CDC advocates names, but doesn't rule out use of coded identifiers. Centers for Disease Control and Prevention.
D015492:AIDS Serodiagnosis; D002487:Centers for Disease Control and Prevention, U.S.; D016358:Contact Tracing; D017408:Guidelines as Topic; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D011159:Population Surveillance / Q000379:methods*; D018907:Privacy / Q000331:legislation & jurisprudence; D014481:United States / Q000453:epidemiology