[AIDS: an imported disease?].

AIDS (acquired immune deficiency syndrome) has been known for 5 years. The first few cases in Switzerland were observed in persons infected outside the country, but this has changed in the last 2 years. The infectious agent is transmitted by sexual intercourse and by sharing of blood contaminated needles and syringes of drug addicts, two factors which are also responsible for most of the virus transmissions in Switzerland. From some African countries there are reports of a high transmission rate probably caused by prostitution.