Serology indicates cytomegalovirus infection is associated with varicella-zoster virus reactivation.

Varicella-zoster virus (VZV) causes chickenpox after which the virus remains latent in neural ganglia. Subsequent reactivation episodes occur, leading mainly to subclinical detection of VZV, but also to the clinical entity herpes zoster. These reactivations are known to occur most frequently amongst immunocompromised individuals, but the incidence of herpes zoster is also known to increase with age, supposedly as a consequence of immunosenescence. Our analysis aims to explore associations between cytomegalovirus (CMV) infection and VZV reactivation by analyzing VZV-specific antibody titers as a function of age, gender, and CMV serostatus. The analysis was repeated on measles and parvovirus B19 antibody titers. At the time of the observations, measles virus circulation was virtually eliminated, whereas parvovirus B19 circulated at lower levels than VZV. Multiple linear regression analyses, using the log-transformed antibody titers, identified a positive association between ageing and VZV antibody titers suggesting that ageing increasingly stimulates VZV reactivation. CMV infection further amplified the positive association between ageing and the reactivation rate. A negative association between CMV infection and VZV antibody titers was found in young individuals, thereby supporting the hypothesis that CMV infection may have a negative effect on the number of B-cells. However, no associations between CMV infection and measles or parvovirus B19 antibody titers occurred, but ageing tended to be associated with a decrease in the antibody titer against parvovirus B19. The combined results thus suggest that both CMV-dependent and CMV-independent immunosenescence occurs. This is supported by an in-depth analysis of VZV, measles and parvovirus B19 antibody titers.