertinent to HCAI rates and risk factors for occurrence.

Risk factors for exposure to influenza a viruses, including subtype H5 viruses, in Thai free-grazing ducks

Free-grazing ducks (FGD) have been associated with highly pathogenic avian influenza (HPAI) H5N1 outbreaks and may be a viral reservoir. In July-August 2010, we assessed influenza exposure of Thai FGD and risk factors thereof. Serum from 6254 ducks was analysed with enzyme-linked immunosorbent assay (ELISA) to detect antibodies to influenza A nucleoprotein (NP), and haemagglutinin H5 protein. Eighty-five per cent (5305 ducks) were seropositive for influenza A. Of the NP-seropositive sera tested with H5 assays (n = 1423), 553 (39%) were H5 ELISA positive and 57 (4%) suspect. Twelve per cent (74 of 610) of H5 ELISA-positive/suspect ducks had H5 titres ≥ 1 : 20 by haemagglutination inhibition. Risk factors for influenza A seropositivity include older age, poultry contact, flock visitors and older purchase age. Study flocks had H5 virus exposure as recently as March 2010, but no HPAI H5N1 outbreaks have been identified in Thailand since 2008, highlighting a need for rigorous FGD surveillance.

Seasonal pasture myopathy/atypical myopathy in North America associated with ingestion of hypoglycin A within seeds of the box elder tree

REASONS FOR PERFORMING STUDY

We hypothesised that seasonal pasture myopathy (SPM), which closely resembles atypical myopathy (AM), was caused by ingestion of a seed-bearing plant abundant in autumn pastures.

OBJECTIVES

To identify a common seed-bearing plant among autumn pastures of horses with SPM, and to determine whether the toxic amino acid hypoglycin A was present in the seeds and whether hypoglycin metabolites were present in SPM horse serum or urine.

METHODS

Twelve SPM cases, 11 SPM pastures and 23 control farms were visited to identify a plant common to all SPM farms in autumn. A common seed was analysed for amino acid composition (n = 7/7) by GC-MS and its toxic metabolite (n = 4/4) identified in conjugated form in serum [tandem mass spectrometry (MS/MS)] and urine [gas chromatography (GC) MS]. Serum acylcarnitines and urine organic acid profiles (n = 7) were determined for SPM horses.

RESULTS

Seeds from box elder trees (Acer negundo) were present on all SPM and 61% of control pastures. Hypoglycin A, known to cause acquired multiple acyl-CoA dehydrogenase deficiency (MADD), was found in box elder seeds. Serum acylcarnitines and urine organic acid profiles in SPM horses were typical for MADD. The hypoglycin A metabolite methylenecyclopropylacetic acid (MCPA), known to be toxic in other species, was found in conjugated form in SPM horse serum and urine. Horses with SPM had longer turn-out, more overgrazed pastures, and less supplemental feeding than control horses.

POTENTIAL RELEVANCE

For the first time, SPM has been linked to a toxin in seeds abundant on autumn pastures whose identified metabolite, MCPA, is known to cause acquired MADD, the pathological mechanism behind SPM and AM. Further research is required to determine the lethal dose of hypoglycin A in horses, as well as factors that affect annual seed burden and hypoglycin A content in Acer species in North America and Europe.

Prevalence, antibiotic resistance and molecular characterisation of Staphylococcus aureus in pigs at agricultural fairs in the USA

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.

Recovery of staphylococci from computer keyboards in a veterinary medical centre and the effect of routine cleaning

Computers play a vital role in veterinary clinics for grading, examining results, updating records, giving discharge instructions and maintaining billing information. Few studies have documented the degree of contamination or practical methods to disinfect computer equipment within the veterinary clinic setting. The intent of the present study was to characterise the frequency of recovery of Staphylococcus species from computer keyboards from a veterinary teaching hospital setting and to evaluate the effect of daily cleaning. From three keyboards in a treatment area, three in a dermatology area and one in office 70 environmental samples were cultured for Staphylococcus. As an indirect measure to assess cleanliness, samples were collected and tested using the 3M Clean-Trace Luminometer (relative light units [RLU]). Of the 25 Staphylococcus recovered 13 were Staphylococcus species, seven Staphylococcus pseudintermedius, four Staphylococcus aureus and one mixed colony of both Staphylococcus species and S pseudintermedius. The median RLU was 2098 (range 132 to 11,590). Routine cleaning decreased the recovering of Staphylococcus and the RLU values. In summary, the study results demonstrate the value of routine cleaning of keyboards and the need for on-going and regular education of staff and students about good hand hygiene.

The potential capability of social media as a component of food safety and food terrorism surveillance systems

Social media (i.e., internet applications and platforms that allow users to create and share content) are a potentially rich data source for foodborne disease surveillance. This commentary qualitatively evaluates social media as a foodborne disease surveillance system component and discusses novel ways that social media may facilitate the detection of intentional and unintentional food contamination.

Antibody prevalence of low-pathogenicity avian influenza and evaluation of management practices in Minnesota backyard poultry flocks

Low-pathogenicity avian influenza (LPAI) viruses have caused illness in poultry and humans with poultry contact. To determine whether there is evidence of exposure to avian influenza viruses (AIV) among backyard poultry in Minnesota and their human caretakers, 150 flocks of backyard birds were sampled for antibodies to AIV from August 2007 through December 2008. One hundred flocks were tested through routine slaughter surveillance by the Minnesota Board of Animal Health and an additional 50 flocks were contacted and sampled by study investigators. Blood was collected from 10 to 13 birds from each flock and a survey of biosecurity and management practices was administered to the flock owner. Blood samples were tested by agar gel immunodiffusion (AGID) for influenza A antibodies. Tested flocks had a median flock size of 100 birds (range: 12-800 birds), and were most commonly owned for meat for personal use (81% of respondents), fun or hobby (58%) and eggs for personal use (56%). Although 7% of flock owners reported that their birds had shown respiratory signs in the previous 3 months, only 1 of 150 flocks tested positive for influenza by AGID. Antibodies to LPAI H6N1 were detected in the positive flock. The owner of the positive flock did not have antibodies to H6 or other common AIV. Based on the findings of this study, the risk of transmission of LPAI viruses from backyard poultry to owners in Minnesota appears to be low under current conditions and management practices.

Decreased use of cervical spine clearance in blunt trauma: the implication of the injury mechanism and distracting injury

BACKGROUND

Cervical spine injury (CSI) can be ruled out based on clinical examination and no X-ray is required if patient is awake, alert, and examinable. This is known as a clinical clearance (CC). Clinicians have decreased the use and reliance of CC and relied more upon X-ray, especially now that computerized tomography (CT) is fast and readily available. The objective of this study was to identify clinical factors, in particular, the injury mechanism and the distracting injuries, which may be associated with CSI. The knowledge may help to improve the use of CC.

METHODS

We retrospectively reviewed the records of all blunt trauma patients who were awake, alert, and examinable, with a Glasgow Coma Scale of 14-15, and who were admitted to our Level 1 Trauma Center during January 1 to December 31, 2005. We excluded patients who presented with gross neurological deficit or who died within 72 h. From the chart review, we collected the demographics; the injury severity score (ISS); the injury mechanism; the presence of distracting injuries (DI) which were defined as bony fractures (divided into upper body, lower body, or both); and the radiographs obtained. Patients who did not receive CC underwent a 3-view plain film X-ray, with or without CT scan. We then divided the group into those with CSI (Case) and those without (Control). We compared the two group variables and performed a multiple logistic regression analysis to identify clinical factors associated with CSI. Statistical significance was accepted with p-value <0.05.

RESULTS

Of the 985 patients evaluated, only 179 (18%) received CC. The remaining did not receive CC and went on to have radiographs. Of these, 76 were diagnosed CSI (Case). On a univariate analysis, the ISS, a motor vehicle collision (MVC) with rollover; MVC with rollover and ejection, the absence of DI, and a lower-body DI were significantly associated with CSI. However, on a multivariate analysis, only an MVC with rollover (odds ratio [OR], 2.326; 95% confidence interval [CI], 1.36-3.97) and a lower-body distracting injury (OR, 0.20; 95% CI, 0.07-0.55) were significantly associated with CSI.

CONCLUSION

The injury mechanism of MVC with rollover may prevent clinicians from utilizing CC, while the presence of a lower-body DI should not. A future and prospective study is needed to better understand the role of the injury mechanism and the distracting injury in relation to CSI.

Methicillin-resistant Staphylococcus aureus in resident animals of a long-term care facility

Animals provide benefits to elderly and chronically ill people by decreasing loneliness, increasing social interactions, and improving mental health. As a result, many hospitals and long-term care facilities allow family pets to visit ill or convalescing patients or support animal-assisted therapy programs. These include programs that have resident animals in long-term care facilities. Despite the benefits, there are concerns about disease transmission between pets and patients. Antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), are a recognized problem in healthcare settings leading to refractory infections and potentially life-threatening illnesses. MRSA has been isolated from numerous animal species, yet few studies are available on the carriage of this pathogen in animals residing in long-term care facilities. Our objective was to characterize MRSA carriage among resident animals in a long-term care facility.

METHODS

To document MRSA colonization, nasal swabs from 12 resident animals (one dogs and 11 cats) of a long-term care facility were collected weekly for 8 weeks. Staphylococcus isolates were characterized by antimicrobial susceptibility and MRSA isolates were further characterized by pulsed-field gel electrophoresis (PFGE). PFGE isolate patterns were compared with an existing database of MRSA isolate patterns at the Minnesota Department of Health.

RESULTS

Two of 11 cats were colonized with MRSA. MRSA was recovered from five of eight weekly samples in one cat and two of eight weekly samples in the other cat. All isolates were classified as USA100 (healthcare-associated strains).

DISCUSSION

Long-term care resident animals may acquire MRSA. Clonally related strains were identified over the 8-week sampling period. It is unclear if pets serve as an on-going source of infection to their human companions in long-term care facilities.

Anaplasma phagocytophilum infection in dogs: 34 cases (2000-2007)

OBJECTIVE- To determine demographic characteristics of dogs from the upper Midwest infected with Anaplasma phagocytophilum and identify clinical and clinicopathologic abnormalities and response to treatment. DESIGN- Retrospective case series and owner telephone survey. ANIMALS- 34 dogs with granulocytic anaplasmosis. PROCEDURES- Records were reviewed for information on signalment, history, physical examination findings, clinicopathologic and serologic findings, and treatment. Owners were contacted by telephone within 4 months after dogs were discharged. RESULTS- Median age was 8 years. Distribution of month of diagnosis was bimodal, with 15 dogs examined during May or June and 11 others examined during October or November. Camping and hiking were the most frequently reported tick exposure activities. Lethargy (25/34) and anorexia (21/34) were the most common initial complaints, fever was the most common clinical sign (27/32), and thrombocytopenia was the most common clinicopathologic abnormality (21/22). Fifteen of 20 dogs were seropositive for antibodies against A phagocytophilum. Doxycycline was prescribed for 31 dogs, and clinical signs and fever resolved within 3 to 5 days. Median time for platelet count to return to reference limits was 7 days. No owners reported clinical sequelae when contacted after dogs were discharged. CONCLUSIONS AND CLINICAL RELEVANCE- Results suggested that granulocytic anaplasmosis should be suspected in dogs in endemic areas examined because of fever, lethargy, or thrombocytopenia, especially in dogs examined during the late spring or early fall. Treatment with doxycycline was successful in resolving clinical signs and thrombocytopenia.

Pets and antimicrobial resistance

Antimicrobial resistance is a growing problem and is a significant public health issue. An increasing number of organisms are developing resistance to many of the antimicrobial agents available for treatment of infections in both humans and animals. These resistant organisms often result in greater disease severity, longer hospitalization, and increased care and treatment costs. This article reviews the current situation of antimicrobial resistance in companion small animals and highlights how important it is for veterinarians to recognize the significance of antimicrobial resistance and to commit to the judicious use of antimicrobial agents.

Diseases pets and people share

Having a companion animal such as a dog, cat, or pocket pet is increasingly popular in the United States. With more human-animal interactions come additional opportunities for disease exchange. This article highlights common zoonoses associated with pets and provides recommendations for preventing disease transmission, including hand hygiene, client or patient education, and appropriate pet care. The article also discusses human diseases in which animals may be mistakenly implicated as the source and the recent identification of human diseases such as methicillin-resistant Staphylococcus aureus in companion animal populations. The article also calls for the strengthening of integrated animal and human surveillance systems and cooperation of medical and veterinary practitioners.

Outbreaks of enteric disease associated with animal contact: not just a foodborne problem anymore

In the past 10 years, an increasing number of outbreaks of enteric disease associated with animals in public settings, such as fairs and petting zoos, have been reported. Fifty-five of these outbreaks that occurred in the United States during 1991-2005 are reviewed in this article. Lessons learned from these outbreaks and recommendations for prevention are also discussed. Physicians should be aware of this important public health problem and play an active role in prevention of human illness associated with animals in public settings.

Circumstances of Bat Encounters and Knowledge of Rabies among Minnesota Residents Submitting Bats for Rabies Testing

Minnesota residents who submitted a bat to the Minnesota Department of Health for rabies testing in 2003 were surveyed by telephone regarding the circumstances of the bat encounter and their knowledge of bats and rabies. Of 442 bats submitted for testing, 12 (3%) tested positive for rabies, and 410 (93%) tested negative; 17 (4%) bats were unsuitable for testing, and three (1%) had equivocal results. A case-control study found that rabid bats were more likely than non-rabid bats to be found in September, found outside, found in a wooded area, unable to fly, acting ill, or acting aggressively. Rabid bats were not more likely than non-rabid bats to be found during the day or to have bitten someone. While most persons submitting bats for rabies testing were aware that bats can carry rabies, few knew they should submit the bat for testing until they sought the advice of an animal control officer, veterinarian, or healthcare provider.

Multidrug-resistant Salmonella Typhimurium in four animal facilities

Within each of 4 outbreaks of S. Typhimurium among humans and animals at companion animal care facilities, isolates were identical or nearly identical.

In 1999 and 2000, 3 state health departments reported 4 outbreaks of gastrointestinal illness due to Salmonella enterica serotype Typhimurium in employees, clients, and client animals from 3 companion animal veterinary clinics and 1 animal shelter. More than 45 persons and companion animals became ill. Four independent investigations resulted in the testing of 19 human samples and >200 animal samples; 18 persons and 36 animals were culture-positive for S. Typhimurium. One outbreak was due to multidrug-resistant S. Typhimurium R-type ACKSSuT, while the other 3 were due to multidrug-resistant S. Typhimurium R-type ACSSuT DT104. This report documents nosocomial transmission of S. Typhimurium and demonstrates that companion animal facilities may serve as foci of transmission for salmonellae between animals and humans if adequate precautions are not followed.

Herd-level factors associated with isolation of Salmonella in a multi-state study of conventional and organic dairy farms

The objective of this study was to evaluate associations between herd characteristics and the isolation of Salmonella from dairy cows in Minnesota, Wisconsin, Michigan, and New York. Study farms were 129 conventional and organic farms enrolled without regard to previous history of Salmonella infection. Herds were sampled at 2-month intervals over a 1-year period. This is the largest study to date on Salmonella shedding in dairy cows and the only study evaluating herd-level risk factors using longitudinal sampling to characterize Salmonella shedding on dairy farms. Salmonella was isolated in fecal samples from 1026 (4.9%) of 20,089 cows. Over the course of the study, 113 (87.6%) of 129 farms had at least one positive cow sample. Multi-variable logistic regression using the generalized estimating equations approach was used to test the association between herd-level risk factors and the dependent variable of within-herd prevalence by visit (number of Salmonella-positive cows/number of cows sampled) after adjustment for effects of herd size, season, state of origin, and the multiple sampling occasions per herd. Factors retained in the final model included lack of use of tiestall or stanchion facilities to house lactating cows (OR=1.9; 95% CI: 1.1-3.3), not storing all purchased concentrate or protein feeds in an enclosed building (OR=2.5; 95% CI: 1.3-4.9), not using monensin in weaned calf or bred heifer diets (OR=3.2; 95% CI: 2.0-5.4), access of lactating or dry cows to surface water (e.g., lake, pond, river, or stream) (OR=2.3; 95% CI: 1.3-3.9), disposal of manure in liquid form (slurry or irrigation, as opposed to disposal of manure by broadcast/solid spreader only) on owned or rented land (OR=1.8; 95% CI: 1.3-3.9), and cows eating or grazing of roughage from fields where manure was applied in solid or liquid form and not plowed under during the same growing season (OR=1.8; 95% CI: 1.0-3.0). A seasonal association was also present as cows were more likely to be Salmonella-positive in summer, spring, and fall compared to winter. Herd size was not associated with Salmonella shedding in the final multi-variable model. The herd-level risk factors identified in this study could potentially be implemented in Salmonella control programs on dairy farms.

Herd-level factors associated with isolation of Salmonella in a multi-state study of conventional and organic dairy farms

The objective of this study was to evaluate associations between herd-level factors and the isolation of Salmonella in calves from dairy farms in Minnesota, Wisconsin, Michigan and New York. Study farms were 129 conventional and organic farms enrolled without regard to previous history of Salmonella infection. Herds were sampled at 2-month intervals over a 1-year period. Salmonella was isolated in fecal samples from 176 (3.8%) of 4673 preweaned calves with 40 (31.0%) of 129 farms having at least one positive calf sample over the course of the study. Multivariable logistic regression using the generalized estimating equations approach was used to evaluate risk factors for Salmonella shedding after adjustment for effects of herd size, season, state of origin and the multiple sampling occasions per herd. Factors retained in the final model that were associated with an increased odds for Salmonella shedding were lack of routine feeding of milk replacer containing antimicrobials to preweaned calves (OR=2.8, 95% CI: 1.4, 5.8), use of maternity housing as a hospital area for sick cows more than once a month (OR=2.1, 95% CI: 1.1, 4.0), and cow prevalence level by visit, categorized into the following four-levels: > or =20% (OR=11.6, 95% CI: 5.7, 23.7), 10-19.9% (OR=4.7, 95% CI: 2.0, 11.5), 0.1-9.9% (OR=3.6, 95% CI: 1.5, 8.7) and 0% (reference level). Herd size was not associated with Salmonella shedding in the final multivariable model.

Horses and the risk of zoonotic infections

Infectious agents are insidious, often changing to adapt to host defenses or treatment advances. Because these challenges will continue, the need to apply standard and transmission-based precautions is important not only in the human hospital setting but in the veterinary clinic setting. In addition, to prevent human infection and potential liability, clinics need to establish program algorithms to prevent disease spread for specific agents or planned procedures to respond to potential nosocomial and zoonotic disease events. These need to be done proactively. Furthermore, more money needs to be dedicated to establish infection control programs and to improve the science of infection control in the veterinary setting.

Reports of zoonotic disease outbreaks associated with animal exhibits and availability of recommendations for preventing zoonotic disease transmission from animals to people in such settings

OBJECTIVE

To assess the number of zoonotic disease outbreaks associated with animal exhibits and identify published recommendations for preventing zoonotic disease transmission from animals to people in exhibit settings.

DESIGN

Literature review and survey of state public health veterinarians and state epidemiologists.

PROCEDURE

MEDLINE and agriculture databases were searched from 1966 through 2000. Retrieved references and additional resources provided by the authors were reviewed. A survey was sent to state public health veterinarians and state epidemiologists to determine whether their states had written recommendations or guidelines for controlling zoonotic diseases in animal exhibition venues, whether their states maintained a listing of animal exhibitors in the state, and whether they had any information on recent outbreaks involving animals in exhibitions.

RESULTS

11 published outbreaks were identified. These outbreaks occurred in a variety of settings including petting zoos, farms, and a zoological park. An additional episode involving exposure to a potentially rabid bear required extensive public health resources. A survey of state public health veterinarians identified 16 additional unpublished outbreaks or incidents. Most states did not have written recommendations or guidelines for controlling zoonotic diseases or any means to disseminate educational materials to animal exhibitors.

CONCLUSIONS

Recent outbreaks of zoonotic diseases associated with contact with animals in exhibition venues highlight concerns for disease transmission to public visitors. Only a handful of states have written guidelines for preventing zoonotic disease transmission in animal exhibition venues, and published recommendations currently available focus on preventing enteric diseases and largely do not address other zoonotic diseases or prevention of bite wounds.

Mites (Acari: Laelapidae) associated with sigmodontinae rodents in Entre Ríos Province, Argentina

The richness, diversity, abundance and prevalence of mite species associated with sigmodontine rodents of different species in Entre Ríos province, Argentina are studied. Five of the six species of mites were reported for the first time in the study area. The richness and diversity of mites was higher on Oligoryzomys flavescens and O. delticola than on Akodon azarae. Androlaelaps rotundus was dominant and exhibited higher values of mean abundance and prevalence on A. azarae, Mysolaelaps microspinosus on O. flavescens and Gigantolaelaps mattogrossensis on O. delticola.

Use of molecular subtyping in surveillance for Salmonella enterica serotype typhimurium

BACKGROUND

Because Salmonella enterica serotype typhimurium is the most common serotype isolated from persons with salmonellosis in the United States, it is difficult to detect unusual clusters or outbreaks. To determine whether molecular subtyping could be useful in public health surveillance for S. enterica serotype typhimurium, the Minnesota Department of Health initiated the routine use of pulsed-field gel electrophoresis (PFGE) of isolates.

METHODS

Beginning in 1994, all S. enterica serotype typhimurium isolates submitted by clinical laboratories to the Department of Health were subtyped by PFGE. A standard questionnaire was used to interview patients about possible sources of infection.

RESULTS

From 1994 through 1998, 998 cases of infection with S. enterica serotype typhimurium were reported to the Minnesota Department of Health (4.4 cases per 100,000 person-years). PFGE was performed on 958 of the isolates (96 percent), and 174 different patterns were identified. Sixteen outbreaks with a common source were identified, accounting for 154 cases. PFGE subtyping made it possible to confirm 10 outbreaks that involved small numbers of cases in institutional settings. Of six larger, community-based outbreaks, four would probably not have been recognized without PFGE subtyping. These four outbreaks accounted for 96 of the 154 culture-confirmed outbreak cases (62 percent). Fifty-six of 209 isolates tested for antimicrobial susceptibility (27 percent) were resistant to at least five antimicrobial agents. The multidrug-resistant isolates identified had unique PFGE patterns.

CONCLUSIONS

Routine molecular subtyping of S. enterica serotype typhimurium by PFGE can improve the detection of outbreaks and aid in the identification of multidrug-resistant strains. Combining routine molecular subtyping with a method of rapid communication among public health authorities can improve surveillance for S. enterica serotype typhimurium infections.

The changing epidemiology of malaria in Minnesota

Malaria cases reported to the Minnesota Department of Health increased from 5 in 1988 to 76 in 1998, paralleling the number of immigrants to Minnesota. In 20% of cases, the Plasmodium species was not identified; 44% of cases were hospitalized. The public health community needs to reevaluate current recommendations for refugee screening, provider and patient education, and laboratory capacity.

Food-borne disease in the 21st century. What challenges await us?

As the world shrinks and international commerce expands, food-borne illness is likely to become a major public health focus worldwide. Improved surveillance, community education, thorough understanding of the food production chain, use of HACCP strategies, and ionizing radiation are all important for reducing the risks. Primary care physicians play a crucial role in surveillance and early reporting, as well as in educating the public on the importance of basic food safety.

Quinolone-resistant Campylobacter jejuni infections in Minnesota, 1992-1998. Investigation Team

BACKGROUND

Increasing resistance to quinolones among campylobacter isolates from humans has been reported in Europe and Asia, but not in the United States. We evaluated resistance to quinolones among campylobacter isolates from Minnesota residents during the period from 1992 through 1998.

METHODS

All 4953 campylobacter isolates from humans received by the Minnesota Department of Health were tested for resistance to nalidixic acid. Resistant isolates and selected sensitive isolates were tested for resistance to ciprofloxacin. We conducted a case-comparison study of patients with ciprofloxacin-resistant Campylobacter jejuni isolated during 1996 and 1997. Domestic chicken was evaluated as a potential source of quinolone-resistant campylobacter.

RESULTS

The proportion of quinolone-resistant C. jejuni isolates from humans increased from 1.3 percent in 1992 to 10.2 percent in 1998 (P<0.001). During 1996 and 1997, infection with quinolone-resistant C. jejuni was associated with foreign travel and with the use of a quinolone before the collection of stool specimens. However, quinolone use could account for no more than 15 percent of the cases from 1996 through 1998. The number of quinolone-resistant infections that were acquired domestically also increased during the period from 1996 through 1998. Ciprofloxacin-resistant C. jejuni was isolated from 14 percent of 91 domestic chicken products obtained from retail markets in 1997. Molecular subtyping showed an association between resistant C. jejuni strains from chicken products and domestically acquired infections in Minnesota residents.

CONCLUSIONS

The increase in quinolone-resistant C. jejuni infections in Minnesota is largely due to infections acquired during foreign travel. However, the number of quinolone-resistant infections acquired domestically has also increased, largely because of the acquisition of resistant strains from poultry. The use of fluoroquinolones in poultry, which began in the United States in 1995, has created a reservoir of resistant C. jejuni.

Animal by-products contaminated with Salmonella in the diets of lactating dairy cows

As part of a total mixed ration, two rumen-fistulated dairy cows were fed meat and bone meal that had been artificially contaminated with Salmonella spp. Samples from the rumen, feces, and milk were taken 3 d/wk and cultured for salmonella. Rectal temperatures and rumen pH were also measured at the time of sample collection. Over the 2-mo study, salmonella were intermittently recovered from rumen contents, from feces, and from necropsy specimens of rumen contents, cecal contents, and mesenteric lymph nodes. No excretion of salmonella in milk was detected. An elevated rumen pH was associated with increased isolation of salmonella. No clinical illness was observed for either cow. Meat and bone meal that has been contaminated with low concentrations of salmonella is unlikely to result in clinical illness in healthy adult lactating cows. However, dairy producers should continue to be concerned about feed biosecurity and water contamination of animal by-products to prevent and control contamination by salmonella.