DNA of adeno-associated virus (AAV) in testicular tissue and in abnormal semen samples

BACKGROUND: Human genital tissues, including spermatozoa, have been found t o be frequently infected with the helper-virus dependent parvovirus, adeno- associated virus (AAV). METHODS: To assess the role of AAV infection in dis orders of the male reproductive system, semen samples from 95 men (includin g 73 men attending a fertility programme) and testicular samples from patie nts with azoospermia (n = 38) or prostate cancer (n = 8) were analysed usin g polymerase chain reaction for the presence of AAV DNA. Semen quality was assessed according to World Health Organization guidelines and the grade of atrophy of testicular biopsies was determined histomorphologically. RESULT S: AAV DNA was detected in 38% (28/73) of ejaculates from men with abnormal semen analyses (oligoasthenozoospermia or asthenozoospermia) and in 4.6% o f normal semen samples (1/22, P = 0.003). DNA from AAV helper-viruses (huma n papillomaviruses, cytomegalovirus) was detected at similar frequencies in normal and abnormal semen samples. In testes, AAV DNA was detected in 10 o ut of 38 biopsies from infertile men (26%), and in 2 out of 8 orchidectomy samples. CONCLUSION: The data show an increased incidence of AAV infection with abnormal semen analysis. Detection of AAV DNA in the testes might poin t to a role for AAV infection in male infertility, possibly by interfering with spermatozoa development.