[Cytomegalovirus infections in healthy adults.].

BACKGROUND: Primary cytomegalovirus (CMV) infections in healthy adults are considered extremely rare. To study the extent of this problem in Iceland we undertook a two year (1989-1990) retrospective study of all new CMV infections in adults. METHODS: All positive tests for CMV antibodies in clinical samples (194) were identified in the sole virology laboratory in Iceland. Patients younger than 16 years and all patients with underlying diseases that could cause immunosuppression were excluded (154). The 40 remaining patients were contacted, their case histories reviewed and their serology for CMV, Epstein-Barr and HIV antibodies remeasured. Primary CMV infection was not confirmed in 14 patients leaving 26 immune competent patients who fullfilled our criteria for primary sym-tomatic CMV infection by the presence of IgM anti-CMV antibodies. RESULTS: Duration of illness in the 26 study patients varied from 1 to 25 weeks, usually 7-10 weeks. Fifteen patients were hospitalized. Diagnostic delay was considerable. Immunological tests (DTH skin test, serum immunoglobulines and lymphocyte differential counts) done 172-2 years after the illness did nor reveal any persistent immune abnormalities except for an absolute increase in the number of CD8+ T lymphocytes Conclusions: We conclude that primary CMV infections in adults are not uncommon and probably underdiagnosed. When adult patients present with non-specific symptoms such as low grade fever, malaise and unexplained fatigue, CMV should be considered or excluded with appropriate serological tests.

IgG subclass response and opsonization of Streptococcus pneumoniae after vaccination of healthy adults.

Studies relating opsonization and IgG antibodies to Streptococcus pneumoniae have yielded contradictory results. This study compared changes in opsonization with IgG subclass response after vaccinating healthy subjects with a 23-valent pneumococcal vaccine. Total IgG and IgG subclass antibodies to pneumococcal polysaccharide types 8, 9, and 19 were measured by ELISA. Opsonic activity was assayed using 3H-labeled bacteria and polymorphonuclear leukocytes in different serum concentrations (5%-40%). A substantial postvaccination increase in total and subclass IgG antibody was observed in most subjects, although variations were seen. Postvaccination sera generally gave rise to enhanced opsonization, and a correlation was found between increases in antibody levels and opsonization. This correlation was closest for IgG1 and IgG4 and generally strongest at the lowest serum concentration, but weak or absent at the highest concentration. Thus, vaccination against S. pneumoniae stimulates a variable increase in specific opsonic activity in health persons that is best demonstrated when serum is a limiting factor in the opsonin assay.