Clinical, diagnostic, and epidemiological features of a community-wide outbreak of canine leptospirosis in a low-prevalence region (Maricopa County, Arizona).

OBJECTIVE: To describe clinical, diagnostic, and epidemiological features of an outbreak of leptospirosis in dogs in Maricopa County, Ariz, from January 2016 through June 2017. ANIMALS: 71 case and 281 control dogs. PROCEDURES: Cases were classified as confirmed, probable, suspect, or not a case on the basis of medical record data that fulfilled clinical, diagnostic, and epidemiological criteria. Potential exposures were assessed by owner survey. For the case-control investigation, control dogs were recruited through owner completion of a July 2017 survey. Summary statistics and ORs for case dog lifestyle factors were reported. RESULTS: 54 dogs were classified as confirmed and 17 as probable cases. For 4 dogs of a household cluster (5 confirmed and 3 probable), the highest microscopic agglutination titer was for serovar Djasiman (Leptospira kirschneri detected by PCR assay), and for 13 dogs of a community outbreak (49 confirmed and 14 probable cases), the highest titer was for serovar Canicola (Leptospira interrogans detected by PCR assay). The 44 case dogs included in the case-control investigation were 7.7 (95% CI, 3.5 to 16.7) and 2.9 times (95% CI, 1.3 to 6.6) as likely as control dogs to have visited dog daycare or to have been kenneled overnight at a boarding facility, respectively, 30 days prior to the onset of clinical signs or diagnosis. CONCLUSIONS AND CLINICAL RELEVANCE: Diagnostic and epidemiological findings indicated 2 outbreaks. Transmission where dogs congregated likely propagated the community outbreak. Outbreaks of leptospiral infections can occur in regions of low prevalence, and a dog's exposure to areas where dogs congregate should be considered when making Leptospira vaccination recommendations.

Knowledge, attitudes, and practices among veterinarians during an outbreak of canine leptospirosis-Maricopa County, Arizona, 2017.

Leptospirosis, caused by Leptospira spp., is a zoonotic bacterial disease important to both human and animal health. Six pathogenic serovars are currently known to commonly infect and cause disease in dogs in the United States. While canine leptospirosis infection is historically rare in Arizona (≤5 cases reported annually) (ADHS unpublished data) several clusters were reported in Maricopa County (MC) during February 2016-January 2017. Public health initiated an outbreak response and developed a knowledge, attitudes, and practices survey for veterinarians. The goals were to determine awareness and general attitudes about canine leptospirosis and to identify gaps in veterinarians' knowledge in treatment and prevention. We distributed a 40-question self-administered online survey to 1058 Arizona Veterinary Medical Association members, made available during February 9-May 15, 2017. We analyzed the results using Pearson's Chi-squared or Fisher's exact test; a P-value <0.05 was considered statistically significant. We analyzed 202 complete responses. Veterinarians from 10 (66%) of 15 Arizona counties were represented. MC practices were more likely to stock leptospirosis vaccine (80%) than other counties combined (58%) (P = 0.004). The average composite knowledge score was 24.4 out of 38 (range 12-37, median 24); 49% of respondents demonstrated higher knowledge as defined by authors, largely in identification of leptospirosis risk factors (86%) and routes of exposure (73%). Fewer than half (45%) of respondents correctly identified the length of time bacteria can be shed in dogs' urine. Eighty-one percent of respondents demonstrated lower knowledge about clinical signs associated with leptospirosis; only 47% of respondents identified eight clinical signs commonly associated with leptospirosis. Sixty-one percent of MC respondents agreed that leptospirosis is an important canine disease in their geographic area, while only 40% of other county respondents agreed (P=0.03). Seventy percent of respondents identified diagnostic testing options. The majority correctly selected infection-control practices in line with recommendations from 2 national clinical guidelines. More respondents would recommend leptospirosis vaccination if dogs traveled or lived in rural areas (87-96%) than if dogs attended day care or were boarded (63%). We identified opportunities for education, including the local epidemiology of leptospirosis, transmission prevention strategies, vaccine safety, testing, clinical identification, and emerging risk factors. Our findings will help guide the design of educational materials for small animal veterinarians in Arizona regarding recommendations for prevention of animal and human leptospirosis infections; these efforts could also shift the culture of reporting companion animal diseases to improve future One Health collaborations.

Despite high-risk exposures, no evidence of zoonotic transmission during a canine outbreak of leptospirosis.

Leptospirosis is a bacterial zoonosis that affects many mammals, including humans and dogs; dogs can transmit the bacteria to humans, but the frequency of transmission and highest risk exposures are poorly understood. During 2016-2017, the Maricopa County Department of Public Health, Arizona Department of Health Services and Centers for Disease Control and Prevention investigated the zoonotic potential of a canine leptospirosis outbreak in the Phoenix metro area. We identified symptomatic persons exposed to canine leptospirosis cases by conducting active and passive surveillance. We tested dog owners (n = 9) and animal care providers (n = 109) for serological evidence of Leptospira spp. infection (via the microscopic agglutination test [MAT]) and interviewed these persons about their specific exposures to canine cases and general exposures to canine blood and urine. Through surveillance, seven symptomatic persons were identified; six were tested and all were negative by MAT, and of these six, four persons were negative by PCR (two did not have PCR testing). All serosurvey participants (n = 118) were also seronegative. Among animal care providers, bare skin contact with urine/blood from a canine case was reported by 23.2%; two persons reported dog urine splashing in their face. Veterinary technicians were more likely to have bare skin contact with blood from a canine case compared to veterinarians and boarding facility staff (p < 0.001). Infection control practices were inconsistent; when working with specimens from a canine leptospirosis case, 44.6% of participants reported always wearing gloves when working with urine (i.e., collecting specimens), and 54.5% always wore gloves when working with blood. Veterinary technicians were also most likely to engage in all activities involving potential urine/blood contact, such as conducting laboratory tests (p < 0.01). We therefore recommend that veterinary technicians specifically receive targeted education about infection control practices. Our results suggest that dog-to-human transmission of leptospirosis is uncommon.