Ureaplasmas as a cause of disease in man and animals: fact or fancy?

There is reluctance by some to regard ureaplasmas as a cause of nongonococcal urethritis in men largely because the organisms may also be found in healthy persons. Could they be no more than passengers in disease? A review of past work suggests that this is not likely, a notion supported by the results of more recent studies. In certain other human diseases, such as urethritis and arthritis in hypogammaglobulinemic patients, the pathogenicity of ureaplasmas appears beyond question. In a variety of other conditions, such as the urethral syndrome in women, infertility, various pregnancy-related problems, and respiratory distress in infants, the situation is confused. It is possible that ureaplasmas have some part to play in all these conditions. However, both old and new information indicates that they do not have a major role in most of them, and that assertions to the contrary are fanciful. In the veterinary field, it is easier to come to conclusions about the role of these organisms, although their involvement in genital tract disease is least well validated. Finally, the occurrence of ureaplasmas in a colony of male and female chimpanzees, some with infertility problems, is presented, and the possible value of this situation in attempting to define the role of ureaplasmas in the human condition is mentioned.