Showing papers in "Journal of Helminthology in 2012"

Assessing the zoonotic potential of Ascaris suum and Trichuris suis: looking to the future from an analysis of the past.

Abstract: The two geohelminths, Ascaris lumbricoides and Trichuris trichiura, infect more than a billion people worldwide but are only reported sporadically in the developed part of the world. In contrast, the closely related species A. suum and T. suis in pigs have a truly global distribution, with infected pigs found in most production systems. In areas where pigs and humans live in close proximity or where pig manure is used as fertilizer on vegetables for human consumption, there is a potential risk of cross-infections. We therefore review this relationship between Ascaris and Trichuris in the human and pig host, with special focus on recent evidence concerning the zoonotic potential of these parasites, and identify some open questions for future research.

Immune monitoring of Trichuris suis egg therapy in multiple sclerosis patients.

Abstract: Initial clinical trials using Trichuris suis eggs (TSO) in autoimmune diseases such as inflammatory bowel disease, revealed a striking suppressive effect on the autoimmune response. Here, we analysed the effect of TSO therapy on the course of multiple sclerosis (MS), as a Th1/Th17-associated autoimmune disease. Different immunological parameters in four patients with secondary progressive MS were surveyed during a 6-month therapy with TSO, focusing on the modulation of T-cell Th1–Th2 balance as well as on the innate immune response. We are able to show a slight downregulation of the Th1-associated cytokine pattern, especially relevant in interleukin (IL)-2 (P < 0.05 after 2 months of therapy), with a temporary increase of Th2-associated cytokines such as IL-4. Furthermore, mild eosinophily and changes in CD4+ and CD8+T cells and natural killer (NK) CD56 bright cell numbers were observed. The findings observed in this group of patients suggest that TSO therapy has a moderate immunomodulatory impact in MS.

Genetic characterization of Echinococcus granulosus in camels, cattle and sheep from the south-east of Iran indicates the presence of the G3 genotype.

Abstract: Echinococcus granulosus, the aetiologic agent of cystic echinococcosis (CE), is one of the most important zoonotic helminthes worldwide. Isolates of the parasite show considerable genetic variation in different intermediate hosts. Several genotypes and species are described in different eco-epidemiological settings. This study investigated E. granulosus genotypes existing in livestock and humans from the province of Kerman, located in south-eastern Iran, using sequencing data of cox1 and nad1 mitochondrial genes. Fifty-eight E. granulosus isolates, including 35 from sheep, 11 from cattle, 9 from camels and 3 from goats, were collected from slaughterhouses throughout Kerman. One human isolate was obtained from a surgical case of CE. Mitochondrial cox1 and nad1 regions were amplified using polymerase chain reaction (PCR) and 38 isolates were sequenced. Genotypes G1 (73.7%), G3 (13.2%) and G6 (13.1%) were identified from the isolates. G1 was the most common genotype from sheep (86.7%), cattle (80%), camels (44.4%) and goats (100%). Sheep, cattle and camels were also found to be infected with the G3 genotype (buffalo strain). The human isolate was identified as the G6 genotype. Results showed that the G3 genotype occurred in different animal hosts in addition to G1 and G6 genotypes.

Zoonotic schistosomiasis in non-human primates: past, present and future activities at the human-wildlife interface in Africa.

Abstract: Schistosomiasis is one of the world's most widely distributed and prevalent parasitic diseases. Less widely recognized is that some species of Schistosoma, including several that commonly affect humans, also cause disease in other mammalian species; in particular, infections in non-human primates are known. With interest increasing in emerging zoonotic diseases, the status of schistosomiasis as a zoonotic infection is in need of re-appraisal, especially in light of advances in application of molecular screening and epidemiological tools where newly reported infections raise general animal welfare and conservation concerns. Focusing on Africa, this review provides a summary of the occurrence of schistosomiasis in non-human primates and discusses new ways in which surveillance for schistosomiasis should be integrated into more effective conservation management and disease control strategies. Emphasis is on the more common forms of human schistosomiasis, their clinical manifestations and epidemiological significance in terms of infection reservoir potential.

Molecular identification of animal isolates of Echinococcus granulosus from Iran using four mitochondrial genes

Abstract: Mitochondrial genes have more power than nuclear genes in reconstructing phylogenetic relationships among closely related species because of their faster sequence evolution. The aim of this study was to use the complete or near-complete sequences from three mitochondrial genes (cox1, nad1 and atp6) and partial sequences of the 12S rRNA gene to infer relationships among isolates of Echinococcus granulosus from Iran. Two hundred and twenty-nine isolates of E. granulosus were collected from cattle, camels, sheep, buffalo and goats from different geographical areas. Most individuals were found to possess the G1 genotype but some of the camel samples belonged to the G6 genotype. Newly designed primers for cox1, nad1 and atp6 genes amplified bands of 1830, 708 and 1157 bp for the G1 genotype and 1856, 705, 1054 bp for the G6 genotype, respectively. The result of this survey showed that atp6 and nad1 genes are good molecular markers for identifying E. granulosus isolates from a range of hosts in Iran.

Sequence variability in two mitochondrial DNA regions and internal transcribed spacer among three cestodes infecting animals and humans from China.

Abstract: Sequence variability in two mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 4 (nad4), and internal transcribed spacer (ITS) of rDNA among and within three cestodes, Spirometra erinaceieuropaei, Taenia multiceps and Taenia hydatigena, from different geographical origins in China was examined. A portion of the cox1 (pcox1), nad4 genes (pnad4) and the ITS (ITS1+5.8S rDNA+ITS2) were amplified separately from individual cestodes by polymerase chain reaction (PCR). Representative amplicons were subjected to sequencing in order to estimate sequence variability. While the intra-specific sequence variations within each of the tapeworm species were 0-0.7% for pcox1, 0-1.7% for pnad4 and 0.1-3.6% for ITS, the inter-specific sequence differences were significantly higher, being 12.1-17.6%, 18.7-26.2% and 31-75.5% for pcox1, pnad4 and ITS, respectively. Phylogenetic analyses based on the pcox1 sequence data revealed that T. multiceps and T. hydatigena were more closely related to the other members of the Taenia genus, and S. erinaceieuropaei was more closely related to the other members of the Spirometra genus. These findings demonstrated clearly the usefulness of mtDNA and rDNA sequences for population genetic studies of these cestodes of socio-economic importance.

Diversity and distribution of nematodes associated with terrestrial slugs in the Western Cape Province of South Africa.

Abstract: A survey of nematodes associated with native and introduced species of terrestrial slugs was conducted in the Western Cape Province of South Africa, in order to gather new data regarding diversity and distribution. A total of 521 terrestrial slugs were collected from 35 localities throughout the Western Cape. All slugs were dissected and examined for the presence of internal nematodes. Extracted nematodes were identified using a combination of molecular (18S rRNA gene sequencing) and morphological techniques. Nematodes were found parasitizing slugs at 14 of the 35 sites examined, amounting to 40% of sample sites. Of all slugs, 6% were infected with nematodes. A total of seven species of nematode were identified in the province, including Agfa flexilis, Angiostoma sp., Phasmarhabditis sp. SA1, Phasmarhabditis sp. SA2, Caenorhabditis elegans, Panagrolaimus sp. and Rhabditis sp. Of these species, four were thought to be parasitic to slugs (A. flexilis, Angiostoma sp., Phasmarhabditis sp. SA1 and Phasmarhabditis sp. SA2), as opposed to forming necromenic or phoretic associations. Three new species of slug-parasitic nematode were identified during this study (Angiostoma sp., Phasmarhabditis sp. SA1 and Phasmarhabditis sp. SA2).

P-glycoproteins of Haemonchus contortus : development of real-time PCR assays for gene expression studies

Abstract: P-glycoproteins (P-gps) are proteins that function as efflux pumps, removing lipophilic xenobiotic compounds from cells. There is evidence that P-gps play a role in the resistance of parasitic nematodes to anthelmintic drugs such as benzimidazoles and macrocyclic lactones. As anthelmintic resistance becomes more common, it is important to identify candidate resistance genes with the aim of understanding the molecular basis of resistance, and of developing assays to detect these resistance-associated changes. We identified several sequences from the genome of the parasite Haemonchus contortus with convincing homology to the known P-gp coding genes of the model nematode Caenorhabditis elegans. Nine of these sequences were successfully amplified by polymerase chain reaction (PCR) and shown to be most similar to the C. elegans sequences for pgp-1, pgp-2, pgp-3, pgp-4, pgp-9, pgp-10, pgp-11, pgp-12 and pgp-14. These partial P-gp sequences from H. contortus were used to design and optimize a quantitative real-time PCR assay to investigate potential changes in the expression levels of P-gp transcripts associated with drug resistance. No significant changes in P-gp mRNA expression levels were found in a rapidly selected ivermectin-resistant parasite isolate compared to its drug-sensitive parent, but the assay has the potential to be used on other isolates in the future to further investigate resistance-associated changes in P-gp gene expression.

Effects of water quality and trophic status on helminth infections in the cyprinid fish, Schizothorax niger Heckel, 1838 from three lakes in the Kashmir Himalayas.

Abstract: Water quality greatly influences the population density of aquatic biota, including parasites. In order to evaluate the relationship between fish parasites and water quality in Kashmir Himalayas, we assessed helminth parasite densities in Schizothorax niger Heckel, 1838 (an endemic cyprinid fish of Kashmir) from three lakes, namely Anchar, Manasbal and Dal, which reflected the varied stages of eutrophication. The overall prevalence of helminth infections was higher in the hypertrophic Anchar Lake (prevalence = 18.6%) compared to Manasbal Lake, which was the least eutrophied (prevalence = 6.4%). Furthermore, mean prevalence of monoxenous and heteroxenous parasites was higher in lakes containing higher levels of water degradation (Anchar and Dal). The mean number of helminth species per fish host was the highest in the hypertrophic lake (1.3 ± 0.3) in comparison to the least eutrophic lake (0.2 ± 1.5). Variability of calculated infection indices (prevalence, mean intensity and mean abundance) revealed that helminth parasite composition in the fish was affected by the lakes' environmental stress (degraded water quality). Therefore, data on the density of helminth parasites in fish can provide supplementary information on the pollution status of a water body.

The prevalence and fertility of hydatid cysts in buffaloes from Iran.

Abstract: Cystic echinococcosis caused by Echinococcus granulosus is considered to be an important parasitic infection in livestock. In the present study, which aimed to determine the epidemiology of hydatidosis in buffalo in Iran, slaughterhouses of West Azerbaijan (Urmia), East Azerbaijan (Tabriz), Ardabil (Ardabil), Gilan (Rasht and Hashtpar) and Khuzestan (Ahvaz) were inspected. Age, sex and infected organs were recorded separately, and the observed cysts were examined for fertility and viability. Our results showed that 344 (9%) of 3832 inspected buffaloes were infected with hydatid cysts. The maximum and minimum infection rates occurred in Khuzestan (9.9%) and Ardabil (8%) provinces, respectively. There was no significant difference in the rate of infection in all provinces. Of 344 infected buffaloes, the rate of fertility was 7.3% and the rate of viability in fertile cysts was 78.75%. Hydatid cysts were more prevalent in female compared with male buffaloes (P < 0.05). There was a positive correlation between the age and number of infected hosts in all provinces except East Azerbaijan. The prevalence of infection in lungs was significantly higher than that in the livers of buffaloes in the provinces studied (P < 0.001). In conclusion, the fertility of hydatid cysts in buffaloes was low, as previously demonstrated in cattle, and this animal may play a minor role in the epidemiology of hydatidosis in Iran.

Genetic variation among Clonorchis sinensis isolates from different geographic regions in China revealed by sequence analyses of four mitochondrial genes.

Abstract: The present study examined sequence variation in four mitochondrial (mt) genes, namely cytochrome c oxidase subunits 1 (cox1) and 2 (cox2), and NADH dehydrogenase subunits 1 and 2 (nad1 and nad2) among Clonorchis sinensis isolates from different endemic regions in China, and their phylogenetic relationships with other zoonotic trematodes were reconstructed. A portion of the cox1 and cox2 genes (pcox1 and pcox2), and nad1 and nad2 genes (pnad1 and pnad2) were amplified separately from individual liver flukes by polymerase chain reaction (PCR) and the amplicons were subjected to sequencing from both directions. The intra-specific sequence variations within C. sinensis were 0-1.6% for pcox1, 0-1.4% for pcox2, 0-0.9% for pnad1 and 0-1.0% for pnad2. Phylogenetic analyses based on the combined sequences of pcox1, pcox2, pnad1 and pnad2 revealed that all the C. sinensis isolates grouped together and were closely related to Opisthorchis felineus. These findings revealed the existence of intra-specific variation in mitochondrial DNA (mtDNA) sequences among C. sinensis isolates from different geographic regions, and demonstrated that mtDNA sequences provide reliable genetic markers for phylogenetic studies of zoonotic trematodes.

Seroprevalence of toxocariasis in hypereosinophilic individuals in Ahwaz, south-western Iran.

Abstract: Eosinophilia in human peripheral blood is caused by different agents, including toxocariasis. The present study aimed to evaluate the prevalence of toxocariasis in hypereosinophilic individuals in the city of Ahwaz, located in south-western Iran, using enzyme-linked immunosorbent assay and Western blot techniques. Serum samples were examined from 100 individuals with peripheral blood eosinophilia and also from another 100 individuals without eosinophilia as the control group. In hypereosinophilic individuals seroprevalence antibodies against Toxocara were found in 19 (19%), of whom 12 (63.15%) were female and 7 (36.85%) were male. Positive sera were subsequently confirmed by Western blot. All of the observed bands ranged from 24 to 100 kDa. Antibodies against Toxocara were found in 1% of the control group, but were not confirmed by Western blot. The results showed significant differences between the frequency of infection within age and gender (P < 0.05); the highest prevalence of infection was observed in adults. Differences between the hypereosinophilic and healthy individuals, in terms of Toxocara infection frequency, also proved significant (P < 0.05).The present study thus confirmed the significant prevalence of toxocariasis as a hygienic problem among hypereosinophilic individuals in this area. It is, therefore, necessary to examine these individuals for toxocariasis.

Assessing host-parasite specificity through coprological analysis: a case study with species of Corynosoma (Acanthocephala: Polymorphidae) from marine mammals.

Abstract: In this paper we report an investigation of the utility of coprological analysis as an alternative technique to study parasite specificity whenever host sampling is problematic; acanthocephalans from marine mammals were used as a model. A total of 252 scats from the South American sea lion, Otaria flavescens, and rectal faeces from 43 franciscanas, Pontoporia blainvillei, from Buenos Aires Province, were examined for acanthocephalans. Specimens of two species, i.e. Corynosoma australe and C. cetaceum, were collected from both host species. In sea lions, 78 out of 145 (37.9%) females of C. australe were gravid and the sex ratio was strongly female-biased. However, none of the 168 females of C. cetaceum collected was gravid and the sex ratio was not female-biased. Conversely, in franciscanas, 14 out of 17 (82.4%) females of C. cetaceum were gravid, but none of 139 females of C. australe was, and the sex ratio of C. cetaceum, but not that of C. australe, was female-biased. In putative non-hosts, the size of worms was similar to that from specimens collected from prey. Results suggest that both acanthocephalans contact sea lions and franciscanas regularly. However, C. australe and C. cetaceum cannot apparently reproduce, nor even grow, in franciscanas and sea lions, respectively. Coprological analysis may represent a useful supplementary method to investigate parasite specificity, particularly when host carcasses are difficult to obtain.

Seroprevalence of Toxocara infection in children and environmental contamination of urban areas in Paraná State, Brazil.

Abstract: The objectives of this study were to evaluate the contamination by eggs of Toxocara in sandy areas or grass lawns of outdoor recreation areas that are used by children, and the frequency of seroprevalence in children, from three cities of fewer than 45,000 inhabitants in Parana, Brazil. From May 2005 to December 2007, five samples were taken from each of 13 sandy sites and 18 grass lawns, all from plazas and public schools. Blood samples from children aged 0-12 years were analysed by immunoassay for anti-Toxocara IgG. The soil samples were processed by floatation and sedimentation. Eggs of Toxocara spp. were present in 44.7% (38/85) of the samples from grassed areas and in 21.4% (15/70) of the sand samples. The lawns were 2.16 times more contaminated than the sand (P = 0.0009). However, the epidemiological variables showed no statistically significant difference between seropositive (36.8%; 130/353), and seronegative children. The rate of seropositivity was higher in children aged 0-5 years (P = 0.03), who were 1.94 times more likely to develop persistent wheezing (P = 0.02).

Molecular characterization of pouched amphistome parasites (Trematoda: Gastrothylacidae) using ribosomal ITS2 sequence and secondary structures.

Abstract: Members of the family Gastrothylacidae (Trematoda: Digenea: Paramphistomata) are parasitic in ruminants throughout Africa and Asia. In north-east India, five species of pouched amphistomes, namely Fischoederius cobboldi, F. elongatus, Gastrothylax crumenifer, Carmyerius spatiosus and Velasquezotrema tripurensis, belonging to this family have been reported so far. In the present study, the molecular phylogeny of these five gastrothylacid species is derived using the second internal transcribed spacer (ITS2) sequence and secondary structure analyses. ITS2 sequence analysis was carried out to see the occurrence of interspecific variations among the species. Phylogenetic analyses were performed for primary sequence data alone as well as the combined sequence-structure information using neighbour-joining and Bayesian approaches. The sequence analysis revealed that there exist considerable interspecific variations among the various gastrothylacid fluke species. In contrast, the inferred secondary structures for the five species using minimum free energy modelling showed structural identities, in conformity with the core four-helix domain structure that has been recently identified as common to almost all eukaryotic taxa. The phylogenetic tree reconstructed using combined sequence-structure data showed a better resolution, as compared to the one using sequence data alone, with the gastrothylacid species forming a monophyletic group that is well separated from members of the other family, Paramphistomidae, of the amphistomid flukes group. The study provides the molecular characterization based on primary sequence data of the rDNA ITS2 region of the gastrothylacid amphistome flukes. Results also demonstrate the phylogenetic utility of the ITS2 sequence-secondary structure data for inferences at higher taxonomic levels.

Infection dynamics of Cichlidogyrus tilapiae and C. sclerosus (Monogenea, Ancyrocephalinae) in Nile tilapia (Oreochromis niloticus L.) from Uganda.

Abstract: The infection dynamics of the gill monogeneans Cichlidogyrus tilapiae and C sclerosus on Oreochromis niloticus with respect to habitat type (reservoir, stream, ponds and cages), host sex, size and seasons was determined between January and November 2008 During the study period, 452% of the 650 fish examined were infected with Cichlidogyrus spp The infected hosts harboured an average of 86 ± 34 parasites/fish Across habitat types, the proportion of infected fish was not statistically different In contrast, the number of parasites recorded on infected fish from different habitat types differed significantly The highest parasite number was recorded in reservoir-dwelling fish and lowest in stream-dwelling hosts Concerning sex, more female O niloticus were infected and harboured a high number of parasites than male and sexually undifferentiated fish A weak negative relationship was found between rainfall and monthly parasite infections However, a higher number of parasites and proportion of infected hosts were found during dry than in wet seasons, except in ponds Results of this study show that differential exposure due to changes in fish behaviour associated with habitat modification and sex may account for the infection difference across the sampled sites Meanwhile, rainfall and the associated hydrological events are important factors regulating monogenean infections in tropical aquatic environments The continuous presence of Cichlidogyrus spp in fish provides evidence of possible parasite outbreaks, indicating the application of biosecurity measures as crucial for the success of intensive fish farming

High levels of Schistosoma mansoni infections among schoolchildren in central Sudan one year after treatment with praziquantel

Abstract: A longitudinal study was conducted to evaluate the impact of praziquantel (PZQ) for the treatment of Schistosoma mansoni infection among schoolchildren in Al Gunaid in Central Sudan. A cohort of schoolchildren (6-15 years of age) was investigated before and 1 year after treatment with a single dose of PZQ 40 mg/kg. Parasitological examinations for S. mansoni were performed before and after treatment, and prevalence and intensity of infection were analysed. Of 2741 schoolchildren recruited from six elementary schools at baseline, 2521 were successfully traced and re-examined at follow-up, with two complete sets of longitudinal parasitological data on S. mansoni. Boys showed significantly higher prevalence of S. mansoni infection than girls. A single dose of PZQ reduced the overall prevalence of S. mansoni infection by 36.7% (from 59.1 to 37.4%) and the intensity of infection by 41.1% (from 116.7 to 68.7 eggs per gram of stool) 1 year after treatment. The reduction in prevalence was significantly higher among the group of children with heavy infections (by 76.1%, from 6.7 to 1.6%) and among girls (by 54.1%, 42.3 to 19.4%) at 1 year after treatment. Thus, in spite of a significant reduction in the prevalence and intensity of S. mansoni infection 1 year after PZQ treatment, the prevalence of the disease was still high and further research is needed on this topic.

The first report on cystic echinococcosis in a cat caused by Echinococcus granulosus sensu stricto (G1).

Abstract: A case of cystic echinococcosis (CE) in a domestic cat is described from Saint Petersburg, Russia. Ultrasonography showed numerous cysts with hyperechoic walls and anechoic contents within the cat's abdominal cavity. Molecular identification based on mitochondrial DNA genes indicated that the causative agent was Echinococcus granulosus sensu stricto (G1 strain). This is the first report of CE in a cat caused by E. granulosus sensu stricto with molecular confirmation.

Sequence variability in three mitochondrial DNA regions of Spirometra erinaceieuropaei spargana of human and animal health significance.

Abstract: Sequence variability in three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 3 (cox3), NADH dehydrogenase subunits 1 and 4 (nad1 and nad4) in Spirometra erinaceieuropaei spargana from different geographical regions in China was examined. A portion of each of the cox3 (pcox3), nad1 (pnad1) and nad4 genes (pnad4) were amplified separately from individual S. erinaceieuropaei spargana by polymerase chain reaction (PCR). Representative amplicons were subjected to sequencing in order to estimate sequence variability. The sequences of pcox3, pnad1 and pnad4 were 541, 607 and 847 bp in length, respectively. The A+T contents of the sequences were 68.39-68.76% (pcox3), 63.76-64.91% (pnad1) and 67.18-67.77% (pnad4), respectively, while the intra-specific sequence variations within each of the S. erinaceieuropaei spargana were 0-1.5% for pcox3, 0-2.8% for pnad1 and 0-2.7% for pnad4. Phylogenetic analysis using neighbour joining (NJ), maximum likelihood (ML) and maximum parsimony (MP) methods, indicated that all the spargana isolates in Hunan Province represented S. erinaceieuropaei. These findings demonstrated clearly the usefulness of the three mtDNA sequences for population genetics studies of S. erinaceieuropaei spargana of human and animal health significance.

The occurrence of Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis and Anaplasma phagocytophium in dogs in China.

Abstract: A survey of the occurrence of Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis and Anaplasma phagocytophium in dogs was undertaken in the People's Republic of China between October 2008 and October 2009. A total of 600 blood samples were taken from dogs in four cities in China: 300 in Beijing, 150 in Shenzhen, 30 in Shanghai and 120 in Zhengzhou. All samples were tested for the heartworm antigen and antibodies of canine B. burgdorferi, E. canis and A. phagocytophium by using the canine SNAP® 4Dx® test kit. The occurrence of D. immitis, B. burgdorferi, E. canis and A. phagocytophium was 1.17% (7/600), 0.17% (1/600), 2.17% (13/600) and 0.5% (3/600), respectively. In Shenzhen city 2% (3/150), 8.67% (13/150) and 2% (3/150) of samples were positive for D. immitis, E. canis and A. phagocytophium, respectively. The occurrence of heartworm antigen was 0.33% (1/300) in Beijing, 2.00% (3/150) in Shenzhen, 3.33% (1/30) in Shanghai and 1.67% (2/120) in Zhengzhou. We found E. canis and A. phagocytophium only at one site, Shenzhen, while the only occurrence of B. burgdorferi was at Beijing. In conclusion, the dog population in China is at potential risk for D. immitis, B. burgdorferi, E. canis and A. phagocytophium infection, the risk being especially high in southern China.

Platynosomum fastosum-induced chronic intrahepatic cholangitis and Spirometra spp. infections in feral cats from Grand Cayman.

Abstract: The occurrence of platynosomiasis and intestinal sparganosis is described in feral cats from Grand Cayman, Cayman Islands. Spirometra spp. was observed within the intestine of 18.18% (10/55) of cats; 1.18% (1/55) of cats demonstrated gross and histological manifestation of parasitism by Platynosomum fastosum, but 14.5% (8/55) of cats had the characteristic pathological manifestations of P. fastosum-induced intrahepatic cholangitis without the concomitant presence of the intraductal trematode. Combined parasitism (Spirometra spp. and P. fastosum) was observed in 9.09% (5/55) of feral cats. Significant pathological findings were only associated with the hepatic fluke, P. fastosum, and were grossly characterized by moderate hepatomegaly with enlarged and dilated bile ducts. Examples of cestodes with morphological features characteristic of Spirometra spp. were observed within the small intestine without any associated pathological lesion. The histopathological evaluation of liver fragments revealed chronic intrahepatic cholangitis with and without the associated intraductal trematode, and was characterized by marked periductal fibrosis, adenomatous proliferation of bile duct epithelium, dilation of intrahepatic bile ducts and portal accumulations of inflammatory cells. The occurrence of the cestode in feral cats coupled with factors that are unique to Grand Cayman makes this island the ideal location for sporadic cases of human sparganosis.

Helminth parasites of the oceanic horse mackerel Trachurus picturatus Bowdich 1825 (Pisces: Carangidae) from Madeira Island, Atlantic Ocean, Portugal.

Abstract: The helminth parasite fauna of the oceanic horse mackerel Trachurus picturatus Bowdich 1825, caught off the Madeira Islands was composed of six different taxa. Prevalence and abundance of larval Anisakis sp. (Nematoda: Anisakidae) and Nybelinia lingualis (Trypanorhyncha: Tentaculariidae), the most common parasite taxa, were 24.3%, 0.9 and 37.9%, 0.7, respectively. Bolbosoma vasculosum (Acanthocephala: Polymorphidae) and the monogeneans Heteraxinoides atlanticus (Monogenea: Heteraxinidae) and Pseudaxine trachuri (Monogenea: Gastrocotylidae) were comparatively rare. The depauperate helminth fauna of the oceanic horse mackerel at Madeira compared to other geographical regions of the north-eastern Atlantic, namely the Azores banks and the West African coast, may be attributed to the paucity of nutrients off oceanic islands and to a low density of the fish population.

The epidemiology of soil-transmitted helminth and protozoan infections in south-west Cameroon.

Abstract: A cross-sectional study of the prevalence, intensity and effects of soil-transmitted helminth and protozoan infections was undertaken among patients at the Buea Hospital Annex located in Buea sub-division of Cameroon. Stool samples from 356 subjects (174 males and 182 females) were collected and processed using standard concentration methods. Our results showed that 31.0% of subjects were infected with intestinal helminths and the prevalence was higher in females (32.4%) than in males (30.5%). A significantly higher prevalence was observed in rural (47.2%) than in urban areas (21.0%); significance < 0.1%. Prevalence was highest among those aged between 6 and 12 years (41.4%). The total prevalence of intestinal helminth infections were 19.3% for Ascaris lumbricoides, 14.0% for hookworm and 11.8% for Trichuris trichiura. The intensity of infection was unevenly distributed, with very heavy loads concentrated in a few individuals. Data also showed that 28.1% (100/356) of the subjects were infected with protozoans. Females showed a higher prevalence (28.6%; 52/182) than males (20.7%; 36/174). Also, there was a significantly higher prevalence in rural (34.0%; 49/144) than urban areas (18.4%; 39/212); significance < 0.1%. The age group 6-12 years again had a higher prevalence (37.1%; 26/70). The total prevalence of intestinal protozoans was: Entamoeba histolytica (24.4%), Entamoeba coli (11.2%) and Giardia lamblia (0.6%). These relatively heavy prevalences in patients may be reduced by appropriate medication and maintaining strict personal hygiene. Health education, clean water supply, good sewage management and a congenial environment will all help to minimize infection.

Pochonia chlamydosporia fungal activity in a solid medium and its crude extract against eggs of Ascaridia galli

Abstract: The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates of Pochonia chlamydosporia in a solid medium and the action of a crude extract of P. chlamydosporia against eggs of Ascaridia galli. To evaluate ovicidal activity in culture medium, 1000 A. galli eggs were plated on Petri dishes containing 2% water-agar with grown fungal isolates (VC1 or VC4) and without fungus (control group) and were examined at 1, 3 and 5 days post-inoculation (assay A). Then, to test the action of crude extracts of P. chlamydosporia (VC1 or VC4), 500 eggs of A. galli were plated on Petri dishes of 4.5 cm diameter with 5 ml of fungal filtrate from each tested isolate. The control group consisted of 500 eggs of A. galli with 10 ml of distilled water on each Petri dish (assay B). Fungal isolates were effective (P < 0.01) at destroying these eggs, showing a type 3 effect at the studied intervals. On the other hand, the crude extract of isolates (VC1 or VC4) reduced the number of A. galli eggs in the treated group compared with the control group by 64.1% and 56.5%, respectively. The results of the present study show that P. chlamydosporia is effective at destroying eggs of A. galli and could therefore be used in the biological control of nematodes.

Levels of infection of gastric nematodes in a flock of great cormorants (Phalacrocorax carbo) from Lake Biwa, Japan.

Abstract: A high prevalence (86.7%) of various species of nematodes was observed in the stomach of great cormorants living in Lake Biwa, Japan. There were varying numbers of adults belonging to two common genera, Eustrongylides Jagerskiold 1909 (Nematoda: Dioctophymatidae) and Contracaecum Railliet & Henry 1912 (Nematoda: Anisakidae). The first included common adenophorean nematodes comprising a single species, Eustrongylides tubifex and the second comprised ascaroid nematodes that contained four named species: Contracaecum rudolphii Hartwich, 1964, Contracaecum microcephalum Yamaguti, 1961, Contracaecum multipapillatum Drasche, 1882 and Contracaecum chubutensis Garbin, 2008. After the prevalence and intensity of the infection had been noted, both types of nematodes were frequently observed to penetrate the mucosa and intrude into the wall of the glandular stomach, where they caused gross haemorrhage and ulceration. The Eustrongylides sp. was predominantly found in a nodular lesion of the proventricular wall, while Contracaecum spp. were observed either free in the lumen of the proventriculus or, on occasion, deeply penetrating its wall. Of the Contracaecum spp., C. rudolphii was the most prevalent. Grossly, large numbers of nematodes were present in infected stomachs (for C. rudolphii intensity was 1-34 and 3-57 nematodes in male birds and 1-21 and 1-32 in females; for C. microcephalum 1-2 and 1 in male birds and 1-2 in females; for C. multipapillatum 2 in male cormorants and no infection in females; for C. chubutensis 1-2 and 1 in male birds and 1-5 and 1 in females and for E. tubifex 1-5 nematodes in male birds and 2-8 in females). Ulcerative inflammation and hyperaemia were the most common pathological presentations, especially in areas that had been invaded by parasites. Microscopically, varying degrees of granulomatous inflammatory reactions were seen, in addition to degenerated nematodes which appeared to have deeply penetrated mucosal surfaces and were surrounded by fibrous connective tissues.

The development of PCR methodology for the identification of species of the tapeworm Moniezia from cattle, goats and sheep in central Vietnam.

Abstract: The aims of this study were to investigate the prevalence of Moniezia spp. in domestic ruminants in central Vietnam and to develop a polymerase chain reaction (PCR) technique to distinguish M. expansa from M. benedeni. Among 2040 examined domestic animals (540 cattle, 800 goats, 700 sheep) Moniezia was recovered from 5.4% of cattle, 16.4% of sheep and 20.6% of goats. A set of primers for PCR was designed to classify M. expansa and M. benedeni based on the amplification of DNA corresponding to the internal transcribed spacer of 5.8S rRNA. The 457 specimens (75 from cattle, 162 from goats, 150 from sheep, 30 from horses, 30 from chickens and 10 from dogs) were subjected to PCR for classification of Moniezia spp. PCR products with the expected sizes were amplified from bovine, ovine and caprine specimens. No specific PCR products were found for specimens from horses, chickens and dogs. Of the 75 specimens from cattle, nine were classified as M. expansa and 66 were M. benedeni. Among 162 caprine specimens, 138 were M. expansa and 24 were M. benedeni. The distribution of M. expansa and M. benedeni in 150 ovine specimens was 132 and 18, respectively. These results show that M. expansa is dominant in goats and sheep, whereas M. benedeni is more common in cattle; PCR can be used for classification of these two species.

Schistosoma haematobium infections in preschool children from two rural communities in Ijebu East, south-western Nigeria.

Abstract: There is an urgent need for information on schistosomiasis in preschool children, who are often excluded in mass treatment programmes. The prevalence and intensity of Schistosoma haematobium infection were determined in preschool children aged ≤ 6 years in two rural communities in Ijebu East, south-western Nigeria. Two urine samples each were collected from 83 preschool children from the two communities, tested for microhaematuria using reagent strips and then processed and examined with a microscope for S. haematobium eggs. Focus group discussions on perceptions of the disease and water contact practices were held in the communities with their guardians, caregivers and preschool children, using an interview guide. The prevalence of S. haematobium in the two communities was 14 (16.9%), with no significant differences (P = 0.661) in infection rate between boys (18.4%) and girls (14.7%). Both prevalence and intensity of infection did not increase significantly with age in both Korede and Obada community. However, there were significant differences in prevalence of infection between the two communities (P = 0.035). There was no association (P = 0.750) between intensity in boys (0.176 eggs/10 ml urine) and girls (0.110 eggs/10 ml urine). Focal group discussions with guardians and caregivers revealed that preschool children acquired infection early in their lives through exposure to infected stream water by their mothers, while the older children visit the stream for playing, bathing and swimming. It has therefore become imperative for preschool children to be included in the planning of schistosomiasis intervention programmes as a means of reducing transmission.

Canine filarial infections in Tuscany, central Italy.

Abstract: This study was conducted in order to investigate the epidemiology of filarial species in a region of central Italy (Tuscany) in dogs that did not undergo prophylaxis for filariasis. From 2007 to 2009, 630 blood samples were collected from 40 kennels throughout the regional territory. Samples were analysed with Knott's modified test and with an enzyme-linked immunosorbent assay (ELISA) for the detection of Dirofilaria immitis antigens, those positive for microfilariae were also subjected to histochemical staining for acid phosphatase activity to validate the identification of the species. An overall elevated prevalence of filariasis (23.2%) was found. Dirofilaria immitis and D. repens were found to be the dominant species, with similar prevalences (12.5% and 12.1% respectively), while Acanthocheilonema reconditum was less common (1.9%). Results of this study indicate that monitoring for filariasis should be kept at a high level. A constant monitoring of the canine sanitary status should also be carried out for the protection of human health, considering the zoonotic potential of filarial worms.

Endoparasite fauna of five Gadiformes fish species from the coast of Chile: host ecology versus phylogeny

Abstract: The aims of the present study were to compare, using multivariate analyses, the degree of similarity of the endoparasite fauna of five fish species belonging to the order Gadiformes: Merluccius gayi, Merluccius australis, Macruronus magellanicus (Gadoidei) and Micromesistius australis and Nezumia pulchella (Macrouroidei), from the southern and central Chilean coast, and to evaluate whether the composition of the endoparasite fauna was determined by phylogenetic or ecological relationships. We employed our database of Merluccius australis, M. magellanicus and Micromesistius australis, which was complemented with published information for M. magellanicus, Merluccius australis, Micromesistius australis, M. gayi and N. pulchella. A higher number of endoparasite species was recorded for Merluccius australis, Micromesistius australis and M. magellanicus, namely Anisakis sp. and Hepatoxylon trichiuri, which is the most prevalent parasite among these hosts. Aporocotyle wilhelmi and Hysterothylacium sp. were detected only in M. gayi, whereas Lepidapedon sp. was found exclusively in N. pulchella. These results suggest that fish ecology rather than host phylogeny was the most important factor for the determination of similarity in parasite composition. This result could be explained by the similar trophic patterns of hosts and by the predominance of generalist larval species among these fish parasite communities.

Evaluation of the immune response induced by DNA vaccines expressing MIF and MCD-1 genes of Trichinella spiralis in BALB/c mice.

Abstract: Plasmids expressing macrophage migration inhibitory factor (MIF) of Trichinella spiralis (TsMIF), multi-cystatin-like domain protein (MCD-1) of T. spiralis (TsMCD-1), or co-expressing TsMIF and TsMCD-1 were constructed with a pVAX1 vector. Their ability to generate a protective immune response against T. spiralis infection was evaluated in BALB/c mice. Groups of mice were immunized twice at 2-week intervals with 100 μg of recombinant plasmids pVAX1-Tsmif, pVAX1-Tsmcd-1 or pVAX1-Tsmif-Tsmcd-1. Control animals were immunized with phosphate-buffered saline (PBS) or blank vector plasmid. Specific antibody levels (IgG, IgG1, IgG2a, IgG2b, IgM, IgA, IgE) against the recombinant protein TsMIF-TsMCD-1, serum cytokines (interferon (IFN)-γ, interleukin (IL)-4, IL-5, transforming growth factor (TGF)-β1 and IL-17) and CD4+/CD8+ T cells were monitored. Challenge infection was performed 2 weeks following the second immunization and worm burden was assayed at 35 days post-challenge. Vaccination with pVAX1-Tsmif induced moderate serum IFN-γ and increases of CD4+ and CD8+ T cells, but no specific immunoglobulin antibody response. Vaccination with pVAX1-Tsmcd-1 induced a predominant Th1 antibody (IgG2a and IgG2b) response and strong levels of serum IFN-γ, and increases of CD4+ T cells. Importantly, co-expression of TsMIF and TsMCD-1 in DNA immunization produced more serum IFN-γ and markedly enhanced CD4+ and CD8+ T cells than the single DNA vaccine of the two genes. Challenge infection demonstrated that immunization with pVAX1-Tsmif-Tsmcd-1 reduced worm burdens (by 23.17%; P < 0.05).