Let anyone drink themselves to death, smoke themselves to death (or even let their own property be used for smoking), shoot up drugs, have damaging anal sex the way the fags do, and so on.
But communicable diseases is/are one of the very few areas where "provide for the common defense" is eminently applicable.
You mean "communicable to randoms" not "communicable to those who choose to expose themselves", as in the following example. Everyone out of the gene pool! Festival Is Called Syphilis Threat Officials fear outbreak from annual party in Palm Springs. Expected are 30,000 gay revelers. With 30,000 gay revelers expected for this weekend's "White Party" in Palm Springs a festival famous for sex and substance abuse public health officials and some gay leaders worry openly that it will fan an epidemic of syphilis. http://www.latimes.com/news/local/la-me-party18apr18,1,3177921.story?coll=la... A case more interesting to libertarian epidemiologists involves fetuses and their state-owned incubators, er, female-type citizen-units: HIV Testing Urged in All Pregnancies Federal health officials will unveil a new HIV (news http://rd.yahoo.com/dailynews/latimes/lo_latimes/inlinks/*http://rd.yahoo.com/DailyNews/manual/*http://search.news.yahoo.com/search/news?p=%22HIV%22&c=&n=20&yn=c&c=news&cs=nw - web sites http://rd.yahoo.com/dailynews/latimes/lo_latimes/inlinks/*http://rd.yahoo.com/DailyNews/manual/*http://search.yahoo.com/bin/search?cs=nw&p=HIV) testing strategy today designed to expand screening among pregnant women and about 200,000 others who are infected with the virus but do not know it. The new strategy by the U.S. Centers for Disease Control and Prevention (news http://rd.yahoo.com/dailynews/latimes/lo_latimes/inlinks/*http://rd.yahoo.com/DailyNews/manual/*http://search.news.yahoo.com/search/news?p=%22Disease%20Control%20and%20Prevention%22&c=&n=20&yn=c&c=news&cs=nw - web sites http://rd.yahoo.com/dailynews/latimes/lo_latimes/inlinks/*http://rd.yahoo.com/DailyNews/manual/*http://search.yahoo.com/search?p=%22Disease+Control+and+Prevention%22&h=c) specifically urges the testing of all pregnant women, rather than relying upon them to volunteer. http://story.news.yahoo.com/news?tmpl=story&u=/trib/20030418/lo_latimes/hiv_testing_urged_in_all_pregnancies