Seroprevalence of Triatoma virus (Dicistroviridae: Cripaviridae) antibodies in Chagas disease patients

Background: Chagas disease is caused by Trypanosoma cruzi, and humans acquire the parasite by exposure to contaminated feces from hematophagous insect vectors known as triatomines. Triatoma virus (TrV) is the sole viral pathogen of triatomines, and is transmitted among insects through the fecal-oral route and, as it happens with T. cruzi, the infected insects release the virus when defecating during or after blood uptake. Methods: In this work, we analysed the occurrence of anti-TrV antibodies in human sera from Chagas disease endemic and non-endemic countries, and developed a mathematical model to estimate the transmission probability of TrV from insects to man, which ranged between 0.00053 and 0.0015. Results: Our results confirm that people with Chagas disease living in Bolivia, Argentina and Mexico have been exposed to TrV, and that TrV is unable to replicate in human hosts. Conclusions: We presented the first experimental evidence of antibodies against TrV structural proteins in human sera.

White spot viral disease in penaeid shrimp: a review

The white spot viral disease in penaeid shrimp affects the development of the global shrimp industry. This paper reviews the viruses that cause the disease, the transmission of the virus, diagnosis and preventive measures.

Shrimp disease management using bioactive marine secondary metabolites: an eco-friendly approach

Vibriosis caused by opportunistic and secondary bacterial pathogens is still a serious disease problem in aquaculture of the black tiger shrimp Penaeus monodon. Attempts were made for controlling shrimp bacterial disease using Marine Secondary Metabolites (MSMs). Findings indicated that the MSMs of seaweed Ulva fasciata and Dendrilla nigra are effective for controlling shrimp bacterial pathogens.

An epizootic of infectious hepatopancreatic and lymphoid organ necrosis disease in cultured Penaeus monodon: a case study

Shrimp disease of viral origin have caused large production losses worldwide. This paper presents a case study of shrimp (Penaeus monodon; Penaeus indicus) epizootic disease, covering an area of 1,050 ha in Andhra Pradesh, India. The disease struck shrimp farms in the area in July 1994. Samples from 26 shrimp farms were studied in the laboratory, and the pattern of the disease and of mortality recorded. The disease was classified as infectious hepatopancreatic and lymphoid organ necrosis disease (IHLN).

Disease Risks Associated with Importation of Nonindigenous Marine Animals

Transfers and introductions of marine species have occurred and are occurring on a worldwide basis, largely in response to perceived needs of expanding aquaculture industries. Greatest interest is in salmon (cage rearing and ocean ranching), shrimp, and bivalve mollusks, although other organisms are being considered. Such movements of animals carry an associated risk of moving pathogens into areas where they did not occur previously, possibly resulting in infections in native species. Many case histories of the effects of introduced pathogens and parasites now exist-enough to suggest that national and international action is necessary. Viral pathogens of shrimp and salmon, as well as protozoan parasites of mollusks and nematode parasites of eels, have entered complex "transfer networks" developed by humans, and have been transported globally with their hosts in several well-documented instances. Examining the records of transfers and introductions of marine species, incomplete as they are, permits the statement of emerging principles-foremost of which is that severe disease outbreaks can result from inadequately controlled or uncontrolled movements of marine animals.

Lethal Parasites in Oysters from Coastal Georgia with Discussion of Disease and Management Implications

Extensive mortalities of oysters, Crassostrea virginica, occurred from 1985 through 1987 in coastal waters of Georgia. Fluid thioglycolate cultures of oysters collected from 16 of 17 locations revealed infections by the apicomplexan parasite Perkinsus marinus. An ascetosporan parasite, Haplosporidium nelsoni, was also observed in histopathological examination of oysters from 4 of the locations. While the range of H. nelsoni currently is recognized as the east coast of the United States from Maine to Florida, this is the first report of the parasite in Georgia waters. This paper documents the occurrence of these two lethal parasites in oysters from coastal waters of Georgia, along with potential disease and management implications. Results of an earlier independent and previously unpublished survey are also discussed which document the presence of P. marinus in Georgia as early as 1966.

Salmon stocks and fisheries in England and Wales, 2001. Preliminary assessment prepared for ICES, April 2002

This report presents a preliminary assessment of the state of salmon stocks and fisheries in England and Wales in 2001 to assist ICES in providing scientific advice to NASCO and to provide early feedback to fishery managers and anglers. The chief indicators of the state o f salmon stocks are normally the catches taken by rod and net fisheries. However, in 2001 angling was affected by the outbreak of foot and mouth disease (FMD), which restricted angling opportunities and access to rod fisheries in many parts of the country for lengthy periods. It is impossible to quantify the impact that FMD had on rod catches, although these were undoubtedly significantly reduced; net fisheries were unaffected by FMD. The declared salmon catch for 2001 (including those fish released alive by anglers) is provisionally estimated at 209 tonnes, representing some 57,000 fish, and comprising 153 tonnes (-43,000 fish) by nets and fixed engines and 56 tonnes (-14,000 fish) by rods. For direct comparison with previous years, it should be noted that the declared catch prior to the issue of a second reminder was about 49 tonnes (see below). An estimated 26 tonnes (43%) of the rod catch was released alive. These figures do not take account of catches of salmon which go unreported (including those taken illegally), and it is estimated that there may have been a total of 33 tonnes of additional fish caught in 2001; approximately 15% of all fish killed.