Various methods are used to remove nonspecific inhibitors from sera before titering viral hemagglutination-inhibiting antibodies. These methods have several undesirable features; some are tedious and time-consuming, some remove antibody along with nonspecific inhibitors, and different techniques are usually required to remove the nonspecific inhibitors for different viruses. This communication ...

During 2012, we identified sampled dogs with elevated levels of antibodies (≥1:40) against A(H1N1)pdm09 virus by using a hemagglutination inhibition (HI) assay (seroprevalence, 24.7%) and a microneutralization (MN) assay (seroprevalence, 10.8%). These high seroprevalences of A(H1N1)pdm09 among dogs without clinical signs of influenza support the premise that dogs may play a role in the human in...

Nonspecific inhibitors of rubella hemagglutination can be removed by treatment of sera with heparin-manganous chloride for use in the hemagglutination-inhibition test. After removal of nonspecific inhibitors by this procedure, an excess of manganous chloride may remain. This may cause the cells to agglutinate, thus obscuring the reading at low serum dilutions. This disadvantage can be overcome ...

TO THE EDITOR—I read with great interest the article by Pathirana et al [1], which demonstrated that a 2-dose vaccination regimen with ASO3 adjuvant is needed to improve immune responses against 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) infection in low responders. The authors, in their discussion, suggested that the rapid induction of antibodies in the responders may have bee...

Avian influenza viruses replicate in a variety of mammals and birds, yet hemagglutination inhibition tests show that postinfection sera from these animals (e.g., ferrets and ducks) have insignificant levels of antibodies (Hinshaw et al., Infect. Immun. 34:354-361, 1981). This suggested that avian influenza viruses, in contrast to mammalian viruses, may not induce a significant humoral response....

A new latex agglutination test for rubella virus was used to test sera with a hemagglutination inhibition titer of -8 (97 specimens) or >256 (158 specimens). Maximum latex agglutination test sensitivity was achieved when low-titer sera were tested undiluted and high-titer sera were diluted (1:10). A modification of the protocol of the manufacturer resulted in a latex agglutination-hemagglutinat...

The diagnostic value of the hemagglutination inhibition test for Newcastle disease has been established for some years (Brandly et al., 1946). The question of the relationship of the hemagglutination inhibition activity (HI) of immune sera to virus-neutralizing activity (SN) or to the refractivity of the host to challenge infection is still one of both fundamental and practical importance. Data...

Serology improves influenza diagnosis by capturing cases missed by reverse transcriptase PCR (RT-PCR). We prospectively evaluated microneutralization and hemagglutination inhibition assays for 2009 influenza A (H1N1) virus diagnosis among 24 RT-PCR-confirmed cases and 98 household contacts. Compared to hemagglutination inhibition, microneutralization demonstrated a higher level of concordance w...

A new latex agglutination test for rubella virus was used to test sera with a hemagglutination inhibition titer of less than or equal to 8 (97 specimens) or greater than or equal to 256 (158 specimens). Maximum latex agglutination test sensitivity was achieved when low-titer sera were tested undiluted and high-titer sera were diluted (1:10). A modification of the protocol of the manufacturer re...