Case Description—A 3-month-old red-lored Amazon parrot (Amazona autumnalis autumnalis) was evaluated for severe lethargy.
Clinical Findings—Avian influenza virus hemagglutinin subtype H5N2 with low pathogenicity was characterized by virus isolation, real-time reverse transcriptase PCR assay, chicken intravenous pathogenicity index, and reference sera. The virus was also determined to be closely related to a virus lineage that had been reported only in Mexico and Central America.
Treatment and Outcome—The chick was admitted to the hospital and placed in quarantine. Supportive care treatment was administered. Although detection of H5 avian influenza virus in birds in the United States typically results in euthanasia of infected birds, an alternative strategy with strict quarantine measures and repeated diagnostic testing was used. The chick recovered from the initial clinical signs after 4 days and was released from quarantine 9 weeks after initial evaluation after 2 consecutive negative virus isolation and real-time reverse transcriptase PCR assay results.
Clinical Relevance—To the authors' knowledge, this is the first report of H5N2 avian influenza A virus isolated from a psittacine bird and represents the first introduction of this virus into the United States, most likely by illegal importation of psittacine birds. Avian influenza A virus should be considered as a differential diagnosis for clinical signs of gastrointestinal tract disease in psittacine birds, especially in birds with an unknown history of origin. Although infection with avian influenza virus subtype H5 is reportable, destruction of birds is not always required.
Objective—To determine necropsy and Mycobacterium
bovis culture results in cattle from herds
with tuberculosis, the role of the bovine NRAMP1
gene in resistance and susceptibility to infection with
M bovis, and the association between magnitude of
the tuberculous lesions and various types of M bovis
Animals—61 cattle from herds with tuberculosis in
Texas and Mexico.
Procedure—61 cattle were evaluated by necropsy;
59 had positive and 2 had negative caudal fold tuberculin
intradermal test (CFT) results. Thirty-three cattle
with positive CFT results were genotyped to evaluate
polymorphism of the 3' untranslated region of
the bovine NRAMP1 gene, using single-stranded
conformational analysis, 9 were resistant to M bovis
with no tuberculous lesions and negative M bovis
culture results, and 24 were susceptible with tuberculous
lesions and positive M bovis culture results.
Isolates of M bovis were analyzed by restriction fragment
length polymorphism (RFLP) on the basis of
IS6110 sequences and direct-repeat fingerprinting
Results—21 (35.6%; 21/59) cattle with positive CFT
results had tuberculous lesions or positive culture
results; in addition, 1 of 2 cattle with negative CFT
results had tuberculous lesions and positive culture
results. Tuberculous lesions were most common in
the thorax (35/63; 55.5%) and lymphoid tissues of the
head (10/63; 15.9%). Tuberculous lesions varied from
1 to 11/animal; 8 of 21 (38.1%) had solitary lesions.
Associations were not found between resistance or
susceptibility to infection with M bovis and polymorphism
in the NRAMP1 gene or between the magnitude
of the lesions and various RFLP types of M bovis
Conclusions and Clinical Relevance—The NRAMP1
gene does not determine resistance and susceptibility
to infection with M bovis in cattle. (Am J Vet Res