Antigens, prepared from 17 strains of Haemophilus paragallinarum by treatment with potassium thiocyanate followed by sonication, uniformly agglutinated glutaraldehyde-fixed chicken erythrocytes and formed specific hemagglutination inhibition antibodies in rabbits. Attempts were made to classify the strains into serotypes by a combination of cross-hemagglutination inhibition and cross-absorption...

newcastle disease (nd) is one of the most serious illnesses of chickens. live vaccines are widely used to prevent chicken from the disease all over the world. to access the effective and potentiate nd vaccine, a homogenous subpopulation from lasota strain was selected following cultivation of the virus on primary chicken embryofibroblast (cef) cells. pathogenicity indices and molecular characte...

Despite several data on influenza infection in dogs, the first natural outbreak of canine influenza virus, closely related to H3N8 equine subtype, dates back to 2004 in Florida. Subsequent studies highlighted the role of dogs in adaptation of H5N1 to mammals and the susceptibility of dogs to different subtypes of influenza. A prevalence study was carried out on 562 sera collected from pet and k...

The Middlebrook-Dubos hemagglutination test with normal red cells and the Boyden hemagglutination test with red cells tanned with tannic acid were shown to be strictly specific, for tubercle polysaccharide and for the protein antigens. The former test detects polysaccharide antibodies and the latter protein antibodies. Convincing evidence is given that polysaccharide does not adhere to the surf...

At present, the hemagglutination inhibition (HI) assay is the sole commercially available serologic method available to detect exposure to ophidian paramyxovirus (OPMV) in snakes. During 2006, 26 eastern massasaugas (Sistrurus catenatus catenatus) were collected, and blood was sampled to determine their OPMV status. Samples from each snake were divided into 3 aliquots and tested by using commer...

The immunity to pandemic influenza A(H1N1)pdm09 in Sweden before and after the outbreaks in 2009 and 2010 was investigated in a seroepidemiological study. Serum samples were collected at four time points: during 2007 (n = 1968), in October 2009 (n = 2218), in May 2010 (n = 2638) and in May 2011 (n = 2513) and were tested for hemagglutination inhibition (HI) antibodies. In 2007, 4.9% of the popu...

Rubella virus antibodies were measured in 300 sera from pregnant women visiting a maternity center by using a new, simple latex test, Rubalex. The results were compared with those obtained by using hemolysis in gel, hemagglutination inhibition, and radioimmunoassay. The sensitivity of the latex test was 100, 98.0, and 99.6% when compared with hemolysis in gel, hemagglutination inhibition, and r...

BACKGROUND Antigenic characterization of influenza viruses is typically based on hemagglutination inhibition (HI) assay data for viral isolates tested against strain-specific postinfection ferret antisera. Here, similar virus characterizations were performed using serological data from humans with primary influenza A(H3N2) infection. METHODS We screened sera collected between 1995 and 2011 fr...

The hemagglutination inhibition test is commonly used for the identification of newly isolated influenza viruses. In this laboratory several difficulties frequently were encountered in typing these new strains after primary isolation by means of this technique. These drawbacks were: (1) Some newly isolated strains are susceptible to nonspecific inhibitors of hemagglutination (Francis, Salk, and...

A radioimmunoassay procedure was developed for determining smallpox and vaccinia antibodies in human sera. The test detected and measured both primary and secondary immune responses in persons infected with variola virus or vaccinia virus. The antibody titers obtained by complement fixation, hemagglutination inhibition, plaque reduction neutralization, and radioimmunoassay methods were compared...