| Traditionally most of our studies were on HIV but gradually we have expanded our interest to other infectious diseases especially but not exclusively those that are sexually transmitted or bloodborne. Using pooled data from 22 cohorts - including the Amsterdam Cohort Studies (ACS) among homosexual men (HM) and drug users (DU) - we showed that in the HAART era compared to the pre-HAART era the death rate strongly decreased but that AIDS opportunistic infections remained the most common cause of death. Over the past 20 years the HIV incidence among DU has become close to zero and injecting risk behavior has strongly declined. Recent HIV infections among DU are mainly related to unprotected (heterosexual) risk behavior but we found no evidence for an increase of risk behavior because of the availibility of HAART (as was found before among HM). Studying the evolution of primary drug resistant HIV-1 infections, we found that in the first years after seroconversion the CD4 decline is slower among persons carrying such resistant viruses versus persons with wild type. In a longitudinal study among hepatitis A (HA) patients, we showed that faecal excretion of HA virus is much longer than originally thought, up till 2 months or more while also the period of viremia in blood can be 42 days. These data have consequences for control measures. Molecular typing of hepatitis C viruses (HCV) from blood donors showed a great diversity and the impossibility to detect such donors through screening for risk behavior. Donor selection is highly effective but insufficient to fully protect against new blood transmissable infections among blood donors. Additional studies were done on the evaluation of the targeted HBV vaccination program in Amsterdam and on Lymphogranuloma venereum. |
