Use of Cross-Sectional Data to Estimate Force of Infectionfor Hiv Infection and Hepatitis C - Absence of Constant Risk

Injecting drug users (IDU) have high risk of acquisition of HIV and other blood-borne viruses, because they frequently share needles, syringes and other injecting paraphernalia. The article describes methodology of estimating force of infection for blood-borne diseases from data on prevalence and injection length. Based on results from 5429 IDU surveyed between 2006 and 2013 it was found that force of infection is at maximum during first months after starting injecting - 0,38 (95%CI=0,24 .. 0,51) for HIV infection and 1,03 (95%CI=0,61 .. 1,46) for hepatitis C. After that risk of infection significantly decrease but is not zero. Also basic reproductive rate by regions and periods of study was estimates. Importance of this approach for public health is demonstrated.