Talk with a health Professional

You can:

* Send an anonymous letter if you're really too bothered.

* Take the person aside, in a place where you feel at ease and tell him. If you feel embarrassed, you can prepare yourself before doing so, it helps.

* If you do not want to face the person, there's always the telephone or Internet ... it's a little less personal but the important thing is that the person to know.

* You can also talk with a health professional ... they can offer you solutions and help to find the words. For example, they can apply to management of public health to take care to warn the person. They will not tell whence comes the information but simply that this person should be treated.