Prevalence of Antibodies to Swine Influenza Virus, Porcine Adenovirus Type 4 and Haemophilus pleuropneumoniae in Quebec Pig Farms with Respiratory Problems

The prevalence of antibodies to three etiological agents involved in swine pneumonia was determined in Quebec pig farms which had experienced problems of mild to severe respiratory problems. Of the 350 sera collected from adults pigs, 67.0%, 18.3% and 46.6% had antibody titers to Haemophilus pleuropneumoniae type 1 and/or 5, to porcine adenovirus type 4 and to swine influenza virus, respectively. Comparatively, the serological prevalence rates for Haemophilus pleuropneumoniae, porcine adenovirus and swine influenza virus were 43.7%, 0% and 3.3% in farms not experiencing respiratory problems.     

The role of rodents and other wildlife in the epidemiology of swine toxoplasmosis

Two swine production units and their contiguous wildlife populations were used for this study. These herds were located 7 miles apart in the major swine producing area of south central Georgia. Herd A had a Toxoplasma gondii antibody prevalence of 27.6% in all ages of swine sampled, with an increased incidence of 13.6% over a 5-month period. This herd was maintained under a semi-range condition. The swine in Herd B were maintained exclusively in concrete floored, enclosed buildings. This herd had a 0.85% T. gondii prevalence. Rodents and a few other wildlife and domestic species were trapped in or around both herds. These animals were examined for Toxoplasma antibodies using the same test procedure utilized for swine sera, the indirect immunofluorescent (IIF) test. Additionally, rodent tissues were homogenized and suspensions prepared for interperitoneal (I/P) inoculation into CF₁ laboratory mice.Rodents and wildlife species examined were: Mus musculus, Peromyscus leucopus, Rattus norvegicus, Sigmodon hispidus, Procyon lotor, and Didelphis marsupalis. Feral and domestic animals other than swine that also were tested for the presence of T. gondii antibodies included two cats, two horses, and a dog. The overall prevalence of T. gondii antibodies in all non-porcine species examined was 67% for those animals in and around the premises of Herd A, and 63% for those in and around Herd B.Toxoplasma infectivity of rodents whose tissues were processed and inoculated into laboratory mice correlated well with the results of the IIF test on the serum of these wild rodents. No tachyzoites of T. gondii were found in the peritoneal exudate of laboratory mice post I/P inoculation with wild rodent tissue, with one exception.While there was no significant difference in Toxoplasma infectivity in non-porcine species on these two premises, management practices appeared to be the determining factor in swine infection with T. gondii. Excluding wildlife precluded infection.     

Efficacy of the Boar-Operated-System to deliver baits to feral swine

Feral swine (Sus scrofa) pose a significant disease threat to livestock and humans. Emerging technologies to reduce feral swine disease transmission risks include fertility control, vaccination, and toxicants. However, for these technologies to be appropriate for field application, a feral swine-specific oral delivery system is needed. We used two field trials to generate information related to appropriate field application of the Boar-Operated-System (BOS?), an oral delivery system designed to provide bait access only to feral swine. Our objectives were to determine whether pre-baiting BOS? units increased bait removal and to evaluate the proportion of feral swine and non-target animals that ingest baits designed to deliver pharmaceuticals through the BOS?. During both trials we used baits housed within 10 BOS? units. We monitored wildlife visitation, bait removal, and ingestion using motion sensing digital photography and baits containing the bait marker tetracycline hydrochloride (TH). During trial 1 we found three of five pre-baited BOS? units were used by feral swine only. Additionally, we found the five BOS? units that were not pre-baited were not used by feral swine or non-target wildlife. During trial 2 we determined bait removal from the BOS? to be reduced by only 10% for feral swine when activated, whereas bait removal from the BOS? by all other wildlife was reduced by 100% when activated. We captured 81 feral swine and 23 raccoons and found 90% and 13% to have TH-marked teeth, respectively. With minor modifications, the BOS? should be considered a valuable tool to be used in feral swine disease management in conjunction with existing technologies.     

Identification of Brucella spp. in feral swine (Sus scrofa) at abattoirs in Texas,USA

Various tissues, nasal swabs, urine and blood samples were collected from 376 feral swine at two federally inspected abattoirs in Texas during six separate sampling periods in 2015. Samples were tested for Brucella spp. by culture and serology. Brucella spp. were cultured from 13.0% of feral swine, and antibodies were detected in 9.8%. Only 32.7% of culture‐positive feral swine were also antibody positive, and 43.2% of antibody‐positive feral swine were culture positive. Approximately, the same number of males (14.0%) and females (12.1%) were culture positive, and slightly more males (10.5%) than females (8.7%) were antibody positive. Our results indicate that serology likely underestimates the prevalence of feral swine infected, and that those who come in contact with feral swine should be aware of the symptoms of infection with Brucella spp. to ensure prompt treatment.     

Prevalence and Characterization of Salmonella Isolated from Feral Pigs Throughout Texas

Feral pigs are one of the most abundant free‐roaming ungulates in the United States, yet their role in the ecology and transmission of foodborne pathogens is poorly understood. Our objectives were to estimate the prevalence of Salmonella shedding among feral pigs throughout Texas, to identify risk factors for infection, and to characterize the isolates. Faecal samples were collected from feral pigs in Texas from June 2013 through May 2015. Standard bacteriologic culture methods were used to isolate Salmonella from samples, and isolates were characterized via serotyping and anti‐microbial susceptibility testing. The prevalence of faecal Salmonella shedding among sampled pigs was 43.9% (194/442), with positive pigs originating from 50 counties. Pigs sampled during fall and summer were significantly more likely to be shedding Salmonella than pigs sampled during winter. High serovar diversity was evident among the isolates, and many of the detected serovars are leading causes of human salmonellosis. The most common serovars were Montevideo (10.0%), Newport (9.1%), and Give (8.2%). Resistance to anti‐microbial agents was rare. The burgeoning feral pig population in the United States may represent an emerging threat to food safety.     

Bacteriophages as antimicrobial agents against major pathogens in swine: a review

In recent years, the development of antibiotic resistant bacteria has become a global concern which has prompted research into the development of alternative disease control strategies for the swine industry. Bacteriophages (viruses that infect bacteria) offer the prospect of a sustainable alternative approach against bacterial pathogens with the flexibility of being applied therapeutically or for biological control purposes. This paper reviews the use of phages as an antimicrobial strategy for controlling critical pathogens including Salmonella and Escherichia coli with an emphasis on the application of phages for improving performance and nutrient digestibility in swine operations as well as in controlling zoonotic human diseases by reducing the bacterial load spread from pork products to humans through the meat.     

Prevalence of sparganosis by county of origin in Florida feral swine

Sparganosis is a parasitic infection in amphibians, reptiles and mammals including feral swine and man. It is caused by migration of the metacestode (spargana) of Spirometra. The primary objective of this study was the determination of the prevalence of gross sparganosis in Florida county of origin in slaughtered feral swine. Tracebacks to county of origin were conducted for Florida feral swine with and without gross sparganosis. Feral swine trapped in Florida and presented for slaughter in a Texas slaughter establishment from May to December 1999 was the sample population.Overall prevalence of sparganosis in Florida feral swine was 6.9%. Because Highlands county had the same prevalence, other counties were compared to it. Sparganosis was detected in 17 Florida counties. Swine originating from Osceola or Hillsborough counties (4.3 and 1.8% prevalence, respectively) had lower prevalence of sparganosis than in Highlands, whereas those from Marion county (21.7% prevalence) had a higher prevalence.Transmission to humans may occur via consumption of infected feral swine, other species of secondary intermediate hosts or the primary intermediate hosts.     

Zoonotic aspects of infections with noroviruses and sapoviruses

The close genetic relationship of noroviruses and sapoviruses found in animals and humans has raised the question whether these viruses have a zoonotic potential. Transmission from animals to humans and vice versa would have far-reaching consequences for epidemiology and food safety. So far animal noro- and sapoviruses have not been found in humans. However detection of human noroviruses in animals as well as simultaneous presence of animal and human viruses in bivalve molluscs suggest a risk of transmission. Furthermore, antibodies against animal noroviruses were detected in humans as well as antibodies against human noroviruses in swine. Experimental infection of gnotobiotic calves and pigs with human noroviruses demonstrated that virus replication and seroconversion can occur. Accordingly the possible role of noro- and sapoviruses as zoonotic agents needs to be further investigated.     

Seroprevalences of antibodies against Bartonella henselae and Toxoplasma gondii and fecal shedding of Cryptosporidium spp, Giardia spp, and Toxocara cati in feral and pet domestic cats

OBJECTIVE: To compare seroprevalences of antibodies against Bartonella henselae and Toxoplasma gondii and fecal shedding of Cryptosporidium spp, Giardia spp, and Toxocara cati in feral and pet domestic cats. DESIGN: Prospective cross-sectional serologic and coprologic survey. ANIMALS: 100 feral cats and 76 pet domestic cats from Randolph County, NC. PROCEDURE: Blood and fecal samples were collected and tested. RESULTS: Percentages of feral cats seropositive for antibodies against B. henselae and T. gondii (93% and 63%, respectively) were significantly higher than percentages of pet cats (75% and 34%). Percentages of feral and pet cats with Cryptosporidium spp (7% of feral cats; 6% of pet cats), Giardia spp (6% of feral cats; 5% of pet cats), and T. cati ova (21% of feral cats; 18% of pet cats) in their feces were not significantly different between populations. Results of CBCs and serum biochemical analyses were not significantly different between feral and pet cats, except that feral cats had a significantly lower median PCV and significantly higher median neutrophil count. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that feral and pet cats had similar baseline health status, as reflected by results of hematologic and serum biochemical testing and similar prevalences of infection with Cryptosporidium spp, Giardia spp, and T. cati. Feral cats did have higher seroprevalences of antibodies against B. henselae and T. gondii than did pet cats, but this likely was related to greater exposure to vectors of these organisms.     

CHLAMYDIA AVIUM DETECTION FROM A RING-NECKED PARAKEET (PSITTACULA KRAMERI) IN FRANCE

The crossing of host species barriers, through the spreading populations of introduced pet animals that become established in the wild, sets the stage for zoonotic pathogen (re)emergence. A literature review on pathogens that are hosted by the ring-necked parakeet (Psittacula krameri), a worldwide introduced pet, highlighted local infections of captive birds by chlamydial agents with high sanitary risk for human health in its introduced range. We searched for these pathogens through cloacal swabs collected from 85 individuals in an invasive population established in the suburban areas of Paris (Ile-de-France) from 5 localities during the winter seasons between 2011 and 2014. Based on quantitative PCR analysis, Chlamydiaceae shedding was detected at too low levels for species identification in 5 birds, but 1 parakeet (found dead) was positive for Chlamydiaceae typed as Chlamydia avium. The only known hosts recorded for C. avium in Europe are feral pigeons (Columba livia) and captive psittacines. This result raises the question of the sanitary risks associated with new pathogen transmission from exotic pets released in the wild, which could locally affect birds and potentially people who feed birds.     

Serological survey of vector-borne zoonotic pathogens in pet cats and cats from animal shelters and feral colonies

Although cats and their arthropod parasites can sometimes be important sources of zoonotic diseases in humans, the extent of exposure among various cat populations to many potential zoonotic agents remains incompletely described. In this study, 170 domestic cats living in private homes, feral cat colonies, and animal shelters from California and Wisconsin were evaluated by serology to determine the levels of exposure to a group of zoonotic vector-borne pathogens. Serological positive test results were observed in 17.2% of cats for Rickettsia rickettsii, 14.9% for R akari, 4.9% for R typhi, 11.1% for R felis, and 14.7% for Bartonella henselae. Although vector-borne disease exposure has been documented previously in cats, the evaluation of multiple pathogens and diverse cat populations simultaneously performed here contributes to our understanding of feline exposure to these zoonotic pathogens.     

Detection of multiple genotypes of calicivirus infection in asymptomatic swine in Taiwan

Noroviruses (NoVs) and sapoviruses (SaVs) of the family Caliciviridae are emerging enteric pathogens in humans and animals. Recent detection of genogroup II norovirus (GII NoV) RNA from swine raises public health concerns about zoonotic transmission of porcine NoVs to humans. However, few papers reported genotype distributions and epidemiological features in swine farms and their genetic relationship to human strains, which was the objective of our study. This study investigated the epidemiological features and genotypes of caliciviruses in swine farms using 533 pig faecal samples from six farms in central and southern Taiwan, tested for viral RNA using RT-PCR targeting the conserved polymerase gene. NoVs and SaVs were detected with a positive rate of 7.1% and 0.6%, respectively. To confirm the positive rate of NoVs, 255 pig faecal samples from two farms in central Taiwan were tested with primer pairs targeting the partial capsid gene of GII, and 32.3% of the positive rate was found. Furthermore, the results from the capsid region suggested a higher positive rate of 41.7% in winter than 26.4% in summer with statistical significance (P < 0.05). Sequence analysis showed 29 strains belonging to GII.4 (human) and nine strains belonging to GII.11 (swine) identified based on the partial polymerase gene. Additional genotypes clustered with GII.2 (human) and GII.18 (swine) were also characterized based on the partial capsid gene. SaVs detected in porcine faecal samples belonged to genogroup III (GIII), which clustered with the PEC-Cowden strain. Our study demonstrated the presence of multiple genotypes of both human and porcine NoVs infecting swine of various ages asymptomatically. Although the zoonotic potential of detected human NoVs in swine was not conclusive owing to the lack of local human faecal samples, our study revealed the importance of monitoring emerging strains in swine to mitigate the potential impact of recombinant NoVs infecting the human population.     

A cross-sectional study of Tritrichomonas foetus infection in feral and shelter cats in Prince Edward Island,Canada

A cross-sectional study examined the occurrence of Tritrichomonas foetus, and other intestinal parasites, in feral and shelter cats in Prince Edward Island (PEI). Fecal samples were collected from 100 feral cats, 100 cats from the PEI Humane Society, and 5 cats from a private residence. The occurrence of T. foetus, based on fecal culture, was 0% in feral and shelter cats. A single positive sample was obtained from an owned Abyssinian cat that was imported to PEI. Intestinal parasites were identified via fecal flotation in 76% of feral cats and 39% of cats from the humane society. Feral cats had a higher incidence of Toxocara cati than cats from the humane society (P < 0.001), conversely, shelter cats had a higher incidence of Cystoisospora spp. (P < 0.001). These results suggest that while T. foetus is not of importance in feral and shelter cats in PEI, imported cats could serve as reservoirs.     

The recreational and commercial importance of feral swine in Florida: Relevance to the possible introduction of African swine fever into the U.S.A.

Florida has the largest population of feral swine in the U.S.A. Feral swine have recreational and economic importance to hunters, trappers, taxidermists, and also to dealers who sell feral swine to hunting clubs. Hunters spent over 522 00 man-days hunting feral swine during the 1980–1981 hunting year. They killed nearly 103 000 hogs which they valued at over $58 each, for a total value of nearly $6 million. Trappers caught 25 000 head valued at about $ 700 000, and landowners collected about $1.2 million in hunting lease fees. Taxidermists received about $389 000 in gross income from mounting feral swine. Sales of feral swine to hunting clubs amounted to about $81 000.

Sales of feral swine through commercial livestock auctions were limited to 1620 head valued at only $16 800 in 1980. Thus, feral swine are important to Florida from a recreational standpoint, but not from the perspective of commercial agriculture.

If African swine fever were to enter Florida, there are many socio-economic factors associated with feral swine that must be carefully evaluated for eradication to be successful.     

Zoonotic disease transmission associated with feral cats in a metropolitan area: A geospatial analysis

Feral cats raise public health concerns due to their large population numbers and ability to harbour pathogens that cause disease in people, pets, and wildlife. Information regarding the potential for feral cats to intersect with areas frequented by humans is lacking. This study examined the potential for feral cats and human territories to overlap in the Richmond metropolitan area of Central Virginia. Feral cats (n = 275) were trapped for monthly trap‐neuter‐release (TNR) clinics from July to November 2016. A geographic information system (GIS) was used to map feral cat trapping locations, elementary and preschools, public parks, and community gardens, and to evaluate the potential for cat interaction with these areas, presuming a maximum habitat radius of 0.44 miles. We found that 8.0% of feral cats in the Richmond metropolitan area had potential to range onto public elementary or preschool property, and 81.5% of feral cats trapped in Richmond City had potential to roam into one or more places of interest, including elementary and preschool grounds, public parks, and community gardens. This provides public health, veterinary, and human health professionals with important information that can be used to focus resources in an effort to reduce zoonosis associated with feral cat populations.     

Swine coronaviruses (SCoVs) and their emerging threats to swine population,inter-species transmission,exploring the susceptibility of pigs for SARS-CoV-2 and zoonotic concerns

Swine coronaviruses (SCoVs) are one of the most devastating pathogens affecting the livelihoods of farmers and swine industry across the world. These include transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), porcine hemagglutinating encephalomyelitis virus (PHEV), swine acute diarrhea syndrome coronavirus (SADS-CoV), and porcine delta coronavirus (PDCoV). Coronaviruses infect a wide variety of animal species and humans because these are having single stranded-RNA that accounts for high mutation rates and thus could break the species barrier. The gastrointestinal, cardiovascular, and nervous systems are the primary organ systems affected by SCoVs. Infection is very common in piglets compared to adult swine causing high mortality in the former. Bat is implicated to be the origin of all CoVs affecting animals and humans. Since pig is the only domestic animal in which CoVs cause a wide range of diseases; new coronaviruses with high zoonotic potential could likely emerge in the future as observed in the past. The recently emerged severe acute respiratory syndrome coronavirus virus-2 (SARS-CoV-2), causing COVID-19 pandemic in humans, has been implicated to have animal origin, also reported from few animal species, though its zoonotic concerns are still under investigation. This review discusses SCoVs and their epidemiology, virology, evolution, pathology, wildlife reservoirs, interspecies transmission, spill-over events and highlighting their emerging threats to swine population. The role of pigs amid ongoing SARS-CoV-2 pandemic will also be discussed. A thorough investigation should be conducted to rule out zoonotic potential of SCoVs and to design appropriate strategies for their prevention and control.     

Exposure of client-owned cats to zoonotic vector-borne pathogens: Clinic-pathological alterations and infection risk analysis

Zoonotic Vector-Borne Diseases (VBDs) represent a relevant health issue for pets and humans. Italy is a major epidemiological hub for feline VBDs, because of suitable conditions for vector biology and disease transmission patterns. The present study investigated the exposure to major zoonotic arthropod-borne pathogens of cats in Italy, along with the evaluation of clinic-pathological features and a risk factor analysis. Out of 167 examined cats, 52 (31.1%) were seropositive for at least one vector-borne pathogen, being positivity for Bartonella henselae the most recorded (18%). Also, various cats seroreacted for Rickettsia felis (10.8%) and Rickettisa typhi (4.2%), Leishmania infantum (3%), Anaplasma phagocytophilum (2.4%) and Ehrlichia canis (2.4%). Forty-six cats were tested also for antibodies against D. immitis and two (4.3%) scored positive. The statistical analysis showed a positive association between flea infestation and seropositivity to B. henselae, other than an association between the administration of monthly ectoparasiticide treatments and seronegativity for Rickettsia spp.; seropositive cats were older than negative animals and the lifestyle (i.e. indoor vs outdoor) was not correlated with exposure to vector-borne pathogens. The majority of seropositive cats appeared clinically healthy or showed aspecific clinical signs. Around 80% of seropositive cats had one or more biochemical and/or complete blood count abnormalities. The present data confirm the endemicity of zoonotic feline VBDs in Italy and indicate that awareness on arthropod infections and transmitted pathogens should be kept high and possible implemented, towards the protection of animal and human health with adequate surveillance plans.     

A review of porcine tonsils in immunity and disease

The porcine tonsils are a group of lymphoepithelial tissues located at the common openings of the gastrointestinal and respiratory tracts. The tonsils participate in a variety of functions involving innate, cellular and humoral immunity at the local and systemic levels. Among these immunological functions is the continuous surveillance for the presence of foreign antigens at the openings of the gastrointestinal and respiratory tracts. Within the pig, the movement of lymphocytes, cytokines and chemotactic molecules from the tonsils to other lymphoid organs confers immunity to other portals of pathogen entry and facilitates an efficient and rapid systemic immune response. In spite of the immunological nature of the tonsils, some microorganisms have acquired adaptations that allow them to circumvent the tonsillar immune defenses and utilize the tonsils as a site of entry, replication and colonization. Several bacterial and viral pathogens persist asymptomatically within the tonsils, making identification of asymptomatic carrier animals difficult in disease control and/or pathogen elimination. This paper reviews the current information on the anatomy, immunology and pathobiology of porcine tonsils and discusses the tonsils as a site of pathogen entry, replication and colonization using Salmonella spp., classical swine fever virus and porcine reproductive and respiratory syndrome virus as examples.     

Seroprevalence of Bartonella species,Coxiella burnetii and Toxoplasma gondii among patients with hematological malignancies: A pilot study in Romania

Patients receiving immunosuppressive cancer treatments in settings where there is a high degree of human–animal interaction may be at increased risk for opportunistic zoonotic infections or reactivation of latent infections. We sought to determine the seroprevalence of selected zoonotic pathogens among patients diagnosed with haematologic malignancies and undergoing chemotherapeutic treatments in Romania, where much of the general population lives and/or works in contact with livestock. A convenience sample of 51 patients with haematologic cancer undergoing chemotherapy at a referral clinic in Cluj‐Napoca, Romania, was surveyed regarding animal exposures. Blood samples were obtained and tested for evidence of infection with Bartonella species, Coxiella burnetii and Toxoplasma gondii, which are important opportunistic zoonotic agents in immunocompromised individuals. 58.8% of participants reported living or working on a farm, and living or working on a farm was associated with contact with livestock and other animals. 37.5% of participants were IgG seroreactive against one or more of five Bartonella antigens, and seroreactivity was statistically associated with living on farms. Farm dwellers were 3.6 times more likely to test IgG seroreactive to Bartonella antibodies than non‐farm dwellers. 47.1% of the participants tested T. gondii IgG positive and 13.7% tested C. burnetii IgG positive, indicating past or latent infection. C. burnetii IgM antibodies were detected in four participants (7.8%), indicating possible recent infection. These results indicate that a large proportion of patients with haematologic cancer in Romania may be at risk for zoonotic infections or for reactivation of latent zoonotic infections, particularly with respect to Bartonella species. Special attention should be paid to cancer patients' exposure to livestock and companion animals in areas where much of the population lives in rural settings.