327 research outputs found
Chigger Mites (Trombiculidae)
No full texthigger mites are parasitic hexapod larvae belonging mainly to the family Trombiculidae, which cause dermatitis (known as trombiculosis or trombiculiasis) in many animal species, including humans. Species of medical and veterinary importance belong to the genus Eutrombicula Ewing, 1938 in the Neotropics and Neartic, Neotrombicula Hirst, 1925 in the Paleartic and Leptotrombidium Nagayo et al., 1916 in the Oriental region. Species of the genus Leptotrombidium are associated with rodents, potentially acting as vectors of rickettsial disease (i.e., scrub typhus) by Orientia tsutsugamushi in humans. Chigger mites have a worldwide distribution and a low host specificity, being able to infest mostly anthropized environments. Their biological life cycle mainly occurs in the environment (i.e., eggs, prelarvae, quiescent protonymphs, active deutonymphs, quiescent tritonymphs and finally adults), with only larvae as parasitic stage on host. Species that occur in temperate regions can complete up to three generations, whereas tropical ones have continuous cycles all year round. The distribution and diversity of chigger mites is given by the environmental conditions, region and host availability. Their pathogenic effect depends on the parasitic load and on the length of the feeding structure (known as stylostome), which varies according to the species of chigger. Although not truly considered chigger mites, the family Leeuwenhoekiidae has two genera of noticeable veterinary importance (Hannemania and Straelensia). Larvae of Hannemania spp. are intradermic, typically associated with amphibians, while those of the genus Straelensia attach within the inner surface of hair follicles of dogs and Iberian ibex (Capra pyrenaica), forming intradermic solid nodules. Topical repellents are used to prevent and control trombiculiasis by avoiding mite bites. Also, the control of rodent populations is effective as a long-term measure to reduce scrub typhus. For intradermic mites, treatment can be achieved with systemic avermectins, whereas topical acaricides are not useful
Zoonotic parasites associated with predation by dogs and cats
No full textOne of the most common behaviors of cats that have an indoor/outdoor lifestyle is to bring hunted “gifts” to their owners, represented by small mammals, reptiles and birds. Access to the outdoors by dogs and cats may represent a problematic issue, since they may be at risk of diseases, traffic accidents and ingestion of toxins. Yet, the impact of this population of roaming dogs and cats predating wildlife is another concerning issue that receives less attention. Despite these risks, most owners still prefer to give outdoor access to their pets to allow them to express their “natural instincts,” such as hunting. Therefore, with a growing population of > 470 million dogs and 373 million cats worldwide, predation not only represents a threat to wildlife, but also a door of transmission for parasitic diseases, some of them of zoonotic concern. In this review, the role played by dogs, and especially cats, in the perpetuation of the biological life cycle of zoonotic parasites through the predation of rodents, reptiles and birds is discussed. Feral and domestics dogs and cats have contributed to the population collapse or extinction of > 63 species of reptiles, mammals and birds. Although the ecological impact of predation on wild populations is well documented, the zoonotic risk of transmission of parasitic diseases has not received significant attention. The parasitic diseases associated to predation vary from protozoan agents, such as toxoplasmosis, to cestodes like sparganosis and even nematodes such as toxocariasis. Raising awareness about predation as a risk of zoonotic parasitic infections in dogs and cats will aid to create responsible ownership and proper actions for controlling feral and free-roaming cat and dog populations worldwide. GRAPHICAL ABSTRACT: [Image: see text
Oestridae Causing Myiasis
No full textDue to their habit of feeding on live tissues, larvae of the family Oestridae are known as causative agents of obligatory myases of many animal species, including humans. This group of flies includes a large number of species, about 150, ranked in four sub-families which cause internal organ myases with formation of subcutaneous warbles (Hypodermatinae) or infestations in the digestive tract (Gasterophilinae), nasal or pharyngeal cavities (Oestrinae) or dermis (Cuterebrinae). Oestrids evolved a high degree of host specificity with complex biological life cycles and strict interaction with the host immune system. Oestrids may impair livestock productions through adult fly disturbance of grazing animals (e.g. reduction in weight gain and milk production), or larval direct damage in infested organs (e.g. ulcers in the mouth and nasal cavities or in the digestive tract), allergic reactions and even death of animals in severe cases. Humans may be occasionally infested with skin, ocular and internal organs myases. For some myiases, such as cattle hypodermoses, migrating larvae elicit both cellular and antibody responsiveness in the host and early serological detection of specific antibodies have allowed the validation of diagnostic tools supporting the decision of treating infested animals. Consequently, the systemic use of macrocyclic lactones has greatly reduced the overall burden of these myases, though they still remain a problem in livestock in many parts of the world. In this chapter, we summarize the epidemiology, life cycle, the medical and veterinary importance as well as the control of the main species belonging to the family Oestridae
Thelazia callipaeda
No full textThelazia callipaeda is a nematode living on the surface of the eyes of domestic and wild carnivores and lagomorphs, being transmitted by zoophilic drosophilids belonging to the genus Phortica. It also infects humans, mainly children and the elderly in poor economic settings. For a long time it has been referred to as the oriental eyeworm for its distribution in many areas of southeast Asia (i.e., from China to Indonesia) and India. Since the early 1990s it has also been reported in Europe, arising in some spots in Italy. In the last 30 years this parasite has been detected throughout Europe in almost all countries as well as in the Balkans. T. callipaeda may cause from mild clinical signs (e.g., lachrymation, conjunctivitis, and keratitis) to corneal ulcers and even blindness, depending on the parasite burden and individual susceptibility. Control strategies are focussed on topical or systemic anthelmintic treatments, whereas the use of repellents seems to be ineffective against the vectors.Not availabl
Acarofauna of Neotropical reptiles: Integrative morphology and vector competence of zoonotic pathogens
No full textThe Neotropical region stands out as a megadiverse area in terms of herpetofauna, hosting more than 4457 species, 2233 of which are distributed across South America. Reptiles are recognized as amplifiers and reservoirs of several pathogens, yet their role in disease cycles and the vectorial potential of their mites and ticks remain poorly understood. These hosts are infested by over 500 species of mites and ticks, classified into 61 genera across 13 families within the orders Trombidiformes (Acariformes), Mesostigmata, and Ixodida (Parasitiformes). Some of these arthropods may serve as vectors of reptile vector-borne diseases (RVBDs), that include bacterial, viral and protozoal pathogens of zoonotic concern. In this article, we explore the main groups of mites and ticks that infest reptiles in the Neotropical region, with a particular focus on vector-borne zoonotic pathogens of reptiles. In addition, we discuss the intricate relationships between these animals, arthropod vectors, and the zoonotic pathogens they may transmit
Adolescent Scalp Dermatitis Associated with Dermatophagoides spp. (Acariformes; Pyroglyphidae) Mite
No full textPurpose Dermatophagoides spp. (Acariformes; Pyroglyphidae), house dust-mite well known as the causative agent of atopic hypersensitivity and allergy could potentially cause severe dermatitis. Herein we report an uncommon case of scalp dermatitis associated with the presence of Dermatophagoides spp.Methods A 17-year old male presented with patchy alopecia on the scalp without intense peeling or itching, surround by unchanged skin and hair. Initially, superficial fungal infection was suspected; however, parasitological examination revealed the presence of live mites.Results All the anatomical measurements and parameters from the specimens were compatible with Dermatophagoides spp.Conclusions Dermatophagoides spp. are not yet confirmed as causative agents of parasitic infestation, but the presence of these mites could have caused an allergic reaction followed by dermatitis with mild-to-moderate clinical manifestations. However, true parasitism as well as phoresy could also be considered. The clinical manifestations caused by house-dust mite cannot be easily recognized and the lack of diagnostic tools is a hindrance that often leads to misdiagnosis and inadequate therapy
Invasive mammalian wildlife and the risk of zoonotic parasites
No full textInvasive wild mammals are present in all continents, with Europe, North America, and the Asian-Pacific region having the largest number of established species. In particular, Europe has been the continent with the highest number of zoonotic parasites associated with invasive wild mammals. These invasive species may represent a major threat for the conservation of native ecosystems and may enter in the transmission cycle of native parasites, or act as spreaders of exotic parasites. Here, we review the role of invasive wild mammals as spreaders of zoonotic parasites, presenting important examples from Europe, America, and the Asia-Pacific region. Finally, we emphasize the need for more research on these mammals and their parasites, especially in areas where their monitoring is scantily performed
Detection and isolation of Leishmania infantum and Leishmania tarentolae in sand flies from a canine leishmaniasis endemic area
No full textSand flies are blood feeding insects known as vectors of Leishmania spp. worldwide, with Leishmania infantum being the most relevant species in Southern Europe. The sympatric occurrence of L. infantum, which causes canine leishmaniasis (CanL), along with the reptile-associated Leishmania tarentolae, triggered the interest to investigate their transmission dynamics in sand fly vectors. Sand flies were collected over two consecutive years (2023–2024) in a CanL endemic area using CDC light traps and were morphologically identified. Female specimens were either screened for Leishmania spp. DNA by quantitative PCR (qPCR) or dissected alive for microscopic detection of flagellates. A total of 3477 sand flies (2076 males and 1401 females) were collected, and the most prevalent species were Sergentomyia minuta (n = 2379) and Phlebotomus perniciosus (n = 1020), followed by Phlebotomus neglectus (n = 44), Phlebotomus perfiliewi (n = 12), andPhlebotomus papatasi (n = 2). Promastigotes were observed microscopically in 13 S. minuta and one P. perniciosus, with L. infantum isolated from the latter. The qPCR analysis revealed that 50.0 % (n = 55/110) and 1.8 % (n = 2/110) of the S. minuta pools scored positive for L. tarentolae and L. infantum, respectively, whereas 25.0 % (n = 3/12) of P. perniciosus pools were positive for L. infantum. Among the individually tested engorged female sand flies, L. tarentolae and L. infantum were amplified from 35.8 % (n = 24/67) and 3.0 % (n = 2/67) of S. minuta, respectively, while 15.5 % (n = 9/58) of the Phlebotomus spp. (i.e., eight P. perniciosus and one Phlebotomus sp.) were positive for L. infantum. These findings confirm the co-circulation of L. infantum and L. tarentolae in sand flies, with a notably high detection rate of trypanosomatids in S. minuta through molecular and microscopic methods
Clinical, haematological and biochemical findings in tigers infected by Leishmania infantum
No full textBackground
A large number of animal species are susceptible to Leishmania infantum (Kinetoplastida, Trypanosomatidae) in endemic areas, including domestic and wild felids such as tigers (Panthera tigris). Knowledge on the infection of this endangered species is still at its infancy, and therefore this study aims to identify clinical presentation and clinicopathological findings of tigers naturally infected by L. infantum.
Results
Tigers either L. infantum-positive (group A) or -negative (group B) were apparently healthy or presented visceral leishmaniasis unrelated conditions, except for one animal in which a large non-healing cutaneous lesion was observed. However, histological exam and immunohistochemistry carried out on the lesion excluded the presence of L. infantum amastigotes. Biochemical analysis showed that the average concentration of total proteins, globulins and haptoglobin were significantly higher (p < 0.01, p = 0.01 and p = 0.02, respectively), while the albumin/globulin ratio significantly lower (p = 0.05) in group A compared with group B. The biochemical alterations were partially confirmed by the serum protein electrophoresis results revealing a significant increase in the total protein value (p = 0.01) and hypergammaglobulinemia (p = 0.03) but an unmodified albumin/globulin ratio in group A.
Conclusions
In this study tigers infected by L. infantum have shown to be mainly asymptomatic. The absence of clinical signs may lead veterinarians to overlook leishmaniasis in animals kept in captivity. Therefore, diagnostic and screening tests as serology should be part of routinely surveillance programs to be performed on tigers in zoological gardens located in endemic areas. Though only few protein-related laboratory abnormalities were recorded in infected animals, they could provide diagnostic clues for a first suspicion of L. infantum infection in tigers. Indeed, considering the high risk of zoonotic transmission in heavily frequented environment as zoos, a prompt diagnosis of L. infantum infection is of pivotal importance
Experimental feeding of Sergentomyia minuta on reptiles and mammals: comparison with Phlebotomus papatasi
No full textBackground: Sergentomyia minuta (Diptera: Phlebotominae) is an abundant sand fly species in the Mediterranean basin and a proven vector of reptile parasite Leishmania (Sauroleishmania) tarentolae. Although it feeds preferentially on reptiles, blood meal analyses and detection of Leishmania (Leishmania) infantum DNA in wild-caught S. minuta suggest that occasional feeding may occur on mammals, including humans. Therefore, it is currently suspected as a potential vector of human pathogens. Methods: A recently established S. minuta colony was allowed to feed on three reptile species (i.e. lizard Podarcis siculus and geckos Tarentola mauritanica and Hemidactylus turcicus) and three mammal species (i.e. mouse, rabbit and human). Sand fly mortality and fecundity were studied in blood-fed females, and the results were compared with Phlebotomus papatasi, vector of Leishmania (L.) major. Blood meal volumes were measured by haemoglobinometry. Results: Sergentomyia minuta fed readily on three reptile species tested, neglected the mouse and the rabbit but took a blood meal on human. However, the percentage of females engorged on human volunteer was low in cage (3%) and feeding on human blood resulted in extended defecation times, higher post-feeding mortality and lower fecundity. The average volumes of blood ingested by females fed on human and gecko were 0.97 μl and 1.02 μl, respectively. Phlebotomus papatasi females readily fed on mouse, rabbit and human volunteer; a lower percentage of females (23%) took blood meal on the T. mauritanica gecko; reptilian blood increased mortality post-feeding but did not affect P. papatasi fecundity. Conclusions: Anthropophilic behaviour of S. minuta was experimentally demonstrated; although sand fly females prefer reptiles as hosts, they were attracted to the human volunteer and took a relatively high volume of blood. Their feeding times were longer than in sand fly species regularly feeding on mammals and their physiological parameters suggest that S. minuta is not adapted well for digestion of mammalian blood. Nevertheless, the ability to bite humans highlights the necessity of further studies on S. minuta vector competence to elucidate its potential role in circulation of Leishmania and phleboviruses pathogenic to humans
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