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Twenty rapid antigen assays were compared for their ability to detect influenza using dilutions of virus culture supernatants from human isolates of influenza A H5N1 (clade 1 and 2 strains), H3N2 and H1N1 viruses, and influenza B. There was variation amongst the rapid antigen assays in their ability to detect different influenza viruses. Six of the 12 assays labeled as distinguishing between influenza A and B had comparable analytical sensitivities for detecting both influenza A H5N1 strains, although their ability to detect influenza A H3N2 and H1N1 strains varied. The two assays claiming H5 specificity did not detect either influenza A H5N1 strains, and the two avian influenza-specific assays detected influenza A H5N1, but missed some influenza A H3N2 virus supernatants. Clinical trials of rapid antigen tests for influenza A H5N1 are limited. For use in a pandemic where novel influenza strains are circulating (such as the current novel influenza A H1N1 09 virus), rapid antigen tests should ideally have comparable sensitivity and specificity for the new strains as for co-circulating seasonal influenza strains.

Serologic testing for antibody to monkey B virus (BV) in macaque sera is problematic due to the biohazardous nature of BV antigens. Herpesvirus papio 2 (HVP2), a herpesvirus of baboons, is nonpathogenic to humans and is genetically and antigenically more closely related to BV than is human herpes simplex virus 1. This paper describes the results of our in-house laboratory that compared a BV antigen-based enzyme-linked immunosorbent assay (ELISA) by commercial testing laboratory and an HVP2-based ELISA in our laboratory by using 447 sera from 290 rhesus monkeys. The HVP2-based ELISA identified as positive 99.11% of the sera identified as BV-positive by the BV ELISA. The BV antigen-based ELISA identified as positive 98.21% of the sera identified as BV-positive by the HVP2-based ELISA. The HVP2 ELISA also identified two BV-negative and six BV-equivocal sera as positive. Both ELISAs identified the same 85 negative and three equivocal samples as negative and equivocal, respectively. The high degree of correlation (weighted kappa coefficient, 0.94) between the two tests indicates that the HVP2 ELISA is a sensitive and reliable assay for in-house testing of the BV status of rhesus monkeys.

Herpesvirus papio 2 (HVP2), which infects baboons, is much more closely related genetically and antigenically to monkey B virus (BV) than to human herpes simplex virus 1(HSV1) and other related herpes viruses. The usefulness of HVP2 as an alternative test antigen in immunoblotting assays to detect BV-antibody in macaque monkey sera was assessed. Six HVP2 proteins reacted with BV-positive sera in immunoblotting. No specific bands could be detected with BV-negative sera. These results show the usefulness of HVP2 antigen as an alternative and safer antigen than authentic BV antigen in detecting BV antibody in immunoblotting.

The prevalence of Herpesvirus papio 2 (HVP2) in several groups of captive and wild-caught baboons was determined by detection of anti-HVP2 antibodies in 133 sera of adult baboons. Over 90% of newly imported (wild-caught) adult olive baboons (Papio anubis) from Kenya and chacma baboons (P. ursinus) from South Africa were found to have anti-HVP2 titers. Similarly, approximately 85% of captive breeding colony baboons (P. anubis and P. cynocephalus) were seropositive for HVP2. Infected animals were generally easily identifiable by enzyme-linked immunosorbent assay because anti-HVP2 IgG titers in immune animals were usually high (16,000 to 64,000). There was little variation in the relative reactivity patterns of individual HVP2-immune sera when tested against herpes simplex viruses 1 and 2, monkey B virus, H. cercopithecus 2, and HVP2, or against different HVP2 strains. Also, differences were not detected between reactivity of olive and chacma baboon immune sera. Analysis of the polypeptide specificity of immune sera by western blot identified four viral antigens that were consistent targets of immune sera. These antigens were the gB glycoprotein, a pair of unidentified glycoproteins of 80 to 100 kDa, the gD glycoprotein, and a series of smaller capsid proteins. Additional viral proteins were variably recognized by individual immune sera. The results of this study indicate that HVP2 is a common infection of baboons; there is little antigenic variation among HVP2 strains; and there are several HVP2 antigens that represent consistent targets of the anti-HVP2 immune response of baboons.