Gastrointestinal pathology in rhesus monkeys with experimental SIV infection.

The updated results of current pathomorphological investigations in SIV-infected rhesus monkeys (Macaca mulatta) are summarized. After experimental infection with several SIVmac251 subtypes and various vaccination trails, 147 rhesus monkeys were morphologically examined until now. The pathology of the gastrointestinal tract in SIV-infected animals resembled those of human cases with HIV and AIDS. Alterations were considered to be primary SIV-induced (SIV enteropathy, giant cell disease) or secondary caused by opportunistic agents. Typical secondary gastrointestinal opportunistic infectious agents were parasites (Cryptosporidium sp., Trichuris sp., Trichomonas sp., Spironucleus sp.), viruses (cytomegalovirus, adenovirus) and bacteria (Mycobacterium simiae). Five animals developed malignant lymphomas involving the intestinal tract. The present observations revealed that SIV infection of rhesus monkeys provide an excellent model for studies on the pathogenesis of HIV in man.