Network-based testing (NBT) services are a broad collection of approaches to identifying, contacting, notifying, testing, providing treatment or prevention, and linking to services contacts and partners of people who are engaged in care.
Research on these services for HIV, hepatitis B, hepatitis C, and other sexually transmitted infections (STIs) is also limited, and few broad systematic reviews or meta-analyses that cover these topics have been completed. WHO led consultative roundtable discussions with researchers conducting studies on NBT in October and November 2024 to gather and synthesize evidence on these services. Informed by this consultative process, this section provides an overview of research on NBT services, with links to publications in this field. While this section provides an overview of significant research findings, these findings are not the result of a systematic review or scientific analysis, and this section is not intended to be an exhaustive literature review.
An extensive body of research has demonstrated that partner services, social network testing, and family testing approaches for HIV are effective at identifying partners and other individuals at risk, increasing testing among these groups, and increasing the positivity of testing when compared with testing in the general population (1-3). Despite this range of evidence for NBT services in HIV, far less direct evidence exists for NBT services for hepatitis B or C, or for other STIs.
The NBT literature index lists papers published in peer-reviewed journals through 2024. Papers are indexed by type of NBT approach, which infection or infections were being tested, and in which population and country. This index is not an exhaustive list of all evidence in this area.
Provider-assisted partner services have shown success in various settings, with HIV test positivity among partners generally ranging from 12% to 86% (4), depending on context and programming, whereas the positivity for most testing programs has fallen below 5% globally (5). When providers assist by notifying partners anonymously, this provider-assisted partner approach appears to improve linkage to care and can encourage re-engagement compared with other passive partner referral approaches in which clients notify partners themselves (6, 7).
Social network testing services (SNS), in which individuals promote testing or other services within their social networks, have also been shown to increase uptake of HIV testing – through HIV self-testing or standard testing – among sexual partners and social contacts of test promoters (8). Social network approaches may also increase the number of first-time testers (9, 10).
Direct evidence for NBT services for other STIs or hepatitis B and C is limited, as well as evidence on using partner services to deliver prevention interventions, or integrating services across HIV, other STIs, and hepatitis B and C. Recent research suggests that providing services for partners of people living with HIV who inject drugs can achieve high rates of case-finding for hepatitis C (7, 11), and that partner services for partners of people with STIs can result in high positivity for HIV testing (12). Testing for both HIV and syphilis using dual rapid diagnostic tests is increasingly being used in antenatal clinics (13).
Although ethical and safety concerns may exist, particularly when these services are driven by yield or test positivity targets or conducted without consent (14), studies have not found significant increases in harm, interpersonal violence or other adverse events (15).
1. Hogben M, McNally T, McPheeters M, Hutchinson AB. The effectiveness of HIV partner counseling and referral services in increasing identification of HIV-positive individuals a systematic review. Am J Prev Med. 2007 Aug;33(2 Suppl):S89-100. https://pubmed.ncbi.nlm.nih.gov/17675019/
2. Landis SE, Schoenbach VJ, Weber DJ, Mittal M, Krishan B, Lewis K, et al. Results of a randomized trial of partner notification in cases of HIV infection in North Carolina. N Engl J Med. 1992 Jan 9;326(2):101–6 https://pubmed.ncbi.nlm.nih.gov/1445500/
3. Brown LB, Miller WC, Kamanga G, Nyirenda N, Mmodzi P, Pettifor A, et al. HIV partner notification is effective and feasible in sub-Saharan Africa: opportunities for HIV treatment and prevention. J Acquir Immune Defic Syndr 1999. 2011 Apr 15;56(5):437–42. https://pubmed.ncbi.nlm.nih.gov/22046601/
4. Dalal S, Johnson C, Fonner V, Kennedy CE, Siegfried N, Figueroa C, et al. Improving HIV test uptake and case finding with assisted partner notification services. AIDS Lond Engl. 2017 Aug 24;31(13):1867–76. https://pubmed.ncbi.nlm.nih.gov/28590326/
5. Giguère K, Eaton JW, Marsh K, Johnson LF, Johnson CC, Ehui E, et al. Trends in knowledge of HIV status and efficiency of HIV testing services in sub-Saharan Africa, 2000–20: a modelling study using survey and HIV testing programme data. Lancet HIV. 2021 Mar 2;8(5):e284–93. https://pubmed.ncbi.nlm.nih.gov/33667411/
6. Koduah Owusu K, Adu-Gyamfi R, Ahmed Z. Strategies To Improve Linkage To HIV Care In Urban Areas Of Sub-Saharan Africa: A Systematic Review. HIVAIDS Auckl NZ. 2019;11:321–32. https://pubmed.ncbi.nlm.nih.gov/31819663/
7. Monroe-Wise A, Mbogo L, Sambai B, Ludwig-Barron N, Guthrie BL, Bukusi D, et al. Efficacy of assisted partner services for people who inject drugs in Kenya to identify partners living with HIV and hepatitis C virus infection: a prospective cohort study. Lancet Glob Health. 2024 May;12(5):e859–67. https://pubmed.ncbi.nlm.nih.gov/38614633/
8. Hu S, Jing F, Fan C, Dai Y, Xie Y, Zhou Y, et al. Social Network Strategies to Distribute HIV Self-testing Kits: A Global Systematic Review and Network Meta-analysis. MedRxiv Prepr Serv Health Sci. 2023 Nov 6;2023.11.05.23298135. https://pubmed.ncbi.nlm.nih.gov/39048927/
9. Choong A, Lyu YM, Johnson CC, Baggaley R, Barr-DiChiara M, Jamil MS, et al. Social network-based approaches to HIV testing: a systematic review and meta-analysis. J Int AIDS Soc. 2024 Sep;27(9):e26353. https://pubmed.ncbi.nlm.nih.gov/39252193/
10. Paiboon N, Songtaweesin WN, Wongharn P, Moonwong J, Khamthi S, Premgamone A, et al. Social Network Strategy to Promote HIV Testing and Linkage to HIV Services among Young men who Have sex with men and Transgender Women in Thailand. J Int Assoc Provid AIDS Care. 2022 Jan-Dec;21:23259582221143672. https://pubmed.ncbi.nlm.nih.gov/36464688/
11. Sambai BC, Kingston H, Monroe-Wise A, Mbogo L, Juma E, Ludwig-Barron N, et al. Characteristics associated with HIV and hepatitis C seroprevalence among sexual and injecting partners of HIV positive persons who inject drugs in Nairobi and coastal Kenya. BMC Infect Dis. 2022 Jan 21;22:73. https://pubmed.ncbi.nlm.nih.gov/35062890/
12. Avoundjian T, Stewart J, Peyton D, Lewis C, Johnson K, Glick SN, et al. Integrating Human Immunodeficiency Virus Testing Into Syphilis Partner Services in Mississippi to Improve Human Immunodeficiency Virus Case Finding. Sex Transm Dis. 2019 Apr;46(4):240–5. https://pubmed.ncbi.nlm.nih.gov/30870325/
13. Fajardo E, Lastrucci C, Bah N, Mingiedi CM, Ba NS, Mosha F, et al. Country adoption of WHO 2019 guidance on HIV testing strategies and algorithms: a policy review across the WHO African region. BMJ Open. 2023 Dec 28;13(12):e071198. https://pubmed.ncbi.nlm.nih.gov/38154882/
14. Ayala G, Bahati M, Balan E, Chang J, Do TD, Fokeerbux NA, et al. Partner Notification: A Community Viewpoint. J Int AIDS Soc. 2019 Jul 19;22(Suppl Suppl 3):e25291 https://pubmed.ncbi.nlm.nih.gov/31321916/
15. Greensides D, Bishop K, Manfredini L, Wong V. Do No Harm: A Review of Social Harms Associated with HIV Partner Notification. Glob Health Sci Pract. 2023 Dec 22;11(6):e2300189. https://pubmed.ncbi.nlm.nih.gov/38135515/