Average Intensity Of Infection Research Articles

Brook Trout, Brown Trout, and Ectoparasitic CopepodsSalmincola edwardsii: Species Interactions as a Proximate Cause of Brook Trout Loss Under Changing Environmental Conditions

AbstractChanges in environmental conditions are expected to affect stream temperature and ultimately the presence of native Brook TroutSalvelinus fontinalisin Wisconsin streams. While change in climate may be an ultimate cause of Brook Trout loss, proximate causes may involve factors other than intolerance to high temperatures. Here I present data to support the hypothesis that species interactions among Brook Trout, naturalized Brown TroutSalmo trutta, and ectoparasitic copepodsSalmincola edwardsiiin the context of changing environmental conditions can lead to declines in Brook Trout recruitment and abundance. WhileS. edwardsiiare endemic to Wisconsin streams and infect Brook Trout, they do not infect Brown Trout.Salmincola edwardsiiwere first documented in Ash Creek, Wisconsin, in 2010 and became epizootic in 2012. Conditions in 2012 conducive to an epizootic included anomalously warm stream temperatures, relative drought conditions, and an increasing sympatric population of Brown Trout. Infection prevalence increased from 42% in April 2012 to 95% in October. Average intensity of infection in 2012 was 5.5 copepods per age‐0 Brook Trout and 16.1 per Brook Trout age 1 and older. Variation in Brook Trout recruitment appeared to be related to stock size and environmental factors, including flood events, Brown Trout abundance, andS. edwardsiiepizootics. In 2012, flow conditions were conducive to salmonid recruitment, but Brook Trout recruitment fell precipitously relative to that of Brown Trout. Recruitment of age‐0 Brook Trout duringS. edwardsiiepizootics in 2012–2014 decreased about 77% and 89% compared with recruitment in 2007–2011 and 2005–2006, respectively. Following three consecutive years ofS. edwardsiiepizootics and poor recruitment, Brook Trout were nearing extirpation from Ash Creek. The data support the hypothesis that species interactions among fish and an ectoparasitic copepod under stressful environmental and ultimately climatic conditions can be a proximate cause of native Brook Trout loss.Received February 15, 2016; accepted July 28, 2016 Published online September 30, 2016

Urogenital schistosomiasis and associated determinant factors among senior high school students in the Dutsin-Ma and Safana Local Government Areas of Katsina State, Nigeria

BackgroundHuman schistosomiasis is a chronic parasitic disease of poverty caused by the cercariae of digenetic trematodes of the genus Schistosoma. The disease is a major source of morbidity and mortality in 77 low- and middle-income countries in the tropics where 700 million people are at risk. In a bid to provide relevant epidemiological information to boost control of urogenital schistosomiasis at the state level in Nigeria, we conducted this study with the aim of investigating the disease’s prevalence and intensity, and the determinant factors responsible for its endemicity.MethodsData on risk factors were obtained from a total of 645 students aged 12─25 years using well- designed questionnaires. Samples were collected between 09:45 and 14:00 in universal bottles. Each10μl centrifuged sample was examined for the eggs of S. haematobium using Motic® (Binocular) Light Microscope (model S-10-P) with a x10 objective. Average infection intensity was recorded as number of eggs per 10 ml of urine sample. Survey data were entered into Microsoft Excel 2010 and analyzed using Epi Info™ 7. Associations among variables were determined using the chi square test and bivariate and multivariate logistic regressions.ResultsPrevalence of urogenital schistosomiasis was 30.54 % among the study population, with a mean infection intensity of 30.27 eggs/10 ml of urine. Prevalence and average intensity were higher in males (28.37 % and 32.21 eggs/10 ml of urine respectively) than in females (2.17 % and 5 eggs/10 ml of urine respectively). Water contact activities (X2 = 29.031, P = 0.0000), sex (male) [X2 = 109.82; P<0.0001], location (Dutsin─Ma) [X2 = 7.19; P = 0.0073], age group 18-20 (X2 = 4.819, P = 0.0281), altitude (531─560 m) [X2 = 6.84, p = 0.0089], fathers doing other brown─collar jobs (X2 = 8.449, P = 0.0037) and mothers’ occupation (X2 = 9.470, P = 0.0021) were found to be significantly associated with urogenital schistosomiasis. Boys were six times more likely to be infected with the cercariae of S. haematobium compared to girls [AOR (95 % CI): 6.34 (4.89─8.22)].ConclusionsDutsin-Ma and Safana were classified as moderate-risk Local Government Areas for urogenital schistosomiasis. The strong association between the disease and mother’s occupation is of utmost importance and suggests a promising control measure: that is, directing health education as well as grassroots mass chemotherapeutic intervention with praziquantel at mothers. A good network including treated pipe-borne water, drainage system, and sewage disposal facilities available should be improved upon. Molluscicides should be provided at highly subsidized rate to help control the disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0158-1) contains supplementary material, which is available to authorized users.

Prevalence of Soil-Transmitted Helminths and Molecular Clarification of Hookworm Species in Ethnic Ede Primary Schoolchildren in Dak Lak Province, Southern Vietnam.

To know the infection status of helminths in primary schoolchildren of southern parts of Vietnam, we performed an epidemiological study in Krong Pac district, Dak Lak Province, Vietnam. A total of 1,206 stool specimens were collected from ethnic Ede schoolchildren in 4 primary schools in 2015 and examined by the Kato-Katz technique. In addition, stool cultures were done by the Harada-Mori method to obtain hookworm larvae and then to clarify the species of hookworms infected. The results showed that the helminth infection rate was 25.0%, including 2.0% Ascaris lumbricoides, 0.33% Trichuris trichiura, and 22.8% hookworm infections. The average intensity of infection was 102.0 eggs per gram of feces (EPG) for Ascaris, 36.0 EPG for Trichuris, and 218.0 EPG for hookworms. ITS1 gene sequences of the hookworm larvae were identical with those of Necator americanus (100% homology) reported in GenBank. It has been confirmed in this study that the hookworm, N. americanus, is a dominant helminth species infected in primary schoolchildren of a southern part of Vietnam. Public health attention is needed for control of hookworm infections among schoolchildren in surveyed areas of Vietnam.

Assessing the performance of multiplexed tandem PCR for the diagnosis of pathogenic genotypes of Theileria orientalis using pooled blood samples from cattle

Oriental theileriosis caused by multiple genotypes of Theileria orientalis is an important tick-borne disease of bovines. Here, we assessed the performance of an established multiplexed tandem PCR (MT-PCR) for the diagnosis of the two recognized, pathogenic genotypes (chitose and ikeda) of T. orientalis in cattle using pooled blood samples. We used a total of 265 cattle blood samples, which were divided into two groups according to previous MT-PCR results for individual samples. Samples in group 1 (n = 155) were from a herd with a relatively high prevalence of T. orientalis infection; and those in group 2 (n = 110) were from four herds with a low prevalence. For group 1, 31 and 15 batches of five- and ten-pooled samples (selected at random), respectively, were formed. For group 2, 22 and 11 batches of five- and ten-pooled samples (selected at random), respectively, were formed. DNAs from individual pooled samples in each batch and group were then tested by MT-PCR. For group 1, the apparent prevalences estimated using the 31 batches of five-pooled samples (97%) and 15 batches of ten-pooled samples (100%) were significantly higher compared with individual samples (75%). For group 2, higher apparent prevalences (9% and 36%) were also recorded for the 22 and 11 batches of pooled samples, respectively, compared with individual samples (7%). Overall, the average infection intensity recorded for the genotypes of chitose and ikeda were considerably lower in pooled compared with individual samples. The diagnostic specificities of MT-PCR were estimated at 95% and 94%, respectively, when batches of five- and ten-pooled samples were tested, and 94% for individual samples. The diagnostic sensitivity of this assay was estimated at 98% same for all individual, five- and ten-pooled samples. This study shows that screening batches of five- and ten-pooled blood samples from cattle herds are similar to those obtained for individual samples, and, importantly, that the reduced cost for the testing of pooled samples represents a considerable saving to herd managers.

Eumetazoan parasites of two marine fish species from Baja California, Mexico:Sebastes miniatus(Jordan &amp; Gilbert, 1880) andCaulolatilus princeps(Jenyns, 1840)

It is hypothesized that two fish species sharing a same demersal habitat might show a similar community of parasites. The aim of this study was to compare the parasite community component of of two marine fishes on the northwest coast of México of economical interest, the vermilion rockfish Sebastes miniatus and the ocean whitefish Caulolatilus princeps. From February to December 2005, 210 specimens of S. miniatus (85–550 mm total length TL) and 91 C. princeps (85–550 mm TL) were obtained from the San Quintín sportfishing catch, at Pacific Baja California. Skin, eyes, fins and gill cavity were examined in situ, and their internal organs removed for later analysis, including a portion of flesh. In S. miniatus, 12 parasite taxa were identified as belonging to Monogenea, Digenea, Cestoda, Nematoda, Acanthocephala and Copepoda; the stomach, pyloric caeca, and intestine (digestive tract) were the most parasitized organs with seven of the 12 species. In S. miniatus, the most abundant parasite was Parabothriocephalus sagitticeps (80.8 individuals/host ± 33.4 SE: standard error), highest prevalence was Microcotyle sebastis (92.6%), and the highest average intensity of infection was the cestode P. sagitticeps (190.4 ± 48.1 SE). The C. princeps showed six species belonging to Monogenea, Digenea, Nematoda and Copepoda; the digestive tract presented the greatest infestation, with four of the six species recorded. The most abundant nematode was Hysterothylacium aduncum (16.5 ± 3.5 individuals/host), the main prevalent species was Anisakis sp., and the highest value of infection intensity was by Hatschekia sp. The nematodes Anisakis sp. and H. aduncum were shared between the two host fishes, and are a zoonotic risk to humans if the fishes are not cooked properly.

Dead or alive? Viability of chytrid zoospores shed from live amphibian hosts.

Pathogens vary in virulence and rates of transmission because of many differences in the host, the pathogen, and their environment. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), affects amphibian hosts differently, causing extinction and population declines in some species but having limited effects on others. Phenotypic differences in zoospore production rates among Bd lineages likely contribute to some of the variation observed among host responses, although no studies have quantified the viability of zoospores shed from live animals. We compared host survivorship, infection intensity, shedding rates, and zoospore viability between 2 species of endangered tropical frogs, Hylomantis lemur and Atelopus zeteki, when exposed to a highly virulent lineage of Bd (JEL 423). We applied a dye to zoospores 30 to 60 min following animal soaks, to estimate shedding rate and proportion of live zoospores shed by different species. The average infection intensity for A. zeteki was nearly 17 times higher (31,455 ± 10,103 zoospore genomic equivalents [ZGEs]) than that of H. lemur (1832 ± 1086 ZGEs), and A. zeteki died earlier than H. lemur. The proportion of viable zoospores was ~80% in both species throughout the experiment, although A. zeteki produced many more zoospores, suggesting it may play a disproportionate role in spreading disease in communities where it occurs, because the large number of viable zoospores they produce might increase infection in other species where they are reintroduced.

Morbidity assessment of Opisthorchis viverrini infection in rural Laos: I. Parasitological, clinical, ultrasonographical and biochemical findings.

BackgroundInfections with the food-borne trematode Opisthorchis viverinni are common in Southeast Asia. In Lao PDR alone, two million people are supposed to be infected. Opisthorchiasis may cause severe liver disease, eventually leading to cholangiocarcinoma. The objective of this study is to assess the eating habits, complaints, symptoms, signs and ultrasonographical findings in three different areas of Savannakhet Province.MethodsStudy participants were recruited in Lahanam village in the flood-prone lowland of, Sonkhone district, Savannakhet Province (group A); in Non Somboon village, a community located on a hilly plateau in the same district (group B); and in staff of Savannakhet Province Hospital, Savannakhet town (group C). Eating habits, complaints and symptoms were recorded by standardized structured questionnaires. Participants were thoroughly examined clinically, and ultrasonography was performed. O. viverrini eggs were looked for in stool and in duodenal fluid. An array of biochemical and haematological parameters potentially related to liver disease was determined. Group A consisted of 45, group B of 31 and group C of 18 individuals.ResultsEating habits were similar in the three groups, except that participants from group C tended to consume less high-risk types of fish dishes and more frequently ate beef and pork. Average intensity of infection (eggs per gram of stool) was low, but significantly higher in group A than in group B and C (p < 0.001). Medical history and complaints were similar in the three groups. Ultrasonography did not reveal any bile duct pathology. The only pathological finding was a slight elevation of ASAT and gamma-GT in a few participants in groups A and B.ConclusionsThe study shows that eating habits favouring the infection with O. viverrini are common in south Laos. Although the average intensity of infection was low, there was a significant difference between the groups, paralleling slightly different eating habits. Clinically, this corresponded to a paucity of liver disease-associated complaints and signs. The low intensity of infection probably explains why no alterations of bile ducts were detectable by ultrasonography.

Enteric neuromodulators and mucus discharge in a fish infected with the intestinal helminth Pomphorhynchus laevis.

BackgroundIn vertebrates, the presence of enteric worms can induce structural changes to the alimentary canal impacting on the neuroendocrine system, altering the proper functioning of the gastrointestinal tract and affecting the occurrence and relative density of endocrine cells (ECs). This account represents the first immunohistochemistry and ultrastructure-based study which documents the intimate relationship between the intestinal mucous cells and ECs in a fish-helminth system, investigating the potential effects of enteric neuromodulators on gut mucus secretion/discharge.MethodsA modified dual immunohisto- and histochemical staining technique was applied on intestinal sections from both infected and uninfected fish. Sections were incubated in antisera to a range of neuromodulators (i.e. leu-enkephalin, met-enkephalin, galanin and serotonin) and the glycoconjugate histochemistry of the mucous cells was determined using a subsequent alcian blue – periodic acid Schiff staining step. Dual fluorescent staining on sections prepared for confocal laser scanning microscopy and transmission electron microscopy were also used to document the relationship between ECs and mucous cells.ResultsFrom a total of 26 specimens of Squalius cephalus sampled from the River Paglia, 16 (i.e. 62 %) specimens were found to harbour an infection of the acanthocephalan Pomphorhynchus laevis (average intensity of infection 9.2 ± 0.8 parasites host−1, mean ± standard error). When acanthocephalans were present, the numbers of mucous cells (most notably those containing acidic or mixed glycoconjugates) and ECs secreting leu-enkephalin, met-enkephalin, galanin, serotonin were significantly higher than those seen on sections from uninfected fish. The relationship between met-enkephalin-like or serotonin-like ECs and lectin DBA positive mucous cells was demonstrated through a dual fluorescent staining. The presence of tight connections and desmosomes between mucous and ECs in transmission electron micrographs provides further evidence of this intimate relationship.ConclusionsThe presence of P. laevis induces an increase in the number of enteric ECs that are immunoreactive to leu- and met-enkephalin, galanin, and serotonin anti-sera. The mucous cells hyperplasia and enhanced mucus secretion in the helminth-infected intestines could be elicited by the increase in the number of ECs which release these regulatory substances.

Investigating the first outbreak of oriental theileriosis in cattle in South Australia using multiplexed tandem PCR (MT-PCR)

This study investigated the first outbreak of oriental theileriosis in a herd of beef cattle in South Australia using a newly established multiplexed tandem PCR (MT-PCR) to identify, differentiate and quantitate the four genotypes (buffeli, chitose, ikeda and type 5) of Theileria orientalis recognised to occur in Australasia. Following clinical diagnosis of oriental theileriosis (based on clinical signs, laboratory findings and post mortem examination), 155 blood samples were collected from individual cows (n=85) and calves (n=70), and tested by MT-PCR. In total, 117 (75.48%) cattle were shown to be test-positive for T. orientalis. All four genotypes were detected, and ikeda had the highest prevalence (90.6%; 106/117), followed by buffeli (83.8%; 98/117), chitose (18.8%; 22/117) and type 5 (5.1%; 6/117). Mixed infections with genotypes buffeli and ikeda had a higher prevalence (55.5%; 65/117) than any other combination of genotypes. The prevalences of buffeli and ikeda were significantly higher (P<0.005) than those of chitose and type 5. The average intensity of infection with genotype ikeda (329,775 DNA copies) was significantly higher (P<0.0001) than buffeli (212,843) and chitose (125,462). This study reinforces the utility of MT-PCR as a diagnostic tool for rapidly investigating oriental theileriosis outbreaks in cattle herds and as a pre-movement screening test for preventing the introduction of this disease into non-endemic regions.

Use of multiplexed tandem PCR to estimate the prevalence and intensity of Theileria orientalis infections in cattle

This study employed a semi-quantitative, multiplexed tandem PCR (MT-PCR) to assess the prevalence and infection intensity of four genotypes (buffeli, chitose, ikeda and type 5) of Theileria orientalis in cattle in Australia. Genomic DNA samples from blood samples (n=448) collected from 27 to 32 dairy cows from each of 15 dairy herds with a history of recent theileriosis outbreaks (Group 1), and from blood samples available from 24 cows with or without oriental theileriosis (Group 2) were tested using MT-PCR. Results revealed that all four genotypes were present in Group 1 cattle; genotype buffeli had the highest prevalence (80.5%), followed by genotypes ikeda (71.4%), chitose (38.6%) and type 5 (20.3%). Genotype ikeda had the highest average infection intensity in the cattle (relating to 55,277 DNA copies), followed by buffeli, chitose and type 5 (6354–51,648 copies). For Group 2, results indicated that genotype ikeda had a significantly higher average intensity of infection than buffeli in symptomatic cattle (P<0.001), and symptomatic cattle had a higher intensity of ikeda than asymptomatic cattle (P=0.004). Future studies should assess the utility of the present MT-PCR assay as a diagnostic and epidemiological tool in other parts of Australasia and the world.

Winter garlic rust (Puccinia spp.) rate under organic and conventional production conditions

Due to low requirements for fertilizers and pesticides, garlic is a valuable crop in organic systems, although production may be hampered by diverse pathogens. In recent years, garlic rust (Puccinia spp.) has been increasingly present in our agro-ecological climate, developing into a significant problem for garlic production. The aim of the study was twofold: i) to monitor winter garlic rust rate in organic and in conventional production, and ii) to monitor genotype sensitivity to the pathogen in both production systems. Trials were conducted in 2012/2013 in Backi Petrovac, Serbia at the Institute of Field and Vegetable Crops in Novi Sad, and included 30 genotypes planted in organic and conventional field, simultaneously. Disease severity was evaluated visually, using a scoring system between zero and five. Overall average infection intensity score in conventional plots was 1.18, and in organic plots 0.79. There was no statistically significant difference between infection intensity in conventional versus organic plots. Nevertheless, reactions of certain genotypes to the causal agents of rust differed across organic and conventional plots ranging from no apparent infection symptoms in organic to severe symptoms in conventional plots.

Identification of anisakid nematode infection on skipjack (Katsuwonus pelamis L.) from savu sea, east nusa tenggara, Indonesia

Nematodes, Anisakis spp, were reported to cause zoonoses in many countries. This parasite commonly infects marine mammals, fish, crustaceans and cephalopods in a wide geographical distribution. Some morphological and molecular studies explained that Anisakis spp.was detected in some marine areas, including Indonesia. This study was aimed to identify the type of nematodes that infect the skipjack tuna (K. pelamis) in Savu Sea. Quantitative description used prevalence studies on the number of fish infected and the average infection intensity, and then we conducted morphological and molecular identification. Morphological analysis was performed on the structure and the characteristic of the larvae. Molecular detection used PCR with ITS (ITS 1, 58s rDNA gene and ITS2), followed by sequencing with the ABI Prisms 3730 XL and the results were analyzed using MEGA 5.03. Taxonomically, the result showed that K. pelamis of Savu Sea, East Nusa Tenggara, Indonesia, was infected by Anisakis typica. * Corresponding Author: L.C. Soewarlan  lady.cindy@ymail.com

Prevalence of Clonorchis sinensis infection in freshwater fishes in northeastern China

The prevalence of Clonorchis sinensis infection in freshwater fishes was surveyed in Heilongjiang Province, northeastern China, between August 2011 and September 2013. Thirteen species of freshwater fish (n=3221) and one species of shrimp (n=93) were collected from Songhua river, Nenjiang river and other lakes or ponds in 37 sites of 15 representative cities in Heilongjiang Province. They were individually examined by digestion technique, and the C. sinensis metacercariae were identified morphologically followed by confirmation using sequences of the second internal transcribed spacer of ribosomal DNA. Ten of the 13 examined species of freshwater fishes were infected with C. sinensis metacercariae, while all shrimps were negative. The overall prevalence of C. sinensis infection in 3221 examined freshwater fishes was 19.96%, with 42.57% (272/639) in Pseudorasbora parva, 22.55% (83/368) in Hemicculter leuciclus, 20.44% (121/592) in Carassius auratus, 17.71% (68/384) in Saurogobio dabryi, 10.85% (23/212) in Rhodeus ocellatus, 10.54% (48/455) in Phoxinus lagowskii, 8.20% (21/256) in Perccottus glehnii, 6.25% (5/80) in Misgurnus anguillicaudatus, 4.55% (1/22) in Xenocypris davidi, and 1.49% (1/67) in Cyprinus carpio. The average infection intensity in P. parva was 103.3 encysted metacercariae per gram of fish meat in Zhaoyuan city. The average prevalence of C. sinensis infection in Songhua river, Nenjiang river and lakes or ponds were 31.96% (503/1574), 11.30% (102/903) and 7.93% (59/744), respectively. The prevalence of C. sinensis infection in Zhaoyuan city (43.68%) was the highest among all sampling locations. These results revealed a high-prevalence of C. sinensis infection in freshwater fishes in Heilongjiang Province, northeastern China, posing significant public health concern.

Fungal infection intensity and zoospore output of Atelopus zeteki, a potential acute chytrid supershedder.

Amphibians vary in their response to infection by the amphibian-killing chytrid fungus, Batrachochytrium dendrobatidis (Bd). Highly susceptible species are the first to decline and/or disappear once Bd arrives at a site. These competent hosts likely facilitate Bd proliferation because of ineffective innate and/or acquired immune defenses. We show that Atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially increases skin Bd infection intensity, achieving intensities that are several orders of magnitude greater than most other species reported. We experimentally infected individuals that were never exposed to Bd (n = 5) or previously exposed to an attenuated Bd strain (JEL427-P39; n = 3). Within seven days post-inoculation, the average Bd infection intensity was 18,213 zoospores (SE: 9,010; range: 0 to 66,928). Both average Bd infection intensity and zoospore output (i.e., the number of zoospores released per minute by an infected individual) increased exponentially until time of death (t50 = 7.018, p<0.001, t46 = 3.164, p = 0.001, respectively). Mean Bd infection intensity and zoospore output at death were 4,334,422 zoospores (SE: 1,236,431) and 23.55 zoospores per minute (SE: 22.78), respectively, with as many as 9,584,158 zoospores on a single individual. The daily percent increases in Bd infection intensity and zoospore output were 35.4% (SE: 0.05) and 13.1% (SE: 0.04), respectively. We also found that Bd infection intensity and zoospore output were positively correlated (t43 = 3.926, p<0.001). All animals died between 22 and 33 days post-inoculation (mean: 28.88; SE: 1.58). Prior Bd infection had no effect on survival, Bd infection intensity, or zoospore output. We conclude that A. zeteki, a highly susceptible amphibian species, may be an acute supershedder. Our results can inform epidemiological models to estimate Bd outbreak probability, especially as they relate to reintroduction programs.

A fungal pathogen of amphibians, Batrachochytrium dendrobatidis, attenuates in pathogenicity with in vitro passages.

Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen’s role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in artificial media for more than six years (JEL427-P39), and one recently thawed from cryopreserved stock (JEL427-P9). In a common garden experiment, we then exposed two different amphibian species, Eleutherodactylus coqui and Atelopus zeteki, to both cultures to test whether Bd attenuates in pathogenicity with in vitro passages. The culture with the shorter passage history, JEL427-P9, had significantly greater zoospore densities over time compared to JEL427-P39. This difference in zoospore production was associated with a difference in pathogenicity for a susceptible amphibian species, indicating that fecundity may be an important virulence factor for Bd. In the 130-day experiment, Atelopus zeteki frogs exposed to the JEL427-P9 culture experienced higher average infection intensity and 100% mortality, compared with 60% mortality for frogs exposed to JEL427-P39. This effect was not observed with Eleutherodactylus coqui, which was able to clear infection. We hypothesize that the differences in phenotypic performance observed with Atelopus zeteki are rooted in changes of the Bd genome. Future investigations enabled by this study will focus on the underlying mechanisms of Bd pathogenicity.

The Influence of Parasitic Infection on the Black Sea Whiting, Merlangius merlangus euxinus (Gadidae), Morphophysiological and Biochemical Parameters

Abstract Complex influence of infection by myxosporeans Myxidium gadi Georgevitsch, 1916; Ceratomyxa merlangi Zaika, 1966 and nematode Hysterothylacium aduncum (Rudolphi, 1802) on the morphophysiological and biochemical parameters of the Black sea whiting Merlangius merlangus euxinus (Nordmann, 1840) were studied. Significant decrease of spleenosomatic index and increase of hepatosomatic index in fish with average and high intensity of infection were found. The dependence of hepatic antioxidant enzyme activities on intensity of infection was observed. Increase of superoxidismutase, catalase, glutation-S-transferase activities in fish with average and high intensity of infection and decrease of peroxidase activity in specimens with average intensity of infection were shown.

A study of the infection and physicochemical characteristics of the marine fish infected by Anisakis L₃ caught in Zhoushan Fishery

The aim of this research was to investigate the third phase Anisakis simplex larvae (Anisakis L₃) infection in marine fish caught in Zhoushan Fishery and to find out its physicochemical and biological characteristics. A total of 444 fish belonging to 29 species were dissected to isolate anisakis larvae which were then morphologically identified. The survival tolerance of Anisakis L₃ were observed in various conditions, such as in different temperature and medium. A total of 218 fish from 21 species were infected by Anisakis simplex larvae, yielding an overall infection rate of 49.10% (218/444). Trichiurus haumela, pneumatophorus japonicus, miichthys miiuy, argyrosomus argentatus and anguilliformes had high infection rate and had an average infection intensity of 15.28 per fish. 3332 Anisakis larvae were detected in 218 fish, among which Anisakis L₃ and Pseudoterranova larvae accounted for 99.46% (3314/3332) and 0.54% (18/3332) respectively. Anisakis L₃ was highly resistant to common condiment. We found the liquor with high concentration of alcohol showed better insecticidal effect than that with low concentration of alcohol (t = 4.105, P < 0.05) and low concentration mebendazole composite was not only more effective than high concentration mebendazole composite (F = 45.198, P < 0.01) but also more effective than other drugs, such as albendazole and mebendazole. Anisakis L₃ could live up to 9 h and 12 h at -20°C, -10°C respectively, however they were very sensitive to high temperature. It has been shown that they could only survive for less than 11 s and 1 s at 50°C and 60°C respectively. The observed Anisakis L₃ infection rate in the marine fish found in Zhoushan Fishery was very high. Anisakis L₃ showed high resistance to low temperature but not to high temperature.

A New Species of Pharyngodonidae (Nematoda) of Tropidurus torquatus (Squamata: Tropiduridae) from Brazil

Parapharyngodon bainae n. sp. (Nematoda:Pharyngodonidae) collected from the small intestine of Tropidurus torquatus (Squamata:Tropiduridae) is described. The new species is the 47 th species in the genus and the 14 th in the Neotropical region. The morphology of male posterior end, ovary position in females, and egg size can be used to differentiate P. bainae from the other congeneric species. Parapharyngodon rotundatus , Parapharyngodon sanisfaciecaudus , and Parapharyngodon riojensis are most closely related to P. bainae. In males of P. sanisfaciecaudus and P. rotundatus , the cloacal lip has a smooth appearance, whereas in P. bainae , males have an echinate cloacal lip. Parapharyngodon riojensis differs from P. bainae because its females have postbulbar ovaries, the eggs are larger, and the esophagi are larger in both sexes. Parapharyngodon spp. nematodes occupy an intermediate phylogenetic position among pharyngodonid parasite lineages in carnivorous and herbivorous reptiles. The average low intensity of infection for P. bainae (4.8 ± 4.6) is typically found in carnivorous reptiles. This fact and the high prevalence value (60%) can be explained by the ingestion of environmental substrata material containing parasite eggs while foraging.

Intestinal schistosomiasis and soil-transmitted helminthiasis in Ugandan schoolchildren: a rapid mapping assessment

Even with a national control programme in place, intestinal schistosomiasis continues to be a major public health problem in school-aged children and other community members in Uganda. This is especially the case in the environments around the Great Lakes, where disease transmission is high, such as Lake Victoria. Moreover, in the most remote areas, some schools might periodically miss large-scale drug administrations owing to inaccessibility. To provide contemporary monitoring and surveillance data, 27 schools along the lakeshore were surveyed with a rapid assessment protocol to determine both prevalence and intensity of Schistosoma mansoni and soil-transmitted helminth infections. In total, 25 (92.6%) of schools were positive for S. mansoni, with an average prevalence across the surveyed children of 42% and average infection intensity of 634 eggs per gram of faeces. Mean prevalence of Trichuris trichiura, Ascaris lumbricoides and hookworm was 12.9%, 9.3% and 2.4%, respectively. Results from questionnaire data revealed a high level of itinerancy among the children, and a total of 38.2% reported to have never received treatment for schistosomiasis, despite 96% living in districts targeted by the national control programme. A birthplace outside of Uganda was a significant predictor for increased risk of schistosomiasis infection (odds ratio (OR) = 9.6), and being resident at a school for less than a year was significantly associated with absence of praziquantel treatment (OR = 0.3). Univariate regression analysis showed a trend of increasing schistosomiasis towards the eastern region of Uganda, while semivariograms of infection prevalence demonstrated a range of spatial autocorrelation of ~78 km. Soil-transmitted helminth infections were more common in the Western region. Our results emphasise how social and demographic variables such as migration may affect epidemiological trends and confound the impact of existing treatment regimes.

THE INFLUENCE OF BIOFUMIGATION ON MYCORRHIZAL FUNGI AND GROWTH OF STRAWBERRIES

Green manure from Brassica plants reduced the micro-organisms in the soil due to biocidal effect. Biofumigation with glucosinolates from Brassica juncea, Sinapis alba and Eruca sativa only partially influenced the mycorrhizal fungi of the strawberry cv. 'Marmolada'. In the field trial the differences in mycorrhizal parameters were not statistically significant between treatments (Brassica juncea, Sinapis alba, Eruca sativa, dazomet, control). The highest frequency of roots with mycorrhizal fungi (F) was observed in the chemical treatment with dazomet (50.3%). In the control, F was 49.2% and it was the lowest in the B. juncea treatment (43.4%). In pot trials, the average F was found in B. juncea, 57.9%, followed by S. alba, 54.9%, E. sativa, 66.8%, dazomet, 2.9% and control, 60.8%. The average intensity of fungi infection (M) was found in B. juncea, 7.4%, then in S. alba, 9.8%, E. sativa, 7.5%, dazomet, 0.0%, and control, 7.1%. The growth of weeds differed a great deal between the trials. In the field trial the number of weeds was higher in the treatments with biocidal plants than with dazomet or in the control. In pot trials S. alba had the biggest influence on the germination of weeds. Differences in yield observed in the field trial were not statistically significant. In pot trials the number of fruits per plant was the highest in E. sativa (8.1), S. alba (7.0), B. juncea (6.9), control (3.7) and dazomet (1.8). Increase of the yield at the treatment with biocidal plants was the result of incorporation of organic matter into the soil and undisturbed activity of mycorrhizal fungi.