RESUMEN
Diseases in introduced broilers can possibly spill over to wild birds on the Galapagos. Knowledge about the current burden of exposure to pathogens in broilers on the Galapagos is very limited. The objective of the study reported here was to measure the burden of exposure to infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Mycoplasma gallisepticum (MG), and intestinal parasites in a sample of broiler chickens on 13 farms on Santa Cruz Island and San Cristobal Island in July 2017. Blood serum samples were tested for detection of antibodies to IBDV, IBV, NDV, and MG by using an IDEXX Enzyme-linked Immunosorbent Assay. In addition, fecal samples and pen bedding environmental samples were processed and analyzed for diagnosis of intestinal parasite eggs under a compound light microscope. The frequency of seropositive broilers to IBDV was 74/130 or 56% (95% CI = 48, 65%), to IBV was 27/130 or 20% (14, 28%), and to NDV was 1/130 or 0.7% (0.1, 4%). All broilers tested negative to MG antibodies. Eimeria spp. infection was common in study broilers. Finally, we observed interaction between broiler chickens and wild birds (finches) inside broiler pens, as well as the presence of backyard chickens inside property limits of study farms. This study produced evidence that exposure to IBDV, IBV, and intestinal parasites in broilers on Santa Cruz Island and San Cristobal Island is important. Study results are relevant because (i) they provide new baseline data on the burden of exposure to avian pathogens in broiler farms, (ii) justify the need to verify standard operating procedures in hatcheries that supply (non-vaccinated) day-old chicks to the Galapagos and (iii) to implement enhanced biosecurity standards on broiler chicken farms to mitigate risk of disease transmission between broilers, backyard poultry, and wild birds on the Galapagos.
Asunto(s)
Pollos/microbiología , Infecciones por Coronavirus/veterinaria , Especies Introducidas , Infecciones por Mycoplasma/veterinaria , Enfermedad de Newcastle/transmisión , Enfermedades Parasitarias en Animales/transmisión , Enfermedades de las Aves de Corral/transmisión , Animales , Anticuerpos Antivirales/sangre , Aves/microbiología , Aves/parasitología , Aves/virología , Pollos/parasitología , Pollos/virología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Ecuador , Monitoreo del Ambiente , Ensayo de Inmunoadsorción Enzimática/veterinaria , Heces/parasitología , Virus de la Bronquitis Infecciosa/inmunología , Infecciones por Mycoplasma/transmisión , Mycoplasma gallisepticum/inmunología , Virus de la Enfermedad de Newcastle/inmunología , Enfermedades Parasitarias en Animales/epidemiología , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/parasitologíaRESUMEN
Dog overpopulation and diseases are hazards to native island species and humans on the Galapagos. The main objective of the study reported here was to estimate the observed human:dog ratio on Santa Cruz Island, Galapagos in September 2016. In addition, dog demographic data were used to model the expected annual dog population growth in the next 10 years. A secondary objective was to measure the burden of dogs infected with intestinal parasites. The observed human:dog ratio was 964:202 (or 4.77:1), which extrapolates to 3290 dogs; an increase of 31% in the dog population on Santa Cruz from 2014 to 2016. Study results show that current spay-neuter efforts (about 300 dogs per year; 60% females, 40% males) are not enough to keep the population stable (i.e., current baseline of 3290 dogs). The frequency of dogs infected with Ancylostoma spp., an intestinal parasite in dogs that can cause cutaneous larval migrans in humans, was 18/44 or 41% (95% CIâ¯=â¯27%, 55%). These results provide the most complete assessment of the dog overpopulation on the Galapagos to date.
Asunto(s)
Enfermedades de los Perros/transmisión , Parasitosis Intestinales/transmisión , Parasitosis Intestinales/veterinaria , Zoonosis , Animales , Demografía , Enfermedades de los Perros/diagnóstico , Perros , Ecuador , Femenino , Humanos , Parasitosis Intestinales/diagnóstico , Masculino , Densidad de Población , Dinámica Poblacional , Crecimiento DemográficoRESUMEN
Dog overpopulation and diseases are hazards to native island species and humans on the Galapagos. Vaccination and importation of dogs are prohibited on the Galapagos. Risk management of these hazards requires the use of science-based risk assessment and risk communication. The objectives of the study reported here were (i) to estimate the human:dog ratio and (ii) the prevalence of and identify exposure factors associated with positive antibody titers to canine distemper virus (CDV) and other pathogens, as well as infection with intestinal parasites in owned dogs on Santa Cruz Island, Galapagos in September 2014. The observed human:dog ratio was 6.148:1 which extrapolates to 2503 dogs (two times more than a recent dog count conducted by Galapagos Biosecurity Agency in March 2014). The proportion of spayed female dogs (50%) was higher, compared to neutered male dogs (30%) (p=0.04). Prevalence of dogs with positive antibody titers to CDV was 36% (95% CI=26, 46%), to canine parvovirus was 89% (95% CI=82, 95%), and to canine adenovirus was 40% (95% CI=30, 51%). The frequency of seropositive dogs to CDV was lower in urban dogs (26%), compared to rural dogs (53%) (p<0.05). A positive interaction effect between rural residence and spay/neuter status on seropositivity to CDV was observed, which we discuss in this report. Because vaccination is prohibited, the dog population on Santa Cruz is susceptible to an outbreak of CDV (particularly among urban dogs) with potential spill over to marine mammals. Dog's age (1-2 or 3-14 years old, compared to younger dogs), and residence (rural, urban) were associated with positive antibody titers to parvovirus, adenovirus, Ehrlichia spp., or Anaplasma spp., as well as infection with Ancylostoma spp., an intestinal parasite in dogs that can be transmitted to humans, particularly children. These results provide the most comprehensive assessment of dog overpopulation and exposure to CDV and other pathogens on the Galapagos to date.