A method is described by which individual bed-bugs, weighing only 5 mg., can be accurately weighed, and their rate of loss of weight measured during starvation.

Fasting bed-bugs were kept for various periods at five temperatures, ranging from 8° C. to 37° C., and at four humidities—0, 30, 60 and 90 per cent. relative humidity—at each temperature. Analysis after the experiments showed that the same amounts of food reserves were used up at each humidity for one temperature, and, as more water was evaporated from those kept in dry air than from those in moist, the proportion of dry matter rose most rapidly in dry air. Protein was the main food reserve used.

Although the rate of loss of water was greatest in dry air, the rate of loss was relatively greater in moist air when the saturation deficiencies are compared. It appears that the insects conserve their water in dry air, but their surface area being so great in comparison with their volume, they cannot prevent all evaporation. This evaporation is at a rate nearly proportional to the saturation deficiency of the air.

In moist air water appears to be evaporated freely. It is suggested that the spiracles are kept closed more in dry air and less in moist, which accounts for the fact that the rate of evaporation is proportionately greatest in moist air.

A comparison is made between the results obtained with Cimex and Rhodnius.

The participation of neutrophil granulocytes in the cellular reaction to skin microfilariae of Onchocerca volvulus was studied by immunohistochemistry. Skin biopsies were obtained from adult Liberian and Ugandan patients with generalized onchocerciasis after exposure to topically applied diethylcarbamazine (DEC) and from untreated patients. After DEC many damaged microfilariae were observed either in dermal infiltrates or in epidermal microabscesses consisting both of neutrophils and eosinophils. Infiltrates and microabscesses contained some intact granulocytes and many neutrophils releasing myeloperoxidase, elastase, lactoferrin, defensin, lysozyme, α1-antitrypsin and α1-antichymotrypsin. Eosinophils discharged peroxidase and cationic proteins. Released granule proteins and remnants of disrupted granulocytes were found on the surface and in close proximity of damaged microfilariae in dermal infiltrates and epidermal microabscesses. In larger microabscesses neutrophils were predominant. These observations show that neutrophils and not only eosinophils recruit, accumulate, localize around and release their helminthotoxic granule proteins such as myeloperoxidase onto or closely around skin microfilariae of O. volvulus after topical DEC administration. The association between these processes and the damage of the microfilariae indicated that neutrophils together with eosinophils attack and damage microfilariae of O. volvulus after DEC treatment in the skin.

Objective.Rhipicephalus sanguineus is the most widespread tick in the world and a vector of many pathogens infecting dogs and humans. To date, there have been no investigations on the biology of R. sanguineus under natural Mediterranean climatic conditions. Methods. The biology of R. sanguineus was studied under laboratory and natural climatic conditions in southern Italy. Several biological parameters were compared in different seasons, and their correlation with climatic data was assessed. Results. The life cycle of R. sanguineus lasted for a mean of 101·4 and 116·2 days under laboratory and environmental conditions respectively. Reproductive parameters of wild-collected females kept in the environment in May were significantly different from first-generation females maintained in September–October, and the correlation between reproductive parameters and climate data varied according to season. Conclusion. These results indicate that the Mediterranean climate affects the biology of R. sanguineus, which compensates its losses during the initial phases of its cycle in spring with high feeding and moulting rates of larvae and nymphs during summer as well as with high egg production during autumn. These results advance our knowledge of the biology of R. sanguineus and will be useful for the understanding of the eco-epidemiology of tick-borne diseases that this tick transmits.

The ciliated protozoan Cryptocaryon irritans, a parasite of seawater fishes, was found to express an antigen that elicits antibodies in rabbits and tiger puffer (Takifugu ruburipes). Serum from rabbits and fish immunized with theronts had agglutination/immobilization activity against theronts in vitro; fish serum antibody levels (measured by enzyme-linked immunosorbent assays: ELISA) correlated with this activity. Anti-theront antibody levels in fish were significantly higher in the immunized group as compared with control fish at 2 weeks after booster immunization (injection of bovine serum albumin; Student's t-test, P<0·01). Biochemical analyses indicated that a Triton X-114-soluble 32 kDa theront integral membrane protein may be the agglutination/immobilization antigen. Indirect immunofluorescence staining of theronts suggested that this 32 kDa antigen was expressed on the surface of cilia. The full-length 32 kDa antigen cDNA contained 1147 basepairs, encoding a 328-amino acid protein including hydrophobic N- and C-termini. As with Tetrahymena and Paramecium spp., TAA and TAG appear to be used as glutamine codons in the 32 kDa antigen gene.

In recent years, Trichomonas gallinae emerged as the causative agent of an infectious disease of passerine birds in Europe leading to epidemic mortality of especially greenfinches Chloris chloris and chaffinches Fringilla coelebs. After the appearance of finch trichomonosis in the UK and Fennoscandia, the disease spread to Central Europe. Finch trichomonosis first reached Austria and Slovenia in 2012. In the present study the genetic heterogeneity of T. gallinae isolates from incidents in Austria and Slovenia were investigated and compared with British isolates. For this purpose comparative sequence analyses of the four genomic loci ITS1-5.8S-ITS2, 18S rRNA, rpb1 and Fe-hydrogenase were performed. The results corroborate that one clonal T. gallinae strain caused the emerging infectious disease within passerine birds and that the disease is continuing to spread in Europe. The same clonal strain was also found in a columbid bird from Austria. Additionally, the present study demonstrates clearly the importance of multi-locus sequence typing for discrimination of circulating T. gallinae strains.

The study aims were to quantify the survivorship of Anguillicola crassus in eels in seawater and investigate transmission in estuarine (50% seawater) and marine (100% seawater) simulated conditions. Most A. crassus were able to survive and reproduce in 50% and 100% seawater eels for up to 6 months and therefore could survive during the spawning migration of eels to the Sargasso Sea. Up to 10% of the parasite metapopulation were damaged after long-term exposure to 50% or 100% seawater. Transmission of A. crassus was completed in 50% and 100% seawater in the laboratory, although infection levels in 100% seawater hosts were always lower. Transmission in estuaries is ecologically possible since the copepod Eurytemora affinis is susceptible to infection and is the dominant autochthonous species in most tidal estuaries in the Northern hemisphere. Transmission at sea is unlikely due to lack of suitable intermediate hosts. The data support the suggestion that dissemination of A. crassus has been facilitated by natural movement of eels in coastal waters. It is possible that A. crassus could impair the success of the eel spawning migration to the Sargasso Sea, although there is no direct evidence to support this.

The biogeographic histories of parasites and pathogens are infrequently compared with those of free-living species, including their hosts. Documenting the frequency with which parasites and pathogens disperse across geographic regions contributes to understanding not only their evolution, but also the likelihood that they may become emerging infectious diseases. Haemosporidian parasites of birds (parasite genera Plasmodium, Haemoproteus and Leucocytozoon) are globally distributed, dipteran-vectored parasites. To date, over 2000 avian haemosporidian lineages have been designated by molecular barcoding methods. To achieve their current distributions, some lineages must have dispersed long distances, often over water. Here we quantify such events using the global avian haemosporidian database MalAvi and additional records primarily from the Americas. We scored lineages as belonging to one or more global biogeographic regions based on infection records. Most lineages were restricted to a single region but some were globally distributed. We also used part of the cytochrome b gene to create genus-level parasite phylogenies and scored well-supported nodes as having descendant lineages in regional sympatry or allopatry. Descendant sister lineages of Plasmodium, Haemoproteus and Leucocytozoon were distributed in allopatry in 11, 16 and 15% of investigated nodes, respectively. Although a small but significant fraction of the molecular variance in cytochrome b of all three genera could be explained by biogeographic region, global parasite dispersal likely contributed to the majority of the unexplained variance. Our results suggest that avian haemosporidian parasites have faced few geographic barriers to dispersal over their evolutionary history.

The localization and distribution of the serotoninergic and peptidergic elements of the nervous system of larval Schistosoma mansoni have been investigated using an indirect immunofluorescence technique in conjunction with confocal scanning laser microscopy (CSLM). A range of antisera was used, raised to the biogenic amine, 5-hydroxytryptamine (5-HT, or serotonin), the vertebrate peptides pancreatic polypeptide (PP), peptide YY (PYY) and neuropeptide Y (NPY) and to the native invertebrate peptide, FMRFamide; all these antisera were shown previously to be immunopositive in the adult worm. No immunoreactivity to 5-HT was detected in any of the larval stages, but both miracidia and cercariae were consistently immunoreactive to all 4 peptides. The peptidergic nervous system of the miracidium is relatively simple, taking the form of a central neural mass with associated paired anterior and posterior nerve tracts. The cercarial peptidergic nervous system comprises a central commissure joining paired anterior ganglia, from which emanate paired dorsal and ventral nerve tracts, which terminate at the body/tail junction. The excretory bladder region of the tail is also immunoreactive for the 4 peptides, and a fine pair of nerve tracts extends the length of the tail shaft. Immunoreactive nerve cell bodies are also evident in the midbody region of the intrasprocystic cercariae, these same structures being immunoreactive for the neuronal marker, neurone-specific enolase (NSE). The organization of the larval peptidergic nervous system is compared to that of the cholinergic nervous system and contrasted with the peptidergic system in the adult worm. The absence of immunoreactivity to 5-HT is discussed in relation to the proposed development of the aminergic nervous system upon establishment in the definitive host.

1. The life cycle of Trypanosoma avium in both its hosts is described.

2. In the vector (Ornithomyia avicularia) it undergoes a cyclical development in the alimentary canal. Multiplication occurs while the flagellate is in the crithi-dial stage, and, finally, pyriform haptomonad crithidia appear in the insect's hind-gut: these change into the infective metacyclic trypanosomes.

3. After penetrating the mucous membranes of the bird (following its ingestion of the louse-fly), the metacyclic trypanosomes probably invade the lymph system, and there develop (by growth alone) into the large forms seen in the bird's blood some 18–24 hr. later.

4. The trypanosomes persist in their natural hosts (but not in canaries) throughout the winter, more-or-less restricted to the bone-marrow. In the spring they reappear in the peripheral blood.

Between December 2007 and March 2009, small mammals were captured in 6 Atlantic Forest patches in Brazil. We assessed tick-host associations and whether they differ among forest strata, sites, seasons, and host age classes or between sexes. Moreover, we assessed the exposure of animals to Rickettsia spp. In total, 432 animals were captured and 808 ticks were found on 32·9% of them. Significant differences were found among host species, collection sites, and forest strata; microhabitat preference was a strong risk factor for tick infestation. The highest tick density rates were recorded in forest fragments settled in rural areas; 91·3% of the ticks were collected from animals trapped in these forest fragments. A high prevalence (68·8%) of antibodies to Rickettsia spp. was detected among animals. This study suggests that disturbed Atlantic Forest fragments provide an environment for ticks and small mammals, which are highly exposed to rickettsiae. It also indicates that forest patches settled in rural areas are usually associated with higher small mammal diversity as well as with higher tick density rates.

The prevalence of Toxoplasma gondii in free-ranging chickens (Gallus domesticus) is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 76 free-range chickens from Guyana, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 50 (65·8%) of 76 chickens with titres of 1:5 in four, 1:10 in one, 1:20 in five, 1:40 in seven, 1:80 in six, 1:160 in eight, 1:320 in four, 1:640 or higher in 15. Hearts and brains of 26 chickens with titres of <1:5 were pooled in 5 batches and bioassayed in mice. Hearts and brains of 50 chickens with titres of 1:5 or higher were bioassayed in mice. Toxoplasma gondii was isolated by bioassay in mice from 35 chickens with MAT titres of 1:20 or higher. All mice inoculated with tissues of 30 infected chickens remained asymptomatic. Toxoplasma gondii isolates from 35 chickens were genotyped using 11 PCR-RFLP markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, a new SAG2, and Apico. A total of 9 genotypes were identified, with 5 genotypes (nos 1, 4, 5, 6 and 7) unique to Guyana, 2 genotypes (nos 2 and 3) previously identified in chickens from Brazil, 1 genotype (no. 8) previously identified in chickens from Brazil, Costa Rica and Nicaragua, and 1 genotype (no. 9) belonging to the clonal type III lineage that exists globally. Infection with 2 genotypes was found from 1 chicken. This is the first report of genetic characterization of T. gondii isolates from any host from Guyana.

The Helminths herein reported are of importance because of their economic and taxonomic relations. To point this out, it is only necessary to mention Haemonchus, whose relation to the Bovidae and Ovidae is equivalent to those of Necator and Ancylostoma to the human host.

Some are well-known roundworms having a world-wide distribution as parasites of animals, and are listed only on account of locality and museum interest; others, especially certain rare forms from uncommon hosts, are of greater interest and are discussed more fully. Certain details, at one time thought not.to be necessary and hence neglected are added because to-day they are indispensable for specific designation.

Because of the abundance of material, it has been possible to supplement accounts given by other authors and to correct some errors due, no doubt, to poor or too few specimens. Several changes in systematic position of known forms and confirmation of others are made.

A new name (D. histrix) is proposed for Dirofilaria subcutanea (Linstow, 1899) Boulenger, 1920. Eustrongylides larvae, of Ciurea, J. 1924, are included under the pre-adult stage of a new species (Eustrongylides wenrichi) because both are alike and their characters fit no other known species. New information is added about Trypanoxyuris trypanuris Vevers, 1923, and Cyrnea coloni Cram, 1927, amending their descriptions.

Descriptions and illustrations of seven new species in as many genera are given. They are Acuaria (Dispharynx) resticula from a groove-billed ani, Ascaridia petrensa from a partridge, Dirofilaria spinosa from a porcupine, Physaloptera multiuteri from a monkey, Subulura pennula from a quail, Spironoura procera from a terrapin, and the above-mentioned pre-adult Eustrongylides wenrichi from a stream pike, brook-trout, calico bass, sunfish, and a frog.

In all there are 162 determinations in 38 genera and 56 species, including new ones, from 150 hosts involving 117 different host species.

Superparasitism and significant cases of parasitism are pointed out because they are of interest to one concerned with incidence and degree of infestation. Numerous records of new host-parasite relations and new localities will be of interest to students of distribution.

We have previously shown the presence of various purine salvage enzymes in Trypanosoma cruzi, including phosphoribosyltransferase, aminohydrolase, kinase, phosphorylase and hydrolase activities. We now report that a similar situation occurs in Leishmania mexicana amazonensis and Trypanosoma brucei brucei. In all three organisms we found higher levels of activity for the phosphoribosyltransferase enzymes than for the nucleoside kinases, suggesting a preference for the salvage of purine bases rather than nucleosides. Similarly, absence of inosine phosphorylase activity suggests that only one route for the salvage of hypoxanthine is available to the three organisms. The most striking difference was that whereas T. cruzi and T. brucei possessed adenosine aminohydrolase activity, this was not detected in L. mexicana; instead adenine amino-hydrolase activity was found. The overall similarity, as judged by the distribution of enzyme activities, of purine salvage in these three members of the kinetoplastida suggest a broad spectrum of activity for any inhibitor acting in this area; the plethora of alternative salvage pathways, however, suggests that in no case would such inhibition be cidal.

With the exception of gudgeon (Gobio gobio) infection of cyprinid fish with the plerocercoid of Ligula intestinalis is associated with a host-tissue response. The nature and specificity of this response has been investigated using transplantation techniques. In roach there is an intense cellular response to implanted Sepharose, Spurr's resin and L. intestinalis, irrespective of donor host species. However, tegument damage only occurs in gudgeon-Ligula and cultured ro&ch-Ligula which has been exposed to gudgeon-plasma. L1 and L2 cell types predominate within the cellular response. Once the host leucocytes have breached the tegument, they migrate over the basal lamina and penetrate into the sub-tegumental region. In gudgeon an intense cellular attack occurs against Sepharose, Spurr's resin, ro&ch-Ligula and cultured gudgeon-Ligula which had been implanted directly or exposed to roach plasma. Tegument damage only occurs in the latter. In contrast, neither direct implantation of gudgeon-Ligula nor cultured roach-Ligula which has been exposed to gudgeon plasma evokes a cellular response. It is suggested that in these two instances, as in natural infections of gudgeon, protective host proteins may be absorbed onto the surface of the parasite.

Among the potential effects of parasitism on host condition, the ‘increased host abilities’ hypothesis is a counterintuitive pattern which might be predicted in complex-life-cycle parasites. In the case of trophic transmission, a parasite increasing its intermediate host's performance facing non-host predators improves its probability of transmission to an adequate, definitive host. In the present study, we investigated the cost of infection with the acanthocephalan Polymorphus minutus on the locomotor/escape performance of its intermediate host, the crustacean Gammarus roeseli. This parasite alters the behaviour of its intermediate host making it more vulnerable to predation by avian definitive hosts. We assessed the swimming speeds of gammarids using a stressful treatment and their escape abilities under predation pressure. Despite the encystment of P. minutus in the abdomen of its intermediate host, infected amphipods had significantly higher swimming speeds than uninfected ones (increases of up to 35%). Furthermore, when interacting with the non-host crustacean predator Dikerogammarus villosus, the highest escape speeds and greatest distances covered by invertebrates were observed for parasitized animals. The altered behaviour observed among the manipulated invertebrates supported the ‘increased host abilities’ hypothesis, which has until now remained untested experimentally. The tactic of increasing the ability of infected intermediate hosts to evade potential predation attempts by non-host species is discussed.

Leptospirosis is a zoonotic bacterial disease of global importance. A large spectrum of asymptomatic animal hosts can carry the infection and contribute to the burden of human disease. Environmental sources of human contamination also point to the importance of a hydrotelluric reservoir. Leptospirosis can be caused by as many as 15 different pathogenic or intermediate Leptospira species. However, classification of these bacteria remains complicated through the use of both serological and genetic classification systems that show poor correlation. With the advent of molecular techniques, DNA-based barcoding offers a conceptual framework that can be used for leptospirosis surveillance as well as source tracking. In this review, we summarize some of the current techniques, highlight significant successes and weaknesses and point to the future opportunities and challenges to successfully establish a widely applicable barcoding scheme for Leptospira.

Since the first description of Marteilia refringens (Paramyxea) in flat oysters Ostrea edulis in 1968 in the Aber Wrach, Brittany (France), the life-cycle of this parasite has remained unknown. However, recent studies, conducted in the ‘claire’ system, have proposed the planktonic copepod Acartia grani as a potential intermediate host for the parasite. Nevertheless, experimental transmission of the parasite through the copepod has failed. Recent studies in this field have reported the presence of the parasite in zooplankton from the bays of the Delta de l'Ebre, a more complex and natural estuarine environment than that of the claire. As a result, 2 new Marteilia host species were proposed: the copepods Oithona sp. (Cyclopoida) and an indeterminate Harpaticoida. Consequently, the objective of the present work was to study the dynamics of Marteilia in the zooplankton community from one of the bays, Alfacs Bay, as well as the dynamics of the parasite in cultivated mussels during 1 complete year. Six different zooplankton taxa appeared to be parasitized by M. refringens, including copepods (3 Calanoida, Acartia discaudata, A. clausi and A. italica; 1 Cyclopoida, Oithona sp.; and 1 Harpacticoida, Euterpina acutifrons), and larval stages of decapod crustaceans (zoea larvae of Brachyura, probably Portumnus sp.). These taxa are thus proposed as new subjects for study, since they could be intermediate hosts in the infection process of mussels by Marteilia.

Most human cases of cryptosporidiosis are caused by Cryptosporidium parvum or Cryptosporidium hominis, but the use of molecular diagnostic methods has revealed that several other less common species or genotypes can also be involved. Here, we describe two unusual causes of cryptosporidiosis, one being the recently described species Cryptosporidium viatorum and the other Cryptosporidium chipmunk genotype I. Two Swedish patients who were infected with C. viatorum had travelled to Kenya and Guatemala, respectively, and two others had been infected with Cryptosporidium chipmunk genotype I in Sweden. None of these four patients were immunocompromised, and all four showed classical symptoms of cryptosporidiosis. We performed extensive molecular characterization, including analysis of four loci. The two C. viatorum isolates were found to differ slightly at the 70-kDa heat shock protein locus, which may indicate a local geographical variation in this species that has previously been described exclusively on the Indian subcontinent.

The dense granule antigen 4 (GRA4) is known as an immundominant antigen of Toxoplasma gondii and, therefore, is considered as a vaccine candidate. For further evaluation of its vaccine effect, a recombinant plasmid and vaccinia virus, both expressing GRA4, were constructed, and a heterologous prime-boost vaccination regime was performed in a mouse model. The mice immunized with the heterologous prime-boost vaccination regime showed a high level of specific antibody response against GRA4 and a significantly high level of gamma interferon (IFN-γ) production and survived completely against a subsequent challenge infection with a lethal dose of T. gondii. In addition, the formation of cysts was inhibited in the mice vaccinated with the heterologous prime-boost vaccination regime. These results demonstrate that the heterologous prime-boost vaccination regime using DNA and a vaccinia virus, both expressing GRA4, could induce both humoral and cellular immune responses and provide effective protection against lethal acute and chronic T. gondii infections in mice.