ABSTRACT
Highly pathogenic avian influenza (HPAI) is a systemic lethal disease of poultry caused by several subtypes of influenza A virus and classified on the basis of serologic reactions to hemagglutinin and neuraminidase surface glycoproteins. In January 2016, a novel subtype of HPAI-H7N8-was diagnosed in a commercial turkey (Meleagris gallopavo) flock in southern Indiana. Clinical signs and history included increased mortality, dyspnea, head tremors, recumbency, and somnolent or unaware birds. Postmortem examination of six recently dead birds showed red-tinged mucous in the choana and trachea and marked pulmonary edema. Histologic lesions in the brain included severe, multifocal lymphohistiocytic meningoencephalitis with foci of malacia, neuronal necrosis, and neuronophagia. All anatomic locations of the brain were affected, although histologic changes in the cerebellum were considered mild. Other histologic lesions included pulmonary congestion and edema, splenic congestion and lymphoid depletion, fibrinoid necrosis of vessels within the spleen, and multifocal pancreatic acinar necrosis. Immunohistochemistry (IHC) was weakly positive for influenza A in the brain; IHC was negative in other tissues tested. The clinical and pathologic characteristics of this case matched previously published material concerning HPAI and add to instances of known or suspected mutation of a low pathogenic virus to a highly pathogenic virus.
Subject(s)
Disease Outbreaks/veterinary , Influenza A virus/physiology , Influenza in Birds/epidemiology , Poultry Diseases/epidemiology , Turkeys , Animals , Diagnosis, Differential , Indiana/epidemiology , Influenza A virus/classification , Influenza A virus/isolation & purification , Influenza in Birds/diagnosis , Influenza in Birds/pathology , Influenza in Birds/virology , Male , Poultry Diseases/diagnosis , Poultry Diseases/pathology , Poultry Diseases/virologyABSTRACT
A novel picornavirus, turkey avisivirus (TuASV), was identified from the feces of turkeys (Meleagris gallopavo) with gastrointestinal disease from a farm in Indiana. Its genome organization is as follows: 5' untranslated region (UTR)(IRES-II) [VP0, VP3, VP1, 2A, 2B, 2C, 3A, 3B, 3C(pro), 3D(pol)] 3' UTR-poly(A). TuASV shares only 34% (P1), 36% (P2), and 35% (P3) amino acid identities with avihepatoviruses, indicating that it potentially represents a novel picornavirus genus.
ABSTRACT
Species and biotype distribution was determined in 44 bovine viral diarrhea virus- (BVDV-) positive samples submitted to the Animal Disease Diagnostic Laboratory (ADDL) in Indiana during 2006-2008. BVDV RNA was detected in the 5'-untranslated region and N(pro) region using reverse transcriptase PCR followed by sequencing analysis of the PCR product. Additionally, cases were classified into one of six categories according to history and/or lesions: acute symptomatic, hemorrhagic, respiratory distress, reproductive, persistent infection (PI), and mucosal disease (MD). Of 44 BVDV-positive samples, 33 were noncytopathic (ncp), 10 were cytopathic (cp), and one presented both ncp and cp biotypes. Sequencing analysis demonstrated that all samples belonged to BVDV-1a, BVDV-1b, or BVDV-2. The most common isolate was ncp BVDV-1b, (44%) followed by ncp BVDV-2a (24%). Among the six categories, respiratory clinical signs were the most common (36%) followed by PI (25%) and MD (16%).