<prompt> True about HIV epidemiology -Children rarely affected10 of HIV infected person progress to AIDSSouthern africa have 72 of total global burdenSeminal secretion is more infectious than vaginal secretion  <response>: Key facts about Epidemiology of HIV infection Reservoir: Cases and carriers Source: Virus is in greatest concentration in blood, seen and CSF Lower concentrations in tear, saliva, breast milk, urine, cervical and vaginal secretions Children under 15 years make only 3 cases Basic modes of transmission Sexual Blood and blood products Neddlessyringes Mother to child transmission MTCT Incubation period : few months to 10 years Ref: Park 25th edition Pgno : 363-367 