Kristy L. Pabilonia

Influenza infection in wild raccoons.

Raccoons can transmit avian and human influenza Influenza Infection in Wild Raccoons

INFLUENZA EXPOSURE IN UNITED STATES FERAL SWINE POPULATIONS

Swine play an important role in the disease ecology of influenza. Having cellular receptors in common with birds and humans, swine provide opportunities for mixed infections and potential for genetic reassortment between avian, human, and porcine influenza. Feral swine populations are rapidly expanding in both numbers and range and are increasingly coming into contact with waterfowl, humans, and agricultural operations. In this study, over 875 feral swine were sampled from six states across the United States for serologic evidence of exposure to influenza. In Oklahoma, Florida, and Missouri, USA, no seropositive feral swine were detected. Seropositive swine were detected in California, Mississippi, and Texas, USA. Antibody prevalences in these states were 1% in Mississippi, 5% in California, and 14.4% in Texas. All seropositive swine were exposed to H3N2 subtype, the predominant subtype currently circulating in domestic swine. The only exceptions were in San Saba County, Texas, where of the 15 seropositive samples, four were positive for H1N1 and seven for both H1N1 and H3N2. In Texas, there was large geographical and temporal variation in antibody prevalence and no obvious connection to domestic swine operations. No evidence of exposure to avian influenza in feral swine was uncovered. From these results it is apparent that influenza in feral swine poses a risk primarily to swine production operations. However, because feral swine share habitat with waterfowl, prey on and scavenge dead and dying birds, are highly mobile, and are increasingly coming into contact with humans, the potential for these animals to become infected with avian or human influenza in addition to swine influenza is a distinct possibility.

Epidemiologic Characterization of Colorado Backyard Bird Flocks

SUMMARY. Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had <50 birds); consist primarily of layer chickens (85.49% of flocks), show chickens (32.18% of flocks), and waterfowl (34.07% of flocks); and are primarily owned for food (meat or egg) production for the family (86.44%) or as pet or hobby birds (42.27%). The backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds. RESUMEN. Caracterización epidemiológica de las parvadas de aves de traspatio en el Estado de Colorado. Las aves gallinacéas de traspatio pueden jugar un papel importante en la propagación de enfermedades infecciosas en las poblaciones de aves comerciales, así como la transmisión de enfermedades zoonóticas a los seres humanos. En el Estado de Colorado se realizó una caracterización epidemiológica de las parvadas de traspatio para reunir información sobre las características generales de las parvadas, el movimiento de aves por los humanos, la interacción entre los humanos y las aves, las prácticas de bioseguridad y salud de la parvada. Los resultados sugieren que las aves de traspatio en Colorado son de tamaño pequeño (el 68.6% de las parvadas tenían menos de 50 aves), que consisten principalmente en gallinas ponedoras (85.49% de las parvadas), pollos de ornato (32.18% de los rebaños) y aves acuáticas (34.07% de las parvadas), y tienen como finalidad la producción de alimentos (carne o huevo) de forma familiar (86.44%) o como aves de compañía o deportivas (42.27%). El medio ambiente de las parvadas de traspatio puede promover la transmisión de enfermedades infecciosa entre las aves, así como la transmisión de las aves a los humanos. Las aves son alojadas con libre acceso al exterior (96.85%), y muchas son trasladadas de su local original (46.06% dentro un año). También es elevado el contacto entre los humanos con las aves de traspatio, las prácticas de bioseguridad son mínimas, y la salud de las aves se ve afectada negativamente por el aumento de su movilización. Un mayor conocimiento de las características de las aves de traspatio y las prácticas de manejo asociadas pueden proporcionar las pautas para el desarrollo de medidas para reducir la transmisión de enfermedades entre las poblaciones de aves, reducir la transmisión de enfermedades de las aves a los seres humanos y aumentar la salud general de las aves de traspatio.

Diffusion of influenza viruses among migratory birds with a focus on the Southwest United States

The Southwest United States, including Arizona and New Mexico, has a diverse climate and is home to many different avian species. We sequenced the hemagglutinin (HA) gene of twenty influenza specimens for the years 2007-2009. This included four from Arizona, and sixteen from New Mexico. We analyzed the sequences and determined the following HA subtypes: H3, H4, H6, H8, and H11. For each subtype, we combined our virus sequences with those from a public database, and inferred phylogeographic models of influenza diffusion. Statistical phylogeography indicated that overall evolutionary diffusion of avian influenza viruses is geographically structured (p<0.05). In addition, we found that diffusion to the Southwest was often from nearby states including California. For H3, H4 and H6, the intra-flyway gene flow rates were significantly (p<0.001) higher than those of inter-flyway. Such rate difference was also observed in H8 and H11, yet, without statistical significance (p=0.132, p=0.190, respectively). Excluding any one flyway from the calculation generated similar results, suggesting that such barrier effect on gene flow rates is not exclusively produced by any single flyway. We also calculated the Bayes factor test for the significant non-zero rates between states and identified significant routes both within and across flyways. Such inter-flyway spread of influenza was probably the result of birds from four flyways co-mingling on breeding grounds in northern regions or marshaling on staging areas post breeding in Canada or Alaska, before moving south each fall. This study provides an initial analysis of evolutionary diffusion of avian influenza virus to and from the Southwest United States. However, more sequences from this region need to be generated to determine the role of host migration and other factors on influenza diffusion.

Human-bird interactions in the United States upland gamebird industry and the potential for zoonotic disease transmission.

Since 1997, highly pathogenic avian influenza subtype H5N1 has emerged to cause severe disease in humans in over 15 countries. Humans who have regular contact with poultry or wild birds may be at greater risk of infection with highly pathogenic avian influenza and other zoonotic avian diseases. To develop preventative measures for transmission of avian influenza to high-risk human populations in the United States, we examined human-bird interactions in the upland gamebird industry. Upland gamebird permit holders were surveyed for information on human-bird contact, biosecurity practices, facility management practices, flock/release environment, and bird health. Results suggest that some upland gamebird facilities provide an environment for extensive and intimate human-bird interaction such that humans associated with these facilities may be at greater risk for zoonotic disease transmission.

Widespread detection of antibodies to Leptospira in feral swine in the United States.

As feral swine continue to expand their geographical range and distribution across the United States, their involvement in crop damage, livestock predation, and pathogen transmission is likely to increase. Despite the relatively recent discovery of feral swine involvement in the aetiology of a variety of pathogens, their propensity to transmit and carry a wide variety of pathogens is disconcerting. We examined sera from 2055 feral swine for antibody presence to six serovars of Leptospira that can also infect humans, livestock or domestic animals. About 13% of all samples tested positive for at least one serovar, suggesting that Leptospira infection is common in feral swine. Further studies to identify the proportion of actively infected animals are needed to more fully understand the risk they pose.

Coxiella burnetii in Northern Fur Seals and Steller Sea Lions of Alaska

Coxiella burnetii, a zoonotic bacterium, has recently been identified in several marine mammal species on the Pacific Coast of North America, but little is known about the epidemiology, transmission, and pathogenesis in these species. We tested sera archived from northern fur seals (NFS, Callorhinus ursinus; n=236) and Steller sea lions (SSL, Eumetopias jubatus; n=72) sampled in Alaska for C. burnetii antibodies, and vaginal swabs from NFS (n=40) for C. burnetii by qPCR. The antibody prevalence in NFS samples from 2009 and 2011 (69%) was significantly higher than in 1994 (49%). The antibody prevalence of SSL samples from 2007 to 2011 was 59%. All NFS vaginal swabs were negative for C. burnetii, despite an 80% antibody prevalence in the matched sera. The significant increase in antibody prevalence in NFS from 1994 to 2011 suggests that the pathogen may be increasingly common or that there is marked temporal variation within the vulnerable NFS population. The high antibody prevalence in SSL suggests that this pathogen may also be significant in the endangered SSL population. These results confirm that C. burnetii is more prevalent within these populations than previously known. More research is needed to determine how this bacterium may affect individual, population, and reproductive health of marine mammals.

Multilaboratory Survey To Evaluate Salmonella Prevalence in Diarrheic and Nondiarrheic Dogs and Cats in the United States between 2012 and 2014

ABSTRACT Eleven laboratories collaborated to determine the periodic prevalence of Salmonella in a population of dogs and cats in the United States visiting veterinary clinics. Fecal samples (2,965) solicited from 11 geographically dispersed veterinary testing laboratories were collected in 36 states between January 2012 and April 2014 and tested using a harmonized method. The overall study prevalence of Salmonella in cats (3 of 542) was <1%. The prevalence in dogs (60 of 2,422) was 2.5%. Diarrhea was present in only 55% of positive dogs; however, 3.8% of the all diarrheic dogs were positive, compared with 1.8% of the nondiarrheic dogs. Salmonella-positive dogs were significantly more likely to have consumed raw food (P = 0.01), to have consumed probiotics (P = 0.002), or to have been given antibiotics (P = 0.01). Rural dogs were also more likely to be Salmonella positive than urban (P = 0.002) or suburban (P = 0.001) dogs. In the 67 isolates, 27 unique serovars were identified, with three dogs having two serovars present. Antimicrobial susceptibility testing of 66 isolates revealed that only four of the isolates were resistant to one or more antibiotics. Additional characterization of the 66 isolates was done using pulsed-field gel electrophoresis and whole-genome sequencing (WGS). Sequence data compared well to resistance phenotypic data and were submitted to the National Center for Biotechnology Information (NCBI). This study suggests an overall decline in prevalence of Salmonella-positive dogs and cats over the last decades and identifies consumption of raw food as a major risk factor for Salmonella infection. Of note is that almost half of the Salmonella-positive animals were clinically nondiarrheic.

Detection and isolation of Influenza A virus subtype H1N1 from a small backyard swine herd in Colorado

Influenza A virus subtype H1N1 A(H1N1)pdm09 was first confirmed in pigs in the United States in October 2009. In November 2010, lungs and intestines from 2 York piglets from a small, privately owned herd were submitted to the Colorado State University Veterinary Diagnostic Laboratory. The submitting veterinarian reported rapid weight loss and signs of pneumonia in the piglets. Gross lesions included caudoventral pneumonia in both piglets, and histologic lesions in the lungs showed characteristics consistent with influenza virus and bacterial infection. Ribonucleic acid extracted from fresh lung homogenates from both piglets was positive for influenza A(H1N1)pdm09 by a real-time reverse transcription polymerase chain reaction. Virus was isolated from lung homogenates from both piglets in Madin–Darby canine kidney cells, as well as in 10-day-old specific pathogen–free embryonated chicken eggs. Sequence analysis showed 98% homology with 2009 H1N1 human isolates from across the United States and 98% homology against two 2009 and 2010 swine isolates from Nebraska and Minnesota. The current report documents the possible transmission of pandemic influenza A(H1N1)2009 virus [A(H1N1)pdm09] from a human being to a small, privately owned backyard swine herd. The owner was employed as a pharmacist, making occupational exposure to the pandemic influenza A(H1N1)pdm09 a possibility.

LIMITED ANTIBODY EVIDENCE OF EXPOSURE TO MYCOBACTERIUM BOVIS IN FERAL SWINE (SUS SCROFA) IN THE USA

Abstract Bovine tuberculosis is a chronic disease of cattle (Bos taurus) caused by the bacterium Mycobacterium bovis. Efforts have been made in the US to eradicate the disease in cattle, but spillover into wildlife and subsequent spillback have impeded progress in some states. In particular, infection in white-tailed deer (Odocoileus virginianus) has been followed by infection in cattle in some Midwestern states. Infection has also been documented in feral swine (Sus scrofa) on the Hawaiian island of Molokai and in various European countries, but no large-scale survey of antibody exposure to the bacteria has been conducted in feral swine in the US. We tested 488 sera from feral swine collected near previously documented outbreaks of bovine tuberculosis in cattle and captive cervids, in addition to 2,237 feral swine sera collected across the US from 1 October 2013 to 30 September 2014. While all but one of the samples were antibody negative, the results are important for establishing baseline negative data since feral swine are capable reservoirs and could be implicated in future outbreaks of the disease.