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We performed a multicenter case-control study on incident cases of giant cell arteritis and polymyalgia, and tested for viruses known to induce multinucleated giant cells in human pathology. IgM directed against Human parainfluenza type 1 virus were shown to be significantly associated with the onset of the disease in 40% of the cases, versus 20% of the controls.

Peroxidase-labeled monoclonal antibodies against respiratory syncytial virus (RSV) and influenza A virus were used for immunoperoxidase staining (IPS) of cell cultures inoculated with nasopharyngeal aspirates. Cells were grown in 24-well plates, and specimens were inoculated by low-speed centrifugation. Cultures were incubated for 2 days at 37 degrees C and then fixed, stained, and observed by light microscopy. IPS was compared with standard virus isolation by using cultures of human diploid fibroblasts and Vero, HEp-2, and HeLa cell lines for RSV and Madin-Darby canine kidney cells for influenza A virus; these cultures were inoculated with specimens that were previously stored at -70 degrees C. Of 40 known RSV-positive specimens, 30 were found to be positive on reinoculation by both methods, and an additional 5 specimens were found to be positive by IPS only. Of 190 specimens tested for influenza A virus, 14 were positive by IPS and in tubes, and a further 8 specimens were positive by IPS only. IPS was also compared with direct detection of viral antigens in nasopharyngeal aspirates by a time-resolved fluoroimmunoassay (TR-FIA). Fresh nasopharyngeal aspirates were inoculated into human diploid fibroblasts and Madin-Darby canine kidney cells and tested for RSV and influenza A virus, respectively, by IPS. Of 110 specimens tested for RSV, 37 were positive in total, 32 were positive by IPS, and 33 were positive by TR-FIA. Of 150 specimens tested for influenza A virus, 39 were positive in total, 35 were positive by IPS, and 34 were positive by TR-FIA. IPS of cultures inoculated by centrifugation and incubated for 2 days is a sensitive method for the diagnosis of respiratory virus infections, and 24-well plates allow for the easy processing of a large number of specimens.

In 1984-1985, an outbreak of respiratory syncytial virus (RSV) infection occurred in two geriatric wards. Among 68 patients (mean age +/- SD = 82.5 +/- 12.5 with respiratory signs, 52 had signs caused by RSV infection. Among all patients, the clinical and serological attack rates were 61.2% and 75.0%, respectively. The most frequent clinical presentation was intensive coughing (96.1%) and fever (96.1%) associated with expectorate (63.5%). The duration of the respiratory symptoms was 5 to 7 days. The disease gradually resolved, although in eight (15.4%) patients complications occurred. For periods of up to 1 year after infection, 172 sera were obtained and tested by complement fixation test (CFT), fluorescent assays for titrating specific IgG, IgA, and IgM, and Western blotting. Specific IgM appeared in six (11.5%) of the infected patients and peaked 2 to 6 months after infection, and there was no significant correlation with severity of clinical symptoms. However, higher peak G and A antibody responses were observed in persons with rales (CFT: P = 0.008; IgG: P = 0.042; IgA: P = 0.020), cough (IgG: P = 0.034), sputum (IgG: P = 0.030), dyspnea (CFT: P = 0.024), conjunctivitis (CFT: P = 0.025), and bronchitis (CFT: P = 0.018). The temporal patterns of IgA and CFT results were found to be similar, whereas IgG peaked later, i.e., between 2 and 6 months. The patients with the most severe symptoms had the highest antibody titers obtained by conventional tests and by Western blots. Thus, RSV can be an epidemic pathogen among elderly persons, although this illness is usually mild.