Partner notification for HIV in Sweden

The Organization, Content, and Case-Finding Effectiveness of HIV Assisted Partner Services in High HIV Morbidity Areas of the United States

BACKGROUND

The contemporary effectiveness of assisted partner notification services (APS) in the United States is uncertain.

SETTING

State and local jurisdictions in the United States that reported ≥300 new HIV diagnoses in 2018 and were participating in the Ending the Epidemic Initiative.

METHODS

The study surveyed health departments to collect data on the content and organization of APS and aggregate data on APS outcomes for 2019. Analyses defined contact and case-finding indices (i.e., sex partners named and newly diagnosed per index case receiving APS) and estimated staff case-finding productivity.

RESULTS

Sixteen (84%) of 19 jurisdictions responded to the survey, providing APS outcome data for 14 areas (74%). Most health departments routinely integrated APS with linkage of cases and partners to HIV care (88%) and pre-exposure prophylaxis (88%). A total of 19,164 persons were newly diagnosed with HIV in the 14 areas. Staff initiated APS investigations on 14,203 cases (74%) and provided APS to 9937 cases (52%). Cases named 6799 partners (contact index = 0.68), of whom 1841 (27%) had previously diagnosed HIV, 2202 (32%) tested HIV negative, 541 (8% of named and 20% of tested partners) were newly diagnosed with HIV, and 2215 (33%) were not known to have tested. Across jurisdictions, the case-finding index was 0.054 (median = 0.05, range 0.015-0.12). Health departments employed 292 full-time equivalent staff to provide APS. These staff identified a median of 2.0 new HIV infections per staff per year. APS accounted for 2.8% of new diagnoses in 2019.

CONCLUSIONS

HIV case-finding resulting from APS in the United States is low.

Improving HIV test uptake and case finding with assisted partner notification services

OBJECTIVE

Despite the enormous expansion of HIV testing services (HTS), an estimated 40% of people with HIV infection remain undiagnosed. To enhance the efficiency of HTS, new approaches are needed. The WHO conducted a systematic review on the effectiveness of assisted partner notification in improving HIV test uptake and diagnosis, and the occurrence of adverse events, to inform the development of normative guidelines.

METHODS

We systematically searched five electronic databases through June 2016. We also contacted experts in the field and study authors for additional information where needed. Eligible studies compared assisted HIV partner notification services to passive or no notification. Where multiple studies reported comparable outcomes, meta-analysis was conducted using a random-effects model to produce relative risks (RRs) or risk ratios and 95% confidence intervals (CIs).

RESULTS

Of 1742 citations identified, four randomized controlled trials and six observational studies totalling 5150 index patients from eight countries were included. Meta-analysis of three individually randomized trials showed that assisted partner notification services resulted in a 1.5-fold increase in HTS uptake among partners compared with passive referral (RR = 1.46; 95% CI: 1.22-1.75; I = 0%). The proportion of HIV-positive partners was 1.5 times higher with assisted partner notification than with passive referral (RR = 1.47; 95% CI: 1.12-1.92; I = 0%). Few instances of violence or harm occurred.

CONCLUSION

Assisted partner notification improved partner testing and diagnosis of HIV-positive partners, with few reports of harm. WHO strongly recommends voluntary assisted HIV partner notification services to be offered as part of a comprehensive package of testing and care.

Some remarks on definition and validity of terms used in models for infectious disease spread

The epidemiology of infectious diseases makes use of a number of terms, such as exposure, infected, carrier, attack rate, and immunity. Researchers who intend to model the spread of epidemics should be aware of the problems with some of these terms. The role played by inapparent, or subclinical, infections is receiving increased attention in infectious disease epidemiology. Patients with such infections may never be reported as cases, which could give rise to problems when, for example, data from national surveillance bodies are being used for modeling. The assignment of patients to different transmission groups must, in most cases, rely on self-reported data from the medical interview. This possible source of bias should be recognized.

Efficacy of partner notification for HIV infection

Since 1985, partner notification has been part of Swedish policy to prevent the spread of human immunodeficiency virus (HIV) infection. Potentially infected partners of a newly diagnosed seropositive patient are notified either by the index patient or by the physician and referred for counselling. The efficacy of this strategy was assessed over 18 months in 1989-90. 365 HIV-seropositive index patients (91% of the 403 patients diagnosed in Sweden during the study period) reported 564 sexual or needle-sharing contacts. 390 contacts were located and counselled and HIV test results are known for 350 of them. In 53 of the 350 cases, previously unknown seropositivity was diagnosed. Partner notification for HIV should be viewed as a strategy to offer counselling and testing to a high-prevalence group of people. In a country where general HIV prevalence is low, the strategy is cost-effective for location and counselling of unknowingly seropositive individuals.