INTESTINAL PARASITOSES IN THE PAST CENTURIES WITH EMPHASIS TO SOCIALLY DISADVANTAGED PEOPLE: AN HISTORICAL LINK?- NATURAL HISTORY OF HIV INFECTION.- IMMUNOPATHOGENESIS OF AIDS.- ADVANCES IN KNOWLEDGE OF THE HIV-RELATED IMPAIRMENT OF MUCOSAL IMMUNITY.- EFFECT OF HIV INFECTION ON GASTROINTESTINAL FUNCTION.- FROM ANIMAL TO MAN (RESERVOIRS AND WAYS OF TRANSMISSION): 1) CRYPTOSPORIDIOSIS, MICROSPORIDIOSIS, ISOSPORIASIS, CYCLOSPORIASIS, LEISHMANIASIS, PNEUMOCYSTOSIS, TOXOPLASMOSIS. 2) MYCOBACTERIUM TUBERCULOSIS, M. AVIUM COMPLEX, AND OTHER MYCOBACTERIOSES: DRUG RESISTANCE, PHENOTYPIC AND GENOTYPIC MARKERS, AND THE MOLECULAR BASIS OF PATHOGENESIS.- WORLDWIDE EPIDEMIOLOGY AND RISKS FOR IMMUNODEFICIENT TRAVELLERS.- ORAL INFECTIONS.- GUT INFECTIONS: ETIOPATHOGENETIC AND CLINICAL REMARKS.- HISTOLOGICAL AND ULTRASTRUCTURAL PATHOLOGY.- SONOGRAPHIC EVIDENCES.- RADIOGRAPHIC EVIDENCES.- LABORATORY DIAGNOSIS AND MICROBIOLOGY: 1) BACTERIA. 2) MYCOBACTERIA. 3) MICROSPORIDIA. 4) CRYPTOSPORIDIUM, AMOEBAE, GIARDIA, LEISHMANIA, TOXOPLASMA, BLASTOCYSTIS.m 5) ISOSPORA BELLI AND EIMERIA (CYCLOSPORA) CAYETANENSIS. 6) FUNGI. 7) STRONGYLOIDES STERCORALIS. 8) HERPESVIRUSES. 9) ENTERIC VIRUSES. 10) LATEST ADVANCES AND TRENDS IN PCR-BASED DIAGNOSTIC METHODS.- CHANGING PATTERNS OF PROPHYLAXIS AND TREATMENT: 1) BACTERIA AND VIRUSES. 2) PARASITES AND FUNGI. - EPIDEMIOLOGY AND COMPREHENSIVE MANAGEMENT OF HIV-RELATED DIARRHEA IN AFRICA: WHAT STRATEGIES FOR AN ENORMOUS CHALLENGE?- UNIQUE PROBLEMS IN DEVELOPING COUNTRIES OTHER THAN AFRICA.- FUTURE TRENDS AND PERSPECTIVES IN THE WORLDWIDE SCENARIO.