Climate change will affect host–parasite dynamics in complex ways. The development of forecast models is necessary for proactive disease management, but past studies have frequently reported thermal performance data in idiosyncratic ways that have limited use for parameterizing thermal host–parasite models. Development of improved forecast models will require strong collaborations between experimental parasitologists and disease modelers. The purpose of this article is to facilitate such collaborations by reviewing practical considerations for describing thermal performance curves of parasite and host performance traits, and using them to predict climate change impacts on host–parasite systems. In the first section, we provide an overview of how thermal performance curves can be embedded in life-cycle–based dynamical models of parasitism, and we outline how such models can capture the net effect of multiple nonlinear temperature dependencies affecting the host–parasite dynamics. We also discuss how macroecological generalities based on the metabolic theory of ecology (MTE) can be used to determine a priori parameter estimates for thermal performance curves to derive null models for data-deficient species, but we note that most of the generalities suggested by MTE remain to be tested for parasites. In the second section, we discuss empirical knowledge gaps for the temperature dependence of parasite and host performance traits, and we outline the types of data that need to be collected to inform MTE-based models for data-deficient species. We specifically emphasize the importance of (1) capturing the entire thermal response of performance traits, including lower and upper temperature thresholds, and (2) experimentally or statistically separating out the thermal responses of different performance traits (e.g., development and mortality) rather than only reporting composite measures (e.g., apparent development). Not adhering to these principles can lead to biased climate change impact predictions. In the third section, we provide a practical guide outlining how experimentalists can contribute to fill data gaps by measuring the temperature dependence of host and parasite performance traits in ways that are systematic, statistically rigorous, and consistent with the requirements of life cycle–based host–parasite models. This guide includes recommendations and practical examples illustrating (1) the use of perturbation analyses to determine experimental priorities, (2) experimental design tips for quantifying thermal response curves, and (3) statistical methods for estimating the parameters of thermal performance curves. Our hope is that this article helps researchers to maximize the value and use of future data collections for both empirical and modelling studies investigating the way in which temperature influences parasitism.

The edible land snail Cornu aspersum (Pulmonata: Stylommatophora) acts as a second intermediate host in the terrestrial life cycle of Brachylaima spp. trematodes, harboring unencysted metacercariae in its kidney. The ingestion of undercooked infected snails by humans may allow metacercariae to potentially develop to adult stage in the intestine, causing brachylaimiasis, as already seen in Australia. The prevalence and dynamics of C. aspersum parasitization by Brachylaima spp. metacercariae in specimens intended for human consumption in Spanish marketplaces were studied. In total, 3,710 C. aspersum specimens were analyzed over 5 yr, which were obtained from public marketplaces in the Spanish cities of Barcelona, Bilbao, Madrid, Tudela, Valencia, and Zaragoza. The overall prevalence was 41.97% (95% CI: 40.38–45.56%). The Tudela marketplace had the highest values for both the seasonal prevalence and abundance in all studies during autumn (93.57% and 3.09, respectively). This market also gave the highest individual metacercarial burden recorded, 212 metacercariae in a single specimen. Overall, the highest prevalence of Brachylaima spp. occurred in autumn (58.65%) and the lowest in winter (22.64%). There was a seasonal effect on prevalence, which increased from summer to autumn and then decreased in winter. In total, 96 experimental Brachylaima adults were obtained from the metacercariae parasitizing the analyzed snails. These were identified through morphometric tools (principal component analysis) as Brachylaima mascomai (56 in Barcelona, 1 in Bilbao, 7 in Tudela, and 3 in Valencia), and Brachylaima llobregatensis (17 in Barcelona, 8 in Bilbao, 1 in Valencia, and 3 in Zaragoza). Logistic regression modeling, conducted to predict the probability of purchasing parasitized snails using city and season as predictors showed a correct prediction overall of 79.0%, with a significant (p = 0.001) risk effect in the Barcelona–autumn interaction (2.551–38.442), a significant (p = 0.049) protection effect in the Tudela–spring interaction (0.076–0.997), a significant (p < 0.001) risk effect in the Tudela–autumn interaction (4.330–78.584), and a significant (p = 0.014) protection effect in the Valencia–spring interaction (0.033–0.687). The high overall prevalence of Brachylaima spp. metacercariae should be a matter of concern for public health authorities, mainly in countries where C. aspersum is consumed.

We describe an unusual case of proventriculitis associated with Cryptosporidium baileyi in a 7-wk-old snowy owl (Bubo scandiacus) chick kept at a zoo. Necropsy of this animal revealed diffuse mucosal thickening of the proventriculus. Subsequent histopathological examinations of the proventriculus showed marked ductal epithelial hyperplasia with intestinal metaplasia and severe inflammatory cell infiltration in the lamina propria and submucosa. These lesions were associated with numerous periodic-acid-Schiff–positive cryptosporidia-like protozoan parasites. Moreover, oocysts found within the lamina propria had a noticeably thicker wall and displayed Ziehl-Neelsen–positive test results. PCR sequencing analyses of the 18S rDNA, actin, and 70 kDa heat shock protein gene loci identified the protozoan to be C. baileyi, of which two novel sets of primers were designed for use with formalin-fixed paraffin-embedded tissue. An epidemiological survey was carried out at the zoo to investigate the source of infection, but all owl species surveyed proved negative for cryptosporidiosis. It is most likely that small animal vectors such as wild birds or rodents were responsible for this particular lethal case. This is the first report of C. baileyi associated with proventriculitis and also the first report of cryptosporidiosis in a raptor species in Asia.

Acanthogyrus (Acanthosentis) kashmirensis n. sp. is described from recently collected acanthocephalan specimens in the Jhelum River in northern Kashmir that are conspecific with Neoechinorhynchus kashmirensis Fotedar and Dhar, 1977 originally described in a Ph.D. thesis in 1972 from 4 species of cyprinid fishes: Tor tor Hamilton, Bangana diplostoma (Heckel) (syn. Labeo diplostoma Heckel), Labeo rohita Hamilton, and Ptychobarbus sp. Steindachner. The poor unpublished diagnosis was followed by 1 uninformative abstract in a scientific meeting in 1977. The acanthocephalan was later designated as invalid because of the lack of a formal published description and absence of information on deposited type or voucher specimens. Recent collections of specimens of the same species were made from 2 other cyprinid species of cyprinid fishes, Schizothorax plagiostomus Heckel and Schizothorax labiatus (McClelland) from the Sandran River, a tributary of the Jhelum River, in southern Kashmir. It is now possible to provide a full description of these specimens and reassign them in the subgenus Acanthosentis Verma and Datta, 1929 based on the finding of circles of vestigial spines at the anterior end of the trunk of male and female specimens. These vestigial spines are barely visible and easy to miss with optical microscopy. The new species is also characterized by having (1) a para-receptacle structure in males and females, (2) unique double Saefftigen's pouches, (3) large round single-nucleated cells in the proboscis, and (4) the lemnisci being either equal or distinctly unequal with no intermediate states. A key to the species of Acanthosentis of the Indian subcontinent is provided. Histopathological sections show extensive damage to the host intestine with subsequent blood loss, cell necrosis, and attempted encapsulation. Results of the energy dispersive X-ray analysis (EDAX) study show hollow hooks high in sulfur but with limited calcium ions. Hooks of most acanthocephalans studied with X-ray scans are solid with high calcium and low sulfur ions.

Sarcocysts of Sarcocystis rommeli were found for the first time in 6 of 34 (17.6%) cattle (Bos taurus) in China. With light microscopy, sarcocysts of S. rommeli were up to 1,130 μm long, with a striated, 4–8-μm-thick cyst wall. Using transmission electron microscopy, the villar protrusions (vp) were 4.7–5.2 × 0.2–0.3 μm, and 0.3–0.5 μm apart from each other. The vp contained microtubules extending from the top of the vp to the middle of the ground substance layer (gsl). A BLAST search of the near full-length 18S rRNA and partial mitochondrial cox1 sequences of S. rommeli revealed 98.7% identity and 99.2% identity with sequences of Sarcocystis bovini in GenBank, respectively. Two domestic cats (Felis catus) fed sarcocysts of S. rommeli shed oocysts/sporocysts in their feces with a prepatent period of 14 to 15 days; the partial mitochondrial cox1 sequences of these oocysts/sporocysts shared the high identities, that is, 99.4% and 99.5%, with cox1 sequences of S. rommeli sarcocysts and S. bovini sarcocysts, respectively. This is the first demonstration of a definitive host for S. rommeli.

Mycteronastes Kearn and Beverley-Burton, 1990 (Monogenoidea: Monocotylidae: Merizocotylinae) was resurrected from subjective synonymy with Merizocotyle Cerfontaine, 1894, and its diagnosis was emended to include monocotylids with a haptor lacking a central loculus and having 5 peripheral (2 bilateral pairs and an unpaired anteromedial loculus), 1 interhamular, and 17 marginal loculi. The 3 species of Mycteronastes accepted herein are parasitic within the olfactory sacs of rays and sawfishes: Mycteronastes icopae (Beverley-Burton and Williams, 1989) Kearn and Beverley-Burton, 1990 (type species) from the giant shovelnose ray, Glaucostegus typus (Anonymous (Bennett)) (Glaucostegidae), in the southwestern Pacific Ocean; Mycteronastes undulatae Kearn and Beverley-Burton, 1990 from the undulate ray, Raja undulata Lacepède (Rajidae), in the northeastern Atlantic Ocean; and Mycteronastes caalusi n. sp. from the smalltooth sawfish, Pristis pectinata Latham (Pristidae), in the Gulf of Mexico. Mycteronastes caalusi is most easily differentiated from its congeners by the combination of having 2 median cephalic papillae, an oval haptor that is wider than the body proper and lacks a deeply scalloped margin, a comparatively large anteromedial peripheral loculus, an unsclerotized male copulatory organ that is wholly anterior to the vaginal pores, a relatively small distal portion of the uterus (ootype chamber) that is mostly anterior to the vaginae, and a delicate uterus. The present study is the first report of a monocotylid from the olfactory sacs of P. pectinata and the first record of a species of Mycteronastes from the Gulf of Mexico. Notes on the taxonomy and systematics of some species assigned to Calicotyle Diesing, 1850 (Monocotylidae: Calicotylinae) are included.

The freshwater fish faunas of the Palaearctic and Nearctic regions show similarities but also notable differences, resulting in diverse distributions of their parasites. Relatively few parasite species occur in both regions and fewer still have been examined using molecular data. We report a rare example of ‘amphi-Pacific' distribution, involving the common Palaearctic parasite, the caryophyllidean cestode Caryophyllaeides fennica (Schneider, 1902), in the chiselmouth Acrocheilus alutaceus Agassiz and Pickering, 1855, an endemic cyprinid in northwestern Nearctic, Oregon. Available information on nonnative fish species in Oregon suggests that the parasite is native to the area and not introduced. Molecular data (18S ribosomal [r]DNA, 28S rDNA, internal transcribed spacer 2, and cytochrome c oxidase subunit 1 gene) indicate very little genetic divergence between representatives from the Palaearctic and Nearctic, and possibly a relatively more recent colonization of the Nearctic region by this cestode via the Beringian land bridge. This is remarkable considering that Acrocheilus has reportedly been in Oregon since the Miocene.

Austrodiplostomum compactum from Nannopterum brasilianus, and its metacercaria from Geophagus sp. and Oreochromis mossambicus captured (1979) at its type locality, Valencia Lake, Venezuela, by the author, are redescribed. The adult is characterized by its large body size, and an oral sucker smaller than the pharynx. The metacercaria has a similar body size as the adult, and the small genital primordia occupy 4.1–7.3% of body length. Experimental infections in chickens with metacercariae of Diplostomulum mordax from brains of Odonthestes bonariensis, captured (2015) at Dique Paso de las Piedras, near Bahia Blanca City, Buenos Aires Province, Argentina, resulted in 10 adults 5 days postexposure. These adults correspond to Austrodiplostomum mordax as described from N. brasilianus at Lacombe Lagoon, Buenos Aires Province, and differ from A. compactum in their smaller body size, and an oral sucker larger than the pharynx. The metacercaria has a similar body size as the adult and differs mainly in that the larger genital primordia occupy 11.6–13.8% of body length. The status of earlier published Austrodiplostomum species in the American continent is discussed in view of available morphological and molecular data. A lectotype of A. mordax is here designated, and Austrodiplostomum ostrowskiae is considered as a new synonym of A. compactum.

Lungworms from the genus Dictyocaulus cause parasitic bronchitis (dictyocaulosis) characterized by coughing and severe lung pathology in both domestic and wild ruminants. In this study we investigated the interrelationships of Dictyocaulus spp. from European bison (Bison bonasus L.), roe deer (Capreolus capreolus), and red deer (Cervus elaphus) by nucleotide sequence analysis spanning the 18S RNA gene (small subunit [SSU]) and internal transcribed spacer 2 (ITS2) regions of the ribosomal gene array as well as the mitochondrial cytochrome c oxidase subunit 1 (cox1). Molecular analyses of sequence data obtained partly with novel primers from between 10 and 50 specimens from each host were carried out. Bayesian inference analysis revealed that each host species was infected with different genotypes. Analysis of cox1 sequence data showed a diverse genetic background and high evolutionary potential of Dictyocaulus taxa. Data from lungworms of European bison revealed a distinct genotype of Dictyocaulus viviparus, whereas Dictyocaulus capreolus was only found in roe deer. In contrast, red deer were infected with a taxon with unique SSU, ITS2, and cox1 sequences. These results indicate the occurrence of a novel genotype from red deer, which differs significantly from the National Center for Biotechnology Information reference sequence of Dictyocaulus eckerti. The molecular evidence was consistent with a morphological study with description and imaging of Dictyocaulus cervi n. sp. recovered from red deer. Dictyocaulus cervi n. sp. can be distinguished from D. eckerti on the basis of the absence of cervical papillae, the occurrence of a single ring of 4 symmetrical submedian cephalic papillae, length of the tail in females, morphometry of the female reproductive system, and measurements of gubernacula in males. In conclusion, our findings further strengthen the idea that the genetic complexity and diversity among Dictyocaulus lungworms infecting wildlife ruminants is larger than previously believed and warrants further investigation.

Gulf Coast spiny softshell turtles, Apalone spinifera aspera (Agassiz, 1857) (Testudines: Trionychidae) from Canoe Lake (33°47′56.16″N, 86°29′25.02″W; Springville, Alabama) and Round Lake (32°41′50.91″N, 87°14′30.39″W; Perry Lakes State Park, Marion, Alabama), were infected by V. robustum Stunkard, 1928, Vasotrema longitestis Byrd, 1939, and Vasotrema rileyae n. sp. The new species differs from its congeners by having papillate suckers, a short testis, an ovary dextral to the oviduct, and a pre-ovarian genital pore that is lateral to the ventral sucker. We studied the newly collected specimens and museum specimens of all congeners to revise the diagnosis of Vasotrema Stunkard, 1926 and redescribe and provide an updated dichotomous key to all species of the genus.

Fish blood flukes of the genus Cardicola (Digenea: Aporocotylidae) are important pathogens in tuna aquaculture. Recent advances in marine blood fluke research have led to the elucidation of the lifecycles of 3 Cardicola spp. infecting tuna; all 3 flukes utilize terebellid polychaetes as the intermediate host. In our survey, we obtained large numbers of Nicolea gracilibranchis infected by larval Cardicola orientalis at our tuna farming site. To determine the spatial and temporal changes in the distribution of N. gracilibranchis surrounding tuna culture cages and their infection by C. orientalis, we conducted monthly sampling for a period of 1 yr. Terebellids were most abundant on the floats and ropes of culture cages, but a significantly higher proportion of infected N. gracilibranchis was detected on ropes, particularly up to 4 m in depth. Cardicola orientalis infection in N. gracilibranchis was clearly seasonal, with a higher infection rate between April and July. Our findings indicate that the infected terebellids inhabit specific microhabitats, and both abiotic and biotic factors likely influence blood fluke infection in the intermediate terebellid host. This information is important to better understand the general biology of marine aporocotylids and may be useful to develop a control strategy for blood fluke infection in tuna aquaculture.

Here, we report a new species, Sarcocystis pantherophisi n. sp., with the Eastern rat snake (Pantherophis alleghaniensis) as natural definitive host and the interferon gamma gene knockout (KO) mouse as the experimental intermediate host. Sporocysts (n = 15) from intestinal contents of the snake were 10.8 × 8.9 μm. Sporocysts were orally infective to KO mice but not to laboratory-raised albino outbred house mice (Mus musculus). The interferon gamma KO mice developed schizont-associated neurological signs, and schizonts were cultivated in vitro from the brain. Mature sarcocysts were found in skeletal muscles of KO mice examined 41 days postinoculation (PI). Sarcocysts were slender, up to 70 μm wide and up to 3.5 mm long. By light microscopy, sarcocysts appeared thin-walled (<1 μm) without projections. By transmission electron microscopy, the sarcocyst wall was a variant of “type 1” (type 1i, new designation). The parasitophorous vacuolar membrane (pvm) had approximately 100-nm-wide × 100-nm-long bleb-like evaginations interspersed with 100-nm-wide × 650-nm-long elongated protrusions at irregular distances, and invaginations into the ground substance layer (gs) for a very short distance (6 nm). The gs was smooth, up to 500 nm thick, without tubules, and contained a few vesicles. Longitudinally cut bradyzoites at 54 days PI were banana-shaped, 7.8 × 2.2 μm (n = 5). Molecular characterization using 18S rRNA, 28S rRNA, ITS-1, and cox1 genes indicated a close relationship with other Sarcocystis parasites that have snake–rodent life cycles. The parasite in the present study was molecularly and biologically similar to a previously reported isolate (designated earlier as Sarcocystis sp. ex Pantherophis alleghaniensis) from P. alleghaniensis, and it was structurally different from other Sarcocystis species so far described.

Here, we report a new species of Sarcocystis with red-tailed hawk (RTH, Buteo jamaicensis) as the natural definitive host and IFN-γ gene knockout (KO) mice as an experimental intermediate host in which sarcocysts form in muscle. Two RTHs submitted to the Carolina Raptor Center, Huntersville, North Carolina, were euthanized because they could not be rehabilitated and released. Fully sporulated 12.5 × 9.9-μm sized sporocysts were found in intestinal scrapings of both hawks. Sporocysts were orally fed to laboratory-reared outbred Swiss Webster mice (SW, Mus musculus) and also to KO mice. The sporocysts were infective for KO mice but not for SW mice. All SW mice remained asymptomatic, and neither schizonts nor sarcocysts were found in any SW mice euthanized on days 54, 77, 103 (n = 2) or 137 post-inoculation (PI). The KO mice developed neurological signs and were necropsied between 52 to 68 days PI. Schizonts/merozoites were found in all KO mice euthanized on days 52, 55 (n = 3), 59, 61 (n = 2), 66, and 68 PI and they were confined to the brain. The predominant lesion was meningoencephalitis characterized by perivascular cuffs, granulomas, and necrosis of the neural tissue. The schizonts/merozoites were located in neural tissue and were apparently extravascular. Brain homogenates from infected KO mice were infective to KO mice by subcutaneous inoculation and when seeded on to CV-1 cells. Microscopic sarcocysts were found in skeletal muscles of 5 of 8 KO mice euthanized between 55–61 days PI. Only a few sarcocysts were detected. Sarcocysts were microscopic, up to 3.5 mm long. When viewed with light microscopy, the sarcocyst wall appeared thin (<1 μm thick) and smooth. By transmission electron microscopy, the sarcocyst wall classified as “type 1j” (new designation). Molecular characterization using 18S rRNA, 28S rRNA, ITS-1, and cox1 genes revealed a close relationship with Sarcocystis microti and Sarcocystis glareoli; both species infect birds as definitive hosts. The parasite in the present study was biologically and molecularly different from species so far described in RTHs and we therefore propose a new species name, Sarcocystis jamaicensis n. sp.

The diversity and taxonomy of diplostomids infecting freshwater fishes of the Indian region are predominantly poorly known. Yet compared to other trematodes, identification and discrimination of diplostomid metacercaria are difficult using morphology and site of infection. The present study provides the first molecular study of a Tylodelphys sp. from India. Specimens of Tylodelphys were collected from the vitreous humor of the eyes and from the brains of siluriform fish, Mystus tengara (Siluriformes: Bagridae) from Hastinapur, Meerut (U.P.), India. Taxonomic studies were performed on the basis of morphological, morphometrical, and molecular analysis. The dissimilarities in morphological and sites of infection between 2 forms of Tylodelphys, designated as Tylodelphys sp. 1 and Tylodelphys sp. 2, suggested that the forms were different species but, after performing molecular analysis, we conclude that despite morphological differences both morphotypes are conspecific.

Chagas disease caused by Trypanosoma cruzi is a burden to millions of people in South and Central America. A sylvatic life cycle of the parasite exists in the Southern United States, but recent studies indicate an active peri-domestic life cycle of T. cruzi in Texas. The United States–Mexico border region in Texas displays areas of high poverty and sub-standard housing conditions which are important risk factors for a potential spill-over transmission to a domestic life cycle including humans. The objectives of the study were to examine short- and long-term temporal variation in vector activity and to evaluate the effect of different combinations of attractants on the capture of potential triatomine vectors. We collected local triatomine vectors (all of them identified as Triatoma gerstaeckeri) from a natural habitat in South Texas during the course of a year. The exact time of collection was recorded to examine the timing of flight activity of the triatomine vector. We also conducted a comparative study of the efficiency of 2 commonly used attractants (light and CO₂) and the combination of those on the capture rate of Tr. gerstaeckeri. Our study indicates a short season of dispersal of Tr. gerstaeckeri (April/May) and it suggests a unimodal distribution of activity peaking between 2 and 3 hr after sunset. Ultra-violet light served as the main attractant of Tr. gerstaeckeri while CO₂ from dry ice did not significantly contribute to the collection of vectors. The pronounced timing of activity in Tr. gerstaeckeri reported in this study contributes to our understanding of the epidemiology of T. cruzi in wildlife and its potential as a Chagas disease vector to humans in the Rio Grande Valley, South Texas.

B-cell superantigens (BC-SAgs) are immunoevasins that have evolved in response to innate catalytic IgM antibodies; germ-line encoded immunoglobulins present in the preimmune repertoire independent of prior antigen exposure. Catalysis is the result of a 2-step process that involves first the formation of a non-covalent bond between the BC-SAg and the immunoglobulin followed by covalent bond formation at the catalytic site resulting in target hydrolysis. Tc24 is a recently described Trypanosoma cruzi BC-SAg hypothesized to play a role in evading the humoral response early in the infection period. We previously demonstrated that exposure to Tc24 following immunization or infection resulted in the depletion of the catalytic IgM response, leaving a gap in the catalytic IgM repertoire. The present report compares the BC-SAg properties of wild-type Tc24 (Tc24-WT) to that of 2 recombinant Tc24 isoforms: Tc24-C2 (Cys to Ser mutations in the 2 most-proximal Cys residues) and Tc24-C4 (Cys to Ser mutations in all 4 Cys residues present). BC-SAg activity was assessed by immunizing mice with the respective isoforms and examining the ability of IgM purified from the respective groups to hydrolyze the 3 Tc24 isoforms. In addition, the ability of IgM purified from naive mice to hydrolyze the Tc24 isoforms was also assessed. Immunization with Tc24-WT, Tc24-C2, or Tc24-C4 resulted in loss of IgM-mediated hydrolysis of Tc24-WT. However, the ability of IgM purified from naive mice (previously shown to hydrolyze Tc24-WT) was less effective in hydrolyzing the 2 Tc24 isoforms. These data demonstrate that although the BC-SAg site in the mutants remained intact, their reduced susceptibility to IgM-mediated hydrolysis suggested that structural changes resulting from the Cys to Ser mutations altered accessibility to the catalytic site in the 2 isoforms.

The life-cycle of a recently described protostrongylid lungworm, Varestrongylus eleguneniensis, which infects caribou, muskoxen, and moose from Arctic and boreal regions of North America, was completed experimentally for the first time. A native North American slug species, Deroceras laeve, was infected with the first-stage larvae (L1) isolated from the feces of wild muskoxen to generate third-stage larvae (L3). These were administered to a captive reindeer calf (250 L3) and an adult captive muskox (380 L3). The prepatent periods for the reindeer and muskox were 56 and 72 days, respectively. Patency lasted for only 19 days in the reindeer, and fecal larval counts were very low (0.09–1.53 larvae per gram of feces). Patency in the muskox was at least 210 days, and likely over 653 days, and the fecal larval counts were higher (0.06–17.8 larvae per gram of feces). This work provides the first experimental completion of the life-cycle of V. eleguneniensis.

During 2016, 153 gulls, including 64 Larus fuscus and 89 Larus michahellis, were found crippled in south Portugal. They died in Wildlife Rehabilitation and Investigation Center-RIAS and were necropsied. Reighardia sternae infected 2 (3%, n = 64) L. fuscus and 4 (4%, n = 89) L. michahellis. Molecular analysis confirmed the morphological identification on the basis of total body length, maximum body width, length of anterior and posterior hooks, total length of oral apparatus, and other features of oral apparatus of R. sternae. Both sequenced individuals in this study displayed 100% sequence identity to R. sternae individuals obtained previously from Larus ridibundus in Spain and to Reighardia sp. from Larus belcheri in Peru. Reighardia sternae is reported here for the first time in L. michahellis and for the first time from Portugal.

Since the early 1990s there has been an increase in the number of cases and geographic expansion of severe mange in the black bear (Ursus americanus) population in Pennsylvania. Although there are 3 species of mites associated with mange in bears, Sarcoptes scabiei has been identified as the etiologic agent in these Pennsylvania cases. Historically, S. scabiei-associated mange in bears has been uncommon and sporadic, although it is widespread and relatively common in canid populations. To better understand this recent emergence of sarcoptic mange in bears in Pennsylvania and nearby states, we genetically characterized S. scabiei samples from black bears in the eastern United States. These sequences were compared with newly acquired S. scabiei sequences from wild canids (red fox [Vulpes vulpes] and coyote [Canis latrans]) and a porcupine (Erethizon dorsatum) from Pennsylvania and Kentucky and also existing sequences in GenBank. The internal transcribed spacer (ITS)-2 region and cytochrome c oxidase subunit 1 (cox1) gene were amplified and sequenced. Twenty-four ITS-2 sequences were obtained from mites from bears (n = 16), red fox (n = 5), coyote (n = 2), and a porcupine. The sequences from bear samples were identical to each other or differed only at polymorphic bases, whereas S. scabiei from canids were more variable, but 2 were identical to S. scabiei sequences from bears. Eighteen cox1 sequences obtained from mites from bears represented 6 novel haplotypes. Phylogenetic analysis of cox1 sequences revealed 4 clades: 2 clades of mites of human origin from Panama or Australia, a clade of mites from rabbits from China, and a large unresolved clade that included the remaining S. scabiei sequences from various hosts and regions, including sequences from the bears from the current study. Although the cox1 gene was more variable than the ITS-2, phylogenetic analyses failed to detect any clustering of S. scabiei from eastern U.S. hosts. Rather, sequences from black bears grouped into a large clade that included S. scabiei from numerous hosts from Europe, Asia, Africa, and Australia. Collectively, these data suggest that the increasing number of S. scabiei cases in northeastern black bears is not due to the emergence and expansion of a single parasite strain.

Ascaris suum is an important intestinal nematode causing economic losses in swine. Anthelminthic treatment is used to control A. suum infections and is part of normal production practices. Treatment with anthelminthic agents results in expulsion of adult worms from the intestinal tract and ends further contamination of the environment with eggs. The present study was conducted to determine the effects of drug treatment on the embryonation of A. suum eggs collected from worms obtained from pigs treated with 4 different commercially available anthelmintics. The effects of treatment with abamectin, doramectin, ivermectin, flubendazole, or no treatment on embryonation of A. suum eggs collected from female A. suum expelled in the feces was determined. The embryonation of eggs obtained from pigs treated with abamectin, doramectin, and ivermectin was not significantly (P > 0.05) different from eggs from non-treated control pigs. In contrast, the embryonation of A. suum eggs collected from worms from pigs treated with flubendazole demonstrated inhibited development, and most eggs remained in the 1-cell stage (85.5%) and only 6.3% of eggs developed larvae. In another experiment, we examined the direct effects of doramectin and flubendazole added to solutions of A. suum eggs collected from non-treated control pigs. Egg cultures were exposed to direct in vitro treatment with 0.04-parts per million (ppm) doramectin or 1.0-ppm flubendazole for 24 hr (highest concentrations [C_max] of drugs in serum) and then embryonation and infectivity for mice was determined. Treatment of eggs in vitro did not significantly effect (P > 0.05) larval development or oral infectivity for mice. Our study demonstrates that flubendazole fed to pigs results in inhibited embryonation of A. suum eggs. However, direct treatment of A. suum eggs in culture for 24 hr with flubendazole did not inhibit embryonation or oral infectivity of in vitro treated eggs. Anthelmintic treatment of pigs in vivo with abamectin, doramectin, and ivermectin had no significant (P > 0.05) effect on embryonation of A. suum eggs, and 24 hr treatment with doramectin in vitro had no direct effects (P > 0.05) on embryonation or oral infectivity of A. suum eggs.