Animals defend themselves against parasites in many ways. Defenses, such as physiological immune responses, are capable of clearing some infections. External parasites that do not feed on blood, however, are not controlled by the physiological immune system. Instead, ectoparasites like feather-feeding lice (Phthiraptera: Ischnocera) are primarily controlled by behavioral defenses such as preening. Here we test the hypothesis that birds able to preen are capable of clearing infestations of feather lice. We experimentally manipulated preening ability in a captive population of rock pigeons (Columba livia) that were infested with identical numbers of feather lice (Columbicola columbae or Campanulotes compar or both). We then monitored the feather louse infestations for 42 wk. Birds with impaired preening remained infested throughout the experiment; in contrast, the prevalence of lice on birds that could preen normally decreased by 50%. These data indicate that it is indeed possible for birds to clear themselves of feather lice, and perhaps other ectoparasites, by preening. We note, however, that captive birds spend more time preening than wild birds, and that they are less likely to be reinfested than wild birds. Thus, additional studies are necessary to determine under what circumstances wild birds can clear themselves of ectoparasites by preening.

Rajonchocotyle Cerfontaine, 1899, species are blood-feeding parasites on the gills of rajiforms. Eight species are considered valid, the most recent of which was described just after World War II. Many of the original descriptions of Rajonchocotyle species are limited in diagnostic value, and comparative museum material is scanty. The genus requires revision, and in support thereof, we provide detailed redescriptions for Rajonchocotyle alba Cerfontaine, 1899, from the type host Rostroraja alba (Lacepède, 1803) and Rajonchocotyle emarginata (Olsson, 1876), Sproston, 1946, from 2 new host records, Raja straeleni Poll, 1951, and Leucoraja wallacei (Hulley, 1970), from South Africa, a new locality record. The generic diagnosis for Rajonchocotyle is amended to include greater details of the male reproductive system and confirms Paul Cerfontaine's and Nora Sproston's historic observations of the morphology of the male copulatory organ consisting of a separate proximal seminal vesicle and a distal cirrus. The lectotype of Rajonchocotyle kenojei Yamaguti, 1938, is assigned, and a comprehensive Rajonchocotyle-host species list is provided, highlighting species records that require further verification, and the purported global host range of R. emarginata is discussed.

The monotypic genus Pneumoatractis Bursey, Reavill, and Greiner, 2009 was erected to allocate nematodes collected from the lungs of the freshwater turtle Podocnemis unifilis Troschel. During a helminthological survey of parasites from freshwater turtles of Tocantins and Xingu rivers, Pará State, eastern Amazon, Brazil, we found nematodes parasitizing the stomach and large intestine of Po. unifilis and Podocnemis expansa Schweigger. We assigned them to a new species of Pneumoatractis, which is described herein. Pneumoatractis gibbonsae n. sp. resembles Pneumoatractis podocnemis by the morphology of the oral opening, the position of the excretory pore, and the lanceolate shape of the spicules, but differs from it in males by having 10 pairs of caudal papillae plus 1 unpaired anterior to cloacal lip, different length of the right spicule, and short gubernaculum; it differs in females by the distances of vulva and anus from the posterior end respectively. We found the new species in a different infection site from that of the type species. Thus, this is the second species of Pneumoatractis described in Po. unifilis and the first in Po. expansa.

Knowledge, attitudes, and practices (KAP) surveys on malaria and antimalarial mass drug administration (MDA) have not received much attention in the Union of the Comoros. This study is a household-based cross-sectional survey using a multi-stage sampling technique aiming at investigating KAP toward malaria and antimalarial MDA with artemisinin-piperaquine among heads of households on Grande Comore Island, the largest island of the Comoros. A predefined structured questionnaire containing socio-demographic characteristics and questions about malaria and antimalarial MDA was administered to 1,368 randomly selected heads of households from 10 malaria-endemic villages on Grande Comore Island. The results showed that 81.4% of the heads of households knew that malaria is a transmissible disease, 77.6% recognized mosquitoes as the vectors of malaria, and 70.8% recognized fever as one of the frequent symptoms of malaria; 40.8% of respondents remembered the name of the antimalarial drug used for MDA, and 62.1% remembered the color of the antimalarial tablets; and 65.1% chose to go to a public health center to seek treatment as their first option within 24 hr of the onset of initial malaria symptoms. This study found that most heads of households had a reasonable level of knowledge about malaria and antimalarial MDA. However, only 7.3% obtained full points on all knowledge-related questions. Misconceptions about malaria cause, transmission, diagnostic method, and antimalarial MDA exist in the community of Grande Comore Island. As the Comoros continues to put great efforts to go toward malaria elimination, the community's KAP on malaria and antimalarial MDA is crucial to guarantee the community's long-term adherence to malaria elimination interventions and could become key to guaranteeing malarial elimination in the Comoros. Therefore, there is a great need to improve malaria prevention awareness through strengthening malaria education and promoting behavioral change. Heads of households should be the core target of malaria education and behavioral change for malaria elimination.

Cutaneous leishmaniasis is caused by infection with the protozoan parasite Leishmania, which resides intracellularly in dermal macrophages (Mø), producing lesions. The skin lesions are characterized by proinflammatory cytokines and growth factors as well as inflammatory hypoxia, creating a stressful microenvironment for Mø. Of importance, not all Mø in lesions harbor parasites. To distinguish the influence of the parasite from the inflammatory microenvironment after Leishmania major (LM) infection on the Mø, we performed single-cell RNA sequencing and compared Mø associated with LM transcripts (or ‘infected’ Mø) with Mø not associated with LM transcripts (or ‘bystander’ Mø) within the lesions. Our findings show coordinated lysosomal expression and regulation signaling with increased cathepsin and H⁺-ATPase transcripts are upregulated in infected compared with bystander Mø. Additionally, eukaryotic initiation factor 2 (EIF2) signaling is downregulated in infected compared with bystander Mø, which includes many small and large ribosomal subunit (Rps and Rpl) transcripts being decreased in Mø harboring parasites. Furthermore, we also find EIF2 signaling including EIF, Rps, and Rpl transcripts being downregulated in bystander Mø compared with Mø from naïve skin. These data suggest that both the parasite and the inflammatory host microenvironment affect the transcription of ribosomal machinery in lesional Mø, thereby potentially affecting the ability of these cells to perform translation, protein synthesis, and thus function. Altogether, these results suggest that both the parasite and host inflammatory microenvironment independently drive transcriptional remodeling in Mø during LM infection in vivo.

A new species of Henneguya Thélohan, 1892 (Bivalvulida: Myxobolidae) is described from the submucosa of the intestine and pyloric ceca of red drum (Sciaenops ocellatus [Linnaeus, 1766] [Perciformes: Sciaenidae]) from the Gulf of Mexico off Gulf Shores, Alabama. Henneguya albomaculata n. sp. differs from all congeners by the combination of myxospore dimensions, polar tubule coil count, the presence of an iodinophilic vacuole in the sporoplasm, and small-subunit ribosomal deoxyribonucleic acid (SSU rDNA) sequence. A phylogenetic analysis of the SSU rDNA recovered H. albomaculata sister to Henneguya cynosioni Dykova, de Buron, Roumillat, and Fiala, 2011 in a clade composed of 11 species of Henneguya and 1 species of Myxobolus Bütschli, 1882 (Bivalvulida: Myxobolidae) that collectively infect fishes in marine or estuarine systems. Histologic sections of infected intestine and pyloric ceca revealed plasmodia of H. albomaculata n. sp. developing in the loose connective tissue of the submucosa. The new species comprises the second species of Henneguya reported from red drum.

Toxoplasma gondii is an important protozoan parasite of humans and animals throughout the world. Black bears are among the animals with the highest seroprevalence of T. gondii in the United States. A rapid point of care (POC) test is commercially available to detect antibodies to T. gondii in humans. We evaluated the utility of the POC test to detect anti–T. gondii antibodies in 100 wild black bears from North Carolina (n = 50) and Pennsylvania (n = 50). In a blind study, sera were tested by the POC test, and results were compared to the modified agglutination test (MAT). Overall, anti–T. gondii antibodies were detected in 76% (76/100) black bears by both MAT and POC tests. One false positive and one false negative result in the POC test were obtained in bears from Pennsylvania. The sensitivity and specificity of the POC test were both 99% when compared to the MAT. Results from our study indicate the POC test could be a useful screening tool for serological surveillance of T. gondii in black bears.

The prevalence of infection with canine heartworm (CHW), Dirofilaria immitis, continues to increase across the United States, regardless of the availability of effective and affordable prophylactic products. Current reports of CHW prevalence as estimated by the Companion Animal Parasite Council (CAPC) are thought to under-represent the true magnitude of the issue because pet dogs that do not receive regular veterinary care are often excluded. This study estimated the prevalence of CHW in pet dogs and associated prophylaxis use in pet dogs in the Cumberland Gap Region with a combined doorstep diagnostic testing approach and caretaker survey. Dogs tested (n ¼ 258) during the summers of 2018 and 2019 revealed a 2.3% (6/258) prevalence in the pet dog population with 33% (2/6) being microfilaremic. Questionnaire data from caretaker interviews revealed that 41.8% (108/258) of the dogs were not receiving CHW prophylaxis. Significant predictors of CHW prophylaxis use identified through logistic regression included pet caretaker awareness of CHW as an important health issue and the use of veterinary services in the year preceding participation in the survey. These results underscore the importance of veterinary-mediated client interaction to create risk awareness of CHW disease and association with prophylaxis compliance.

The parasites infecting invasive carps in North America (all Cypriniformes: Xenocyprididae: grass carp, Ctenopharyngodon idella [Valenciennes, 1844]; silver carp, Hypophthalmichthys molitrix [Valenciennes, 1844]; bighead carp, Hypophthalmichthys nobilis [Richardson, 1845]; and black carp, Mylopharyngodon piceus [Richardson, 1846]) are little studied, and no parasite has been reported from silver carp there. We herein surveyed silver carp from Barkley Reservoir and Cheatham Reservoir (Cumberland River, Tennessee; June and December 2021) and the White River (Arkansas; May 2022) and collected numerous monogenoid specimens infecting the pores on the outer face of the gill raker plate. We heat-killed, formalin-fixed, and routinely stained some specimens for morphology and preserved others in 95% ethanol for DNA extraction and sequencing of the large subunit ribosomal DNA (28S). We identified our specimens as Dactylogyrus cf. skrjabini because they had a dorsal anchor deep root that is much longer than the superficial root, an approximately parallel penis and accessory piece, and a relatively large marginal hook pair V. No type specimen of Dactylogyrus skrjabini Akhmerov, 1954 (type host and locality is silver carp, Amur River, Russia) is publicly available, but we borrowed several vouchers (NSMT-Pl 6393) that infected the gill rakers of silver carp captured in the Watarase River, Japan. The original description of D. skrjabini was highly stylized and diagrammatical, differing from the specimens we studied from North America and Japan by the dorsal anchor having a superficial root and shaft that comprise a strongly C-shaped hook (the superficial root curves toward the dorsal anchor point) (vs. superficial root straight, at ∼45° angle to deep root and directed away from the dorsal anchor point), a single, much reduced transverse bar that is narrow for its entire breadth (vs. dorsal and ventral transverse bars robust and broad, having an irregular outline), an accessory piece that lacks digitiform projections (vs. accessory piece with 4 digitiform projections), and an accessory piece that lacks a half cardioid-shaped process (vs. accessory piece having a half cardioid-shaped process). Our 28S sequences (generated from 4 specimens of D. cf. skrjabini: 2 from Tennessee [763 base pairs (bp)] and 2 from Arkansas [776 bp]) were identical to 1 ascribed to D. skrjabini from Japan. The present study is the first verifiable and credible report of a parasite from silver carp in North America and the first nucleotide information for a parasite from silver carp in North America.

Grassland birds have been declining substantially for the past several years. Habitat loss, degradation, and fragmentation as well as climate change are all thought to be the main drivers of the decline. However, as the declines continue to accelerate, it is becoming imperative to examine other factors that may contribute to population fluctuations. The nematodes Oxyspirura petrowi, Aulonocephalus pennula, and Physaloptera sp. are commonly found infecting northern bobwhite (Colinus virginianus), a game species of economic importance, and all 3 nematodes use insects as an intermediate host. Here we used polymerase chain reaction techniques to determine the occurrence of the 3 nematodes in 7 insect orders to uncover epidemiological patterns of the greatest potential for transmission to northern bobwhite. Insects were collected from March through September using sweep nets and pitfall traps. An R × C chi-squared test with Monte Carlo simulation was used to determine differences in the occurrence of the parasites across taxa and time. The results of the statistical analysis showed the nematodes are predominantly found in the order Orthoptera, and A. pennula and Physaloptera sp. showed epidemiological patterns in insects. However, no such pattern was observed with O. petrowi. An explanation for the lack of epidemiological pattern in O. petrowi is proposed and the diversity of known insect hosts of the 3 nematodes is increased.

Ixodid ticks are hematophagous obligatory ectoparasites that occur worldwide and transmit pathogens to humans and other vertebrates, causing economic livestock losses. The Arabian camel (Camelus dromedarius Linnaeus, 1758) is an important livestock animal in Saudi Arabia that is vulnerable to parasitism by ticks. The diversity and intensity of ticks on Arabian camels in certain localities in the Medina and Qassim regions of Saudi Arabia were determined. One hundred forty camels were examined for ticks, and 106 were infested (98 females, 8 males). A total of 452 ixodid ticks (267 males, 185 females) were collected from the infested Arabian camels. The tick infestation prevalence was 83.1% and 36.4% in female and male camels, respectively (female camels harbored significantly more ticks than did male camels). The recorded tick species were Hyalomma dromedarii Koch, 1844 (84.5%); Hyalomma truncatum Koch, 1844 (11.1%); Hyalomma impeltatum Schulze and Schlottke, 1929 (4.2%); and Hyalomma scupense Schulze, 1919 (0.22%). Hyalomma dromedarii was the predominant tick species in most regions, with a mean intensity of 2.15 ± 0.29 ticks/camel (2.5 ± 0.53 male ticks/camel, 1.8 ± 0.21 female ticks/camel). The proportion of male ticks was higher than that of female ticks (59.1 vs. 40.9%). To the best of our knowledge, this is the first survey of ixodid ticks on Arabian camels in Medina and Qassim, Saudi Arabia.

The identity of a larval bucephalid infecting the eastern oyster, Crassostrea virginica (Gmelin, 1791), from a tidal river in Virginia is investigated using ribosomal deoxyribonucleic acid (rDNA). The internal transcribed spacer (ITS1, 5.8S, ITS2) region and a portion of the 28S rDNA were isolated from genomic DNA from sporocysts containing cercariae and compared with sequences from GenBank and from our previous collections of possibly related bucephalids. The studied larval bucephalid was 100% identical at the ITS1, 5.8S, and partial 28S rDNA sequences with Prosorhynchoides paralichthydis (Corkum, 1961) Curran and Overstreet, 2009; however, it differed from P. paralichthydis by 6 bases plus 3 deletions in the ITS2 region. This level of variation at the ITS2 region has been demonstrated among some Indo-Pacific species of Prosorhynchoides Dollfus, 1929, suggesting that the larval bucephalid represents an unidentified or innominate species of Prosorhynchoides that is closely related to P. paralichthydis.