To promote and secure health in prison, testing for infectious diseases and vaccination is a major opportunity, and does have an impact on the health of the incarcerated, the correctional employees and the communities to which the inmates return. Vaccination for Hepatitis B and A is highly recommended for prisoners. Drug testing on the other hand, in particular mandatory drug testing in prison can have adverse effects (encourages people to switch from smoking drugs like Cannabis to injecting drugs like heroin in order to avoid detection). Mandatory drug testing is expensive and can be counterproductive. Treatment for prisoners involves the treatment for drug dependency and infectious diseases. Upon entering the prison, prisoners with AIDS should be offered treatment with highly active anti-retroviral therapy (HAART), which is an effective treatment. Similar to AIDS, treatment for HCV is safe and feasible.

The establishment of prison-based substitution treatment proved to be as effective in reducing mortality, crime and re-incarceration rates and HCV as in the community. Evidence for the effectiveness of prison needle exchange programmes (PNEP) has been gathered in a number of very different prison settings: PNEP reduces needle sharing, can increase uptake of drug treatment as well as the safety in the prison, and can reduce abscesses and fatal overdoses. It does not increase injecting drug use, nor has it shown any other negative effects. Condoms are likely to be the most effective method for preventing sexually transmitted diseases (STDs). No serious negative effects of condom distribution in prisons have been found, and the free availability of condoms seems feasible in a wide range of prison settings.