Search

Three species of chigger mites are recorded in our collections from four species of cricetid rodents on Chiloé Island (southern Chile, Los Lagos Region), an area endemic to scrub typhus (Orientia sp.). Two species are described as new—Herpetacarus (Abonnencia) eloisae sp. nov. and Quadraseta chiloensis sp. nov. One species, Paratrombicula goffiStekolnikov and González-Acuña 2012, is for the first time recorded on a mammal host (one species of cricetid rodent), and its distribution is extended to the Los Lagos Region of Chile. The genus ProschoengastiaVercammen-Grandjean, 1967 is synonymized with the subgenus Herpetacarus (Abonnencia)Vercammen-Grandjean, 1960, and four new combinations are established: Herpetacarus (Abonnencia) herniosa (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) insolita (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) macrochaeta (Brennan and Jones, 1961), comb. nov., and Herpetacarus (Abonnencia) antarctica (Stekolnikov and Gonzalez-Acuña, 2015), comb. nov.

The American mink, Neovison vison, is an invasive species in Chile. Its impact on native fauna and public health has not been studied in depth in the country. In this study, we searched for gastrointestinal parasites, including helminths and zoonotic Cryptosporidium sp., the presence of Trichinella sp. in muscle, and the renal carriage of pathogenic Leptospira sp. in minks caught on Navarino Island, "Magallanes y la Antartica Chilena" Region, and Maullin and Ancud, "Los Lagos" Region, Chile. A total of 58, 15, and 21 minks from Navarino Island, Maullin, and Ancud, respectively, were examined for Trichinella sp. (artificial digestion of muscle). A total of 36, 11, and 17 minks from Navarino Island, Maullin, and Ancud, respectively, were examined for pathogenic Leptospira species (molecular detection of LipL32 gen fragment in renal tissue) infection. Finally, 45, 11, and 17 minks from Navarino Island, Maullin, and Ancud, respectively, were analyzed to detect gastrointestinal parasites (by optical inspection of the digestive tract for helminths, and by both Ziehl-Neelsen stain and molecular detection of small subunit-ribosomal DNA for Cryptosporidium species). Trichinella larvae were not observed. Pathogenic Leptospira sp. was detected in 22 samples: 15 from Navarino Island, 3 from Maullin, and 4 from Ancud. Two nematodes, belonging to Ascaridinae (subfamily) and Pterygodermatites (Paucipectines) sp., were found in samples of two minks from Navarino Island. Oocysts and DNA of Cryptosporidium sp. were detected in three fecal samples from Navarino Island. Further studies could determine the zoonotic potential of Cryptosporidium sp., as well as the potential impact of the zoonotic Leptospira sp. on the human population of the Navarino Island, Maullin, and Ancud districts. The enemy release theory could explain the low helminth species richness in the minks. In addition, we did not find evidence of parasite transmission from native fauna.

Background Trichinellosis is a zoonotic disease with a worldwide distribution. It is caused by several species of nematodes in the genus Trichinella. Trichinella spp. are transmitted through predation or carrion consumption and occur in domestic and sylvatic cycles. In humans trichinellosis occurs due to the consumption of raw or undercooked, infected meat and is mainly associated with the household slaughter of pigs or the consumption of game animals without veterinary inspection, a cultural practice that is difficult to resolve. Therefore, knowledge of this parasite’s reservoir is relevant for better implementing public health strategies. The aim of this study was to assess the presence of Trichinella sp. in several carnivore and omnivore vertebrates in central-southern Chile. Methods We collected muscle tissue from a total of 53 animals from 15 species and were digested to detect Trichinella larvae which were further identified to species level using molecular techniques. Results We detected Trichinella larvae in Leopardus guigna (Felidae) and Galictis cuja (Mustelidae). We identified the larvae collected from L. guigna as Trichinella spiralis, but we were unable to molecularly characterize the larvae from G. cuja. This is the first record of Trichinella in a native mustelid of South America and the first record of T. spiralis in L. guigna. This study identified two novel hosts; however, further work is needed to identify the role that these and other hosts play in the cycle of Trichinella in Chile.

Myiopsitta monachus is an invasive psittacine with wide distribution due to the pet trade. Its large communal nests and synanthropic nature contribute to its successful colonization of cities, from where it seems to be expanding in range and numbers. This is relevant with regard to pathogens that invasive species may harbor, especially when host populations thrive. We aimed to identify an abundant mite found in invasive monk parakeet chicks that had been collected in Santiago during 2017 and 2018. Through morphological and molecular identification of the 18S ribosomal RNA gene, we confirmed the presence of Ornithonyssus bursa. This was the first report of this mite in Chile. This mite is common in native and invasive monk parakeet populations and may affect other birds, including domestic fowl. Further, this mite bites people and can be a potential vector of pathogens such as bacteria or viruses. We conclude that this parasite was likely introduced with the parakeet and discuss possible ecological, health and economic consequences of this new potential pest. Resumo Myiopsitta monachus é um psitacídeo invasor amplamente distribuído devido ao tráfico de animais selvagens. Os grandes ninhos comunitários construídos e sua condição de espécies sinantrópicas contribuem para a colonização bem-sucedida das cidades, onde parece estar expandindo sua distribuição e número de indivíduos. Isso é relevante, quando se trata de patógenos que os invasores podem abrigar, especialmente quando as populações hospedeiras prosperam. O objetivo deste trabalho foi identificar um ácaro abundante, encontrado em filhotes de periquitos-monge introduzidos em Santiago, Chile, coletados durante 2017 e 2018. Por meio da identificação morfológica e molecular do gene do RNA ribossômico 18S, foi confirmada a presença de Ornithonyssus bursa, sendo o primeiro registro para o Chile. Esse ácaro é comum em populações nativas e introduzidas de periquitos-monge e pode afetar outras aves, incluindo aves domésticas. Além disso, esse ácaro pode picar pessoas e pode ser um potencial vetor de patógenos, como bactérias ou vírus. Conclui-se que esse parasita provavelmente foi introduzido com o periquito e foram discutidas as possíveis consequências ecológicas de saúde e econômicas dessa nova praga em potencial.

Trichinellosis is a zoonosis with worldwide distribution. Several hosts have been recognized around the world; however, there is a lack of knowledge of the role of feral mammals in Chile in its transmission. Herein, we tested muscle samples from 555 individuals among American minks (Neovison vison Schreber, 1777. n = 100) and several myomorph rodent species (Muridae and Cricetidae. n = 455) from southern Chile by artificial digestion to detect Trichinella larvae and identified the larvae at the species level through molecular analyses. Rodents were captured in agricultural and wild protected areas of several administrative regions (hereafter: region), while minks were captured in agricultural areas of the Los Rios region. Trichinella spiralis larvae were detected in a synanthropic black rat (0.24%) of the Nuble region and in seven minks (7%) trapped in agricultural areas of the Los Rios region. The present results suggest that T. spiralis circulation is restricted to synanthropic rodents and minks living in agricultural areas where the parasite circulates among domesticated pigs. This study represents the first record of T. spiralis in a mustelid mammal in South America, increasing the number of feral species that could participate in the reservoir.

Invasive populations are a threat to biodiversity, resulting in the loss of species, and also a threat to human health, participating in the reservoir of diseases. Rodents are among the most important invasive species worldwide. Chile is a country that features island conditions in terms of geography and has been widely invaded by allochthonous rodents. In this mini-review, we updated the literature on macro-parasites infecting both native and invasive rodents and of vector-borne pathogens in continental Chile in order to assess the relative importance of invasive rodents from both ecological and public health points of view. A total of 174 parasite species were found, with Siphonaptera representing the most diverse group. When examining how parasites are shared between native and introduced rodents, the analysis suggests that parasites circulate freely within recipient populations, and are not significantly transmitted from source populations. Further, generalist parasites are typically more prone to being shared between native and introduced rodents. Most zoonotic parasites were reported in invasive rodents, suggesting that these rodents must represent a public health concern. Although several vector-borne pathogens have been reported in rodents or ectoparasites, most of the recently emerging research has illustrated that there is a lack of evidence on rodent–vector-borne zoonoses in most pathogens.

Background Scrub typhus is an emerging vector-borne zoonosis, caused by Orientia spp. and transmitted by larvae of trombiculid mites, called chiggers. It mainly occurs within a region of the Asia-Pacific called the tsutsugamushi triangle, where rodents are known as the most relevant hosts for the trombiculid vector. However, the reservoir(s) and vector(s) of the scrub typhus outside Asia-Pacific are unknown. The disease has recently been discovered on and is considered endemic for Chiloé Island in southern Chile. The aim of the present work was to detect and determine the prevalence of chiggers on different rodent species captured in probable sites for the transmission of orientiae responsible for scrub typhus on Chiloé Island in southern Chile and to molecularly examine collected chiggers for the presence of Orientia DNA. Methodology/Principal findings During the austral summer 2018, rodents were live-trapped in six sites and examined for chigger infestation. All study sites were rural areas on Chiloé Island, previously identified as probable localities where human cases acquired the scrub typhus. During a total of 4,713 trap-nights, 244 rodents of seven species were captured: the most abundant was Abrothrix olivacea. Chiggers were detected on all seven rodent species with a 55% prevalence rate. Chiggers showed low host specificity and varied according to site specific host abundance. Three genera of trombiculids were identified. Herpetacarus was the most abundant genus (93%), prevalent in five of the six sites. Infestation rates showed site specific differences, which were statistically significant using a GLM model with binomial errors. Molecular analyses proved that 21 of 133 (15.8%) mite pools were positive for Orientia species, all of them belonged to the genus Herpetacarus. Conclusions/Significance This study firstly reports the presence of different rodent-associated chigger mites positive for Orientia sp., in a region endemic for scrub typhus in southern Chile. Herpetacarus and two other genera of mites were found with high infestation rates of rodents in sites previously identified as probable exposure of scrub typhus cases. A substantial percentage of mite pools were positive for Orientia DNA, suggesting that chigger mites serve as vectors and reservoirs of this emerging zoonosis in South America., Author summary Scrub typhus is a chigger-transmitted zoonotic infection caused by Orientia species, which is endemic to the tsutsugamushi triangle in Asia-Pacific region. Recently, a focus of scrub typhus in South America has been confirmed on Chiloé Island in southern Chile. However, the vectors of scrub typhus in this region remain unknown. We undertook a survey to study the presence of chiggers on different rodent species in areas identified as probable sites of exposure to scrub typhus on Chiloé Island. The study showed that 55% of rodents were infested by trombiculids. Three mite genera were identified, of which Herpetacarus was the most abundant. Chiggers showed low host specificity, but spatial differences. Using molecular techniques, the trombiculid mites were found to be infected with Orientia species. These findings suggest that chigger mites play a role in the life cycle and transmission of this emerging infectious disease in Chile.

This research aimed to determine the presence of paramphistomids in cattle slaughtered in a slaughterhouse of the Ñuble Region of Chile, to identify flukes and to analyze the frequency of these parasites in the Maule, Ñuble, and Biobío administrative regions of Chile. Between October of 2016 and April of 2017, rumens of 494 cattle were examined for flukes in the forestomachs. Worms were identified morphologically and, in addition, molecular analysis of the internal transcriber spacer region 2 of the fluke’s DNA was done and phylogenetic analyses were performed with Bayesian inference in 14 worms. The frequency was analyzed by locality (low- or highlands) and age. The overall frequency was 11.24%. The district with the highest frequency of presentation was Chillán Viejo (30.8%). Districts in the lowlands had similar frequencies to those in the mountain lands (p=0.1). The frequency of flukes was significantly higher in adult animals than in young ones (p

Hannemania larvae are parasites of amphibians in North and South America. In Chile, only one species of Hannemania has been reported from Batrachyla taeniata (banded wood frog). The objective of the study was to determine the abundance and body distribution of Hannemania among three amphibians from Antuco (Biobío Region, Chile): Pleurodema thaul (13 adults; Chile four-eyed frog), Pleurodema bufonina (5 adults; large four-eyed frog), and Rhinella spinulosa (15 adults and 16 juveniles; warty toad). Amphibians (82.75 %; n = 49) were infested with Hannemania. The infestation rate in R. spinulosa juveniles was lower than in adults (68 versus 100%, respectively; mean larval intensity: juvenile = 3.2 ± 2.5 and adult = 17.3 ± 16.3). Mean intensity of larval infestation in P. bufonina (63.2 ± 47.9) was higher than in the other two species of amphibians (R. spinulosa adult: 17.3 ± 16.3; R. spinulosa juvenile: 3.2 ± 2.5; P. thaul: 11.62 ± 7.8). There was no significant association between body size and mean intensity of infestation. The inguinal region, ventrum, and dorsal forearm region were the most parasitized. These body zones would be in direct contact with the substrate making the infestation easier for the larvae. This study represents the first record of Hannemania sp. in P. bufonina, R. spinulosa, and P. thaul in Chile.

Rattus rattus is a widely distributed, invasive species that presentsan important role in disease transmission, either directly or through vectorarthropods such as fleas. These black rats can transmit a wide variety of pathogens, including bacteria of the genus Bartonella, which can cause diseases in humans and animals. In Chile, no data are available identifying fleas from synanthropic rodents as Bartonella vectors. The aim of this study was to investigate the prevalence of Bartonella spp. in the fleas of R. rattus in areas with different climate conditions and featuring different human population densities. In all, 174 fleas collected from 261 R. rattus captured from 30 localities with different human densities (cities, villages, and wild areas) across five hydrographic zones of Chile (hyper-arid, arid, semi-arid, sub-humid, and hyper-humid) were examined. Bartonella spp. presence was determined through polymerase chain reaction, using gltA and rpoB genes, which were concatenated to perform a similarity analysis with BLAST and phylogenetic analysis.Results: Overall, 15 fleas species were identified; Bartonella gltA and rpoB fragments were detected in 21.2% (37/174) and 19.5% (34/174) of fleas, respectively. A total of 10 of the 15 fleas species found were positive for Bartonella DNA. Leptopsylla segnis was the most commonly collected flea species (n = 55), and it also presented a high prevalence of Bartonella DNA (P% = 34.5%). The highest numbers of fleas of this species were collected in villages of the arid zone. There were no seasonal differences in the prevalence of Bartonella DNA. The presence of Bartonella DNA in fleas was recorded in all hydrographic areas, and the arid zone presented the highest prevalence of this species. Regarding areas with different human densities, the highest prevalence was noted in the villages (34.8% gltA and 31.8% rpoB), followed by cities (14.8% gltA and 11.1% rpoB) and wild areas (7.4% gltA and 14.8% rpoB). The BLAST analysis showed a high similitude (>96%) with four uncharacterized Bartonella genotypes and with two species with zoonotic potential: B. mastomydisand B. tribocorum. The phylogenetic analysis showed a close relationship withB. elizabethae and B. tribocorum. This is the first study to provide evidence of the presence of Bartonella in fleas of R. rattus in Chile, indicating that the villages and arid zone correspond to areas with higher infection risk. Fil: Moreno Salas, Lucila. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanografía. Departamento de Zoología; Chile Fil: Espinoza Carniglia, Mario Virgilio. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanografía. Departamento de Zoología; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Lizama Schmeisser, Nicol. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanografía. Departamento de Zoología; Chile Fil: Torres, L. Gonzalo. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanografía. Departamento de Zoología; Chile. Universidad Austral de Chile; Chile Fil: Silva de la Fuente, María Carolina. Universidad de Concepción; Chile. Universidad San Sebastian.; Chile Fil: Lareschi, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: González Acuña, Daniel. Universidad de Concepción; Chile

The family Trombiculidae is one of the most diverse and cosmopolitan (Walter et al. 2009). In Chile, the family Trombiculidae is represented by six genera associated with reptiles: Eutrombicula Ewing; Microtrombicula Ewing; Paratrombicula Goff & Whitaker; Whartonacarus (Brennan & Jones); Diaguitacarus Stekolnikov & Gonzalez-Acuna and Proschoengastia Vercammen-Grandjean and two genera associated with rodents Chilacarus Webb, Bennett & Loomis and Poliremotus Brennan & Goff (Stekolnikov & Gonzalez-Acuna 2015).