During 2013–2014, adult ticks were collected on the vegetation and subadult ticks were collected from small mammals [Didelphis aurita Wied-Neuwied, Sooretamys angouya (Fischer), Euryoryzomys russatus (Wagner), Akodon montensis Thomas, Oxymycterus judex Thomas] in an Atlantic rainforest reserve in southern Brazil. Analyses of the external morphology of the adult ticks revealed that they represent a new species, Amblyomma yucumense n. sp. Partial 16S rRNA sequences generated from males, females, and nymphs were identical to each other and closest (95% identity) to corresponding sequences of Amblyomma dubitatum Neumann. A. yucumense is morphologically and genetically closest related to A. dubitatum. Dorsally, male of these species can be separated by major longitudinal pale orange stripes associated with a pseudoscutum indicated by a pale stripe in A. yucumense, in contrast to pale creamy longitudinal stripes and absence of pseudoscutum in A. dubitatum. Ventrally, male coxal I spurs are separated by a space narrower than external spur width in A. yucumense, and wider than external spur width in A. dubitatum. Females of the two species can be separated by coxal I spurs, longer in A. yucumense than in A. dubitatum. In addition, the adult capitulum and ventral idiosoma of A. yucumense are generally dark brown colored, while A. dubitatum is yellowish or light brown colored. The nymph of A. yucumense differs from A. dubitatum by the scutal cervical groove length, slightly shorter in the former species. Currently, A. yucumense is restricted to southern Brazil.

Background: The canine heartwormDirofilaria immitis,a filarioid nematode of dogs and other carnivores, is widespread in the USA and the world. Over 20 different mosquito species serve as intermediate hosts ofD. immitis, but their contribution to transmission varies according to factors like host feeding patterns, geographic locations and climatic conditions. The yellow fever mosquito,Aedes aegypti,is a competent vector ofD. immitisbut is often dismissed as a vector of veterinary relevance given its anthropophilic feeding behavior. We evaluated the prevalence ofD.immitisin pet dogs along the USA-Mexico border and assessed whetherAe.aegyptiin the area are naturally infected with heartworm and are potentially acting as a vector.Methods: A total of 200 whole blood samples collected from pet dogs in the Lower Rio Grande Valley in south Texas from 2016 to 2019 were included in this study. Canine serum samples forD. immitiswere tested using the DiroCHEK® Canine Heartworm Antigen Test Kit pre- and post-immune complex dissociations (ICD) and blood samples were tested using high-resolution melt (HRM) quantitative PCR (qPCR) and a probe-based qPCR. Additionally, mosquito specimens were collected and identified, andAe. aegyptiheads, abdomens and pools were tested using conventional PCR (cPCR) and HRM qPCR.Results: Overall, heartworm prevalence in dogs aged > 6 months was 40.8% (64/157) when the results from all testing modalities were considered. Heartworm antigen was detected in 33.5% and 40.7% of the dogs using DiroCHEK® pre- and post-ICD, respectively. By molecular screening, 20.1% of dogs tested positive with probe-based qPCR, while only one tested positive with HRM qPCR. Of theAe. aegyptiabdomens from blood-fedAe. aeygptitested, 20 (21.7%) from mosquitoes that fed on dogs and four (7%) from those that fed on humans tested positive for heartworm. AmongAe. aegyptiheads from blood-fedAe. aeygpti, two (1.1%) were positive based on cPCR and four (2.5%) were positive based on HRM qPCR. NoD. immitisDNA was detected in the 208 pools of whole bodies (358 individuals) ofAe. aegyptigravid females.Conclusions: Our study highlights a high prevalence of heartworm in dogs in south Texas and provides evidence thatAe. aegypticould be contributing to heartworm transmission in canine populations in this region.Graphical

Leptospirosis is a disease of worldwide distribution that affects man and several animal species. Domestic and wild animals can behave as reservoirs of the agent. The aim of this study was to evaluate the frequency of anti-Leptospira spp. antibodies in dogs and wild small mammals from rural properties and conservation units of three municipalities of Rio Grande do Sul State, Brazil. Sera were collected from 192 domestic dogs and 132 small mammals, namely rodents of the Cricetidae and Caviidae families and marsupials of the Didelphidae family. The study used Microscopic Agglutination Test (MAT) against 23 serovars of Leptospira spp. Overall, 9.90% (19/192) dogs, and 1.51% (2/132) small mammals were seropositive. Leptospira interrogans serovar Australis was the most frequent serovar in dogs and antibodies against L. interrogans serovar Pomona were detected in a dog and a small mammal belonging to the same municipality. We conclude that in the regions studied the frequency of seropositivity in dogs is low, and leptospires do not seem to be circulating in small mammals, yet, further research is necessary to assess the real role that these animals may have for leptospirosis in the studied areas. This is the first serological survey in small mammals, including wild rodents, in the area that encompasses conservation units of great importance to Rio Grande do Sul state.

We identified a Thelazia callipaeda eyeworm in an American black bear in Pennsylvania, USA, on the basis of its morphological features and molecular analysis. Our finding highlights emergence of a T. callipaeda worm sylvatic transmission cycle in the United States.

Purpose In the present study, we described the most prevalent clinical symptoms, the most affected organs, and the macro and microscopic lesions associated with cutaneous leishmaniasis.