Siphonaptera parasites of wild rodents and marsupials trapped in three mountain ranges of the Atlantic Forest in Southeastern Brazil

Flea parasitism in wild mammals in the metropolitan region of Sorocaba, São Paulo, Brazil

Fleas are eurixenous ectoparasites that can parasitize different species of warm-blooded animals, including humans, with the possibility of causing irritation and blood spoliation. They are vectors responsible for the transmission of numerous pathogens and have a wide geographical distribution, more frequently in warm regions. Domestic animals (dogs and cats) are preferred hosts, but parasitism can also occur in wild hosts, with a greater variety of parasitic species and strong interaction between these siphonapters and their hosts. During the period from January 2021 to June 2023, flea specimens were collected from wild animals coming from the metropolitan region of Sorocaba, São Paulo. Some of these animals were animals from the zoo's own stock, which were diagnosed with parasitism during routine examinations and others were rescued from the natural environment and sent to the zoo. The flea specimens collected were packed in alcohol 700 GL and sent for microscopic diagnosis. Four groups were diagnosed at the specific level: Ctenocephalides felis, Rhopalopsyllus lutzi, R. lugrubis and Tunga penetrans, and two groups as unidentified species, belonging to the genera Rhopalopsyllus and Polygenis. The parasitized animals were all mammals, belonging to eleven different species, distributed in the Orders Carnivora, Didelphimorphia, Rodentia and Cingulata. Studies on the parasitofauna of wild animals contribute to a greater knowledge about the distribution of parasitic agents and their relationships with the host species.

Specificity of fleas associated with opossums in a landscape gradient in the Paranaense Rainforest Ecoregion

The degree of host specificity of fleas varies from highly specific (monoxenous) to opportunistic (polyxenous). Specific parasite-host associations can be observed among some flea families and tribes and mammalian orders, such as fleas of the tribe Tritopsyllini (Ctenophthalmidae, Doratopsyllinae) and opossums (Didelphimorphia). Specimens of the family Didelphidae are common hosts of fleas of the genus Adoratopsylla (Ewing, 1925). In northern Argentina, Adoratopsylla (Adoratopsylla) antiquorum antiquorum (Rothschild, 1904) and Adoratopsylla (Tritopsylla) intermedia intermedia (Wagner, 1901) were recorded preferentially parasitizing opossums. In order to study parasite/host relationships, fleas were collected from opossums captured in different environments in the Paranaense Rainforest ecoregion, northern Misiones province between 2016 and 2018. A total of 287 fleas were collected from 110 opossums. The fleas were identified as Pulicidae: Ctenocephalides felis felis (Bouché, 1835); Rhopalopsyllidae: Polygenis (Polygenis) rimatus (Jordan, 1932), Polygenis (Polygenis) roberti roberti (Rothschild, 1905); Ctenophthalmidae: A. (T.) i. intermedia, A. (A.) a. antiquorum, Adoratopsylla (Adoratopsylla) antiquorum ronnai (Guimarães, 1954). We report for the first time in Argentina a male specimen of A. (A.) a. ronnai collected on Didelphis albiventris (Lund, 1840) (Didelphidae), and male and female specimens of P. (P.) r. roberti collected on Didelphis aurita (Wied-Neuwied, 1826), and we describe the expansion of the geographic and host distribution of fleas to the Paranaense Rainforest ecoregion. Our records reinforce the specific association between Adoratopsylla and Polygenis fleas and didelphid opossums, mentioned in the literature for the Atlantic Forest ecoregion in Brazil. Furthermore, we observed that flea communities in opossums change in a landscape gradient, with invasive cat fleas and euryxenous fleas common in anthropized areas, and endemic fleas common in natural areas. Our results underline the importance for public health and veterinary medicine the analysis of flea circulation between wild and urban environments due to the risk of pathogen transmission.

Tungiasis in domestic, wild, and synanthropic animals in Brazil

Tungiasis is an ectoparasitic skin disease of humans and warm-blooded animals caused by fleas of the genus Tunga (Jarocki, 1938). Dogs, cats, pigs, and synanthropic rodents are the main animal reservoirs. Of the 14 known species, 12 are found in Latin America and, among these, eight are found in Brazil, including the two zoonotic species Tunga penetrans and Tunga trimamillata. Tunga penetrans predominates among humans and Brazilian pets, where the dog is the most affected species, and its presence is a risk factor associated with the disease in humans. Tunga spp. are widely distributed throughout the national territory, with T. penetrans being the most dispersed and the most frequent in animals from endemic areas, especially in underprivileged communities. Infections in animals, associated with inadequate management, favor the spread and perpetuation of the disease. Intense injuries can result in sequelae and serious clinical conditions, compromising the health, welfare, and productivity of animals, as well as leading to death. Health precariousness, lack of control and neglect in the management of populations of domestic and synanthropic animals, poor hygiene habits of individuals, lack of information from both the population and related professionals, lack of effective treatment, and of perception of tungiasis as a disease are among the main challenges for the control of this parasitosis. As recommended for other zoonotic Neglected Tropical Diseases, strategies based on the concept of One Health can guarantee more effective results in the fight against human and animal tungiasis.

Didelphis spp. opossums and their parasites in the Americas: A One Health perspective

Medium sized opossums (Didelphis spp.) are among the most fascinating mammals of the Americas, playing important ecological roles (e.g., dispersal of seeds and control of insect populations) in the environment they inhabit. Nevertheless, as synanthropic animals, they are well adapted to human dwellings, occupying shelters within the cities, peripheral areas, and rural settings. These marsupials can harbor numerous pathogens, which may affect people, pets, and livestock. Among those, some protozoa (e.g., Leishmania infantum, Trypanosoma cruzi, Toxoplasma gondii), helminths (e.g., Ancylostoma caninum, Trichinella spiralis, Alaria marcianae, Paragonimus spp.) and arthropods (e.g., ticks, fleas) present substantial public health and veterinary importance, due to their capacity to cause disease in humans, domestic animals, and wildlife. Here, we reviewed the role played by opossums on the spreading of zoonotic parasites, vectors, and vector-borne pathogens, highlighting the risks of pathogens transmission due to the direct and indirect interaction of humans and domestic animals with Didelphis spp. in the Americas.

Detection of Bartonella sp. and a novel spotted fever group Rickettsia sp. in Neotropical fleas of wild rodents (Cricetidae) from Southern Brazil

The Neotropical region shows a great diversity of fleas, comprising more than 50 genera. The importance of the study of fleas is linked to their potential role as disease vectors. The aim of this study is to investigate the presence of Rickettsia spp. and Bartonella spp. in Neotropical fleas collected from wild rodents in Southern Brazil. From 350 rodents captured, 30 were parasitized by fleas. A total of 61 fleas belonging to two genera and six different species were collected (Craneopsylla minerva minerva, Polygenis occidentalis occidentalis, Polygenis platensis, Polygenis pradoi, Polygenis rimatus, and Polygenis roberti roberti). In 13 % of fleas of three different species (C. minerva, P. platensis, and P. pradoi) Rickettsia sp. DNA was found. Phylogenetic analysis of concatenated sequences of gltA, htrA, and ompA genes showed that Rickettsia sp. found in rodent fleas (referred as strain Taim) grouped together with Spotted Fever Group Rickettsia. In reference to Bartonella spp., five genotypes were identified in seven fleas of two species (C. minerva and P. platensis) and in five rodent spleens. Also, 207 frozen samples of wild rodents were screened for these pathogens: while none was positive for Rickettsia spp.; five rodent spleens were PCR-positive for Bartonella spp.. Herein, we show the detection of potential novel variants of Bartonella sp. and Rickettsia sp. in fleas collected of wild rodents from Southern Brazil. Further studies are needed to fully characterize these microorganisms, as well as to improve the knowledge on the potential role of Neotropical flea species as diseases vectors.

Ticks, fleas and endosymbionts in the ectoparasite fauna of the black-eared opossum Dipelphis aurita in Brazil

Ticks and fleas are essential vectors of pathogens that affect humans and animals, and among their hosts, synanthropic animals such as the black-eared opossum, Didelphis aurita, play a role in public health due to their ability to move between urban centers and forested areas in Brazil. This study aimed to assess the ectoparasite fauna of D. aurita, as well as the presence of pathogens and endosymbionts in ticks and fleas. Opossums (n = 58) captured in Tomahawk livetraps were examined for ectoparasites, and their blood sampled for further analysis. Additionally, spleen samples were collected in individuals found dead. Samples were PCR screened for Rickettsia spp., Borrelia spp., Anaplasmataceae, and Babesia spp. Two tick species were morphologically identified as Ixodes loricatus 24/58 (41.4%) and Amblyomma sculptum 1/58 (1.7%). For fleas, Ctenocephalides felis was detected in 60.3% (35/58) of the animals, and Xenopsylla cheopis in 5.2% (3/58). PCR analysis detected Anaplasmataceae DNA in 34% (16/47) of pooled samples of C. felis, and in 66.7% (2/3) pooled samples of X. cheopis. Sequence analysis revealed Wolbachia pipientis symbiont in all positive samples. Tick, blood and spleen samples were all negative for the microorganisms assessed. These findings suggest that these arthropods circulate among wildlife and urban environments, which may implicate in their participation in the cycle of zoonotic pathogens among opossums, humans and companion animals.

Fleas associated with sigmodontine rodents and marsupials from the Paranaense Forest in Northeastern Argentina

Fleas from the Paranaense Forest in northeastern Argentina are studied. Herein we provided a list of specimens identified, which includes host species and geographical distribution for each taxa, as well as some comments on the morphology, distribution and epidemiological importance when available. The following eight species and subspecies of fleas belonging to four families were identified: Ctenocephalides felis felis (Pulicidae), Craneopsylla minerva minerva (Stephanocircidae), Polygenis (Polygenis) platensis, Polygenis (Polygenis) roberti beebei, Polygenis (Neopolygenis) pradoi, Polygenis (Neopolygenis) pygaerus (Rhopalopsyllidae), Adoratopsylla (Adoratopsylla) antiquorum antiquorum, and Adoratopsylla (Tritopsylla) intermedia intermedia (Ctenophthalmidae). The results obtained increase to eleven the known diversity of fleas in the Argentinean Paranaense Forest area. Seven new flea-host associations are reported for the first time. In addition, all the species and subspecies are mentioned for the first time for the province of Misiones. Besides, the results contribute to the knowledge of mammal ectoparasites and to their biodiversity of the Province, necessary to a better understanding of their role as parasites themselves and vectors of zoonotic importance.

Multivariate discrimination among cryptic mites of the genus Androlaelaps (Acari: Mesostigmata: Laelapidae) parasitic of sympatric akodontine rodents (Cricetidae: Sigmodontinae) in northeastern Argentina: possible evidence of host switch followed by speciation, with the description of two new species

Laelapids are among the most common ectoparasites of rodents. Currently, it is under discussion whether there is a single polixenous species that parasites a variety of hosts, or whether there are cryptic species highly host specific. Herein, multivariate morphometric analyses of cryptic sympatric laelapids of the genus Androlaelaps allowed us to identify different species. These species are specific of their akodontine hosts, Akodon montensis and Thaptomys nigrita, in localities situated in northeastern Argentina. In addition, we analyzed similar laelapids associated with the akodontines Deltamys kempi and Akodon cursor. Using principle component analyses we differentiated four laelapid species, each one host specific, independent of sympatry of the hosts, and without geographical variation. From these four species, we described two new species (Androlaelaps navonae n. sp. and Androlaelaps wingei n. sp.). We determined the four species based on a range of variations in several characters, mainly size. These four laelapid species belong to the Androlaelaps rotundus species group, specific to akodontines. These species are very similar among them but differ from the remainder species of the group by their small size, distance between j6 setae similar to the distance between the z5 setae, strong ventral setae, opisthogaster with 13 pairs of strong setae (one close to the distal margin of epigynal shield), and anal shield wider than long. Further studies will elucidate whether they constitute a new laelapid genus. Phylogenetic and ecological factors influencing host-specificity are discussed, and we propose that host colonization could have taken place by host switching of a single laelapid species among rodent species, followed by speciation.

Neosomes of tungid fleas on wild and domestic animals

Tunga is the most specialized genus among the Siphonaptera because adult females penetrate into the skin of their hosts and, after mating and fertilization, undergo hypertrophy, forming an enlarged structure known as the neosome. In humans and other warm-blooded animals, neosomes cause tungiasis, which arises due to the action of opportunistic agents. Although its effects on humans and domestic animals are well described in the literature, little is known about the impact of tungiasis on wild animals. This review focuses on the morphology, taxonomy, geographical distribution, hosts, prevalence, sites of attachment, and impact of tungid neosomes on wild and domestic animals. Because neosomes are the most characteristic form of the genus Tunga and also the form most frequently found in hosts, they are here differentiated and illustrated to aid in the identification of the 13 currently known species. Perspectives for future studies regarding the possibility of discovering other sand flea species, adaptation to new hosts, and the transfer of tungids between hosts in natural and modified habitats are also presented.

A new species of Tunga (Siphonaptera: Tungidae) from Brazil with a key to the adult species and neosomes

Tunga bossii new species of tungid sand flea belonging to the caecata group is described with illustrations of the adult female, parasitizing the wild rodent Delomys dorsalis (Hensel) from Brazilian Atlantic Forest. Tunga bossii differs from the ten other known species of Tunginae by the size of the first segment of the maxillary palp and the presence of two bristles at the base of the maxilla. Tunga bossii also can be differentiated from other species of the T. caecata group by the eye morphology. A key to the adult species and neosomes of the genus Tunga also is included.

Checklist de Siphonaptera (Insecta) do Estado de São Paulo

As pulgas são insetos hematófagos na fase adulta e que atuam como agentes infestantes ou como vetores de patógenos. Seus hospedeiros são animais endotérmicos, essencialmente mamíferos e, predominantemente roedores. A sifonapterofauna do Estado de São Paulo representa 61,3% (38/62) da brasileira, sendo a mais rica quando comparada com outros estados em número de espécies ou gêneros. Algumas espécies são conhecidas apenas por um dos sexos; outras, através de pequeno número de exemplares colecionados. Quatro espécies (10,5%) são endêmicas no Estado. No Brasil, a principal coleção de pulgas está depositada no Museu de Zoologia da USP.

Siphonaptera associated with wild mammals from the Central Atlantic Forest Biodiversity Corridor in southeastern Brazil

We collected 379 samples of eight flea species from 235 specimens of wild mammals captured in three areas of the Central Atlantic Forest Corridor in the state of Espírito Santo, southeastern Brazil, between August 2006 and February 2008. Among the 22 mammal species, we found eight species of marsupials (order Didelphimorphia), 13 species of rodents (order Rodentia), and one species of wild cat (order Carnivora). The total prevalence of infestation was 28.1%, with similar percentages in rodents (26.4%) and marsupials (29.5%). The infestation in the southern area was 3 times higher than that observed in the northern area. The infestation by single flea species was > 6 times higher than the total number of double and triple infestations. The mean abundance of fleas was 1.61. The flea female/male ratio was 1.38, ranging from 0.95 in Adoratopsylla (Tritopsylla) intermedia intermedia (Wagner) to 1.81 in Hechtiella nitidus (Johnson) in the most flea species infested. We report three new records of flea species in the state of Espírito Santo, and eight new host records.

Blood parasites, total plasma protein and packed cell volume of small wild mammals trapped in three mountain ranges of the Atlantic Forest in Southeastern Brazil

A study of blood parasites in small wild non-flying mammals was undertaken in three areas of the Atlantic Forest in Southeastern Brazil: Serra de Itatiaia, RJ, Serra da Bocaina, SP and Serra da Fartura, SP, from June 1999 to May 2001. A total of 450 animals (15 species) were captured in traps and it was observed in 15.5% of the blood smears the presence of Haemobartonella sp. and Babesia sp. in red blood cells. There was no statistically significant difference between parasited and non-parasited specimens regarding total plasma protein, packed cell volume and body weight, which strongly suggests that these specimens might be parasite reservoirs.

What are the factors determining the probability of discovering a flea species (Siphonaptera)?

Our aim was to determine which of four variables (number of host species exploited by the parasite, taxonomic distinctness of these hosts, geographic range of the principal host, and year of description of this host) was the best predictor of description date of fleas. The study used previously published data on 297 flea species parasitic on 197 species of small mammals from 34 different regions of the Holarctic and one region from the Neotropics. We used both simple linear and multiple regressions to evaluate the relationships between the four predictor variables and the year of flea description, on species values as well as on phylogenetically independent contrasts. Whether or not the analyses controlled for flea phylogeny, all predictor variables correlated significantly with year of flea description when tested separately. In multiple regressions, however, the number of exploited host species was the best predictor of the date of flea description, with the geographic range of the principal host species as well as the date of its description having a lesser, though significant, influence. Overall, our results indicate that a flea species is more likely to be discovered and described early if its biological characteristics (exploitation of many host species) and those of its hosts (long-known to science, broad geographic distributions) increase its chances of being included in a collection. Because the variables we investigated only explained about 10-11% of the variation in year of description among flea species, other factors must be important, such as temporal variability in the activity of flea taxonomists.