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Human immunodeficiency virus type 1 (HIV-1) sequences that pre-date the recognition of AIDS are critical to defining the time of origin and the timescale of virus evolution. A viral sequence from 1959 (ZR59) is the oldest known HIV-1 infection. Other historically documented sequences, important calibration points to convert evolutionary distance into time, are lacking, however; ZR59 is the only one sampled before 1976. Here we report the amplification and characterization of viral sequences from a Bouin's-fixed paraffin-embedded lymph node biopsy specimen obtained in 1960 from an adult female in Léopoldville, Belgian Congo (now Kinshasa, Democratic Republic of the Congo (DRC)), and we use them to conduct the first comparative evolutionary genetic study of early pre-AIDS epidemic HIV-1 group M viruses. Phylogenetic analyses position this viral sequence (DRC60) closest to the ancestral node of subtype A (excluding A2). Relaxed molecular clock analyses incorporating DRC60 and ZR59 date the most recent common ancestor of the M group to near the beginning of the twentieth century. The sizeable genetic distance between DRC60 and ZR59 directly demonstrates that diversification of HIV-1 in west-central Africa occurred long before the recognized AIDS pandemic. The recovery of viral gene sequences from decades-old paraffin-embedded tissues opens the door to a detailed palaeovirological investigation of the evolutionary history of HIV-1 that is not accessible by other methods.

To determine the aetiology of persistent diarrhoea in African patients with acquired immunodeficiency syndrome (AIDS), 42 patients with human immunodeficiency virus (HIV) and persistent diarrhoea were enrolled in a microbiological, endoscopic, and histological study. Cryptosporidium was the intestinal parasite most often identified (30%); Isospora belli was found in 12% of the patients. Histological examination of the duodenal mucosa showed a non-specific inflammatory reaction in a significantly higher number of HIV-seropositive patients (82%) than HIV-seronegative controls without diarrhoea (52%) (p = 0.02). Lymphocytes were more likely to be found in inflammatory reactions in HIV-seropositive patients than in controls (p less than 0.0001). Pathogens were observed in histological sections of the duodenum of HIV-seropositive patients only (p = 0.002) and included cryptosporidia (four patients) Isospora belli (one), Strongyloides stercoralis (one), and Cryptococcus neoformans (one). On histological examination the rectal mucosa of HIV-seropositive patients and controls was similar, except eosinophils were more likely to be present in inflammatory reaction in HIV-seropositive patients (p = 0.05) and enteric pathogens were observed only in HIV-seropositive patients (cytomegalovirus inclusion bodies (one) and Schistosoma mansoni (two). The aetiology of persistent diarrhoea in most African AIDS patients remains unclear.