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Fish-borne zoonotic nematodes may infect humans when fish or squid are ingested raw or inadequately cooked. Human infections may have serious consequences, including the unexpected deaths of infected people. This kind of disease is poorly known in general, and the characteristics of such infections in South American countries as a whole have never been assessed. In this paper the present status of fish-borne nematodiases in humans in South American countries is characterized. Potentially zoonotic nematode species are very common in both freshwater and marine fish in South America. Reports of human infections have only been found in some countries, and their incidence (especially with anisakids and Gnathostoma spp.) varies from country to country. Apparently they are more abundant in countries with strong traditions of eating raw fish, and are more frequent on the western coast of South America. So far fish-borne nematodes have been reported in Argentina, Brazil, Chile, Colombia, Ecuador and Peru. In recent years, cases of human infection have appeared in probably underestimated numbers. People need to be clearly informed about risky feeding habits, and physicians need to learn more about zoonotic diseases. [ABSTRACT FROM AUTHOR]

As a significant zoonosis, cystic echinococcosis (CE) is endemic in some parts of the world, such as the Middle East. There are studies on the prevalence of this infection in animal and human reservoirs in Iran; hence, we conducted this meta-analysis to elucidate the prevalence of CE in Iran. English (PubMed, Scopus, Web of Science, Science Direct and Google Scholar) and Persian (Magiran, Iran Medex, Iran Doc and SID) databases were explored. In the case of definitive, animal and human intermediate hosts, 37, 90 and 33 studies, respectively, have been included in the current review from January 1990 to December 2015. According to outcomes of the heterogeneity test, either Der Simonian and Laird's random-effects method or Mantel–Haenszel's fixed-effects method were employed to pool the estimations. The pooled prevalence of Echinococcus granulosus infection in definitive hosts was calculated as 23.6% (95% confidence interval (CI) = 17.6–30.1%). The weighted prevalence of animal and human hydatidosis was calculated as 15.6% (95% CI = 14.2–17.1%) and 4.2% (95% CI = 3.0–5.5%), respectively. Meanwhile, most cases of human hydatidosis were in southern Iran, with a prevalence of 5.8% (3.2–9.2%). In terms of human hydatidosis, more infections were found in rural regions, and mostly in female individuals. Egger's regression test revealed publication bias, with a remarkable impact on total prevalence of the infection in animal intermediate hosts (P < 0.001), while it was not significant in human hosts (P = 0.4) and definitive hosts (P = 0.3). According to the weighted estimated prevalence of cystic echinococcosis and its financial burden, implementing appropriate control programmes should be compulsory to decrease the burden of the disease in Iran. [ABSTRACT FROM AUTHOR]

Wastewater use for crop irrigation and aquaculture is commonly practiced by communities situated close to wastewater treatment ponds. The objective of this study was to characterize Salmonella spp. and their antimicrobial susceptibility patterns among isolates from wastewater and Tilapia fish. A total of 123 Salmonella spp. isolates were isolated from 52 water and 21 fish intestinal samples. Genotyping of Salmonella spp. isolates was done by Pulsed-field Gel Electrophoresis (PFGE). Antimicrobial susceptibility testing was done by the minimal inhibitory concentration (MIC) technique. A total of 123 Salmonella spp. isolates represented 13 different serovars and 22 PFGE groups. Salmonella serovars showed resistance to 8 out of 14 antimicrobials; sulfamethaxazole (94%), streptomycin (61%), tetracycline (22%), ciprofloxacin and nalidixic acid (17%), trimethoprim (11%); gentamycin and chloramphenicol (6%). Salmonella Kentucky, S. Chandans, S. Durban and S. Kiambu showed multiple antimicrobial resistance to 7, 6 and 3 antimicrobials, respectively. This study has demonstrated that wastewater at the study sites is contaminated with Salmonella spp. which are resistant to common antimicrobials used for treatment of diseases in humans. Wastewater may, therefore, contaminate pristine surface water bodies and foodstuffs including fish and irrigated crops as well as food handlers. [ABSTRACT FROM AUTHOR]

During an extensive survey of fish parasites along the Malabar coast of India we observed exceptionally high or even massive infection of the narrow-barred Spanish mackerel, Scomberomorus commerson (Scombridae), with parasitic copepods Cybicola armatus. Such infection has not hitherto been reported. The copepods occurred on the gills of its host and the infection persisted for many years (the survey lasted from January 2010 to July 2014). The overall prevalence was very high (95%); out of a total of 981 fish studied, 933 were infected, and the maximum intensity reached 42. The highest rate of infection (prevalence 99.2%) was observed in medium sized fish (36.0-79.9 cm). We found this parasite only on S. commerson even though we examined 81 fish species, including five of the family Scombridae. Interestingly, the parasite exhibits strict site specificity and microhabitat preference. A significant proportion of them was seen attached to pseudobranchs rather than to main gill arches. Significantly, the body size of the parasite was positively correlated with that of the host fish. Our SEM micrographs contributed new facts to this copepod's morphology by illustrating for the first time the ventral part of its cephalothorax, illustrating the nature of attachment, and by finding a new structure - a premaxillary pad. We demonstrated the haematophagous nature of C. armatus by finding and documenting the host's blood cells in the parasite's intestine. [ABSTRACT FROM AUTHOR]

Vibrio vulnificus is a bacterium responsible for severe gastroenteritis, sepsis and wound infections. Gastroenteritis and sepsis are commonly associated with the consumption of raw oysters, whereas wound infection is often associated with the handling of contaminated fish. Although classical virulence factors of this emerging pathogen are well characterised, there remains a paucity of knowledge regarding the general biology of this species. To investigate the presence of previously unreported virulence factors, we applied whole genome sequencing to a panel of ten V. vulnificus strains with varying virulence potentials. This identified two novel type 6 secretion systems (T6SSs), systems that are known to have a role in bacterial virulence and population dynamics. By utilising a range of molecular techniques and assays we have demonstrated the functionality of one of these T6SSs. Furthermore, we have shown that this system is subject to thermoregulation and is negatively regulated by increasing salinity concentrations. This secretion system was also shown to be involved in the killing of V. vulnificus strains that did not possess this system and a model is proposed as to how this interaction may contribute to population dynamics within V. vulnificus strains. In addition to this intra-species killing, this system also contributes to the killing of inter bacterial species and may have a role in the general composition of Vibrio species in the environment. [ABSTRACT FROM AUTHOR]

A bacteria-parasite challenge model was used to study the role of sea lice, Lepeophtheirus salmonis (Copepoda), as a vector of Aeromonas salmonicida subsp. salmonicida. Three hypotheses were tested: (i) L. salmonis can acquire A. salmonicida subsp. salmonicida via water bath exposure; (ii) L. salmonis can acquire the bacteria via parasitizing infected Atlantic salmon, Salmo salar; and (iii) L. salmonis can transmit the bacteria to naïve Atlantic salmon via parasitism. Adult L. salmonis exposed to varying A. salmonicida subsp. salmonicida suspensions (101-107 cells mL−1) for 1.0, 3.0 or 6.0 h acquired the bacteria externally (12.5-100%) and internally (10.0-100%), with higher prevalences associated with the highest concentrations and exposures. After exposure to 107 cells mL−1, viable A. salmonicida subsp. salmonicida could be isolated from the external carapace of L. salmonis for 120 h. Lepeophtheirus salmonis also acquired the bacteria externally and internally from parasitizing infected fish. Bacterial transmission was observed only when L. salmonis had acquired the pathogen internally via feeding on 'donor fish' and then by parasitizing smaller (<50 g) 'naive' fish. Under specific experimental conditions, L. salmonis can transfer A. salmonicida subsp. salmonicida via parasitism; however, its role as a mechanical or biological vector was not defined. [ABSTRACT FROM AUTHOR]

Background: Edwardsiella tarda, is a serious bacterial pathogen affecting a broad range of aquaculture fish species. The bacterium has also been reported as a human pathogen, however recent studies have dissociated the fish pathogenic Edwardsiella from those isolated from humans by placing them in a new species, E. piscicida. Here we report the first case of Edwardsiellosis in cultured sharpsnout sea breams, Diplodus puntazzo in Greece. Case presentation: The disease has affected cultured sharpsnout sea breams of a commercial fish farm in a single location in East Greece. Two populations of sharpsnout sea breams stocked in two consecutive years in floating cages presented signs of disease which included nodules and abscesses in spleen and kidney, morbidity and cumulative mortality reaching 5.3 %. Using microbiological, biochemical and molecular tools we have identified Edwardsiella sp. as the main aetiological factor of the disease. Following phylogenetic analysis the bacterial isolates are grouped with the newly described Edwardsiella piscicida species. Conclusions: This is the first report of Edwardsiellosis in this species but most importantly in sea cage-cultured fish in the Mediterranean which may pose a serious threat for aquaculture fish species in this region. [ABSTRACT FROM AUTHOR]

Fish-borne zoonotic trematodes (FZT) including heterophyids and opisthorchiids are prevalent in native and aquaculture fish in Southeast Asia. FZT are reported highly prevalent in juvenile aquaculture fish that belonged to the family Heterophyidae, particularly Haplorchis taichui. Aquaculture fish are reported to have varying levels of natural infection with H. taichui, but data for their susceptibility as well as resistance to infection are not available. The aim of this study was to determine the susceptibility of five aquaculture fish to H. taichui. Experimental infections were performed by exposing fish individually to 0 (control), 50, 100, or 200 H. taichui cercariae for 12 h. Metacercarial burden was measured at 45 days postinfection. Three out of five fish species, silver barb ( Barbonymus gonionotus), common carp ( Cyprinus carpio), and mrigal ( Cirrhinus mrigala), were highly susceptible to H. taichui infection with percentage ranging from 93.33 to 100 %. The Nile and red tilapia were not susceptible to infection. Among the susceptible fish species, silver barb had higher intensity of H. taichui metacercariae than common carp and mrigal ( P < 0.001). Metacercarial burden significantly correlated with the dose of cercarial infection ( P < 0.001). Our findings that common aquaculture fish species have varying degrees of susceptibility to H. taichui infection provide important information to reduce parasite transmission in aquaculture fish. [ABSTRACT FROM AUTHOR]

To inform Dracunculus medinensis (Guinea worm) eradication efforts, we evaluated the role of fish as transport hosts for Dracunculus worms. Ferrets fed fish that had ingested infected copepods became infected, highlighting the importance of recommendations to cook fish, bury entrails, and prevent dogs from consuming raw fish and entrails. [ABSTRACT FROM AUTHOR]

The recurrent emergence of infections outbreaks associated with shellfish consumption is an important health problem, which results in substantial economic losses to the seafood industry. Even after depuration, shellfish is still involved in outbreaks caused by pathogenic bacteria, which increases the demand for new efficient strategies to control the shellfish infection transmission. Phage therapy during the shellfish depuration is a promising approach, but its success depends on a detailed understanding of the dynamics of bacterial communities in the harvesting waters. This study intends to evaluate the seasonal dynamics of the overall bacterial communities, disease-causing bacterial populations and bacterial sanitary quality indicators in two authorized harvesting-zones at Ria de Aveiro. During the hot season, the total bacterial community presented high complexity and new prevalent populations of the main shellfish pathogenic bacteria emerged. These results indicate that the spring/summer season is a critical period during which phage therapy should be applied. [ABSTRACT FROM AUTHOR]

Abstract: Fish-borne zoonotic trematodes (FZT) are a major public health problem. It is estimated that in Vietnam 26,366 “disability-adjusted life years” (DALYs) are lost due to FZT. Fish from aquaculture are a main source of protein and of great economic importance in both rural and urban areas. The objective of this study was to compare the impact on transmission of FZT to juvenile fish of drug treatment intervention of final hosts, and pond management interventions on fingerlings produced in nurseries producing Rohu carp in Northern Vietnam. The study design was a parallel group design of nurseries with two intervention groups; a drug treatment of human and animal groups and a farm management group (control of snail vectors and fecal pollution of pond). A third group (non-intervention) served as control. Fish were examined for FZT metacercariae prevalence and intensity before and after interventions, along with density of potential host pond snails. Fecal exams for FZT infections in farm household humans, dogs and cats were also performed. The results showed that although FZT prevalence in fish was not significantly reduced, the intensity of metacercariae in fish from ponds receiving management interventions was reduced 91.7% compared to before interventions. The intensity of FZT was also significantly lower in the pond management group, compared to the drug treatment group and the control group after interventions. The results demonstrate that improving farm and pond management practices can be effective in reducing FZT infections without using drug treatment. This study also highlighted certain obstacles to attaining higher levels of protection for which more research is needed. A major challenge is the ability to completely isolate (or bio-secure) the pond from its surrounding environment, especially surrounding water sources which may harbor snails and cercariae that can contaminate the pond through water resupply or runoff. Another is the unknown risk from piscivorous birds, host for intestinal FZT. The strategies employed in this study now need long-term evaluation on a regional basis, the outcome of which could be the development of good management practices crucial to ensuring a good quality product that benefits farmers and the consumers. [Copyright &y& Elsevier]

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Ciguatera fish poisoning (CFP) is a serious health problem in tropical regions and is caused by the bioaccumulation of lipophilic toxins produced by dinoflagellates in the genus Gambierdiscus. Gambierdiscus species are morphologically similar and are difficult to distinguish from one another even when using scanning electron microscopy. Improved identification and detection methods that are sensitive and rapid are needed to identify toxic species and investigate potential distribution and abundance patterns in relation to incidences of CFP. This study presents the first species-specific, semi-quantitative polymerase chain reaction (qPCR) assays that can be used to address these questions. These assays are specific for five Gambierdiscus species and one undescribed ribotype. The assays utilized a SYBR green format and targeted unique sequences found within the SSU, ITS, and the D1/D3 LSU ribosomal domains. Standard curves were constructed using known concentrations of cultured cells and 10-fold serial dilutions of rDNA PCR amplicons containing the target sequence for each specific assay. Assay sensitivity and accuracy were tested using DNA extracts purified from known concentrations of multiple Gambierdiscus species. The qPCR assays were used to assess Gambierdiscus species diversity and abundance in samples collected from nearshore areas adjacent to Ft. Pierce and Jupiter, Florida USA. The results indicated that the practical limit of detection for each assay was 10 cells per sample. Most interestingly, the qPCR analysis revealed that as many as four species of Gambierdiscus were present in a single macrophyte sample. [ABSTRACT FROM AUTHOR]

Giardiasis is a re-emerging infectious disease of worldwide significance caused by Giardia duodenalis. This study investigated the occurrence of zoonotic G. duodenalis assemblages in fish to explore the possible role of fish in the epidemiology of human giardiasis. For this purpose, 92 fish ( Tilapia nilotica and Mugil cephalus) collected from (fish farms and Nile River) at different governorates in Egypt were examined for the presence of G. duodenalis in their feces by using enzyme linked immunosorbent assay, then positive fecal samples were tested by duplex PCR for identification of triose phosphate isomerase ( tpi) gene specific for zoonotic assemblages A and B. The overall prevalence of G. duodenalis in the examined fish was 3.3%, while the detection rates among the examined fish species were 2.9% and 4.2% for T. nilotica and M. cephalus, respectively. G. duodenalis was detected in the feces of both farmed and wild fish whereas all isolates were genotyped as assemblage A. In conclusion, the occurrence of zoonotic G. duodenalis assemblage A in the examined fish species at two different aquatic environments underlines the possibility of fish to be an additional reservoir for zoonotic G. duodenalis assemblages that contributes in the contamination of water with this pathogen and thus the role of fish in the epidemiology of human giardiasis cannot be ruled out. [ABSTRACT FROM AUTHOR]

Abstract: The prevalence of fish-borne trematodes in humans and their molecular identification was investigated in the Rang Dong commune of Nam Dinh province, Vietnam, between January 2009 and December 2010. A total of 405 people in this commune were interviewed on the habit of eating raw fish and all of their stool samples were collected using the Kato-Katz technique for examination of the presence of fish-borne trematodes. The worms (and eggs) were first morphologically examined, counted, described and identified, then the representative isolates were subjected for molecular species confirmation. A total of 385 adult flukes collected from 10 patients were morphologically identified to species and defined as Clonorchis sinensis (14.58%) in Opisthorchiidae family, Haplorchis taichui (32.29%), Haplorchis pumilio (52.08%) and Centrocestus formosanus (1.04%) in Heterophyidae family. A high rate (77.8%) of the interviewees was found to have the habit of eating raw fish. This habit was attributed to the high infection rate of fish-borne trematode in humans (22.72%; OR=2.486). The infection rate of fish-borne trematodes in males was higher (29.3%) than that in females (16.0%) and increased by age, reaching the highest in the patients aged 40–59years (28.2–28.7%). The infection intensity of fish-borne trematode was found light (336 EPG). Adult flukes were collected from a group of the patients with the highest intensity of infection and subjected to molecular and phylogenetic analysis using a portion (326bp) of mitochondrial cox1. Phylogenetic tree inferred from cox1 sequences using sequence data for 34 isolates of opisthorchid, heterophyid, fasciolid, paragonimid, schistosomid trematodes and taeniid cestodes revealed that they are distinct groups. The newly collected with the known clonorchid and heterophyid isolates form the well defined taxonomic groups, respectively, confirming that C. sinensis and Haplorchis spp. (H. pumilio and H. taichui) were among the collected samples. [Copyright &y& Elsevier]

Abstract: Consumption of mackerel (Scomber japonicus) is very widespread in Morocco, where its production is an important economic pillar. We investigated the prevalence of infection by Anisakis spp. in mackerel caught in Moroccan waters, analyzing infection risk factors. The prevalence was generally higher in fish from the Atlantic (67.9%) than from the Mediterranean (57.0%), but they did not differ in the mean abundance, intensity, or prevalence of muscle parasitization. A. pegreffii was the predominant species (82.6% of larvae) followed by the hybrid A. simplex s.s./A. pegreffii (16.3%). Only one L3 of A. simplex s.s. was found in a specimen of S. japonicus from the Atlantic. Mackerel infection was associated with total fish weight, gonad weight, catch area, and catch season. However, muscle infection was associated solely with total weight and parasite loads. The consumption of lower-weight mackerel may be a good prophylactic measure against human anisakiasis. [Copyright &y& Elsevier]

Abstract: The relationship between chemical exposure and disease outbreak in fish has not been fully defined due to the limitations of experimental systems (model fish and pathogens). Therefore, we constructed a system using the Japanese flounder, Paralichthys olivaceus, and viral haemorrhagic septicemia virus (VHSV), and evaluated it by heavy oil (HO) exposure. The fish were exposed to HO at 0.3, 0.03, 0.003, and 0g/L following VHSV infection at doses of 102.5 or 103.5 tissue culture infectious dose (TCID)50/fish. As a result, groups given the dual stressors showed more than 90% mortality. Although VHSV infection at 102.5 and 103.5 TCID50/fish without HO exposure also induced high mortality, at 68.8% and 81.3%, respectively, HO exposure induced faster and higher mortality in the virus carrier fish, indicating that chemical stressors raise the risk of disease outbreak in fish. The experimental system established in this study could be useful for chemical risk assessment. [Copyright &y& Elsevier]

Abstract: Opisthorchiasis is a fish borne parasitic infection caused by helminths of the genus Opisthorchis (Digenea, Opisthorchiidae), affecting humans and other fish-eating mammals. Despite Opisthorchis felineus was first described in Italy in 1884, no cases of human opisthorchiasis were reported in this country until 2004; from then on, 4 outbreaks due to this species have been recorded in Central Italy. Following the more relevant of these outbreaks, involving 34 people in August 2007, snails, fishes and fecal samples collected from the Bolsena and Bracciano lakes (Central Italy) were analyzed in order to define the cycle of O. felineus in the area and investigate its prevalence in the different hosts. Pools of 20–40 snails each (4983 specimens altogether) of the genus Bithynia were analyzed by PCR for parasite DNA detection. Eight hundred and ninety-four fish belonging to 12 species were collected from the two lakes and tested for metacercariae both by muscle compression and digestion techniques. Eighty-seven fecal samples of 5 putative definitive host species were collected very close to the two lakes and tested for parasite eggs detection by formalin–ethyl acetate concentration technique. Identification at the species level of metacercariae and eggs, respectively, from fish and stool was confirmed by PCR analysis and sequencing. O. felineus DNA was detected in 0.08% (overall minimum infection rate) of snails of the genus Bithynia from the two lakes. The tench, Tinca tinca, was the only fish found infested in both lakes (prevalence 88.5%). O. felineus eggs were found only in cat feces (prevalence 46.4%). The tench represents the only threat for the human consumption in the study area while Coregonus sp., the most economically important species for the local fishery and frequently consumed raw marinated, resulted to be not infected. The high prevalence recorded both in fish and in definitive host suggests a widespread and massive presence of the parasite in the area. Further studies are needed to better investigate the possible role of some cyprinids species as intermediate hosts, in order to check their safety for human consumption. [Copyright &y& Elsevier]

This paper assesses the value of health risks related to recreational shellfish harvesting. Combining revealed and stated preferences data from an on-site survey and using a pseudo-panel approach shows that people significantly value health risks. The combination of stated and revealed preferences data is realised through the introduction of the concept of a “hypothetical twin site”. Addressing on-site sampling issues within the framework of a random-effect Poisson gamma model allows a derivation of more accurate estimates of welfare measures. Results also suggest that the demand for recreational shellfish harvesting is an inferior good. [Copyright &y& Elsevier]

Abstract: Fish-borne zoonotic trematodes, such as Clonorchis sinensis, heterophyids and others, constitute a public health concern in parts of northern Vietnam and infections with these trematodes are often thought to be linked to fish culture. One common fish culture system is the integrated fish-livestock (VAC) ponds where individual households have 1 or more ponds. Fish fry, mainly of various carp species, produced in hatcheries, not necessarily local, are introduced into nursery ponds and after approximately 6 weeks, juvenile fishes are transferred to household ponds, referred to as grow-out ponds. Grow-out ponds are usually fertilized with organic debris, including animal excreta, to stimulate algal growth and subsequently fish growth. This paper describes the distribution of freshwater snails and occurrence of trematode infections in these in VAC ponds and associated habitats as part of a major study on risk factors of FZT infections in cultured fish in two communes, Nghia Lac and Nghia Phu, Nghia Hung District, Nam Dinh Province. The area is under intense rice cultivation with an extensive canal network supplying fields and also household VAC ponds. A total of 16 snail species was found and four were widely distributed i.e. Angulyagra polyzonata, Melanoides tuberculata, Bithynia fuchsiana and Pomacea insularum. Snail diversity and counts were higher in nursery ponds than in grow-out ponds. Species of the families Thiaridae and Viviparidae were more abundant than other species in VAC ponds while species of the Bithyniidae, Stenothyridae and Planorbidae dominated in rice fields and small canals. Trematode infections were found in eight snail species and among these M. tuberculata had the highest overall prevalence of infection (13.28%). No trematode infections were found in species of the Viviparidae and Ampullaridae except for metacercariae. Parapleurolophocercous and pleurolophocercous cercariae constituted the most common type of cercariae recovered, contributing 40.6% of all infections followed by echinostome cercariae (35.0%) and xiphidiocercariae (17.3%). Bithynia fuschiana and M. tuberculata had the most diverse trematode fauna. C. sinensis was not recorded in this study. The VAC pond system in this area, is very important for transmission of minute intestinal trematodes while they play little role in transmission of C. sinensis as its intermediate hosts, bithynid snails, rarely occur in these ponds. From a public health perspective this is positive as the effects of infections with intestinal trematodes are considered mild. On the other hand it is possible that even such subtle effects could have importance in public health as transmission is very intense in the area. And this in combination with the aquaculture importance, reduced marketability of fishes with high metacercariae loads, warrants that control efforts against these trematodes are initiated to reduce transmission in this production system. [Copyright &y& Elsevier]

Abstract: The complete life cycle of the trematode Ascocotyle (Phagicola) longa (Digenea: Heterophyidae) is elucidated by natural observation validated by experimental infections. The natural first intermediate host of A. (P.) longa, an agent of human heterophyiasis in Brazil, is the cochliopid snail Heleobia australis (new first intermediate host). Metacercariae were found encysted in the body musculature, heart, stomach, liver, kidney, spleen, gonads and mesentery of mullets Mugil liza. Hamsters Mesocricetus auratus were experimentally infected with metacercariae of A. (P.) longa obtained from the mullets, and the adults recovered were used to infect the snails H. australis. Rediae and cercariae of A. (P.) longa are described for the first time. The ultrastructure of the tegument of A. (P.) longa shows a change in spination pattern from the cercaria with single-pointed spines to the metacercaria and adult with multipointed, brush-shaped spines. The life cycle of A. (P.) longa is related to estuaries and coastal lagoons where the recruitment of mugilid juveniles occurs. The high prevalence (100%) of A. (P.) longa encysted in the mullets examined within the urban area of Rio de Janeiro indicates the potentially great public health impact of the consumption of raw mullets. [Copyright &y& Elsevier]

Biological transport by migratory animals is increasingly recognized as important to the long-range dispersal of toxic contaminants. Mercury (Hg) contamination is a widespread environmental concern with serious health implications for humans and wildlife. Due to their unique life history, anadromous salmon may act as important vectors for this contaminant, transferring Hg between marine and freshwater ecosystems. Previous analyses have considered contaminant transport by salmon to be unidirectional. These studies have evaluated Hg import to freshwater by spawning adults, but have not quantitatively assessed export through the migration of juveniles to the ocean. To determine the total Hg burden to freshwater systems by sockeye salmon, we reconstructed the net transport of Hg to the Wood River System in Bristol Bay, Alaska accounting for fluxes in (via adults) and out (via juveniles) of the system. Hg concentrations were higher in juvenile than adult salmon. Hg export from freshwater systems by salmon ranged from 3 to 30% of total import Proportional export by smolts may be higher for populations under heavy exploitation with strong density dependence in juvenile recruitment. Full consideration of contaminant loading by migratory species requires attention to the relative contaminant flux at all life history stages and the effects of density dependent growth and survival. [ABSTRACT FROM AUTHOR]

Parasitic crustaceans serve as both hosts and vectors of viruses as well as of parasites and other microbial pathogenic agents. Few of the presumably numerous associations are known, but many can be anticipated. Recently, branchiurans and gnathiid isopods have been documented to host helminths and blood parasites. Because the agents can be observed readily with a microscope, these are better recognized than are the smaller viral, bacterial, and fungal agents. Some agents are harmful to the host of the crustacean parasite and others are not. Viruses probably fit both these categories, since viruses that do not appear pathogenic are often seen in ultrastructural images from a range of invertebrate hosts, including crustaceans. Some viruses have been implicated in causing disease in the host, at least under appropriate conditions. For example, lymphocystis virus may possibly be transmitted to the dermis of its fish hosts by copepods and to the visceral organs by a cymothoid isopod. Similarly, argulid branchiurans seem to transmit the viral agent of spring viremia of carp as well as carp pox, and copepods have been implicated in transmitting infectious hematopoietic necrosis, infectious salmon anemia, and infectious pancreatic necrosis to salmon. Other viruses can be vectored to their hosts through an additional animal. We exposed three viruses, Taura syndrome virus (TSV), white spot syndrome virus (WSSV), and yellowhead virus (YHV), all of which cause mortalities in wild and cultured penaeid shrimps, to crustacean parasites on fish and crabs. Using real-time polymerase chain reaction analysis, we show that TSV in the cyclopoid copepod Ergasilus manicatus on the gill filaments of the Gulf killifish, Fundulus grandis, the acorn barnacle Chelonibia patula on the carapace of the blue crab, Callinectes sapidus, and gooseneck barnacle Octolasmis rnuelleri on the gills of C. sapidus, can replicate for at least 2 weeks and establish what should be an infective dose. This result was additionally supported by positive in situ hybridization reactions. All three parasites are the first known non-penaeid hosts in which replication occurs. The mean log copy number of WSSV also suggested that replication occurred in E. manicatus. The mean log copy number of YHV gradually decreased in all three parasites and both hosts over the 2-week period. The vector relationships indicate an additional potential means of transmitting and disseminating the disease-causing agents to the highly susceptible and economically valuable penaeid shrimp hosts. [ABSTRACT FROM AUTHOR]

With the development of modern molecular techniques, the shellfish enteric viruses became easily detectable. In this study, we evaluated the efficiency of four methods quoted in the literature to extract hepatitis A virus (HAV) from naturally contaminated mussel tissues and to identify the viral material by a sensitive reverse transcriptase–polymerase chain reaction (RT–PCR). The results obtained after real-time RT–PCR showed a decreasing efficiency for HAV mussel extraction with glycine buffer, borate buffer, saline beef–polyvinylpyrrolidone (PVP) and saline beef buffer, respectively, as it was reported in previous works. However, the sensitivity of HAV extraction method using glycine buffer in artificial contaminated mussel was insufficient to allow the detection of HAV at a concentration below 102 50% tissue culture infective doses. Running the real-time amplification reaction with a mixture containing PVP and T4 gene 32 protein has removed RT–PCR inhibitors and has improved sensitivity of this technique in comparison with conventional RT–PCR. [ABSTRACT FROM AUTHOR]

This 1-year (September 2000 to August 2001) prospective study investigated the presence of hepatitis A virus (HAV) in the population of Monastir, Tunisia (86 serum samples), in the influents and effluents of two wastewater treatment plants, and in shellfish harvested in the coastal areas of Monastir, Bizerte and Sfax (January 2001 to May 2001). The virus was detected by RT-PCR using primers targeted at the VP3–VP1 region. An epidemic of HAV infection was observed during the winter months, with a peak in January. The presence of the virus was relatively constant in the influents and effluents of the wastewater treatment plants, and the virus was found in shellfish from the Monastir area during the months of January and February. The genotype IA strain was recovered most frequently from human serum and wastewater samples. The observation that the peak of the epidemic was during the winter months suggests that transmission of HAV is related to climatic factors and, presumably, to shellfish consumption. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to detect the main pathogenic human RNA enteric viruses able to persist in the environment such as astrovirus, enterovirus, norovirus and hepatitis A virus (HAV) in shellfish collected from two locations in northern Tunisia. Methods and Results: Viruses were eluted from digestive tissues and concentrated by polyethylene glycol precipitation before nucleic acid extraction and purification. After checking for inhibitors, all viruses were detected by reverse transcription-polymerase chain reaction (RT-PCR) and confirmed by hybridization. Overall, 83% of the samples were found positive for at least one virus. Astrovirus was detected in 61% of the samples, norovirus in 35% and HAV in 26%. Surprisingly, only one sample was found positive for enterovirus. Conclusions: The mean number of positive samples found in this study is in accordance with the data found in the literature, indicating that no real difference exists in this respect among countries studied. A notable exception is HAV, which reflects the epidemiological status of the population. Significance and Impact of the Study: This study highlights the interest to analyse shellfish samples from different production areas. These data will be helpful to understand virus circulation and to improve shellfish safety. The results, which confirm contamination, necessitate the development of appropriate studies and monitoring in all shellfish-producing countries. [ABSTRACT FROM AUTHOR]

Because of the worldwide popularization of Japanese cuisine, the traditional Japanese fish dishes sushi and sashimi that are served in Japanese restaurants and sushi bars have been suspected of causing fishborne parasitic zoonoses, especially anisakiasis. In addition, an array of freshwater and brackish-water fish and wild animal meats, which are important sources of infection with zoonotic parasites, are served as sushi and sashimi in rural areas of Japan. Such fishborne and foodborne parasitic zoonoses are also endemic in many Asian countries that have related traditional cooking styles. Despite the recent increase in the number of travelers to areas where these zoonoses are endemic, travelers and even infectious disease specialists are unaware of the risk of infection associated with eating exotic ethnic dishes. The aim of this review is to provide practical background information regarding representative fishborne and foodborne parasitic zoonoses endemic in Asian countries. [ABSTRACT FROM AUTHOR]

Vibrio vulnificus is a naturally occurring estuarine bacterium often associated with disease such as septicemia in humans following consumption of raw and lightly cooked seafood. In China and neighboring countries, rapid economic growth has encouraged increased consumption of seafood, and dietary habits are changing, with more people eating raw fish. In this study, the prevalence of V. vulnificus was investigated in 48 samples from 11 species of live seafood available from markets in coastal cities of China. The bacterium was detected in four of four razor clam samples, in seven of seven giant tiger prawn samples, and in five of nine mantis shrimp samples. The bacterium was also found in water samples of the prawn aquaria at the markets. The maximum level of V. vulnificus was 3.4 log CFU/g in the razor clam samples and 4.9 log CFU/g in the prawn samples by a direct spreading method. Differential bacterial counts on the prawn body revealed that most of the bacteria were found on the shells (exoskeletons), with very few in the edible muscle. However, dense populations can be found in the intestines. Biochemical tests indicated that the isolates of V. vulnificus were biotype 1 strain, which is pathogenic to humans. These isolates were susceptible to ampicillin, penicillin, kanamycin, streptomycin, and erythromycin. These results suggest that V. vulnificus is a potential health hazard to humans in cities consuming and handling live shellfish, especially giant tiger prawns. [ABSTRACT FROM AUTHOR]

Reference strains of infectious pancreatic necrosis virus resembling the 10 recognized serotypes and local isolates of aquabirnaviruses isolated in northwestern Spain from reservoirs (mollusks) and from asymptomatic and carrier cultured fish were genotyped by restriction fragment length polymorphism (RFLP) and nucleic acid sequence analyses. The RFLP analysis yielded seven genogroups, each of which was clearly correlated with a serotype. Sequence analysis of the three open reading frames provided quite similar results in terms of genogrouping. Based on the results of this study and in order to unify the two types of assays, we propose placing aquabirnaviruses into six genogroups, four of which can be subdivided into two genotypes based on a two-step restriction analysis. The genotyping corresponds with serotyping as follows: genogroup I includes two genotypes corresponding to serotypes A9 (genotype 1.1) and A1 (genotype I.2); genogroup II corresponds to serotype A3; genogroup III includes genotypes III.1 (serotype A2) and 111.2 (serotype B1); genogroups IV and V include two genotypes, each corresponding to serotypes A5, A6, A7, and A8 (genotypes IV.I, IV.2, V.I, and V.2, respectively);and genogroup VI corresponds to serotype A4. As expected, most local isolates belonged to genotype III.1 and genogroup II. However, a few local isolates corresponded to the American types of genogroup I. Finally, based on the results of this study and due to its simplicity, the two-step restriction analysis assay is proposed as a method for typing new isolates of aquabirnaviruses, and the results correspond to the results of conventional serotyping. [ABSTRACT FROM AUTHOR]

Outbreaks of shellfish-associated infection have been reported for more than a century. Since the early 1970s, the global consumption of shellfish has increased considerably -- and with it, the reports of outbreaks of infection. Most of these reports have originated from the United States, but Europe and, to a lesser extent, Asia and Australia have also been represented. The majority of outbreaks have been linked to oysters, followed by clams and mussels. Hepatitis A virus caused the largest ever shellfish-associated outbreak, but caliciviruses have caused the highest number of outbreaks; Vibrio species lead the list of bacterial pathogens. The prognosis of shellfish-associated infections is generally good, except for outbreaks of Vibrio vulnificus infection, which have a mortality rate of up to 50% in vulnerable people. Conventional and molecular techniques should be applied to better identify the causative agents, thereby enabling more-targeted control measures in growing, harvesting, and shipping bivalves. [ABSTRACT FROM AUTHOR]

Lactococcus garvieae ( LG) endocarditis is a rare disease in humans. There are only about 16 reported cases in the world. We report a 76-year-old male patient with LG endocarditis. In depth interview with the patient revealed that 2 weeks prior to admission, he had eaten sushi containing raw fish. Unlike many of the other infections reported, which were on a native mitral valve, our patient's vegetation was on a prosthetic aortic valve. [ABSTRACT FROM AUTHOR]

Scratch tests with different fish products (fish juice from fillets, meat (fillet), skin, slime, juice from fish boxes and hold in the fishing boats, and entrails were performed in 145 volunteers. All fish products were able to cause irritant skin reactions. Itching and erythema were the predominant symptoms and severe itch reactions occurred more often than severe erythema. The symptoms, in general, were mild to moderate compared to histamine. We found that the postmortem age of the fish was of great importance to the frequency and severity of the symptoms. Only the protein fraction of fish products caused symptoms. Our results are in accordance with the subjective complaints and clinical findings among workers in the fish processing industry. [ABSTRACT FROM AUTHOR]

The article focuses on a study done to detect the presence of Neorickettsia in the digestive tract of fish from southeast Asia. The bacteria of the genus Neorickettsia are intracellular bacteria of the family, Anaplasmataceae, and are transmitted to humans and animals by the ingestion of raw fish, snails or aquatic insects. The study revealed that the fish are likely to be parasitised by a variety of Anaplasmataceae and new cooking styles might led to the emergence of a new human disease.

Presents the results of a study on the bacterial and viral safety of shellfish. Development of methods to detect microorganisms in oysters, clams and mussels; Groups of pathogens that infect the molluscan shellfish trade; Information on intervention strategies that sanitize raw shellfish and other virus-contaminated foods.

The high cost of synthetic; molluscicides has farced many developing countries whore schistosomiasis is endemic to seek alternative controls. Preliminary trials indicate that endod, a naturally occurring plant molluscicide, could he cultivated and processed very cheaply by rural communities. This research merits stronger support than it now receives. [ABSTRACT FROM AUTHOR]

The article offers information on the study of bio vectors by researcher Kathryn Hargan. Topics discussed include views on bioaccumulating contaminants, including polychlorinated biphenyls as industrial pollution; sockeye salmon as transporters of contaminants in sea water; and study for the Polar Environmental Centre of lake contamination on Bear Island in the Barents Sea.

This section offers medical-related news briefs in the U.S. as of June 11, 2014. A study found that swamp eels found in ethnic food markets in the U.S. may be a source of the foodborne illness gnathostomiasis. Results of a study show that outreach testing with rapid hepatitis C virus (HCV) kits can detect many active infections. A report show a decline in teen birth rate in 2012.

The article presents a study investigating cyprinid herpesvirus type 3 (CyHV-3) in goldfish cohabiting with CyHV-3-infected koi carp. The study aims to seek where CyHV-3 resides between outbreaks and seasons and suggests that goldfish can act as carriers or transmitters for CyHV-3 without being affected by a lethal disease.