The role of chewing lice (Phthiraptera: Philopteridae) as intermediate hosts in the transmission of Hymenolepis microps (Cestoda: Cyclophyllidea) from the willow ptarmigan Lagopus lagopus (Aves: Tetraonidae).

The cestode Hymenolepis microps is an intestinal parasite of tetraonid birds, including the willow ptarmigan (Lagopus lagopus). This parasite is able to maintain a high prevalence and intensity throughout the year, even in a subarctic environment in bird populations with relatively low host densities, indicating effective transmission routes. Willow ptarmigan consume mainly vegetal material and active consumption of invertebrates is confined to the first two or three weeks of life. Ptarmigan are infected by different species of ectoparasites, of which two species of feather lice, Lagopoecus affinis and Goniodes lagopi, are the most abundant. In this study, we explored the hypothesis that feather lice may be suitable intermediate hosts for H. microps. We applied histological techniques and light microscopy to investigate lice for the presence of larval cestode stages (cysticercoids). We found 12 cysticercoid-like structures inside chewing lice collected on L. lagopus hosts harbouring H. microps. In addition, a polymerase chain reaction (PCR) screening of Ischnocera lice DNA, targeting the 18S rRNA gene of the cestode, showed positive results for two different short fragments of the 18S rRNA gene of H. microps which were sequenced from lice collected on birds. Both independent lines of evidence support the hypothesis that Ischnocera lice might be suitable intermediate hosts in the life cycle of H. microps in L. lagopus.

Detection of Leishmania infantum in animals and their ectoparasites by conventional PCR and real time PCR.

Visceral leishmaniosis (VL) is a parasitic disease caused by Leishmania infantum, which is primarily transmitted by phlebotomine sandflies. However, there has been much speculation on the role of other arthropods in the transmission of VL. Thus, the aim of this study was to assess the presence of L. infantum in cats, dogs and their ectoparasites in a VL-endemic area in northeastern Brazil. DNA was extracted from blood samples and ectoparasites, tested by conventional PCR (cPCR) and quantitative real time PCR (qPCR) targeting the L. infantum kinetoplast DNA. A total of 280 blood samples (from five cats and 275 dogs) and 117 ectoparasites from dogs were collected. Animals were apparently healthy and not previously tested by serological or molecular diagnostic methods. Overall, 213 (76.1 %) animals and 51 (43.6 %) ectoparasites were positive to L. infantum, with mean parasite loads of 795.2, 31.9 and 9.1 fg in dogs, cats and ectoparasites, respectively. Concerning the positivity between dogs and their ectoparasites, 32 (15.3 %) positive dogs were parasitized by positive ectoparasites. The overall concordance between the PCR protocols used was 59.2 %, with qPCR being more efficient than cPCR; 34.1 % of all positive samples were exclusively positive by qPCR. The high number of positive animals and ectoparasites also indicates that they could serve as sentinels or indicators of the circulation of L. infantum in risk areas.

Origin of clothing lice indicates early clothing use by anatomically modern humans in Africa.

Clothing use is an important modern behavior that contributed to the successful expansion of humans into higher latitudes and cold climates. Previous research suggests that clothing use originated anywhere between 40,000 and 3 Ma, though there is little direct archaeological, fossil, or genetic evidence to support more specific estimates. Since clothing lice evolved from head louse ancestors once humans adopted clothing, dating the emergence of clothing lice may provide more specific estimates of the origin of clothing use. Here, we use a Bayesian coalescent modeling approach to estimate that clothing lice diverged from head louse ancestors at least by 83,000 and possibly as early as 170,000 years ago. Our analysis suggests that the use of clothing likely originated with anatomically modern humans in Africa and reinforces a broad trend of modern human developments in Africa during the Middle to Late Pleistocene.

Forest edges affect ectoparasite infestation patterns of small mammalian hosts in fragmented forests in Madagascar.

Habitat loss and fragmentation drive the worldwide depletion of biodiversity. Although it is known that anthropogenic disturbances severely affect host and ecosystem integrity, effects on parasites are largely understudied. This study aims to investigate if and how habitat fragmentation affects the composition of ectoparasite communities on small mammalian hosts in two networks of dry deciduous forest fragments in northwestern Madagascar. Forest sites differing in size, proportion of edge habitat and host density were studied in the Ankarafantsika National Park and in the Mariarano region. A total of 924 individuals of two mouse lemur species, Microcebus murinus (n = 200) and Microcebus ravelobensis (n = 426), and two rodent species, endemic Eliurus myoxinus (n = 114) and introduced Rattus rattus (n = 184), were captured to assess ectoparasite infestations. Ectoparasite prevalence and ectoparasite species richness were statistically related to nine ecological variables applying generalized linear mixed models. Hosts harbored ticks (Haemaphysalis microcebi), mites (Schoutedenichia microcebi, Listrophoroides spp., Laelaptidae gen. spp.) and sucking lice (Lemurpediculus spp., Polyplax sp., Hoplopleuridae gen. sp.). Parasite prevalence differed significantly between host species for all detected parasite taxa. Proximity to the forest edge led to a significant reduction in ectoparasites. Parasite-specific edge effects were observed up to a distance of 750 m from the forest edge. The obtained results imply that habitat fragmentation impacts ectoparasite communities, in particular by negatively affecting temporary parasite species. The results are best explained by an interplay of parasite life cycles, responses to changes in abiotic factors induced by edges and host-specific responses to habitat fragmentation. The negative responses of most studied ectoparasite taxa to forest edges and habitat fragmentation demonstrate their ecological vulnerability that may eventually threaten the integrity of ecosystems and potentially impact ectoparasite biodiversity worldwide.

A mallophaga, Trinoton anserinum, as a cyclodevelopmental vector for a heartworm parasite of waterfowl.

The biting louse Trinoton anserinum serves as the intermediate host in the life cycle of the filarial heartworm, Sarconema eurycerca. Microfilariae, second-, and third-stage larvae were dissected from 39 of 89 lice infesting whistling swans, Cygnus columbianus columbianus, in North America and mute swans, Cygnus olor, in the Black Sea, U.S.S.R. Infective third-stage larvae obtained from lice collected from heartworm-parasitized whistling swans were injected subcutaneously into each of two hand-reared, nonparasitized mute swan cygnets. Both of these birds developed heartworm infections, one becoming microfilaremic at 14 weeks. The results of this study provide conclusive evidence that a mallophagan serves as a natural cyclodevelopmental vector of a filarial parasite.

How do seasonality and host traits influence the distribution patterns of parasites on juveniles and adults of Columba livia?

Parasites may influence host fitness and consequently exert a selective pressure on distinct phenotypes of the host population. This pressure can result in an evolutionary response, maintaining only individuals with certain traits in the population. The present study was aimed at identifying the morphological characteristics of juveniles and adults of Columba livia that may influence the distribution patterns of lice, Pseudolynchia canariensis and Haemoproteus columbae and how the populations of these parasites vary throughout the seasons of the year. Between July 2012 and July 2014, 377 specimens of C. livia were captured. We observed a significant increase in the mean intensities of infestation by pigeon flies and lice, as well as in species richness of ectoparasites during the warmest seasons, suggesting a reproductive synchrony between ectoparasites and host species. Bill length, body mass, and body length did not affect the infestation levels of ectoparasites on adults and juveniles of C. livia with three distinct plumage colors. In juveniles, plumage color affected only the mean intensity of infestation by lice, with Spread individuals as the most infested. This indicates that melanin in feathers was not an effective barrier against ectoparasites.

Comparative ultrastructural study of the cuticle of larvae and adults of Centrorhynchus milvus Ward, 1956 (Acanthocephala, Centrorhynchidae).

The cuticle of Centrorhynchus milvus acanthella and cystacanth larvae, obtained from the terrestrial crustacean Porcellionides pruinosus, is roughly 0.2 micron thick. The cuticle of juveniles encysted in toads, paratenic hosts, measures up to 0.5 micron whereas that of adults may exceed 2 microns in thickness. In all cases it is perforated by numerous pores that communicate with the hypoderm. During larval development, the numerous endocytotic vacuoles observed in acanthella 3, 4, and 5 and cystacanths became elongated canals in juveniles and adults. There is no significant ultrastructural modification in the cuticle. In the larvae, on the other hand, there was progressive thickening of the cyst wall.

Blood-sucking lice may disseminate Trypanosoma cruzi infection in baboons.

Trypanosoma cruzi (Schyzotrypanum, Chagas, 1909), and Chagas disease are endemic in captive-reared baboons at the Southwest Foundation for Biomedical Research, San Antonio, Texas. We obtained PCR amplification products from DNA extracted from sucking lice collected from the hair and skin of T. cruzi-infected baboons, with specific nested sets of primers for the protozoan kinetoplast DNA, and nuclear DNA. These products were hybridized to their complementary internal sequences. Selected sequences were cloned and sequencing established the presence of T. cruzi nuclear DNA, and minicircle kDNA. Competitive PCR with a kDNA set of primers determined the quantity of approximately 23.9 +/- 18.2 T. cruzi per louse. This finding suggests that the louse may be a vector incidentally contributing to the dissemination of T. cruzi infection in the baboon colony.

[Case of the transmission of the rat trypanosome by lice]. / Sluchai peredachi krysinoi tripanosomy vshami.

Data are given on the laboratory spontaneous occurrence of trypanosomiasis in young rats. It was demonstrated that the louse Polyplax spinulosa is the main mechanical vector of Trypanosoma lewisi. Unlike the case of the real host, the flea, the trypanosomes do not undergo the whole developmental cycle in the louse.

[Ectoparasites of small mammals in the eastern portion of the Baikal-Amure mainline]. / Ektoparazity melkikh mlekopitaiushchikh vostochnoi chasti BAMa.

11.501 ectoparasites of 45 species were collected from small mammals (rodents, shrews and double-toothed rodents) in the north-eastern part of Priamurje. The parasitecoenoses are formed in general by gamasid mites (60.4%) and lice(24.7%) but faunistically fleas (19 species or 42.2%) are dominant. Among all ectoparasites the gamasid mites, Laelaps clethrionomydis and Hirstionyssus isabellinus, and the louse Hoplopleura acanthopus account for 64.9%. The impoverishment of the arthropod fauna in the northern part of Priamurje as compared to southern ones proceeds at the expence of chigger mites and more thermophilous species of gamasids and ixodids. With cultivation of forests the content of members of parasitecoenoses becomes more homogenous and their abundance falls.

[Ectoparasites of small mammals, their nests and of the nests of birds in the floodplain of the Kamchatka River]. / Ektoparazity melkikh mlekopitaiushchikh, ikh gnezd i gnezd ptits v poime reki Kamchatki.

The paper presents data on the specific composition and abundance of bloodsucking arthropods parasitic on small mammals and birds in the valley of the Kamchatka river. One species of ixodids, I. lividus, 9 species of gamasids, P. crassipes, E. kraepelini, G. bispinosus, V. bujakova, H. casalis, H. mandschuricus, M. decoloratus, P. bujakovae, Macroheles sp., and one species of fleas, C. riparius, were first recorded from Kamchatka. 723 rodents were bacteriologically examined for tularemia with negative results.

Detection and quantification of Leishmania braziliensis in ectoparasites from dogs.

American cutaneous leishmaniasis (ACL) is a disease caused by different species of Leishmania protozoa, Leishmania braziliensis being the main species found in Brazil. In this study, two rural areas in Pernambuco, northeastern Brazil, where ACL is endemic, were selected. Genomic DNA was extracted from canine ectoparasites (ticks, fleas, and lice) and tested using a conventional PCR and a quantitative real time PCR. A total of 117 ectoparasites were collected, being 50 (42.74%) of them positive for L. braziliensis (in at least one PCR protocol), with a mean parasite load of 14.14 fg/µL. Furthermore, 46 (92.00%) positive ectoparasites were collected from positive dogs and 4 (8.00%) from negative ones. This study reports the detection of L. braziliensis DNA in ectoparasites, but does not prove their vector competence. Certainly, experimental transmission studies are necessary to assess their role, if any, in the transmission of Leishmania parasites to dogs.

Ectoparasites of dogs in home environments on the Caribbean slope of Costa Rica / Ectoparasitos de cães no ambiente doméstico da vertente Caribe, Costa Rica

Reports on ectoparasites on dogs in Central America are scarce. The aim of this study was to identify flea, louse and tick species infesting dogs in home environments on the Caribbean slope of Costa Rica, and determine their frequency and coexistence. Ectoparasites were collected from dogs in 83 rural homes at five study sites. Specimens were identified and separated according to species. Fleas were the most common ectoparasite (G = 22,217, DF = 8, p = 0.004). Ctenocephalides felis and Pulex simulans were found in 83% and 55% of the homes with ectoparasites, respectively. Trichodectes canis (13%), Heterodoxus spiniger (10%), Rhipicephalus sanguineus (18%), Rhipicephalus (Boophilus) microplus (5%) and Amblyomma ovale (8%) were also present. More than one species was collected in most cases (66%), and the most common combination was C. felis and P. simulans (59% of homes with fleas). The high frequency of P. simulans emphasizes the need for adequate identification. This was the first study involving different ectoparasites of dogs in Costa Rica, as well as the first report of T. canis in this country. The relative frequency and coexistence of these ectoparasites in the home environment may have implications for animal and human health.

Relatos de ectoparasitos em cães da América Central são escassos. O objetivo deste estudo foi identificar espécies de pulgas, piolhos e carrapatos que infestam os cães no ambiente doméstico da vertente Caribe da Costa Rica, determinando sua frequência e coexistência. Foram coletados ectoparasitos de cães em 83 casas rurais de cinco sítios do estudo. Os indivíduos foram separados e identificados. Os ectoparasitos mais comuns foram as pulgas (G = 22.217, DF = 8, p = 0.004). Ctenocephalides felis e Pulex simulans foram observados em 83% e 55% das moradias com ectoparasitos, respectivamente. Da mesma forma também foram observados Trichodectes canis (13%), Heterodoxus spiniger (10%), Rhipicephalus sanguineus (18%), Rhipicephalus (Boophilus) microplus (5%) e Amblyomma ovale (8%). Na maioria dos casos, mais de uma espécie foi achada (66%), sendo que a combinação mais comum foi C. felis e P. simulans (59% de moradias com pulgas). A frequência alta de P. simulans ressalta a necessidade de sua adequada identificação. Este é o primeiro estudo que envolve diferentes ectoparasitas de cães na Costa Rica, da mesma forma, é o primeiro relato de T. canis no país. A frequência relativa e coexistência destes ectoparasitos no ambiente domiciliar poderiam ter implicações na saúde animal e humana.