HBc positivity, however, was not elevated. annual conversion rate. MCV immunoglobulin G levels remained detectable up FZD3 to 25 years after exposure. No signs, symptoms, or routine diagnostic test results were associated with MCV infection, and no correlation between HIV infection or AIDS progression and MCV infection was noted. An initial correlation between chronic hepatitis B virus infection and MCV prevalence could not be confirmed among MCV seroconverters or in studies of a second hepatitis B virusChyperendemic cohort from Qidong, China. In adults, MCV is typically an asymptomatic, common, and commensal viral infection that initiates rare cancers after virus (rather than host cell) mutations. Keywords: viruses, MSM, men who have sex with men, Merkel cell polyomavirus, MCV, Merkel cell carcinoma, MCPyV, epidemiology, seroconversion, Pennsylvania, USA, China, HIV/AIDS and other retroviruses, research Merkel cell carcinoma (MCC) is a rare but aggressive skin cancer most commonly occurring among the Bis-NH2-PEG2 elderly and among immunosuppressed persons, including AIDS patients (not associated with signs or symptoms of illness in adult gay and bisexual men. MCV prevalence plateaued for men 35C45 years of age in our study, which is consistent with primary MCV infection occurring mainly among children and young adults (23). We found MCV prevalence among participants was 79.3% with a 6.6% annual seroconversion rate, which suggested widespread circulation of the virus. Our study suggests that MCV infection is a highly prevalent infection among adults that is often asymptomatic. We cannot exclude rare illnesses occurring from primary MCV infection, however, or illness mild enough not to be reported by our cohort participants. These results, and those of others, indicate that active MCV transmission is common even though MCV-related cancer Bis-NH2-PEG2 Bis-NH2-PEG2 is rare (33). Signs and symptoms Bis-NH2-PEG2 for primary MCV infection were not found in our study. An important caveat is that MACS participants self-reported symptoms at 6-month intervals, and minor symptoms may have been forgotten between study visits. MACS is a closely monitored cohort study designed to study risk factors and natural history of HIV in homosexual and bisexual men in the United States. Participants in this study were all sexually active adult men, most of whom were already positive for MCV, and so caution is needed in generalizing our results to other populations (e.g., women, children, non-US populations). We cannot exclude, for example, the possibility of symptoms or disease after primary pediatric MCV infection. Weak correlations that did not reach a level of significance in our study, such as lower hemoglobin and hematocrit values after MCV seroconversion, might be reconciled by testing in other cohorts. We did find an unexpected correlation between prevalent MCV infection and chronic HBV carriage for MACS participants. HBc positivity, however, was not elevated. When MCV seroconverters were examined, no correlation was found between Bis-NH2-PEG2 MCV infection and HBsAg positivity, and only a weak but nonsignificant association was present for HBc values. It is likely that most of the MACS men were exposed to HBV as adults through unprotected sex or parenteral exposure. None of our other comparisons suggest that either of these routes of infection is significant for MCV, although we can infer that MCV infection (a childhood infection that primarily occurs before onset of sexual activity) (23) likely preceded HBV infection in most participants. To further investigate the relationship between MCV and HBV infection, we examined HBV-hyperendemic samples from eastern China that likely represent mainly vertical or early childhood horizontal HBV infections. No correlation with MCV infection was found. Because of selection to ensure sufficient numbers of HBV-exposed participants, the Qidong study group cannot be assumed to represent a community serosurvey. Nonetheless, our results indicate widespread MCV infection among Asian adults similar to that seen for North Americans. It is unlikely that MCV and HBV are biologically linked in any significant manner, but caution is needed in interpreting these results since modes of HBV infection for MACS and Qidong participants are different. MCV appears to be a life-long, chronic infection that may cause continuous antigen stimulation. Recent studies have shown that detection of MCV antibodies is improved by use.
