This study aimed to genetically characterize spotted fever group rickettsiae (SFGR) in questing ixodid ticks from Israel and to identify risk factors associated with SFGR-positive ticks using molecular techniques and geographic information systems (GIS) analysis. 1039 ticks from the genus Rhipicephalus were collected during 2014. 109/1039 (10·49%) carried SFGR-DNA of either Rickettsia massiliae (95), ‘Candidatus Rickettsia barbariae’ (8) or Rickettsia conorii (6). Higher prevalence of SFGR was found in Rhipicephalus turanicus (18·00%) compared with Rhipicephalus sanguineus sensu lato (3·22%). Rickettsia massiliae was the most commonly detected species and the most widely disseminated throughout Israel (87·15% of all Rickettsia-positive ticks). GIS analysis revealed that Central and Northern coastal regions are at high risk for SFGR. The presence of ticks was significantly associated with normalized difference vegetation index and temperature variation over the course of the year. The presence of rickettsiae was significantly associated with brown type soils, higher land surface temperature and higher precipitation. The latter parameters may contribute to infection of the tick with SFGR. Health care professionals should be aware of the possible exposure of local communities and travellers to R. massillae. Molecular and geographical information can help professionals to identify areas that are susceptible to SFGR-infected ticks.

Chagas Disease is a zoonosis caused by the parasite Trypanosoma cruzi. Several high-resolution markers have subdivided T. cruzi taxon into at least seven lineages or Discrete Typing Units (DTUs) (TcI-TcVI and TcBat). Trypanosoma cruzi I is the most diverse and geographically widespread DTU. Recently a TcI genotype related to domestic cycles was proposed and named as TcIDOM. Herein, we combined traditional markers and housekeeping genes and applied a Multispecies Coalescent method to explore intra-TcI relationships, lineage boundaries and genetic diversity in a random set of isolates and DNA sequences retrieved from Genbank from different countries in the Americas. We found further evidence supporting TcIDOM as an independent and emerging genotype of TcI at least in Colombia and Venezuela. We also found evidence of high phylogenetic incongruence between parasite's gene trees (including introgression) and embedded species trees, and a lack of genetic structure among geography and hosts, illustrating the complex dynamics and epidemiology of TcI across the Americas. These findings provide novel insights into T. cruzi systematics and epidemiology and support the need to assess parasite diversity and lineage boundaries through hypothesis testing using different approaches to those traditionally employed, including the Bayesian Multispecies coalescent method.

1. Six new furcocercous cercariae from the north-western United States are described and comparisons with similar forms are made.

2. On the basis of the structure of Cercaria tuckerensis spec. nov. and three cercariae reported in the recent literature it is possible to characterise more precisely the Elvae group, which now contains eight members.

3. The execretory system of Cercaria elvae Miller, 1923, was re-studied and found to differ from the original description. The bearing of this sort of error on Faust's use of excretory system formulae is touched upon.

4. Cercaria burti Miller, 1923, originally described from northern Michigan, is reported from San Juan Island.

5. Certain features of the morphology and biology of the furcocercous cercariae are discussed in the light of this and other recent studies.

6. Check List II of the furcocercous cercariae, with eighteen larvae, is given.

In the upper part of the small intestine of a Bennett's kangaroo, Macropus bennetti, there was found many parasitic worms which, although closely related to Nematodirus, differ from members of this genus sufficiently to warrant separation into a distinct genus.

Giardia, a common enteric protozoan parasite is a well-recognized cause of diarrhoeal illness. The detailed mechanism of diarrhoea due to this infection is not well understood. A 58 kDa enterotoxin (ESP) was purified from the excretory–secretory product of the parasite. The present study was designed to investigate the mode of action of this enterotoxin of G. lamblia in mice enterocytes. An increase in cyclic adenosine monophosphate level, as well as intracellular Ca2+ concentration, was observed in the ESP-triggered enterocytes. The levels of phospholipase Cγ1 and inositol triphosphate were found to be upregulated. The activity of protein kinase C (PKC) in the enterocytes was also enhanced following stimulation with the ESP. An increase in the level of reactive oxygen species in ESP-stimulated cells correlated well with the decline in the activity of antioxidant enzymes (superoxide dismutase and catalase). The significantly high levels of nitrite and citrulline indicated the generation of reactive nitrogen intermediates in the ESP-triggered enterocytes. Thus, ESP could induce cross-talk among the different signal transduction pathways in the enterocytes, which could together bring about a common secretory response.

An initial observation converning the failure of [3H]thymidine at high specific activity to be incorporated into the DNA of Crithidia fasciculata for more than a brief intitial period has been correlated with the presence at high specific activity in the organism of thymidine phosphorylase activity with an equilibrium in the direction of catabolism. This enzyme degrades thymidine to thymine which is not utilized by the organism. The enzyme has also been shown to be present in a number of other trypanosomatids, including the culture forms of Trypanosoma cruzi, where the specific activity was nearly as high as that in C. fasciculata.

Evidence is presented that in C. fasciculata, the culture forms of T. cruzi and possibly other species of trypanosomatid, the thymidine phosphorylase, together with a thymidylate phosphatase, forms a catabolic pathway which degrades thymine nucleotides to thymine, which is then excreated. About 60% of the thymine nucleotides made by organisms appear to be matabolized through the pathway, suggesting that their synthesis is not subject to completely effective regulatory control.

Cell death mechanisms in Trypanosoma cruzi have not been disclosed in detail though different conventional techniques have been used in the classification of parasite-cell death type. Nuclear magnetic resonance (NMR) has successfully been used as a tool to evaluate the onset of apoptosis in a number of higher eukaryote-cell models analysing the ratio of CH2/CH3 integration from the visible mobile lipids (VML). Surprisingly, this versatile non-invasive spectroscopy technique has never been employed with this purpose in T. cruzi. In the present study it is shown that under different parasite death-conditions the ratio CH2/CH3 varied drastically. Thus, T. cruzi epimastigotes in apoptotic conditions increase significantly this ratio while in necrotic as well as in autophagic situations the parasites maintain the VML, CH2/CH3 ratio, in normal values. Additionally, other VML markers commonly used in these studies, such as the change in the region of methyl-choline moiety, -N+(CH3)3, exhibited different particular patterns according to the type of cell death. Our results suggest that the 1H NMR-VML technique is an adequate tool to discriminate different T. cruzi death pathways.

The present paper deals with a collection of parasites from Malay, kindly sent to Prof. Keilin at the Molteno Institute by G. B. Purvis, F.R.C.V.S., to whom the writer wishes to express his appreciation of the painstaking and scientific way in which the collection was carried out. The specimens were all very carefully sorted and clearly labelled, and the majority extremely well preserved.

Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma (T.) gondii. Limited data are available on the occurrence of T. gondii in women especially pregnant women in Pakistan. The present study aimed to determine the occurrence and risk factors associated with T. gondii in pregnant and non-pregnant women in Punjab Province, Pakistan. A cross-sectional study was conducted and 593 samples were collected from pregnant (n = 293) and non-pregnant (n = 300) women of District Headquarter Hospitals of Chiniot, Faisalabad, Jhang and Okara, Pakistan. Data related to demographic parameters and risk factors were collected using a pretested questionnaire on blood sampling day. Serum samples were screened for antibodies (IgG) against T. gondii using ELISA. A univariant and binomial logistic regression was applied to estimate the association between seropositive and explanatory variables considering the 95% confidence interval. P value ⩽0.05 was considered statistically significant for all analysis. Out of 593, 44 (7.42%) women were seropositive for T. gondii IgG antibodies. Occupation, age, sampling location, socioeconomic status, contact with cat, pregnancy status and trimester of pregnancy were significantly associated with seropositivity for T. gondii antibodies. Location and trimester of pregnancy were identified as potential risk factors for T. gondii seropositivity based on binomial logistic regression. Toxoplasma gondii is prevalent in pregnant and non-pregnant women. Therefore, now a necessitated awareness is required to instruct the individuals about these infectious diseases (toxoplasmosis) and their control strategies to maintain the health of human population. Moreover, health awareness among public can help the minimization of T. gondii infection during pregnancy and subsequent risk of congenital toxoplasmosis.

An analysis of interstrain variation between 12 inbred and 4 congenic rat strains in the expression of immunity against Trichinella spiralis is reported. All rat strains expressed strong rapid expulsion which resulted in the elimination of 88–98% of a challenge infection of muscle larvae. In contrast, substantial interstrain variation in the rate of adult worm expulsion in the primary infection as evident. By day 10 after infection, BUF and YO strains had < 50 worms left in the intestine whereas BI and WKA strain rats had barely begun rejection, with approximately 1000 worms present in the gut for both strains. All other rat strains fell within these extremes in a continuous gradation. There was no clustering of rat strains into phenotypic groups with comparable worm burdens as seen with mice. The number of muscle larvae that established after the primary infection showed less variation than had adult worm burden in the primary infection and there was only a weak correlation of muscle larvae burden with numbers of intestinal adults present at 10 days. Comparison of MHC matched or MHC-disparate rat strains on a PVG background suggested that non-MHC genes determined the principal adult worm rejection characteristics of a given strain. The absence of phenotypic variation in the expression of rapid expulsion in rats reinforces the biological distinction between rat rapid expulsion and the ‘rapid expulsion’ defined for mice

Our knowledge regarding the biology of Hippoboscidae is but fragmentary. Leuckart (1858) and Pratt (1900) have described the embryology of Melophagus ovinus L. Austen (1903), who described the puparium of Hippobosca maculata Leach, found that the females soon starve when removed from their host. Austen continues: “It is believed that the females of the genus Hippobosca deposit their larvae on the ground, but it is not definitely known, whether they bury them or merely place them on the surface. Several pupae of H. maculata have been found in the calf sheds of the King Institute, but it is not clear, as to whether they were intentionally or accidentally deposited there.” Theobald (1908), on the contrary, asserts that female H. camelina and H. maculata attach their pupae to their host's hair. Massonat (1909) relates that the pupation period of H. equina varies with the temperature.

Reasons are given for rejecting a recent proposal to change the names Anisakis simplex to Capsularia marina, Anisakis to Capsularia, Anisakinae to Capsulariinae and Porrocaecum decipiens to P. piscium. The question of the possibility of identifying the larval forms of Ascaridae occurring in fishes is discussed.

Sampling of the fish community was carried out for 20 years in the Mirgenbach reservoir, in North-Eastern France. The prevalence and the mean intensity of Ligula intestinalis (Cestoda) were analysed in roach (Rutilus rutilus) and silver bream (Blicca bjoerkna) populations, the main two infected species. The aim of this study was to investigate the host switch from roach to silver bream and the consequences of L. intestinalis infestation in silver bream, which is an unusual host for this parasite as Ligula parasitism in silver bream appears to be rare. We analysed in detail the relationships between parasitism index (PI), gonadosomatic index (GSI), perivisceral fat abundance (PFA) and condition index (CI) in the silver bream population. In 1998, prevalence of L. intestinalis highlighted a clear host switch from roach to silver bream. In the silver bream population, young fish were the most severely infected and the impact of plerocercoids appeared to be different depending on the host sex. In male silver bream, plerocercoids drew energy from fat reserves even if GSI was also slightly impacted. On the contrary, in females energy was diverted from gonad maturation rather than from perivisceral fat reserves. No significant difference was observed in terms of CI in either sex.

The development of resistance in mice to reinfection with Schistosoma mansoni was recorded during an early chronic infection, and compared with hepatic portal pathological and vascular changes. The latter were assessed using a microsphere injection technique. The degree of acquired resistance was directly dependent on the patent worm burden and the time post-infection. Strong correlations were noted between the development of resistance and the appearance of parasite eggs in the lungs and spleens of infected hosts. Weaker associations were present between resistance and other aspects of the disease pathology, such as portal hypertension and organ weights. The appearance of injected microspheres in the lungs and spleens correlated well with the appearance of eggs in those organs and with the development of resistance. The levels of resistance had risen and microspheres were detected in the lungs, before the development of major extra-hepatic, porta-systemic collateral vessels. It is concluded that intra-hepatic vascular alterations may be a causal factor in the development of resistance, preventing the sequestration of migrating schistosomula in the liver. It is estimated that as much as 70–75% of the recorded resistance can be attributed to this immunologically non-specific mechanism.

P. gallinaceum was cultivated in tissue cultures for 1 year. The cultures showed the same high-grade infection as has been observed previously with Toxoplasma and Trypanosoma cruzi, and made possible new observations upon the living parasite.

It has not been possible to obtain in vitro the passage from the exo- into the endoerythrocytic form.

The parasites can survive in tissue cultures, maintained at room temperature, for 23 days.

Observations concerning the periodicity and the phases of the cycle in tissue cultures are being investigated.

Host and record. Several males and females were collected from the skin of a sailfish, Histiophorus gladius Day, caught off the south coast of Ceylon in December, 1931. Since then this form was found to occur commonly as an external parasite on the skin of many of the sailfish and swordfish found in Ceylon waters.

1. The description of the female and nymph of the so-called variety I. percavatus var. rothschildi is enlarged.

2. As far as the evidence is available it parasitizes marine birds and is probably a three-host tick.

3. Its systematic affinities are discussed, and since I. percavatus is synonymous with I. auritulus, then the variety of Nuttall & Warburton should be raised to the specific rank of I. rothschildi.

Reduction of neotetrazolium in the presence of succinate is used as a quantitative assay for succinic dehydrogenase activity in homogenates of Hymenolepis microstoma, and nitro blue tetrazolium and thiazolyl blue tetrazolium-cobalt are employed with cryostat sections for its histochemical localization in adults and cysticercoids. The highest concentrations of the enzyme occur in the anterior region of the worm (scolex, neck, and immature proglottids), lesser amounts in the region of mature and early gravid segments, and least amounts in the gravid region of the strobila. Primary sites of succinic dehydrogenase activity are the mitochondrial layer of the cuticle and the cells of the subcuticle. In the anterior region the entire parenchyma shows uniformly high concentrations of enzyme activity. This reaction decreases posteriorly until, in the gravid region, only the subcuticle and the mitochondrial layer of the cuticle display activity. Intense activity was also noted in the layer just under the shells of the eggs. The ovary and immature testes show high enzyme concentrations; however, in the testes, the concentration diminishes as the organs mature. In the scolex, the rostellum and the muscles of the suckers show higher enzyme activity than the surrounding tissues. The scolex, inner membrane, and tail of the cysticercoid show uniformly high concentrations of formazan.

Host–parasite co-evolutionary studies can shed light on diversity and the processes that shape it. Molecular methods have proven to be an indispensable tool in this task, often uncovering unseen diversity. This study used two nuclear markers (18S rRNA and 28S rRNA) and one mitochondrial (cytochrome oxidase subunit I) marker to investigate the diversity of nematodes of the family Pharyngodonidae parasitizing New Zealand (NZ) lizards (lygosomine skinks and diplodactylid geckos) and to explore their co-evolutionary history. A Bayesian approach was used to infer phylogenetic relationships of the parasitic nematodes. Analyses revealed that nematodes parasitizing skinks, currently classified as Skrjabinodon, are more closely related to Spauligodon than to Skrjabinodon infecting NZ geckos. Genetic analyses also uncovered previously undetected diversity within NZ gecko nematodes and provided evidence for several provisionally cryptic species. We also examined the level of host–parasite phylogenetic congruence using a global-fit approach. Significant congruence was detected between gecko-Skrjabinodon phylogenies, but our results indicated that strict co-speciation is not the main co-evolutionary process shaping the associations between NZ skinks and geckos and their parasitic nematodes. However, further sampling is required to fully resolve co-phylogenetic patterns of diversification in this host–parasite system.

1. Cucumaricola notabilis, a new genus and species of Copepoda, occurs in cysts in the coelom of Cucumaria frauenfeldi Ludwig collected at Sea Point, Blaauwberg Strand and Dalebrook in the Cape Peninsula.

2. An account is given of the features of the sexually dimorphic males and females.

3. Fertilized eggs and nauplius larvae are also contained in the cysts and, from observations on living material, it has been established that, after escaping from the cysts, the larvae metamorphose within a short period into the copepodid stage. There are two copepodid stages, the first an active swimming form and the second a quiescent phase from which the juvenile parasite develops.

4. Although of uncertain systematic position, this parasite seems to be nearly related to the Chondracanthidae. This conclusion is based on the similarity of the trunk appendages of the adult female to those of Acanthochondria as described by Oakley (1930), and also on the general agreement of the ontogeny with that of Acanthochondria cornuta investigated by Heegaard in 1947. It is further suggested that it may be assigned to the key devised by Delamare Deboutteville & Nunes-Ruivo (1955) for certain copepod parasites having some affinity with the Chondracanthidae.