Brucella suis and farm biosecurity: assessing risk in pigs raised outdoors in New York State

OBJECTIVE

To evaluate the Brucella suis exposure status of pigs raised with outdoor access on farms in New York State and assess biosecurity and management practices of those farms.

ANIMALS

250 pigs that were raised for commercial purposes, had access to the outdoors, and were > 4 months of age on 24 farms in New York State.

PROCEDURES

Farms were randomly selected from a sampling frame generated for the study and contacted to recruit them to participate. Participating farms were provided a questionnaire to complete. Up to 30 pigs per farm were tested for serum anti-Brucella antibodies.

RESULTS

Farm were classified as seasonal and year round. Seasonal farms raised pigs for slaughter, and year-round farms bred pigs, raised them for slaughter, and sold live pigs to others to raise. None of the 250 pigs had antibodies to Brucella spp. Nevertheless, the biosecurity assessment revealed a need for enhanced practices in procurement and management of swine in a wide range of areas.

CLINICAL RELEVANCE

There was no evidence for ongoing B suis infection on these swine farms in New York State, but biosecurity and preventive practices at these facilities could be improved to prevent the introduction and spread of B suis and other pathogens.

Primary care clinical provider knowledge and experiences in the diagnosis and treatment of tick-borne illness: a qualitative assessment from a Lyme disease endemic community

BACKGROUND

Primary care and frontline healthcare providers are often the first point of contact for patients experiencing tick-borne disease (TBD) but face challenges when recognizing and diagnosing these diseases. The specific aim of this study was to gain a qualitative understanding of frontline and primary care providers' knowledge and practices for identifying TBDs in patients.

METHODS

From fall 2018 to spring 2019, three focus groups were conducted with primary care providers practicing in a small-town community endemic to Lyme disease (LD) and with emerging incidence of additional TBDs. A follow up online survey was distributed to urgent and emergency care providers in the small-town community and an academic medical center within the referral network of the local clinical community in spring and summer 2019. Qualitative analysis of focus group data was performed following a grounded theory approach and survey responses were analyzed through the calculation of descriptive statistics.

RESULTS

Fourteen clinicians from three primary care practices participated in focus groups, and 24 urgent and emergency care clinicians completed the survey questionnaire. Four overarching themes emerged from focus group data which were corroborated by survey data. Themes highlighted a moderate level of awareness on diagnosis and treatment of LD among participants and limited knowledge of diagnosis and treatment for two other regionally relevant TBDs, anaplasmosis and babesiosis. Providers described challenges and frustrations in counseling patients with strong preconceptions of LD diagnosis and treatment in the context of chronic infection. Providers desired additional point-of-care resources to facilitate patient education and correct misinformation on the diagnosis and treatment of TBDs.

CONCLUSIONS

Through this small study, it appears that clinicians in the small-town and academic medical center settings are experiencing uncertainties related to TBD recognition, diagnosis, and patient communication. These findings can inform the development of point-of-care resources to aid in patient-provider communication regarding TBDs and inform the development of continuing medical education programs for frontline and primary care providers.

Clinicopathological findings in 41 dogs (2008-2018) naturally infected with Ehrlichia ewingii

Background

Ehrlichia ewingii is the most seroprevalent Ehrlichia‐infecting dogs in the southern and mid‐western United States. Fever, lameness, and polyarthritis are commonly reported findings in dogs naturally infected with E. ewingii.

Objectives

To evaluate clinicopathologic findings in a population of dogs naturally infected with E. ewingii.

Animals

Forty‐one dogs PCR positive for E. ewingii and PCR negative for other targeted vector‐borne organisms.

Methods

Retrospective study. Clinical and clinicopathologic data including physical examination findings, CBC, serum biochemistry, urinalysis (UA), symmetric dimethylarginine (SDMA), and vector‐borne disease diagnostic results were reviewed.

Results

Frequent clinical diagnoses other than ehrlichiosis (28/41; 68.3%) were renal disease (7/41; 17.1%) and immune‐mediated hemolytic anemia (IMHA) (6/41; 14.6%). The most frequent physical examination finding was joint pain (14/41; 34.1%). Prominent hematologic and biochemical abnormalities included abnormal lymphocyte counts (22/36; 61.1%); neutrophilia (21/37; 56.8%); increased alkaline phosphatase (20/35; 57.1%) and alanine transaminase (14/35; 40%) activities; and increased SDMA concentration (11/34; 32.4%). Urinalysis abnormalities included proteinuria (20/27; 74%), most with inactive sediments (16/20; 80%). Dogs were seroreactive by Ehrlichia canis immunofluorescence assay (IFA; 17/39; 43.6%) and Ehrlichia ELISA (34/41; 82.9%). Seroreactivity by IFA for other vector‐borne pathogens included Bartonella (1/39; 2.6%), Rickettsia rickettsii (spotted‐fever group rickettsiae) (12/39; 30.8%), and Borrelia burgdorferi by ELISA (1/41; 2.4%).

Conclusions and Clinical Importance

Renal disease, IMHA, proteinuria, neutrophilia, abnormal lymphocytes, and increased liver enzyme activities were common in this group of E. ewingii‐infected dogs. Studies are needed to determine if E. ewingii contributes to comorbidities or is a precipitating factor in clinical syndromes in persistently infected dogs.

Doxycycline treatment efficacy in dogs with naturally occurring Anaplasma phagocytophilum infection

OBJECTIVES

To evaluate doxycycline treatment efficacy and post-treatment pathogen persistence in dogs naturally infected with Anaplasma phagocytophilum in endemic regions of the USA.

MATERIALS AND METHODS

Symptomatic dogs in four US states (MN, WI, CT and CA) were evaluated before treatment with doxycycline and approximately 30 and 60 days post-treatment. Clinicopathological parameters, co-exposures and A. phagocytophilum DNA in whole blood and lymph node samples were compared between A. phagocytophilum infected and uninfected dogs.

RESULTS

In total, 42 dogs fulfilled the inclusion criteria, with 16 dogs (38%) blood PCR-positive and 26 dogs (62%) blood PCR-negative for A. phagocytophilum. At initial evaluation, the proportion of clinicopathological abnormalities was similar between A. phagocytophilum infected and uninfected dogs, although thrombocytopenia and lymphopenia were statistically more prevalent among A. phagocytophilum infected dogs. Treatment with doxycycline resulted in resolution of all clinical abnormalities in infected dogs; four dogs had persistent haematological abnormalities, including mild leukopenia, eosinopenia and lymphopenia. All 16 infected dogs became blood PCR-negative approximately 30 and 60 days after treatment onset. Additionally, 13/13 (100%) lymph node specimens tested post-treatment were PCR-negative. Select clinicopathological abnormalities persisted in uninfected dogs after treatment.

CLINICAL SIGNIFICANCE

The results of this study support the efficacy of doxycycline therapy for clinical treatment of dogs naturally infected with A. phagocytophilum in the USA. This study did not find clinical, haematological or microbiological indicators that supported the persistence of A. phagocytophilum infection in naturally infected dogs following treatment with doxycycline for 28 days.

Regional seroreactivity and vector-borne disease co-exposures in dogs in the United States from 2004-2010: utility of canine surveillance

Vector-borne disease (VBD) pathogens remain an emerging health concern for animals and humans throughout the world. Surveillance studies of ticks and humans have made substantial contributions to our knowledge of VBD epidemiology trends, but long-term VBD surveillance data of dogs in the United States is limited. This seroreactivity study assessed US temporal and regional trends and co-exposures to Anaplasma, Babesia, Bartonella, Borrelia burgdorferi, Dirofilaria immitis, Ehrlichia spp., and spotted fever group Rickettsia in dogs from 2004-2010. Dog serum samples (N=14,496) were submitted to the North Carolina State University, College of Veterinary Medicine, Vector Borne Disease Diagnostic Laboratory for vector-borne pathogens diagnostic testing using immunofluorescent antibody (IFA) and enzyme-linked immunosorbent assay (ELISA) assays. These convenience samples were retrospectively reviewed and analyzed. The largest proportion of samples originated from the South (47.6%), with the highest percent of seroreactive samples observed in the Midatlantic (43.4%), compared to other US regions. The overall seroreactivity of evaluated VBD antigens were Rickettsia rickettsia (10.4%), B. burgdorferi (5.2%), Ehrlichia spp. (4.3%), Bartonella henselae (3.8%), Anaplasma spp. (1.9%), Bartonella vinsonii subsp. berkhoffii (1.5%), Babesia canis (1.1%), and D. immitis (0.8%). Significant regional and annual seroreactivity variation was observed with B. burgdorferi, Ehrlichia, and Rickettsia exposures. Seasonal seroreactivity variation was evident with Rickettsia. Seroreactivity to more than one antigen was present in 16.5% of exposed dogs. Nationally, the most prevalent co-exposure was Rickettsia with Ehrlichia spp. (5.3%), and the highest odds of co-exposure was associated with Anaplasma spp. and B. burgdorferi (odds ratio=6.6; 95% confidence interval 5.0, 8.8). Notable annual and regional seroreactivity variation was observed with certain pathogens over 7 years of study, suggesting canine surveillance studies may have value in contributing to future VBD knowledge.