training on preventive health care are also organised with the support of the prison administration. They can and should rely on the experience, facilities and tools that many NGOs have for training on HIV/Aids and hepatitis B and C, and they should also try to persuade prison administrations to seek their support in this regard. Various methodologies of education can and should be applied: face‑to‑face education, group discussions, role plays, theatre sketches followed by discussion, leafets, flms and other audiovisual tools. Peer education seems to be especially efective for injecting drug users. Invitation to screening by VCCT (voluntary confdential counselling and testing) should be an integral part of education. 3.4 Reduction of drug supply and demand The importance of intensifed checks and searches to prevent drug supply in prison is beyond any doubt. Because of the high number of imprisoned drug‑dependent persons, prisons are a favourite target of the illegal drug mar‑ ket, prison subcultures and unofcial power structures in many prisons in the world, which are dominated by the interests of this illegal market. Reality has shown that checks and searches cannot keep prisons completely free of drugs. It has been reasoned that searches alone, without being accompanied by other preventive measures, might even be counterproductive in prevention of the spread of parenteral transmissible infections: drugs packed in tiny volumes are easy to smuggle into prisons in comparison to the more voluminous injection instruments. This results in drug supply without adequate injection‑equipment supply, with the consequence of repetitive and shared use of scarce injection equipment and thus virus transmission. As in the community, a well‑balanced four‑pillar policy – enforcement, prevention, harm reduction and treatment – can more efciently reduce the risks of drug use in prison while preventing the spread of transmissible diseases by injecting drugs. It should be kept in mind that, according to the principles of medical ethics and international recommendations, health‑care professionals caring for prisoners should never involve themselves in checks, searches, body searches or drug tests done for security reasons, or they may lose the trust of their patients.10 These actions are exclusively the duty of the security staf. If a physician is 10. CM: The ethical and organisational aspects of health care in prison. Recommendation R (1998) 7; The CPT Standards 2002 (rev. 2011); World Medical Association: WMA Statement on Body Searches of Prisoners (Budapest 1993, rev. 2005). Preventing the spread of HIV/Aids and hepatitis B/C in prisons Page 55