USC News: To prevent the spread of HIV among the homeless, researchers turn to math

USC researchers have teamed up with Los Angeles social workers to address a public- health problem — the spread of HIV — using an unlikely method: mathematics.

Social workers at My Friend’s Place [http://myfriendsplace.org] , a nonprofit agency that helps Los Angeles’ homeless youth become more self-sufficient, have been working to prevent the spread of HIV among homeless teens and young adults.

They’ve relied in part on word-of-mouth, but have had limited success. Transient young adults often have fluid friendships; if two friends stop hanging out, a social worker’s street campaign could come to an end.