Estimated herd prevalence and sequence types of Coxiella burnetii in bulk tank milk samples from commercial dairies in Indiana.

BACKGROUND: Coxiella burnetii is the etiologic agent of Q fever, a zoonotic disease causing influenza-like illness, pregnancy loss, cardiovascular disease and chronic fatigue syndrome in people. C. burnetii is considered to be enzootic in ruminants, but clinical signs of infection do not always manifest. National studies have documented the presence of C. burnetii in dairy herds in Indiana. This represents an opportunity to better characterize the distribution and prevalence of C. burnetii infection at the state scale, allowing evaluation of the need for surveillance and response planning to occur at this level. A cross-sectional study was conducted to estimate the herd prevalence of C. burnetii in commercial cattle dairies in Indiana and characterize the strains of C. burnetii within these dairies. RESULTS: Bulk tank milk samples were collected between June and August of 2011 by the Indiana State Board of Animal Health (ISBOAH). A total of 316 of these samples were tested for the IS1111 transposon of C. burnetii using quantitative real time polymerase chain reaction (PCR). Single nucleotide polymorphism (SNP) genotyping was used to identify the multispacer sequence genotypes (ST) present in samples where the IS1111 transposon was identified. The geographic distribution of dairies testing positive for C. burnetii DNA and the identified STs were also evaluated. The estimated overall herd prevalence for C. burnetii DNA was 61.1 % (95 % CI 55.6-66.3 %). The highest estimated regional prevalence was 70.2 % in the Central region of Indiana. An ST was identifiable in 74 of the positive 178 samples (41.6 %) and none of the 10 negative samples tested. Of these samples, 71 (95.9 %) were identified as ST20, 2 (2.7 %) as ST8 and a combination of ST20 and ST8 was identified in a single sample. CONCLUSIONS: C. burnetii is present in dairy herds throughout Indiana. Indiana follows national trends with ST20 most commonly identified. The presence of multiple STs in a single bulk tank sample indicates that multiple strains of C. burnetii can circulate within a herd. This supports potential transmission of C. burnetii between goats and cattle, presenting the potential for a switch in the dominant genotype found in a given species.

A cross-sectional study to estimate prevalence of periodontal disease in a population of dogs (Canis familiaris) in commercial breeding facilities in Indiana and Illinois.

The objectives of this cross-sectional study were: 1) to estimate the prevalence and characterize the severity of periodontal disease in a population of dogs housed in commercial breeding facilities; 2) to characterize PD preventive care utilized by facility owners; and 3) to assess inter-rater reliability of a visual scoring assessment tool. Adult dogs (N = 445) representing 42 breeds at 24 CB facilities in Indiana and Illinois were assessed. Periodontal disease was scored visually using the American Veterinary Dental Collage 0-IV scale. Inter-rater reliability was assessed on 198 dogs and facility owners were asked to provide information about the preventive care utilized. The overall prevalence of periodontal disease (Grades I-IV) was 86.3% (95% CI: 82.9, 89.3). An ordered logistic regression analysis found age (OR = 1.4; 95% CI 1.24, 1.54; P<0.0001), facility (OR = 1.13; 95% CI 1.09, 1.18; P<0.0001), sex (OR = 1.7; 95% CI 1.12, 2.65; P = 0.013), and non-professional dental scaling (OR = 2.82; 95% CI 1.34, 5.91; P = 0.006) to be statistically significant. Inter-rater reliability analysis found agreement to be 86.2%, with a weighted kappa of 0.4731 (95% CI 0.3847, 0.5615) indicating moderate agreement. Risk of periodontal disease increased with increasing age. Additionally, a trend toward decreasing risk with increasing weight was also found, although it was not statistically significant. The trends identified agree with studies that have evaluated periodontal disease in the companion dog population and do not support the assumption that the dental health of dogs in commercial breeding facilities is worse than that of the population as a whole. Although there were few cases of severe periodontal disease and all facilities employed some type of preventive care in this sample, the large number of dogs with some degree of disease (Grades I-IV) suggests that further investigation of preventive care is warranted.

Evaluating the validity and reliability of a visual dental scale for detection of periodontal disease (PD) in non-anesthetized dogs (Canis familiaris).

Periodontal disease is one of the most common conditions affecting companion dogs. The objectives of this cross-sectional study were: to determine 1) the agreement between visual assessments (VA) of periodontal disease (PD) performed on awake dogs and the reference standard (RS) of a dental examination and radiographs performed with the dog under general anesthesia, and 2) inter-rater reliability (IRR) for two individuals performing VAs of PD on the same dogs. One hundred and eight dogs were recruited from three veterinary practices. An oral examination and visual PD staging based on the American Veterinary Dental College's (AVDC) 5-point scale was performed by the investigators prior to general anesthesia and the dental procedure. After the anesthetic evaluation and radiographs, the attending veterinarian staged each dog based on the AVDC's 5-point scale. Agreement between the VA and RS as well as IRR were determined using percent agreement and a weighted kappa statistic. Eighty-nine dogs received a complete oral examination under general anesthesia with periodontal probing and full-mouth radiographs. Fifty-nine dogs received a VA by both raters. VA agreed with the RS 41.57% of the time with a weighted kappa of 0.42 (95% confidence interval 0.29-0.55), indicating moderate agreement. Between raters, VA agreed 61.02% of the time with a weighted kappa of 0.63 (95% confidence interval 0.49-0.76), indicating substantial IRR. The results of this study reinforce the idea that an oral examination in an awake dog can be a helpful screening tool, but should not be considered a comprehensive evaluation of periodontal health. In facilities housing large numbers of dogs such as shelters, breeding kennels, and research facilities, use of a VA can aid in identifying and prioritizing dogs most in need of procedures such as professional cleaning, periodontal treatment, including closed root planing, or surgical care.

Detection of hemoplasma infection of goats by use of a quantitative polymerase chain reaction assay and risk factor analysis for infection.

OBJECTIVE To develop and validate a real-time quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma ovis in goats and investigate the prevalence and risk factors for hemoplasma infection of goats located in Indiana. ANIMALS 362 adult female goats on 61 farms. PROCEDURES Primers were designed for amplification of a fragment of the dnaK gene of M ovis by use of a qPCR assay. Blood samples were collected into EDTA-containing tubes for use in total DNA extraction, blood film evaluation, and determination of PCV. Limit of detection, intra-assay variability, interassay variability, and specificity of the assay were determined. RESULTS Reaction efficiency of the qPCR assay was 94.45% (R(2), 0.99; slope, -3.4623), and the assay consistently detected as few as 10 copies of plasmid/reaction. Prevalence of infection in goats on the basis of results for the qPCR assay was 18.0% (95% confidence interval, 14% to 22%), with infected goats ranging from 1 to 14 years old, whereby 61% (95% confidence interval, 47% to 73%) of the farms had at least 1 infected goat. Bacterial load in goats infected with M ovis ranged from 1.05 × 10(3) target copies/mL of blood to 1.85 × 10(5) target copies/mL of blood; however, no bacteria were observed on blood films. Production use of a goat was the only risk factor significantly associated with hemoplasma infection. CONCLUSIONS AND CLINICAL RELEVANCE The qPCR assay was more sensitive for detecting hemoplasma infection than was evaluation of a blood film, and production use of a goat was a risk factor for infection.

A cross sectional study evaluating the prevalence of Coxiella burnetii, potential risk factors for infection, and agreement between diagnostic methods in goats in Indiana.

Coxiella burnetii is the etiologic agent of the zoonotic disease Q fever and is considered to be endemic in domestic ruminants. Small ruminants in particular are important reservoirs for human infection. Serologic and molecular methods are both available for diagnosis of infection with C. burnetii, but there has been little research evaluating the prevalence of this organism in small ruminants outside of the context of clinical disease outbreaks. The objectives of this study were to estimate seroprevalence of C. burnetii and the prevalence of shedding of C. burnetii DNA in milk by goats in Indiana, USA, to evaluate potential risk factors for association with C. burnetii exposure and shedding, and to assess the level of agreement between the enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR) tests used to estimate prevalence. A total of 649 does over 1 year of age and not pregnant at the time of sampling were included in the study. Serum samples were collected from 608 does representing 89 farms. Milk samples were collected from 387 does representing 85 farms. Both milk and serum samples were collected from 356 does representing 80 farms. The estimated individual seroprevalence and shedding prevalence in milk adjusted for clustering were 3.1% (n=23/608, 95% CI: 1.2-7.0%) and 2.5% (n=9/387, 9.5% CI: 1.0-5.6%) respectively. Estimated adjusted herd level C. burnetii seroprevalence and herd level shedding prevalence were 11.5% (n=10/89, 95% CI: 6.4-20.1%) and 7.0% (n=6/85, 95% CI: 3.3-14.6%) respectively. Based on a generalized estimating equation model (GEE), meat breeds of goat had 7.0 times increased odds of shedding C. burnetii DNA in milk samples as compared to dairy breeds. Agreement between tests as determined by Cohen's kappa was poor at both the individual (kappa=0.04, 95% CI: -0.1 to 0.2) and herd (kappa=0.2, 95% CI: -0.1 to 0.5) levels. This indicates that serologic screening alone is unlikely to prevent the introduction of does shedding C. burnetii into herds.