Case-finding effectiveness of partner notification and cluster investigation for sexually transmitted diseases/HIV.

Objective: To assess the case-finding effectiveness of partner notification (PN) and cluster investigation for sexually transmitted disease (STD)/human immunodeficiency virus (HIV). Study: Literature review and quantitative summary. Results: Since 1975, the median case-finding yield for syphilis, gonorrhea, and chlamydia PN reported in the literature is about 1 new case found for every 4 or 5 cases interviewed. The yield from HIV PN is approximately half as large, although there is substantial variability in yield across reports for each disease. Published reports underline the central role provider referral plays in effective PN and casefinding. Successful PN is more likely with index cases who are of majority ethnicity and detected through screening or spontaneous presentation for care with symptoms and with partners with whom index cases have had sexual contact that is recent, frequent, and of long duration. The case-finding yield for HIV PN also is much higher when cases are diagnosed through confidential, rather than anonymous, testing. Cluster investigation and related strategies tend to have lower case-finding yields than PN but can play a very useful casefinding role, especially in settings with high disease incidence. Conclusions: STD/HIV PN and cluster investigation can contribute meaningfully to case finding. More research is needed to strengthen the empiric foundation of PN and related strategies, including the impact they have on disease transmission. Partner notification (PN), or contact tracing, has long been a cornerstone of efforts to control the spread of sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV). 1‐3 The PN process involves persons diagnosed with disease informing sexual partners (and drug-injection partners, in the case of HIV) about their exposure to infection and the need for medical examination and treatment. Often this process begins when a public health worker counsels a patient about PN and elicits his or her partners who may have been exposed to the infection. Typically, the patient and public health worker then make a plan about who—the patient and/or the public health worker—will notify particular partners and ensure their medical evaluation and treatment. PN serves 3 main purposes: epidemiology, ethics, and case finding. 4 Epidemiology is a valuable function of PN, 5,6 as the process reveals the sociogeographic context and sexual/injection networks in which transmission takes place. PN also fulfills the ethical duty to warn persons exposed to serious infections. The third and original purpose of PN is case finding. The identification, examination, and treatment of contacts to disease are crucial for interrupting transmission of infectious diseases such as STD and HIV. In this article, I review the empirical evidence on the casefinding effectiveness of PN and similar approaches for controlling STD/HIV. Various aspects of the literature on the effectiveness of PN have been reviewed many times over the past 20 years. 1‐3,7‐18 My review complements this prior work by providing a comprehensive update and an in-depth assessment of case-finding effectiveness. In addition, I also provide a review of research on the relative case-finding effectiveness of different PN referral strategies, factors associated with successful PN, innovative strategies for PN, coverage of PN, and impact of PN on disease transmission.