To detect avian pneumovirus (APV) in central North America, nasal turbinates or choanal deft tissues from domestic turkeys and wild birds were examined for the presence of APV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), whereas serum samples from domestic turkeys were analyzed for APV antibodies by enzyme-linked immunosorbent assay (ELISA). In 2002, the seroprevalence of disease in domestic turkeys in Minnesota remained high (42.3% of the flocks). In addition, there is evidence the disease has spread to turkey flocks in North Dakota (8.2%), South Dakota (7%), Iowa (10%), and Wisconsin (8.6%) as detected by RT-PCR and/or ELISA. House sparrows and ring-billed gulls sampled in Minnesota and snow geese from Saskatchewan, Canada, were found to harbor APV RNA. Sequence analysis of wild bird APV strains showed high amino acid sequence identity among wild bird isolates (<97%) and between wild bird and turkey viral isolates (93.2%-99.3%). This study demonstrated that APV infections were present in domestic turkey flocks and wild birds outside the state of Minnesota; however, the role of wild birds in spreading APV to domestic turkeys remains unclear.

Abstract. Antibodies to avian pneumovirus (APV) were first detected in Minnesota turkeys in 1997. Virus isolation was attempted on 32 samples (28 tracheal swabs, 4 pools of trachea and turbinates) that were positive for APV by reverse transcriptase polymerase chain reaction (RT-PCR). The cell cultures used were chicken embryo fibroblast (CEF), Vero cells, and QT-35 cells. Five virus isolates were obtained from these samples, and the identity of the isolates was confirmed by RT-PCR. Four isolates were obtained by inoculation of CEF cells, and 1 isolate was obtained in QT-35 cells after 3-7 blind passages in cell cultures. Vero cells did not yield any isolate on primary isolation; however, all 5 isolates could be adapted to grow in Vero cells following primary isolation in CEF or QT-35 cells. This is the first report of isolation of APV in Minnesota and also the first report of primary isolation of APV in QT-35 cells.An acute, upper respiratory tract disease of turkeys, turkey rhinotracheitis (TRT), has been reported from many countries since the late 1970s. 10 The clinical signs consist of profuse ocular and nasal discharge, facial edema or swelling, and respiratory distress. In laying birds, a drop in egg production associated with slight respiratory distress is observed. The clinical signs become more severe if complicated by secondary bacterial infections. The morbidity is often 100%, and the mortality ranges from 0.4% to 90%. 11 The disease is caused by TRT virus (TRTV), which is classified on the basis of polypeptide and messenger RNA analyses as an avian pneumovirus (APV) in the subfamily Pneumovirinae of family Paramyxoviridae. 11 Besides being the cause of TRT in turkeys, TRTV is also suggested to cause swollen head syndrome in chickens. 2,3,13,15 The TRTV infection of turkeys has been reported in many countries, e.g., Great Britain, South Africa, France, Israel, Spain, Germany, Italy, and The Netherlands. 11 Nucleotide sequencing and serologic studies using polyclonal and monoclonal antibodies showed that TRTV could be separated into 2 groups. Subgroup A includes the early British and French strains, and subgroup B includes the other continental European strains. 9 In the USA, clinical signs of APV infection were first reported in turkey flocks in Colorado in 1996. Before that, the USA, 12 Canada, 7 and Australia 1 were considered to be free from APV. However, APV was isolated from turkey flocks in Colorado in February 1997. 14 Outbreaks of similar illness were reported in Minnesota in March 1997 with clinical signs of depression, coughing, sinusitis, airsacculitis, and mortality. Because Minnesota is one of the major turkeyproducing states, APV infections in that state can have a significant economic impact.Routine methods for the primary isolation of APV consist of specimen inoculation (tracheal swabs, trachea, turbinate, lungs) in embryonated chicken eggs (ECE) or turkey eggs (ETE) or in tracheal organ cultures (TOC). Subsequently, the virus is adapted to chicken embryo fibroblast (CEF) or Vero cells....

Abstract. Avian pneumovirus (APV) infection of turkeys in Minnesota was first confirmed in March 1997. Serum samples (n ϭ 5,194) from 539 submissions to Minnesota Veterinary Diagnostic Laboratory were tested by a modified enzyme-linked immunosorbent assay (ELISA). Of these, 2,528 (48.7%) samples from 269 submissions were positive and 2,666 (51.3%) samples from 270 submissions were negative for APV antibodies. Most positive samples were from Kandiyohi, Stearns, Morrison, and Meeker counties in Minnesota. In addition, 10 samples from South Dakota were positive. The sensitivity and specificity of the ELISA test with anti-chicken and anti-turkey conjugates were compared by testing field and experimental sera. The ELISA test with antiturkey conjugate was more sensitive than that with anti-chicken conjugate. The ELISA tests with antigens prepared with APV strains isolated from Colorado and Minnesota were also compared. No difference was detectable. Currently, the Minnesota Veterinary Diagnostic Laboratory uses an antigen prepared from the Colorado isolate of APV and a goat anti-turkey conjugate in the ELISA test.Turkey rhinotracheitis, caused by turkey rhinotracheitis virus (TRTV), was first detected in South Africa in the late 1970s 2 and was subsequently reported from Great Britain, South Africa, France, Israel, Spain, Germany, Italy, and The Netherlands. 1,15 The TRTV is an avian pneumovirus that belongs to family Paramyxoviridae, subfamily Pneumovirinae. It is an enveloped virus that lacks hemagglutination and neuraminidase activities and contains a nonsegmented, negative-sense, single-stranded RNA. The virus has been separated into 2 subgroups, the subgroup A being formed by the early British and French isolates and the subgroup B, by the other continental European strains. 4,5,13 The diagnosis of TRTV infection is based on the isolation and identification of the virus and/or serology. Because of the fastidious nature of the virus, the isolation of TRTV is very difficult and time consuming. The detection of TRTV antibodies, on the other hand, may be more rapid and economical when compared with virus isolation and reverse transcriptase-polymerase chain reaction. 6,12 Serum antibodies to TRTV have been detected by indirect immunofluorescence assay (IFA), virus neutralization, and enzyme-linked immunosorbent assay (ELISA). 3,7,9,10,16,118 Outbreaks of avian pneumovirus (APV) infection were reported in Minnesota turkeys for the first time in March 1997. The clinical signs consisted of depression, coughing, sinusitis, airsacculitis, and mortality. Several isolates of APV were isolated from infected turkey flocks. 8 Earlier, an APV was isolated from infected turkey flocks in Colorado.

Salmonella Typhimurium isolates from feed ingredients or poultry sources isolated during 1995 to 1997 from different geographical locations within Minnesota were examined for the presence of Salmonella Typhimurium definitive type 104 (DT104). Antibiotic susceptibility studies indicated that 15 of 50 isolates of Salmonella Typhimurium had an antibiotic resistance pattern (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) that is usually observed with multidrug-resistant Salmonella Typhimurium DT104. Of the 15 isolates showing the antibiotic resistance pattern, 8 isolates were phage type 104, 3 isolates were typed as phage type 104 complex, and the remaining 4 isolates belonged to phage types 193, 81, and 126. DT104 was recovered from both feed ingredients and poultry samples. Of the seven feed ingredient-associated Salmonella Typhimurium isolates, four were DT104, whereas only 7 of 43 poultry-associated Salmonella Typhimurium isolates were DT104. A repetitive sequence-based polymerase chain reaction (rep-PCR) of 50 isolates of Salmonella Typhimurium representing 13 phage types identified seven distinct fingerprint profiles. No correlation between phage type and rep-PCR type was noticed. Eleven Salmonella Typhimurium isolates belonging to DT104 and its complex were grouped into two closely related rep-PCR types.

The avian pneumovirus (APV) outbreak in the United States is concentrated in the north-central region, particularly in Minnesota, where more outbreaks in commercial turkeys occur in the spring (April to May) and autumn (October to December). Comparison of the nucleotide and amino acid sequences of nucleoprotein (N), phosphoprotein (P), matrix (M), fusion (F), and second matrix (M2) genes of 15 U.S. APV strains isolated between 1996 and 1999 revealed between 89 and 94% nucleotide sequence identity and 81 to 95% amino acid sequence identity. In contrast, genes from U.S. viruses had 41 to 77% nucleotide sequence identity and 52 to 78% predicted amino acid sequence identity with European subgroup A or B viruses, confirming that U.S. viruses belonged to a separate subgroup. Of the five proteins analyzed in U.S. viruses, P was the most variable (81% amino acid sequence identity) and N was the most conserved (95% amino acid sequence identity). Phylogenetic comparison of subgroups A, B, and C viruses indicated that A and B viruses were more closely related to each other than either A or B viruses were to C viruses.The Turkey rhinotracheitis virus, commonly referred to as avian pneumovirus (APV), is a member of the Paramyxoviridae family that causes acute rhinotracheitis in turkeys that is characterized by coughing, nasal discharge, tracheal rales, foamy conjunctivitis, and sinusitis in turkeys of all ages. In laying birds, there is a transient drop in egg production, along with mild respiratory tract illness (11). Uncomplicated cases have low mortality (2 to 5%), but APV infections accompanied by secondary infections (bacterial and/or viral) can result in up to 25% mortality (11). APV was first detected in South Africa in 1978 but was isolated soon thereafter in the United Kingdom,