Detection of cold-adapted vaccine-strain influenza virus using two commercial assays.
Because of the contagious nature of influenza virus it is necessary to identify infected individuals after the virus is introduced into a population. The aim of this study was to characterise influenza virus detection with commercially available assays after intranasal vaccinating horses with cold-adapted influenza virus. Seven horses were vaccinated and placed with 3 unvaccinated horses. Nasal secretion samples were evaluated using 2 antigen detection assays. All 10 horses were positive in the Flu OIA assay during the study period, but only one horse was positive on one sample using the Directigen Flu A assay. Horses were most likely to be positive during the first 3 days following vaccination, and several horses were intermittently positive for several days after this. Obtaining positive test results from nonvaccinated, incontact horses suggests they became infected with vaccine-strain virus that was shed by vaccinated horses. These results are important for the correct interpretation of influenza antigen detection tests in situations when this modified-live intranasal vaccine has been used.
College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
E N
EN
Adam
P S
PS
Morley
K E
KE
Chmielewski
J
J
Carman
G
G
Gonzales
D000281:Administration, Intranasal; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000032:analysis*; D005260:Female; D006734:Horse Diseases / Q000276:immunology / Q000517:prevention & control* / Q000635:transmission; D006736:Horses; D007118:Immunoassay / Q000662:veterinary; D007124:Immunoenzyme Techniques / Q000662:veterinary; D007252:Influenza Vaccines / Q000008:administration & dosage*; D008297:Male; D009297:Nasal Mucosa / Q000276:immunology / Q000378:metabolism / Q000821:virology; D009975:Orthomyxoviridae / Q000276:immunology / Q000302:isolation & purification*; D009976:Orthomyxoviridae Infections / Q000517:prevention & control / Q000635:transmission / Q000662:veterinary*; D011933:Reagent Kits, Diagnostic / Q000662:veterinary; D012680:Sensitivity and Specificity; D017201:Virus Shedding
D000914:Antibodies, Viral; D000956:Antigens, Viral; D007252:Influenza Vaccines; D011933:Reagent Kits, Diagnostic