Echinococcosis is a re-emerging zoonotic disease in Kyrgyzstan. In 2012, an echinococcosis control scheme was started that included dosing owned dogs in the Alay Valley, Kyrgyzstan with praziquantel. Control programmes require large investments of money and resources; as such it is important to evaluate how well these are meeting their targets. However, problems associated with echinococcosis control schemes include remoteness and semi-nomadic customs of affected communities, and lack of resources. These same problems apply to control scheme evaluations, and quick and easy assessment tools are highly desirable. Lot quality assurance sampling was used to assess the impact of approximately 2 years of echinococcosis control in the Alay valley. A pre-intervention coproELISA prevalence was established, and a 75% threshold for dosing compliance was set based on previous studies. Ten communities were visited in 2013 and 2014, with 18–21 dogs sampled per community, and questionnaires administered to dog owners. After 21 months of control efforts, 8/10 communities showed evidence of reaching the 75% praziquantel dosing target, although only 3/10 showed evidence of a reduction in coproELISA prevalence. This is understandable, since years of sustained control are required to effectively control echinococcosis, and efforts in the Alay valley should be and are being continued.

1. Experiments upon Xenopsylla cheopis Roths. are described which were carried out to discover if feeding influenced duration of life or had any effect upon the survival of the sexes or upon the relationship between duration of life and saturation deficiency of the atmosphere.

2. Fleas fed once before starvation lived longer than unfed fleas. There was no difference between survival of the sexes and no direct proportion between survival times and saturation deficiency.

3. Fleas kept with the host for 7 days before starvation lived still longer. Females lived considerably longer than males, but there was still no direct proportion between survival times and saturation deficiency.

Linnaeus (1747) described and figured (reproduced in Fig. 1) a parasitic Copepod from the gills of a Gadus, which he designated Lernaea cauda duplici tereti, and defined in these words: Thorax seu corpus molle, album, subrotundum, convexum, carnosum; antice obtusum, seu potius retusum, latere utroque notatum, denticulo molle antrorsum spectante. Collum tenue longiusculum, caput trilobum dilatatum; lobo intermedio obverse eordato. Cauda pone thoracem ex duobus corpusoulis pallidis longitudine thoracis. Brachia sub thorace, ad latera colli utrinque duo, quorum pars exterius bilobum, interius ovatum.

A new species of the giant phyllobothriid genus Dinobothrium (D. keilini n.sp.) is described from the blue shark (Carcharinus glaucus); it is compared with D. planum Linton, found for the first time from British waters, in the basking shark (Cetorhinus maximus), and the structure of both is discussed in relation to that of the genotype, D. septaria van Beneden. A fourth species, D. paciferum n.sp., also from the basking shark, is described, and though only a tenth the size of the other species, it shares most of their diagnostic scolex characters. It has eight true suckers above the four pendent bothria: in D. planum there are four true suckers and four pseudo-suckers, while in D. keilini there are only four true suckers, and D. septaria is said to have four pseudo-suckers alone. The nomenclature of the older species is revised, and the genus redefined.

Attention is directed to the adaptations in these large cestodes which facilitate interchange with the substratum: the development of lateral furrows through which the main excretory canals open to the exterior. There is also a ventral furrow, which in the nascent segments is an open cleft: this accommodates the growing uterus and permits a protracted gravid phase of the proglottides in situ. The effect is of five longitudinal hinges, which allow of considerable lateral expansion of the thick-walled strobilus. The smaller D. paciferum lacks these modifications, and the cylindrical segments are apparently detached in the gravid state. An explanation is offered for the conflicting accounts of the lateral extent of the vitellaria in this genus: there is a lateral contraction of the ventral vitelline reticulum as the ovarian phase waxes. In D. paciferum the vitellaria completely encircle the proglottis at the inception of the ovarian phase.

Notes are given on the selachiàn hosts examined, their food and the other parasites present. The relationships of Dinobothrium to other phyllobothriid genera and to Tetrabothrius are discussed.

In one electric ray, Torpedo nobiliana, a single immature strobilus of another kind of phyllobothriid was found; it is probably a new species of Monorygma, though it has slight resemblances to Calyptrobothrium—a genus characteristic of electric rays. The boat-shaped bothria are held at an angle from the scolex by contractile buttress-like wings, and at their proximal end there is a relatively large and complex sucker. Affinities with related genera are discussed and the nomenclature of Monorygma angusta (Linton) is emended.

The genome of Plasmodium falciparum has one of the most skewed base-pair compositions of any eukaryote, with an AT content of 80–90%. As start and stop codons are AT-rich, the probability of finding upstream open reading frames (uORFs) in messenger RNAs (mRNAs) is high and parasite mRNAs have an average of 11 uORFs in their leader sequences. Similar to other eukaryotes, uORFs repress the translation of the downstream open reading frame (dORF) in P. falciparum, yet the parasite translation machinery is able to bypass these uORFs and reach the dORF to initiate translation. This can happen by leaky scanning and/or reinitiation.

In this report, we assessed leaky scanning and reinitiation by studying the effect of uORFs on the translation of a dORF, in this case, the luciferase reporter gene, and showed that both mechanisms are employed in the asexual blood stages of P. falciparum. Furthermore, in addition to the codon usage of the uORF, translation of the dORF is governed by the Kozak sequence and length of the uORF, and inter-cistronic distance between the uORF and dORF. Based on these features whole-genome data was analysed to uncover classes of genes that might be regulated by uORFs. This study indicates that leaky scanning and reinitiation appear to be widespread in asexual stages of P. falciparum, which may require modifications of existing factors that are involved in translation initiation in addition to novel, parasite-specific proteins.

Macroparasites are generally aggregated within their hosts with infection and aggregation levels resulting from a continuous arms race between maintaining high mating probability and host mortality low for which host and environmentally related factors contribute to some extent. Here, infection and aggregation patterns of the macroendoparasites infecting the flatfish Citharus linguatula, Arnoglossus laterna, Lepidorhombus boscii, Scophthalmus rhombus and Platichthys flesus in 3 areas along the Portuguese coast were analysed. Of the 21 macroendoparasite species found only 1 infected all hosts and most were host or area exclusive. For each host-parasite system, values of the indices varied between areas and macroendoparasites were not always aggregated; in fact, some macroendoparasites were generally uniformly distributed, which can be related to specific density-dependent regulation mechanisms. No general pattern was found for infection or aggregation levels of the 3 species infecting more than 2 hosts along the Portuguese coast, i.e. Lecithochirium rufoviride, Nybelinia lingualis and Anisakis simplex s.l., suggesting that regulation mechanisms are not species specific but are locally determined, with host ecology playing a significant role.

Praziquantel (PZQ) is the drug of choice for schistosomiasis. The potential drug resistance necessitates the search for adjunct or alternative therapies to PZQ. Previous functional genomics has shown that RNAi inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) gene in Schistosoma adult worms significantly improved the effectiveness of PZQ. Here we tested the in vitro efficacy of 15 selective and non-selective CaMK inhibitors against Schistosoma mansoni and showed that PZQ efficacy was improved against refractory juvenile parasites when combined with these CaMK inhibitors. By measuring CaMK activity and the mobility of adult S. mansoni, we identified two non-selective CaMK inhibitors, Staurosporine (STSP) and 1Naphthyl PP1 (1NAPP1), as promising candidates for further study. The impact of STSP and 1NAPP1 was investigated in mice infected with S. mansoni in the presence or absence of a sub-lethal dose of PZQ against 2- and 7-day-old schistosomula and adults. Treatment with STSP/PZQ induced a significant (47–68%) liver egg burden reduction compared with mice treated with PZQ alone. The findings indicate that the combination of STSP and PZQ dosages significantly improved anti-schistosomal activity compared to PZQ alone, demonstrating the potential of selective and non-selective CaMK/kinase inhibitors as a combination therapy with PZQ in treating schistosomiasis.

Host manipulation whereby a parasite increases its transmission to a subsequent host by altering the behaviour of its current host is very far spread. It also occurs in host–parasite systems that are widely distributed. This offers the potential for local adaptation. The tapeworm Schistocephalus solidus modifies its first intermediate copepod host's predation susceptibility to suit its own needs by reducing its activity before it becomes infective and increasing it thereafter. To investigate potential differences in host manipulation between different populations and test for potential local adaptation with regard to host manipulation, I experimentally infected hosts from two distinct populations with parasites from either population in a fully crossed design. Host manipulation differed between populations mostly once the parasite had reached infectivity. These differences in infective parasites were mostly due to differences between different parasite populations. In not yet infective parasites, however, host population also had a significant effect on host manipulation. There was no evidence of local adaptation; parasites were able to manipulate foreign and local hosts equally well. Likewise, hosts were equally poor at resisting host manipulation by local and foreign parasites.

Apicomplexan parasites are well-known to modulate their host cells at diverse functional levels. As such, apicomplexan-induced alteration of host cellular cell cycle was described and appeared dependent on both, parasite species and host cell type. As a striking evidence of species-specific reactions, we here show that Eimeria bovis drives primary bovine umbilical vein endothelial cells (BUVECs) into a senescence-like phenotype during merogony I. In line with senescence characteristics, E. bovis induces a phenotypic change in host cell nuclei being characterized by nucleolar fusion and heterochromatin-enriched peripheries. By fibrillarin staining we confirm nucleoli sizes to be increased and their number per nucleus to be reduced in E. bovis-infected BUVECs. Additionally, nuclei of E. bovis-infected BUVECs showed enhanced signals for HH3K9me2 as heterochromatin marker thereby indicating an infection-induced change in heterochromatin transition. Furthermore, E. bovis-infected BUVECs show an enhanced β-galactosidase activity, which is a well-known marker of senescence. Referring to cell cycle progression, protein abundance profiles in E. bovis-infected endothelial cells revealed an up-regulation of cyclin E1 thereby indicating a cell cycle arrest at G1/S transition, signifying a senescence key feature. Similarly, abundance of G2 phase-specific cyclin B1 was found to be downregulated at the late phase of macromeront formation. Overall, these data indicate that the slow proliferative intracellular parasite E. bovis drives its host endothelial cells in a senescence-like status. So far, it remains to be elucidated whether this phenomenon indeed reflects an intentionally induced mechanism to profit from host cell-derived energy and metabolites present in a non-dividing cellular status.

Indoor transmission of Ascaris suum partly depends on the physico-chemical conditions in bedding material. Temperature, pH, aqueous ammonia, moisture, occurrence and development of A. suum eggs were therefore compared in different areas (resting, intermediate and latrine) of two deep litter pens on an organic farm in four seasons. There was some variation, but mean ammonia levels were generally very low (1·0–2·6 mm) and pH levels were moderate (8·04–8·88) in all three areas. Relatively, resting areas were characterized by overall moderate moisture (36%) and moderately high temperature (35·7 °C) levels. The area contained few eggs (50 eggs g−1 DM) of which 17% were viable, and though only 4% were larvated and 0·7% appeared infective, it was more than in the other areas. Intermediate areas had moderate moisture (43%) and high temperature (43·6 °C) levels. There were many eggs (523 eggs g−1 DM), but overall viability was very low (5%) and few eggs were larvated (0·004%) or even infective (0·002%). Latrines typically had high moisture (79%) and moderate temperature (30 °C) levels. The concentration of eggs was very high (1444 egg g−1 DM) and though 32% were viable, none had developed larval stages. The large majority of A. suum eggs appear to die and only few become infective while in the deep litter. However, a large fraction of eggs may remain viable for some time and could thus contaminate agricultural land and develop to infectivity, if the manure is not composted appropriately.

Species richness and diversity of macroparasite assemblages were compared among American eels (Anguilla rostrata) from Nova Scotia, European eels (A. anguilla) from the United Kingdom (Kennedy, Bush & Aho, 1986; Esch et al. 1988; Kennedy, 1990, 1993), and Australian eels (A. reinhardtii) from Queensland (Kennedy, 1995). Community richness and diversity of the macroparasite fauna of American and European eels did not differ significantly for total parasite component communities, intestinal parasite component communities, and intestinal parasite infracommunities. The similarities in richness and diversity between the parasite communities of American and European eels are not surprising given the common, recent origin of these sister species. However, differences in species composition were noted between Nova Scotia and the UK. Both species of eels were infected by a nearly identical suite of specialists, but differences occurred in the species number and composition of generalist parasites. In addition, generalist species were rarely dominant in Nova Scotia, but commonly so in the UK. These differences can be attributed to the differences in the freshwater fish fauna and their parasites that occur between Nova Scotia and the UK. American and European eels are derived from a common ancestor and, whereas they have carried with them a common suite of specialist parasites during their brief period of independence, they acquired different suites of generalists apparently from their respective continental faunas after they diverged. In contrast, parasite communities of American and European eels were significantly less diverse and speciose than those of Australian eels regardless of scale (total component community, intestinal component community, intestinal infracommunity). These results support the notion that parasite communities have had more time to evolve and/or that tropical conditions have promoted parasite speciation in Australian eels.

Previously immunized rats of different ages were exposed either to one large, or several small challenge infections with the nematode, Nippostrongylus brasiliensis. The number of secondary worms harboured by each of these rats was then determined on the fourteenth day after exposure to challenge. It was found that worms adapted more efficiently to host immunity when both (a) the rats were less than 11 weeks old when challenged and (b) the challenge was given in small repeated doses over a period of weeks. The age of the rats on exposure to the immunizing primary infection, however, had little or no affect per se on the subsequent establishment of immune-adapted worms. It is tentatively suggested that the failure of worms to adapt effectively to the acquired immunity of older rats resulted from the acquisition by these rats of a fully competent cellular immune response.

Small vessels showing inflammatory cell infiltrates were invariably observed in the vicinity of intact Toxoplasma tissue cysts within the brains of mice congenitally infected with the protozoan. Lymphocytes were observed in intimate contact with the luminal aspect of the endothelium, penetrating into the thickened basal lamina and in the perivascular area, which also contained macrophages and neutrophilic granulocytes. Rarely, lymphocytes were observed attached to the outer membrane of the host neurone which contained a Toxoplasma tissue cyst and within the inflammatory infiltrate associated with a disintegrating cyst. An hypothesis is presented which combines these morphological observations to explain the events associated with tissue cyst associated recrudescence of latent Toxoplasma infection in mouse brain.

The phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruzi prototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50 value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in this in vitro assay on BT, both compounds triggered important damages in T. cruzi that lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 on T. cruzi trypomastigotes.

When Acridine Orange was dispersed in cod-liver oil, its characteristic green fluorescence remained unaltered following absorption of this mixture into the peripheral circulation from the intestine. This result implies that there was little or no change in the lipid or its suspensoid as a result of undergoing this physiological process. The selective combination of this dye in aqueous solution with the cytoplasmic components of specimens of Trypanosoma lewisi, also present in the blood smears with the droplets of the green-appearing oil, resulted in an alteration of fluorescence as indicated by the rose red appearance of these organisms.

The present findings on the absorption of lipid droplets, containing a fluorochrome, by trypanosomes occurring simultaneously in the circulation of rats confirm similar observations reported by Wotton & Halsey (1957). The possibility is suggested again that fats and oils may serve as pharmacological vehicles for orally administered trypanosomides for the elimination of trypanosomes.

Part of this study was carried out in the department of Zoology and Anatomy of the University of Nebraska, Lincoln, Nebraska, and was supported in part by a grant from the Nebraska Heart Association for 1959. We would like also to extend our appreciation to the Division of Laboratories of the Nebraska State Health Department of Lincoln, Nebraska, for the use of their ‘Fluorex’, ultraviolet illumination microscope unit.

1. Crithidia pulicis, n. sp., is a parasite of the alimentary tract of the human flea, Pulex irritans.

2. The fleas used in this investigation were bred to the third generation in special “flea cages” on the human body. “Wild” fleas were examined and yielded the same parasite. Both larvae and adult fleas were examined.

3. C. pulicis exhibits pre-flagellate, flagellate and post-flagellate stages in its life history and these phases gradually develop, the one from the other.

4. The flagellate form is very active, movement being accomplished by means of the myonemes of the membrane and body.

5. Pre-flagellates (figs. 1−8) are oval bodies, from 2·3 μ to 7 μ long by 1·5 μ to 4·5 μ broad. The nucleus contains much chromatin and a small karyosome may be present. The blepharoplast is large. The flagellum develops from a chromatophile area. The rate of acquisition of flagellum and membrane varies in individual parasites. Division rosettes are frequent. The pre-flagellates have a somewhat frail appearance.

6. The flagellates of C. pulicis (figs. 9−17) are 26 μ to 65 μ long. Their cytoplasm is richly but finely granular, the nucleus well marked, the blepharoplast large, showing slight variations in shape. Chromidia may be present. The undulating membrane is large, well marked and possesses myonemes which can be detected in the living organism. The free flagellum is relatively short.

7. Post-flagellates (figs. 23−36) are from 3 μ to 6 μ. by 2·0 μ to 4·6 μ. They occur in the rectum and dejecta of the fleas. They are produced by concentration of the protoplasm round the nucleus and blepharoplast with absorption of the membrane and flagellum and finally the production of a thin varnish-like coat.

8. Longitudinal division (figs. 15−22) is the method of multiplication. It occurs in the pre-flagellate and flagellate stages. It may be symmetrical or asymmetric. Division is initiated by that of the blepharoplast, followed by that of the flagellum, membrane and nucleus and finally the body cytoplasm. Two types of asymmetric division have been observed.

9. The method of infection is contaminative, the post-flagellates in the faeces being the source of infection. There is no evidence of hereditary infection.

10. Crithidia pulicis is a member of the genus Crithidia, and is a true parasite of the insect, Pulex irritans.

The hosts of the new Schizogregarine herein described are the larvae of Dolichopodid flies: Syslenus adpropinquans Loew and S. scholtzii Loew which live in the decomposed sap or wood-pulp filling the wounds of Elm and Horsechestnut trees. The larvae used for the present study have been obtained from two trees only: an Elm tree standing on the Caius College playing ground at Newnham and a Horse-chestnut tree standing on the Downing site. The new parasite Schizocystis legeri n.sp., in company with a gregarine Dendrorhynchus systeni Keilin (1920), often completely fills the lumen of the host's midgut, but, even when heavily parasitised, the host does not show any sign of infection. The latter can only be detected when the larvae, slightly pressed between a slide and a coverslip, are examined under the microscope.

The ability of animals to cope with an increasing parasite load, in terms of resilience and resistance, may be affected by both nutrient supply and demand. Here, we hypothesized that host nutrition and growth potential interact and influence the ability of mice to cope with different parasite doses. Mice selected for high (ROH) or low (ROL) body weight were fed a low (40 g/kg; LP) or high (230 g/kg; HP) protein diet and infected with 0, 50, 100, 150, 200 or 250 L3 infective Heligmosomoides bakeri larvae. ROH-LP mice grew less at doses of 150 L3 and above, whilst growth of ROH-HP and of ROL mice was not affected by infection pressure. Total worm burdens reached a plateau at doses of 150L3, whilst ROH mice excreted fewer worm eggs than ROL mice. Serum antibodies increased with infection dose and ROH mice were found to have higher parasite-specific IgG1 titres than ROL mice. In contrast, ROL had higher total IgE titres than ROH mice, only on HP diets. The interaction between host nutrition and growth potential appears to differentially affect resilience and resistance in mice. However, the results support the view that parasitism penalises performance in animals selected for higher growth.