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Wild rodents often harbor Cryptosporidium species that can be transmitted to multiple mammal hosts. In Chile, little is known about Cryptosporidium in wild rodents, and available studies have been focused on morphological findings with no molecular-based evidence. A longitudinal survey was conducted between 2021 and 2022 to investigate the occurrence of Cryptosporidium spp. in populations of the Darwin's leaf-eared mouse (Phyllotis darwini) living in protected and rural transitional areas in north-central Chile, using staining and molecular methods. A total of 247 fecal samples were collected and examined by the modified Ziehl-Neelsen (ZN) staining test, 54 of which were positive for Cryptosporidium-like oocysts. Molecular analyses were carried out by PCR of the partial 18S ribosomal RNA and 60 kDa glycoprotein (gp60) genes. Cryptosporidium infection was confirmed in 34 samples (13.7 %) based on the PCR amplification, and individual (i.e., sex, and body mass index) and ecological variables (i.e., type of site and season) were not statistically significant (p > 0.05). Using the nucleotide sequencing of the partial 18S rRNA gene, Cryptosporidium parvum was identified in nine isolates. Also, C. parvum subgenotype family IIa was determined in seven samples by the partial gp60 gene, including the subtype IIaA17G4R1 in two samples. This is the first molecular evidence of Cryptosporidium parvum IIa in Phyllotis darwini in Chile. These results indicate potential cross-species transmition between wild rodents and domestic-wild animals in north-central Chile. More research is needed to understand better the role of wild rodents in the transmission of Cryptosporidium spp. in Chile.

RESUMEN

Despite the extensive information on the effects of habitat alteration on the structure of helminth communities in small mammals, the evidence is still inconclusive. A systematic review was carried out using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guideline to compile and synthesize available literature on the influence of habitat alteration on the structure of helminth communities in small mammals. The aim of this review was to describe the variation in infection rates of helminth species associated with habitat alteration and to discuss the theoretical framework that may explain such changes in relation to parasite, host, and environmental features. Twenty-three scientific articles published between 2005 and 2022 were reviewed, 22 of which investigated parasite prevalence, 10 parasite burden, and 14 parasite richness in both altered and natural habitats. Information in assessed articles suggests that the structure of helminth communities in small mammals can be impacted by anthropogenic habitat alteration in various ways. Infection rates of monoxenous and heteroxenous helminths may increase or decrease in small mammals depending on whether their hosts (definitive and intermediate) are available, and environmental and host conditions modify the survival and transmission of parasitic forms. Also, given that habitat alteration may favor inter-species contacts, transmission rates of low host-specific helminths could be increased due to exposure to new reservoir hosts. In a continually changing world, it is essential to assess the spatio-temporal variations of helminth communities in wildlife inhabiting altered and natural habitats to determine potential impacts on wildlife conservation and public health.

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Parasitic infections are frequent in cosmopolitan feral pigeons (Columba livia domestica) that live in cities, but little is known about the effects of parasites in urban feral pigeon populations. A survey was conducted to evaluate the occurrence of endoparasites and the risk factors of feral pigeons in the city of Loja in southern Ecuador between August and October 2019. A total of 166 fecal samples and 80 peripheral blood smears were collected and examined by the McMaster flotation method and Giemsa staining, respectively. The prevalence of gastrointestinal parasites was 79.51% (132/166). Parasites included: Ascaridia columbae in 13.64% (18/132), Capillaria sp. in 3.79% (5/132), Eimeria sp. in 25% (33/132), unidentified coccidia in 75% (99/132), and an unidentified nematode egg in 0.7% (1/132). The presence of intracellular gamonts of Haemoproteus sp. was found in 87.50% (70/80) of examined blood smears. The frequency and intensity of nematodes were different according to the site. Haemoproteus infection was more frequent in individuals with low body mass index. More research should be undertaken to understand parasitic infections and their effects on cosmopolitan synanthropic feral pigeons.

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Captive birds in zoological settings often harbor parasites, but little information is available about the potential for free-ranging avifauna to act as a source of infection. This review summarizes the gastrointestinal parasites found in zoo birds globally and in seven common free-ranging avian species [mallard (Anas platyrhynchos), Eurasian blackbird (Turdus merula), common starling (Sturnus vulgaris), Eurasian jackdaw (Corvus monedula), house sparrow (Passer domesticus), European robin (Erithacus rubecula), and rock dove (Columba livia)] to identify the overlap and discuss the potential for cross-species transmission. Over 70 references were assessed, and papers spanned over 90 years from 1925 to 2019. A total of 60 studies from 1987 to 2019 met the eligibility criteria. All examined free-ranging avifauna harbored parasite species that were also reported in zoo birds, except for the European jackdaw. Parasites reported in captive and free-ranging birds include nematodes (Capillaria caudinflata, Dispharynx nasuta, Ornithostrongylus quadriradiatus, Strongyloides avium, Syngamus trachea, and Tetrameres fissispina), cestodes (Dicranotaenia coronula, Diorchis stefanskii, Fimbriaria fasciolaris, and Raillietina cesticillus, Sobolevicanthus gracilis), trematode (Echinostoma revolutum), and protozoa (Cryptosporidium baileyi). Although no study effectively proved cross-transmission either experimentally or by genetic analysis, these parasites demonstrate low host specificity and a high potential for parasite sharing. There is potential for parasite sharing whenever determinants such as host specificity, life cycle, and husbandry are favorable. More research should be carried out to describe parasites in both captive and free-ranging birds in zoological settings and the likelihood of cross-infection. Such information would contribute to evidence-based control measures, enhancing effective husbandry and preventive medicine protocols.