Comparison of a direct antigen enzyme immunoassay, Herpchek, with cell culture for detection of herpes simplex virus from clinical specimens.

Direct enzyme immunoassay (Herpchek) was compared with culture on 21,522 specimens mainly from asymptomatic women for herpes simplex virus detection. Sensitivity and specificity were 73.8 and 97.7%, respectively. The 33% detection rate by enzyme immunoassay in 5 h increased to 43% when the enzyme immunoassay was combined with culture. Herpchek alone was not sensitive enough, but in combination with culture, maximum detection was achieved.

Spin-amplified culture followed by enzyme immunoassay for detection of herpes simplex virus in patient specimens: a comparative study.

In a comparative study it was found that a combination technique of spin-amplified culture and detection of herpes simplex virus (HSV) antigen in 48-h incubated cell culture lysate by a HSV antigen detection enzyme immunoassay kit (Dupont Herpchek) detected the largest number (227) of confirmed HSV positives when compared to standard cell culture (191) and direct Herpchek (146) on the same 415 clinical specimens.

Herpes simplex virus antigen direct detection in standard virus transport medium by Du Pont Herpchek enzyme-linked immunosorbent assay.

A commercial 5-h direct herpes simplex virus (HSV) antigen detection enzyme immunoassay kit (Du Pont Herpchek) was compared with a cell culture isolation system by using primary rabbit kidney and MRC-5 cells with 779 clinical specimens received in virus transport medium and with stock tissue culture preparations of HSV types 1 and 2. In the first study of 422 specimens from symptomatic patients, Herpchek detected 110 of 111 HSV-positive specimens (26.3% of all specimens), with a sensitivity of 99% and a specificity of 100%. In the second study of 357 specimens primarily from asymptomatic pregnant women, however, Herpchek detected 70 of 119 HSV-positive specimens (33% of all specimens), with a sensitivity of 58.8% and a specificity of 99.5%. Stock virus dilution experiments showed that Herpchek was 10 to 100 times less sensitive than culture. Herpchek was found to be an acceptable test for symptomatic patients, but for asymptomatic patients shedding a low titer of HSV it was not as sensitive and cell culture of Herpchek-negative specimens is recommended for such cases.

The diagnosis of human immunodeficiency virus infection: progress in less than five years.

Diagnostic tests for human immunodeficiency virus first became commercially available in 1985, only two years after the virus was discovered. In the short period of time since then, we have witnessed improvements in antibody detection methods, refinements in culture techniques, and the introduction of antigen and nucleic acid detection methods, including the polymerase chain reaction. These diagnostic tools as well as their advantages and disadvantages are reviewed in this report.

Comparison of antibodies for rapid detection of cytomegalovirus.

Antibodies were compared for use in the spin-amplified shell vial method for rapid cytomegalovirus detection. Commercial antibodies by Du Pont Co., Whittaker M.A. Bioproducts, Bartels Immunodiagnostic, Virostat, and Serono Diagnostics were compared at incubation times of 16 to 48 h on 22 patient specimens. Only the Du Pont antibody showed 100% sensitivity and specificity and no nonspecific reactions.

Enzyme-linked immunosorbent assay spin amplification technique for herpes simplex virus antigen detection.

A comparative study of herpes simplex virus diagnosis by standard cell culture and a new hybrid test (enzyme-linked immunosorbent assay spin amplification technique) was done on 300 specimens. The new test was found to be equally sensitive and specific, much less expensive to perform, and to report all results in 48 h.

Diagnostic virology in a community hospital.

Seven and one-half years of experience in a small diagnostic virology laboratory of a large inner-city hospital are reported. Seven hundred fifty-one viruses were isolated from over 8,000 specimens, using two types of tissue culture cells, human and monkey kidney. The most common isolates were Herpes simplex viruses (HSV) and Enteroviruses. Similar results have been reported by larger laboratories. Sensitivity for HSV in monkey kidney cells was only 75 percent that in human cells. An enzyme-linked immunosorbent assay (ELISA) for cytomegalovirus (CMV) was found to be a suitable substitute for the traditional complement fixation test (CF). IgM antibodies were not found in all HSV infections, but these antibodies did appear before CF antibodies in some cases. Monoclonal antibodies to HSV were effective in typing isolates, but for detection of viral antigen in brain smears of HSV encephalitis patients, polyclonal antibody gave better results.

Indirect fluorescent-antibody test for human cytomegalovirus infection in the absence of interfering immunoglobulin G receptors.

The presence of immunoglobulin G receptors in human fibroblasts infected with human cytomegalovirus (CMV) resulted in a nonspecific cytoplasmic reaction in the indirect fluorescent-antibody test. Both CMV antibody-positive and antibody-negative sera from human or other animal species produced the cytoplasmic reaction. The substitution of a simian CMV strain for the human virus successfully eliminated this cytoplasmic reaction and, thus, allowed for the observation of virus-induced fluorescent intranuclear inclusions. With the latter system, CMV antibody titers in human sera were equivalent to those obtained by using the human virus and, in addition, allowed for the detection of relatively low-titered serum samples in which antibody measurement was difficult when human CMV-infected cells were used in the indirect fluorescent-antibody test.

Persistent infection with bovine herpesvirus-1 (infectious bovine rhinotracheitis virus) in cultured hamster cells.

Bovine herpesvirus-1 infection in hamster embryo cells was found to be dependent upon input multiplicity; productive infection was achieved at input multiplicities greater than one, while persistent infection was established when input multiplicities were about 0.5. This persistence was characterized by a noncyclic, minimal degree of cytopathic effect with a low level of released virus. Maintenance of the persistently infected cultures did not require external supportive measures. Subcultivation of the persistently infected cultures led to virus replication followed by CPE and then cell regrowth. With 3 to 4 weeks after subcultivation a persistent infection was re-established. The possible mechanism for the bovine herpesvirus persistence in hamster cells is discussed.

Failure to SV40-transformed lizard cells to induce tumors in autogeneic or allogeneic hosts.

Lizard cells from the tails of geckos were readily morphologically and antigenically transformed in vitro by SV40 virus. Neither autografts of these cells nor allografts of SV40 transformed gecko embryo cells produced tumors in animals under observation for 1 to 3 years.

Induction of tumors by a guinea pig herpesvirus-transformed hamster cell line.

Syrian hamster embryo cells that had been transformed in vitro by guinea pig herpes-like virus (GPHLV) were found to be oncogenic when inoculated into hamster sc or ip. Of 71 animals inoculated, 30 showed tumors at the site of inoculation. Tumors appeared 4-23 weeks after inoculation of the transformed cells at passage 37 or higher. Inbred and randombred hamsters of all ages were susceptible. Upon microscopic examination the tumors were characterized as fibrosarcomas. The cultured hamster tumor cells were easily transplanted into hamsters, but produced no evidence of tumors when inoculated into guinea pigs. Infectious GPHLV was not isolated from the tumor cells, but GPHLV-specific surface antigens were detected in tumor cells by immunofluorescence of GPHLV antiserum produced in rabbits. Sera from tumor-bearing hamsters did not contain GPHLV-neutralizing antibodies, but sera from 4 of 23 hamsters bearing primary tumors and 12 of 41 bearing transplanted tumors produced nuclear fluorescence in cells infected with GPHLV, thus establishing the relationship between the guinea pig herpesvirus and the hamster tumors.

Growth characteristics of bovine herpesvirus 1 (infectious bovine rhinotracheitis) in human diploid cell strain WI-38.

IBR virus was found to replicate in WI-38 cells. At a high input multiplicity the virus yield was comparable to that obtained in bovine cells, but comparable degree of CPE took longer to achieve. At a low input multiplicity of IBR virus, such as may be encountered in virus contaminated bovine serum, virus yield was only about 1% of that in bovine cells, with 50% of the cells showing CPE, followed by cell regrowth. Infectious virus was not recoverable from the regrown cells by 5 weeks after initial infection, and these regrown cells were susceptible to reinfection with IBR virus. Aging of WI-38 cells in cultures for as little as 1 week reduced IBR virus yield to 90% less than the yield from the same lot of cells inoculated 7 days earlier.