Dirofilaria repens is a vector-borne filaroid helminth of carnivorous animals, primarily domesticated dogs. Humans are considered to be accidental hosts in which D. repens rarely reach sexual maturity but induce local inflammation, mainly in subcutaneous and ocular tissues. In the current study, we present the detection of multiple adults of D. repens, endosymbiont Wolbachia sp. and microfilariae by molecular analysis in peripheral tissues and bloodstream of a human host. A subsequent meta-analysis of published literature identified 21 cases of human infection with adult D. repens producing microfilariae. Within the study population, there were 13 (59.09%) males, eight (36.36%) females and, in one (4.55%) case, sex was not reported. A total of 11 (50.00%) cases had subcutaneous dirofilariasis, six (27.27%) had ocular dirofiliariasis, with single cases (4.55% each) of genital, mammary, lymphatic and a combination of subcutaneous and pulmonary dirofilariasis described. In one (4.55%) case, the primary anatomical site of adult D. repens could not be found. D. repens microfilariae were detected in the local tissue (local microfilariasis) in 11 (50.00%) cases and the peripheral blood (microfilaremia) in 11 (50.50%) cases. Final identification of D. repens microfilariae was based on morphological detection in 14 (63.64%) cases, and molecular detection in eight (36.36%) cases. The results of this study suggest that humans may act as a final host for D. repens, however its role as a source of D. repens infection is less clear.

Analgesic products for piglet castration are critically needed. This requires extensive animal experimentation such as to meet regulatory-required proof of efficacy. At present, there are no validated methods of assessing pain in neonatal piglets. This poses challenges for investigators to optimize trial design and to meet ethical obligations to minimize the number of animals needed. Pain in neonatal piglets may be subtle, transient, and/or variably expressed and, in the absence of validated methods, investigators must rely on using a range of biochemical, physiological and behavioural variables, many of which appear to have very low (or unknown) sensitivity or specificity for documenting pain, or pain-relieving effects. A previous systematic review of this subject was hampered by the high degree of variability in the literature base both in terms of methods used to assess pain and pain mitigation, as well as in outcomes reported. In this setting we provide a narrative review to assist in determining the optimal methods currently available to detect piglet pain during castration and methods to mitigate castration-induced pain. In overview, the optimal outcome variables identified are nociceptive motor and vocal response scores during castration and quantitative sensory-threshold response testing and pain-associated behaviour scores following castration.

Background: Wildlife species carry a remarkable diversity of trypanosomes. The detection of trypanosome infection in native Australian fauna is central to understanding their diversity and host-parasite associations. The implementation of total RNA sequencing (meta-transcriptomics) in trypanosome surveillance and diagnosis provides a powerful methodological approach to better understand the host species distribution of this important group of parasites.Methods: We implemented a meta-transcriptomic approach to detect trypanosomes in a variety of tissues (brain, liver, lung, skin, gonads) sampled from native Australian wildlife, comprising four marsupials (koala,Phascolarctos cinereus; southern brown bandicoot,Isoodon obesulus; swamp wallaby,Wallabia bicolor; bare-nosed wombat,Vombatus ursinus), one bird (regent honeyeater,Anthochaera phrygia) and one amphibian (eastern dwarf tree frog,Litoria fallax). Samples corresponded to both clinically healthy and diseased individuals. Sequencing reads werede novoassembled into contigs and annotated. The evolutionary relationships among the trypanosomatid sequences identified were determined through phylogenetic analysis of18SrRNA sequences.Results: We detected trypanosome sequences in all six species of vertebrates sampled, with positive samples in multiple organs and tissues confirmed by PCR. Phylogenetic analysis indicated that the trypanosomes infecting marsupials were related to those previously detected in placental and marsupial mammals, while the trypanosome in the regent honeyeater grouped with avian trypanosomes. In contrast, we provide the first evidence for a trypanosome in the eastern dwarf tree frog that was phylogenetically distinct from those described in other amphibians.Conclusions: To our knowledge, this is the first meta-transcriptomic analysis of trypanosomes in native Australian wildlife, expanding the known genetic diversity of these important parasites. We demonstrated that RNA sequencing is sufficiently sensitive to detect low numbers ofTrypanosomatranscripts and from diverse hosts and tissues types, thereby representing an effective means to detect trypanosomes that are divergent in genome sequence.

Human dirofilariasis is a disease historically linked to the Mediterranean area. For the last few decades, however, Dirofilaria nematodes have been spreading, both in terms of prevalence and the geographical expansion in non-endemic areas. Currently, cases of human dirofilariasis are recorded in more than 40 countries worldwide. Croatia is considered an endemic area of the Adriatic basin. In a nationwide investigation, new and previously published cases of human dirofilariasis in Croatia were analyzed. Since 1996, 30 cases of human dirofilariosis were reported in Croatia. A total of 14 (46,67%) cases were from the coastal and 16 (53,33%) from continental regions of the country. Based on anatomical location, 13 (43,33%) cases were subcutaneous, 12 (40%) were ocular and five (16,67%) occurred in the reproductive organs. In all 30 cases, Dirofilaria repens was identified as the causative agent. An increase in air temperature as climate change, changes in mosquito fauna, high prevalence of D. repens in dogs and limited use of chemoprophylaxis are possible risk factors for Dirofilaria infection in the Croatian population. Since reporting to epidemiological services is not mandatory in this country, the real number of human dirofilariasis cases is probably significantly higher than published. This emphasizes the need for mandatory reporting of human cases and surveillance of Dirofilaria infection in dogs and mosquitoes in Croatia, following the “One Health” concept.

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