ABSTRACT
Processes that allow viral hemorrhagic septicemia (VHS) virus to persist in the marine environment remain enigmatic, owing largely to the presence of covert and cryptic infections in marine fishes during typical sub-epizootic periods. As such, marine host reservoirs for VHS virus have not been fully demonstrated, nor have the mechanism(s) by which infected hosts contribute to virus perpetuation and transmission. Here, we demonstrate that after surviving VHS, convalesced Pacific herring continue to shed virus at a low rate for extended periods. Further, exposure of previously naïve conspecific sentinels to this shed virus can result in infections for at least 6 mo after cessation of overt disease. This transmission mechanism was not necessarily dependent on the magnitude of the disease outbreak, as prolonged transmission occurred from 2 groups of donor herring that experienced cumulative mortalities of 4 and 29%. The results further suggest that the virus persists in association with the gills of fully recovered individuals, and long-term viral shedding or shedding relapses are related to cooler or decreasing water temperatures. These results provide support for a new VHS virus perpetuation paradigm in the marine environment, whereby the virus can be maintained in convalesced survivors and trafficked from these carriers to sympatric susceptible individuals.
Subject(s)
Fish Diseases , Hemorrhagic Septicemia, Viral , Novirhabdovirus , Animals , Disease Outbreaks , Fish Diseases/epidemiology , Fishes , Virus SheddingSubject(s)
Enema/adverse effects , Hirschsprung Disease/diagnostic imaging , Intestinal Perforation/diagnostic imaging , Iopamidol , Diagnosis, Differential , Humans , Infant, Newborn , Intestinal Perforation/etiology , Male , Pneumoperitoneum/diagnostic imaging , Pneumoperitoneum/etiology , RadiographyABSTRACT
Radionuclide bone imaging in pediatric patients occasionally shows a focus of distinct localized increase of radiotracer uptake at the ischiopubic synchondrosis. Correlation of radionuclide bone images and conventional radiographs of this area in a group of pediatric patients demonstrates the positive bone scans to correlate with the period of beginning but incomplete fusion of the synchondrosis. This represents a normal phase of skeletal development that radiographically and scintigraphically may mimic disease and should not be confused with a focus of pathologic activity.
