Abstract The objective of this study was to report helminth parasite species of Passer domesticus (Linnaeus, 1758) (sparrow) and to analyze infection rates in relation to total length, body mass and sexual gender of hosts. Each of the 100 sparrows caught in the urban area of Pelotas, Rio Grande do Sul, Brazil, was weighed, measured, submitted to euthanasia and necropsied for collection of helminths. The helminths and their respective prevalence were: Synhimantus (Dispharynx) nasuta (2%), Aproctella sp. (1%) (Nematoda), Prosthogonimus ovatus (8%), Eumegacetes sp. (2%), Tanaisia zarudnyi (4%) (Digenea), Choanotaenia passerina (26%) (Cestoda), and Mediorhynchus sp. (2%) (Acanthocephala). The prevalence and mean intensity of infection of the C. passerina between male and female hosts did not present significant differences, and there was no correlation between the abundance of parasite species, body mass and total length of the sparrows. The helminth fauna of P. domesticus has remained the same throughout the propagation of this bird for new geographical areas and ecosystems, with the exception of the nematode Aproctella sp., found for the first time parasitizing this host.

Resumen El objetivo de este estudio fue registrar a las especies de helmintos parásitos de Passer domesticus (Linnaeus, 1758) (gorrión) y analizar los índices de infección en relación al género sexual, peso y tamaño de los hospedadores. Para ello, cada uno de los 100 gorriones capturados en el área urbana de Pelotas, Rio Grande do Sul, Brasil, fue pesado, medido, sometido a eutanasia y a uma necropsia para la recolección de helmintos. Los helmintos y sus respectivas prevalencias fueron: Synhimantus (Dispharynx) nasuta (2%), Aproctella sp. (1%) (Nematoda), Prosthogonimus ovatus (8%), Eumegacetes sp. (2%), Tanaisia zarudnyi (4%) (Digenea), Choanotaenia passerina (26%) (Cestoda), y Mediorhynchus sp. (2%) (Acanthocephala). La prevalencia e intensidad media de la infección por C. passerina entre hospedadores machos y hembras no presentó diferencia significativa, así como no hubo correlación entre la abundancia de esta especie, su masa corporal y la longitud total de los gorriones. La helmintofauna de P. domesticus se ha mantenido a lo largo de la propagación del ave a nuevas áreas geográficas y ecosistemas, con excepción del nemátodo Aproctella sp., encontrado por primera vez parasitando a dicho hospedero.

Resumo O objetivo deste estudo foi relatar duas espécies de ácaros nasais parasitos do sistema respiratório de Passer domesticus (Linnaeus, 1758) (pardal) e seus respectivos índices parasitológicos. Para isso, foram examinados ao estereomicroscópio, cavidade nasal, traqueia, pulmão e sacos aéreos de 100 pardais capturados na área urbana de Pelotas, Rio Grande do Sul, Brasil. Sternostoma tracheacolum Lawrence, 1948 ocorreu na traqueia e/ou pulmão de 13 aves (13%) com intensidade média de 6,7 ácaros/hospedeiro infectado e Ptilonyssus hirsti (Castro & Pereira, 1947) na cavidade nasal de um único pardal (1%), não havendo coinfecção. A prevalência e intensidade média de infecção por S. tracheacolum entre hospedeiros machos e fêmeas não apresentou diferença significativa. Este relato caracteriza o primeiro registro de S. tracheacolum parasitando P. domesticus no Brasil e de P. hirsti em pardais no RS, Brasil, e seus respectivos índices de infecção.

Abstract We report the occurrence and infection parameters of two species of nasal mites in Passer domesticus (Linnaeus, 1758) (house sparrow). Nasal passages, trachea, lungs, and air sacs of 100 house sparrows captured in an urban area at the city of Pelotas, State of Rio Grande do Sul, southern Brazil, were examined with a stereomicroscope. The mite, Sternostoma tracheacolum Lawrence, 1948 was present in the trachea and/or lungs (or both) of 13 birds (13%) at a mean intensity of 6.7 mites/infected host. Ptilonyssus hirsti (Castro & Pereira, 1947) was found in the nasal cavity of 1 sparrow (1%); coinfection was not observed in this bird. There was no significant difference in the prevalence and mean intensity of infection of S. tracheacolum between male and female birds. To our knowledge, this is the first study reporting the occurrence of S. tracheacolum in P. domesticus in Brazil and the presence of P. hirsti in P. domesticus from Rio Grande do Sul, Brazil. This is the first survey to provide the infection parameters of each of these mites in house sparrows.