Predicting how elevated temperatures from climate change alter host–parasite interactions requires understandings of how warming affects host susceptibility and parasite virulence. Here, the effect of elevated water temperature and parasite exposure level was tested on parasite prevalence, abundance and burden, and on fish growth, using Pomphorhynchus laevis and its fish host Squalius cephalus. At 60 days post-exposure, prevalence was higher at the elevated temperature (22 °C) than ambient temperature (18 °C), with infections achieved at considerably lower levels of exposure. Whilst parasite number was significantly higher in infected fish at 22 °C, both mean parasite weight and parasite burden was significantly higher at 18 °C. There were, however, no significant relationships between fish growth rate and temperature, parasite exposure, and the infection parameters. Thus, whilst elevated temperature significantly influenced parasite infection rates, it also impacted parasite development rates, suggesting warming could have complex implications for parasite dynamics and host resistance.

Existing algorithms for predicting species' distributions sit on a continuum between purely statistical and purely biological approaches. Most of the existing algorithms are aspatial because they do not consider the spatial context, the occurrence of the species or conditions conducive to the species' existence, in neighbouring areas. The geostatistical techniques of kriging and cokriging are presented in an attempt to encourage biologists more frequently to consider them. Unlike deterministic spatial techniques they provide estimates of prediction errors. The assumptions and applications of common geostatistical techniques are presented with worked examples drawn from a dataset of the bluetongue outbreak in northwest Europe in 2006. Emphasis is placed on the importance and interpretation of weights in geostatistical calculations. Covarying environmental data may be used to improve predictions of species’ distributions, but only if their sampling frequency is greater than that of the species’ or disease data. Cokriging techniques are unable to determine the biological significance or importance of such environmental data, because they are not designed to do so.

Haematophagous insect vectors of arthropod-borne viruses (arboviruses) feed repeatedly. Consequently, they can transmit arboviruses to more than one host during the same developmental stage (intra-stadial transmission). By contrast, ixodid ticks generally feed only once at each parasitic stage (larva, nymph, and adult) and hence they have only one opportunity for tick-borne virus transmission per stadium (inter-stadial transmission). Under natural conditions, tick-infested hosts may die (from disease or other causes) before the ticks have completed their long period of engorgement. A laboratory model was used to investigate the consequences of premature host death on tick-borne virus transmission. We report intra-stadial transmission of Thogoto virus by the nymphal, male, and female ticks of Rhipicephalus appendiculatus. Tick-borne Thogoto virus infection caused viraemia and death of hamsters before the nymphal and adult ticks feeding on them had completed engorgement. The resulting partially fed ticks were allowed to continue engorgement on new, uninfected hosts (interrupted feeding). During feeding on the subsequent hosts, they transmitted the virus intra-stadially to susceptible hosts (hamsters), and to uninfected co-feeding ticks on non-susceptible hosts (guinea-pigs). Intra-stadial transmission, mediated by interrupted feeding, may help explain outbreaks of rapid and fatal tick-borne viral diseases, and the epidemiology as well as evolution of virulence, in a susceptible host population. Additionally, intra-stadial transmission provides an increased risk of tick-borne pathogen transmission to humans and domestic animals during slaughter and game hunting.

In host–parasite relationships, parasite prevalence and abundance can vary over time, potentially impacting how hosts are affected by infection. Here, the pathology, growth, condition and diet of a juvenile Cyprinus carpio cohort infected with the non-native cestode Bothriocephalus acheilognathi was measured in October 2012 (end of their first summer of life), April 2013 (end of first winter) and October 2013 (end of second summer). Pathology revealed consistent impacts, including severe compression and architectural modification of the intestine. At the end of the first summer, there was no difference in lengths and condition of the infected and uninfected fish. However, at the end of the winter period, the condition of infected fish was significantly reduced and by the end of their second summer, the infected fish were significantly smaller and remained in significantly reduced condition. Their diets were significantly different over time; infected fish consumed significantly higher proportions of food items <53 µm than uninfected individuals, a likely consequence of impaired functional traits due to infection. Thus, the sub-lethal impacts of this parasite, namely changes in histopathology, growth and trophic niche were dependent on time and/or age of the fish.

Parasites manipulate their hosts’ phenotype to increase their own fitness. Like any evolutionary adaptation, parasitic manipulations should be costly. Though it is difficult to measure costs of the manipulation directly, they can be evaluated using an indirect approach. For instance, theory suggests that as the parasite infrapopulation grows, the investment of individual parasites in host manipulation decreases, because of cost sharing. Another assumption is that in environments where manipulation does not pay off for the parasite, it can decrease its investment in the manipulation to save resources. We experimentally infected rainbow trout Oncorhynchus mykiss with the immature larvae of the trematode Diplostomum pseudospathaceum, to test these assumptions. Immature D. pseudospathaceum metacercariae are known for their ability to manipulate the behaviour of their host enhancing its anti-predator defenses to avoid concomitant predation. We found that the growth rate of individual parasites in rainbow trout increased with the infrapopulation size (positive density-dependence) suggesting cost sharing. Moreover, parasites adjusted their growth to the intensity of infection within the eye lens where they were localized suggesting population density sensing. Results of this study support the hypothesis that macroparasites can adjust their growth rate and manipulation investment according to cost sharing level and infrapopulation size.

The principal aim of this study was to optimize the diagnosis of canine neuroangiostrongyliasis (NA). In total, 92 cases were seen between 2010 and 2020. Dogs were aged from 7 weeks to 14 years (median 5 months), with 73/90 (81%) less than 6 months and 1.7 times as many males as females. The disease became more common over the study period. Most cases (86%) were seen between March and July. Cerebrospinal fluid (CSF) was obtained from the cisterna magna in 77 dogs, the lumbar cistern in f5, and both sites in 3. Nucleated cell counts for 84 specimens ranged from 1 to 146 150 cells μL−1 (median 4500). Percentage eosinophils varied from 0 to 98% (median 83%). When both cisternal and lumbar CSF were collected, inflammation was more severe caudally. Seventy-three CSF specimens were subjected to enzyme-linked immunosorbent assay (ELISA) testing for antibodies against A. cantonensis; 61 (84%) tested positive, titres ranging from <100 to ⩾12 800 (median 1600). Sixty-one CSF specimens were subjected to real-time quantitative polymerase chain reaction (qPCR) testing using a new protocol targeting a bioinformatically-informed repetitive genetic target; 53/61 samples (87%) tested positive, CT values ranging from 23.4 to 39.5 (median 30.0). For 57 dogs, it was possible to compare CSF ELISA serology and qPCR. ELISA and qPCR were both positive in 40 dogs, in 5 dogs the ELISA was positive while the qPCR was negative, in 9 dogs the qPCR was positive but the ELISA was negative, while in 3 dogs both the ELISA and qPCR were negative. NA is an emerging infectious disease of dogs in Sydney, Australia.

Angiostrongylus cantonensis is a parasitic nematode of rodents and a leading aetiological agent of eosinophilic meningitis in humans. Definitive diagnosis is difficult, often relying on immunodiagnostic methods which utilize crude antigens. New immunodiagnostic methods based on recombinant proteins are being developed, and ideally these methods would be made available worldwide. Identification of diagnostic targets, as well as studies on the biology of the parasite, are limited by a lack of molecular information on Angiostrongylus spp. available in databases. In this study we present data collected from DNA random high-throughput sequencing together with proteomic analyses and a cDNA walking methodology to identify and obtain the nucleotide or amino acid sequences of unknown immunoreactive proteins. 28 080 putative ORFs were obtained, of which 3371 had homology to other deposited protein sequences. Using the A. cantonensis genomic sequences, 156 putative ORFs, matching peptide sequences obtained from previous proteomic studies, were considered novel, with no homology to existing sequences. Full-length coding sequences of eight antigenic target proteins were obtained. In this study we generated not only the complete nucleotide sequences of the antigenic protein targets but also a large amount of genomic data which may help facilitate future genomic, proteomic, transcriptomic or metabolomic studies on Angiostrongylus.

The drug-metabolizing enzymes of some helminths can deactivate anthelmintics and therefore partially protect helminths against these drugs' toxic effect. The aim of our study was to assess the activity of the main drug-metabolizing enzymes and evaluate the metabolism of selected anthelmintics (albendazole, flubendazole, mebendazole) in the rat tapeworm Hymenolepis diminuta, a species often used as a model tapeworm. In vitro and ex vivo experiments were performed. Metabolites of the anthelmintics were detected and identified by HPLC with spectrofluorometric or mass–spectrometric detection. The enzymes of H. diminuta are able to reduce the carbonyl group of flubendazole, mebendazole and several other xenobiotics. Although the activity of a number of oxidation enzymes was determined, no oxidative metabolites of albendazole were detected. Regarding conjugation enzymes, a high activity of glutathione S-transferase was observed. A methyl derivative of reduced flubendazole was the only conjugation metabolite identified in ex vivo incubations of H. diminuta with anthelmintics. The results revealed that H. diminuta metabolized flubendazole and mebendazole, but not albendazole. The biotransformation pathways found in H. diminuta differ from those described in Moniezia expanza and suggest the interspecies differences in drug metabolism not only among classes of helminths, but even among tapeworms.

Thirty Holstein Friesian heifer calves, 3 months of age, were used to evaluate whether a low primary infection with Dictyocaulus viviparus would result in immunity against challenge infection 5 or 12 weeks later. Fifteen calves were experimentally infected with 30 larvae at day 0, while the other calves remained as uninfected controls. On day thirty-five 6 primary infected (G1) and 6 non-infected calves (G2) were challenged with 2000 larvae. These groups were necropsied on day 70. On day 84 the remaining 9 primary infected (G3) and 9 non-infected (G4) calves were similarly challenged and necropsied on day 119. Respiratory signs developed in most calves from approximately 2 weeks after challenge, but signs were more severe in G2 and G4 than in G1 and G3. The low primary infection resulted in significantly reduced faecal larval excretion (>80%) and worm burdens (>70%). In the primary infected groups the proportion of female worms in the worm burden was increased, suggesting that part of the developed immunity affected survival of the worms after their establishment in the host. Worm lengths and worm fecundity were also significantly reduced. All observed effects were stronger following challenge on day 84 than on day 35, but the effect of the duration of a primary infection (contrast between G1 and G3) was only statistically significant in the case of mean faecal larval excretion on the day of necropsy (P<0.05) and fecundity (P<0.05).

Cystoisospora (Isospora) belli is a coccidian parasite of humans. It can cause serious digestive disorders involving infection of intestines, biliary tract and gallbladder, especially in those with depressed immunity. It has a direct fecal–oral transmission cycle. After ingestion of sporulated oocysts, the parasite multiplies asexually and sexually within host epithelial cells, resulting in unsporulated oocysts that are excreted in feces. The details of asexual and sexual stages are not known and certain inclusions in epithelial cells in biopsy samples have been erroneously identified recently as C. belli. Here, we provide details of developmental stages of C. belli in two patients, in duodenal biopsy of one and biliary epithelium of the other. Immature and mature asexual stages (schizonts/meronts) were seen in epithelial cells. The merozoites were seen singly, in pairs and in groups in single parasitophorous vacuole (pv) in host cytoplasm. Immature and mature meronts were seen together in the same pv; up to eight nuclei were seen in meronts that retained elongated crescent shape; round multinucleated schizonts, seen in other coccidians, were not found. Meronts were up to 25 µm long and contained up to ten merozoites that were 8–11 µm long. The merozoites and meronts contained PAS-positive granules. Microgamonts (male) contained up to 30 nuclei that were arranged at the periphery and had condensed chromatin; 1–3 PAS-positive, eosinophilic, residual bodies were left when microgametes were formed. The microgametes were 4 µm long and PAS-negative. All stages of macrogamonts, including oocysts were PAS-positive. The detailed description of the life cycle stages of C. belli reported here should facilitate in histopathologic diagnosis of this parasite.

Temperature is expected to modulate the responses of organisms to stress. Here, we aimed to assess the influence of temperature on the interaction between parasitism and fungicide contamination. Specifically, using the cladoceran Daphnia as a model system, we explored the isolated and interactive effects of parasite challenge (yeast Metschnikowia bicuspidata) and exposure to fungicides (copper sulphate and tebuconazole) at two temperatures (17 and 20 °C), in a fully factorial design. Confirming a previous study, M. bicuspidata infection and copper exposure caused independent effects on Daphnia life history, whereas infection was permanently suppressed with tebuconazole exposure. Here, we show that higher temperature generally increased the virulence of the parasite, with the hosts developing signs of infection earlier, reproducing less and dying at an earlier age. These effects were consistent across copper concentrations, whereas the joint effects of temperature (which enhanced the difference between non-infected and infected hosts) and the anti-parasitic action of tebuconazole resulted in a more pronounced parasite × tebuconazole interaction at the higher temperature. Thus, besides independently influencing parasite and contaminant effects, the temperature can act as a modulator of interactions between pollution and disease.

A model simulating Dictyocaulus viviparus infection in calves is described. The present paper only deals with the parasitic phase of the life-cycle. Descriptions are given for establishment, development rate of juvenile stages, mortality rates of both juvenile and adult stages, and fecundity. Literature data were used to to develop parameter functions and to estimate initial values for constants. Development of acquired immunity, defined as the proportional ability of the host to reduce the number of parasite individuals in some stage or about to move into a next stage, against establishment (protection) or affecting mortality rates of juvenile or adult parasite stages has been included. The effect of immunity on one parameter or process is viewed as distinctly separate from the effect on another. Preliminary comparisons between model prediction and observations gives encouraging results, indicating that the model simulates experimental D. viviparus infection in calves reasonably well. Some quantitative discrepancies between prediction and observation make clear however, that not all parts of the model are accurate. Further experimentation is needed to re-evaluate current model description and to improve model simulation.

Immunophilins comprise two protein families, cyclophilins (CYPs) and FK506-binding proteins (FKBPs), and are the major receptors for the immunosuppressive drugs cyclosporin A (CsA) and FK506 (tacrolimus), respectively. Most eukaryotic species have at least one immunophilin and some of them have been associated with pathogenesis of infectious or parasitic diseases or the action of antiparasitic drugs. The human malarial parasite Plasmodium falciparum has 13 immunophilin or immunophilin-like genes but the functions of their products are unknown. We set out to identify the parasite proteins that interact with the major CYPs, PfCYP19A and PfCYP19B, and the FKBP, PfFKBP35, using a combination of co-immunoprecipitation and yeast two-hybrid screening. We identified a cohort of putative interacting partners and further investigation of some of these revealed potentially novel roles in parasite biology. We demonstrated that (i) P. falciparum CYPs interacted with the heat shock protein 70, (ii) treatment of parasites with CYP ligands disrupted transport of the rhoptry-associated protein 1, and (iii) PfFKBP35 interacted with parasite histones in a way that might modulate gene expression. These findings begin to elucidate the functions of immunophilins in malaria. Furthermore, the known antimalarial effects of CsA, FK506 and non-immunosuppressive derivatives of these immunophilin ligands could be mediated through these partner proteins.

1. While investigating the parasites of the holly leaf-miner (Phytomyza ilicis Curt.) with a view to utilizing them in the control of this troublesome pest of holly in western Canada, a species of Opius, which on examination proved to be new to science, was reared from the fly puparia.

2. A fairly complete account of the general systematics, distribution, biology, and morphology of the various developmental stages of this parasite is set down in the preceding pages. The primary larva is particularly interesting because of its unusual orientation. After the anatomical details had been worked out it was discovered that the concave side of the larva, which would normally be regarded as the ventral surface, is actually the dorsal one.

3. The genus Opius, whose distribution is world-wide, contains a very large number of species which parasitize important economic pests. In temperate regions the insects which suffer most from their attacks are species of Pegomyia, Agromyza, Rhagoletis, Phytomyza and Cerodonta, whilst in tropical and subtropical areas the most favoured hosts belong to one or other of the two genera Dacus and Anastrepha.

4. The host relationship of the genus, because of its importance from both economic and taxonomic standpoints, is discussed at some length.

5. In the first stadium Opius ilicis is a larval parasite, but the three succeeding instars live in the host pupa, and the imago emerges from the puparium. A very interesting phase in the life history of this parasite occurs towards the end of the first stage. At this point the development of the larva is arrested and further growth cannot take place until the host has pupated.

6. Very little work has so far been carried out on the larval morphology of the Opiinae, but that done up to the present, including the foregoing descriptions, would seem to indicate that the larvae of this tribe form a fairly homogeneous group. The main distinguishing characters of these larvae are listed in section VII of this paper.

7. It is pointed out that O. ilicis, in spite of being intrinsically inferior to Chrysocharis gemma, is responsible for the destruction of a certain number of hosts which escape the attentions of the latter parasite, and although the percentage accounted for is small (maximum parasitism in 1939 4%), it nevertheless fills a particular niche of its own, and so must be of some definite value in the scheme of control.

8. The chief method employed by the first instar of Chrysocharis gemma in the destruction of rival Opius larvae would appear to be direct mandibular attack. Several reasons have been put forward to account for the decided inferiority which is exhibited by the Braconid when it comes into conflict with this Chalcid.

9. In section X, a number of interesting points which have a general bearing on the study of parasite larvae are discussed. These include the cephalic skeleton and its probable function in successive instars, the taxonomic value of this structure in the parasitic Hymenoptera, the apparent absence of a tracheal system in the second and third instar larvae of O. ilicis, and arrested development in the Opiinae and some related forms.

1. A key to the laelaptid paraphages of Myriapoda is given.

2. Hypoaspis (Hypoaspis) spirostrepti Oudms is transferred to the subgenus Jululadaps. J. rotundatus Berl. is regarded as a synonym of this species.

3. Hypoaspis (Hypoaspis) indicus Vitzth. is regarded as a synonym of Julolaelaps luctator Berl.

4. Hypoaspis (Coleolaelaps) amazon is figured.

5. The subgenus Julolaelaps is defined and a key given to the species. The type species is figured.

6. Three new species are described, namely Hypoaspis (Julolaelaps) peritremalis, H. (J.) myriapodalis and H. (J.) pararotundatus.

7. A list of all the known species of Laelaptidae occurring on millipedes is given.

Anopheles elutus females are attracted by human beings. The human body eliminates certain substances which exert an attraction. The expired air alone is sufficient to attract the mosquitoes. Mild air currents may play an important part in carrying and directing these attracting factors towards the mosquitoes.

Hsp90 is a widely distributed and highly conserved molecular chaperone that is ubiquitously expressed throughout nature, being one of the most abundant proteins within non-stressed cells. This chaperone is up-regulated following stressful events and has been involved in many cellular processes. In Toxoplasma gondii, Hsp90 could be linked with many essential processes of the parasite such as host cell invasion, replication and tachyzoite-bradyzoite interconversion. A Protein-Protein Interaction (PPI) network approach of TgHsp90 has allowed inferring how these processes may be altered. In addition, data mining of T. gondii phosphoproteome and acetylome has allowed the generation of the phosphorylation and acetylation map of TgHsp90. This review focuses on the potential roles of TgHsp90 in parasite biology and the analysis of experimental data in comparison with its counterparts in yeast and humans.

The life-cycle of S. gallinarum may be briefly summarised as follows:

Commencing with the ordinary parasite in the blood of the fowl, the spirochaete grows until it reaches a certain length (16 μ–19 μ) and then divides by the peculiar mode of transverse division described above. This process is repeated and is probably the only method of multiplication of the parasite within the blood. When the spirochaetes disappear from the circulation some of them break up into coccoid bodies which, however, do not usually redevelop in the fowl. When the spirochaetes are ingested by Argas persicus, some of them pass through the gut wall into the coelomic fluid. From this medium they bore their way into the cells of the various organs of the tick and there break up into a number of coccoid bodies. These intracellular forms multiply by ordinary fission in the cells of the Malpighian tubules and gonads. Some of the coccoid bodies are formed in the lumen of the gut and Malpighian tubules. The result is that some of the coccoid bodies may be present in the Malpighian secretion and excrement of an infected tick and when mixed with the coxal fluid may gain entry into another fowl by the open wound caused by the tick's bite. They then elongate and redevelop into ordinary spirochaetes in the blood of the fowl, and the cycle may be repeated.