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1.
Parasitol Res ; 121(5): 1281-1293, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35314892

RESUMEN

The haematophagous mite Ornithonyssus sylviarum may cause important economic losses in commercial poultry farms whilst also potentially affecting the health of farm workers. The dynamics of this ectoparasite has been linked to several factors, including wild birds, fomites, farm workers, management of hen houses, and host traits. Along two consecutive years, we carried out systematic sampling at three laying hen farms located in Santa Fe province, Argentina, with the aim of identifying factors that may influence O. sylviarum prevalence and intensity. We found that the density of feathers around the hen vent area and the presence of Menoponidae lice were negatively associated with mite abundance. We also found that the density of hens in the cages was negatively associated with mite prevalence, suggesting a possible dilution effect, whereas prior reports found a positive association with hen density. In addition, summer was the season with minimum mite prevalences and intensities, contrary to previous studies in northern farms where warm weather appeared to prompt an increase in mite populations. Another factor associated with mite intensity was age, but this effect varied depending on the season, which hints that the association between hen's age and mites is complex. Basic epidemiological knowledge on O. sylviarum in poultry farms from South America may aid in a more efficient and integrative approach to its control.


Asunto(s)
Infestaciones por Ácaros , Ácaros , Enfermedades de las Aves de Corral , Animales , Argentina/epidemiología , Pollos/parasitología , Granjas , Infestaciones por Ácaros/epidemiología , Infestaciones por Ácaros/parasitología , Infestaciones por Ácaros/veterinaria , Aves de Corral , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/parasitología , Prevalencia
2.
Parasitol Res ; 120(11): 3905-3908, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34561752

RESUMEN

The majority of known Philornis species (Diptera: Muscidae) cause subcutaneous myiasis in Neotropical altricial and semi-altricial nestlings. Generating information about these parasites is of relevance as they are a threat for the conservation of some wild bird species and also because they are an excellent model to study the ecology of host-parasite interactions. Although there are records of this parasitism in adult birds, the parasitic larvae are primarily associated with nestlings. However, systematic surveys including active search for larvae in older birds have been very scarce. Here we present results from a survey conducted along 6 years and encompassing a sample of 3029 subadult and adult birds in Santa Fe province, Argentina, where broods are frequently parasitised by the Philornis torquans complex. We found only one dipteran larva parasitising a greater thornbird. This larva was morphologically compatible with Philornis. Given the extremely low estimated prevalence (1/3029 = 0.03%), we conclude that the presence of larvae in subadult and adult birds is an extremely rare event in the studied bird community and that the species belonging to the P. torquans complex present in central Argentina are almost exclusively parasites of nestlings.


Asunto(s)
Muscidae , Miasis , Animales , Argentina/epidemiología , Aves , Larva
3.
Vet Parasitol ; 284: 109203, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32827991

RESUMEN

Wild birds may be considered a possible source of parasitic mesostigmatid mites for poultry, but only few studies explored this hypothesis. In addition, there is very little information about the parasitic mites present in commercial poultry systems from southern South America. To contribute with data on parasitic mesostigmatid mites at the domestic-wildlife interface, we conducted a study in which samples were systematically collected from laying hens and wild birds (adults and nestlings), for two years at three commercial laying hen farms. The occurrence of mesostigmatid mites were compared among hosts. A proportion of the collected mites were morphologically identified to the species level, finding that host preference varied greatly depending on mite species: laying hens were only parasitized by Ornithonyssus sylviarum, wild bird nestlings were mostly parasitized by Ornithonyssus bursa, and in small proportion, by O. sylviarum, while adult passerines were parasitized by both Ornithonyssus species, and sporadically by Pellonyssus cf. reedi and Dermanyssus cf. triscutatus. In laying hens, there was intra- and inter-annual variability in mite occurrence, but no consistent seasonal pattern, whereas in adult wild birds, mites showed the highest prevalence in spring and the lowest in summer. Not coinciding with this general pattern, the occurrence of O. bursa matched the reproductive activity of wild birds. A phylogenetic analysis based on a fragment of the 16S rRNA gene was carried out for a subsample of the mites collected, showing that the O. sylviarum mites present on adult wild birds and laying hens had the same haplotype (100% identity). Additionally, mites obtained from wild birds morphologically identified as O. bursa presented two distinctive haplotypes (89.8% identity), one phylogenetically related to O. sylviarum and the other to O. monteiroi. These findings show that in central Argentina commercial laying hens are parasitized mainly by O. sylviarum while wild birds are also hosts to other mite species. Adult wild passerines, especially house sparrows, may be a source of O. sylviarum for commercial poultry.


Asunto(s)
Animales Salvajes/parasitología , Enfermedades de las Aves/parasitología , Infestaciones por Ácaros/veterinaria , Ácaros/clasificación , Ácaros/fisiología , Passeriformes/parasitología , Enfermedades de las Aves de Corral/parasitología , Animales , Argentina , Reservorios de Enfermedades , Haplotipos , Infestaciones por Ácaros/parasitología , Filogenia , Aves de Corral/parasitología , ARN Ribosómico 16S/genética
4.
Parasitol Res ; 119(7): 2337-2342, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32500371

RESUMEN

Philornis flies Meinert (Diptera: Muscidae) have been documented parasitizing over 250 bird species, some of which are endemic species threatened with extinction. Philornis parasitism is hypothesized to affect nestlings disproportionately more than adult birds because limited mobility and exposed skin of nestlings increase their vulnerability to parasitism. We used a comprehensive literature review and our recent fieldwork in the Dominican Republic, Puerto Rico, and Grenada to challenge the idea that parasitism by subcutaneous Philornis species is a phenomenon primarily found in nestlings, a fact that has not been quantified to date. Of the 265 reviewed publications, 125 (49%) reported incidences of parasitism by subcutaneous Philornis, but only 12 included the sampling of adult breeding birds. Nine of these publications (75%) reported Philornis parasitism in adults of ten bird species. During fieldwork in the Dominican Republic, Puerto Rico, and Grenada, we documented 14 instances of parasitism of adult birds of seven avian species. From literature review and fieldwork, adults of at least fifteen bird species across 12 families and four orders of birds were parasitized by at least five Philornis species. In both the published literature and fieldwork, incidences of parasitism of adult birds occurred predominantly in females and was frequently associated with incubation. Although our findings indicate that Philornis parasitism of adult birds is more common than widely presumed, parasite prevalence is still greater in nestlings. In the future, we recommend surveys of adult birds to better understand host-Philornis relationships across life stages. This information may be essential for the development of effective control measures of Philornis to ensure the long-term protection of bird species of conservation concern.


Asunto(s)
Aves/parasitología , Muscidae/fisiología , Animales , Aves/clasificación , Femenino , Incidencia , Larva/clasificación , Larva/fisiología , Masculino , Muscidae/clasificación , Comportamiento de Nidificación , Prevalencia , Indias Occidentales/epidemiología
5.
Int J Parasitol ; 48(6): 445-455, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29391194

RESUMEN

Hosts counteract infections using two distinct defence strategies, resistance (reduction in pathogen fitness) and tolerance (limitation of infection damage). These strategies have been minimally investigated in multi-host systems, where they may vary across host species, entailing consequences both for hosts (virulence) and parasites (transmission). Comprehending the interplay among resistance, tolerance, virulence and parasite success is highly relevant for our understanding of the ecology and evolution of infectious and parasitic diseases. Our work investigated the interaction between an insect parasite and its most common bird host species, focusing on two relevant questions: (i) are defence strategies different between main and alternative hosts and, (ii) what are the consequences (virulence and parasite success) of different defence strategies? We conducted a matched field experiment and longitudinal studies at the host and the parasite levels under natural conditions, using a system comprising Philornis torquans flies and three bird hosts - the main host and two of the most frequently used alternative hosts. We found that main and alternative hosts have contrasting defence strategies, which gave rise in turn to contrasting virulence and parasite success. In the main bird host, minor loss of fitness, no detectable immune response, and high parasite success suggest a strategy of high tolerance and negligible resistance. Alternative hosts, on the contrary, resisted by mounting inflammatory responses, although with very different efficiency, which resulted in highly dissimilar parasite success and virulence. These results show clearly distinct defence strategies between main and alternative hosts in a natural multi-host system. They also highlight the importance of defence strategies in determining virulence and infection dynamics, and hint that defence efficiency is a crucial intervening element in these processes.


Asunto(s)
Enfermedades de las Aves/parasitología , Muscidae/fisiología , Miasis/veterinaria , Animales , Argentina , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/inmunología , Aves , Susceptibilidad a Enfermedades , Bosques , Especificidad del Huésped , Miasis/epidemiología , Miasis/inmunología , Miasis/parasitología
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