Background Partner notification (PN) is seen as a vital tool to break HIV/STI transmission chains. In the Netherlands, studies assessing PN effectiveness were lacking. Here, we evaluated effectiveness of current PN practises in STI clinics to provide recommendations to further enhance PN.

Methods PN outcomes were collected through a newly developed registration system from index patients with HIV, syphilis, and gonorrhoea visiting five STI centres in 2010–2011. PN outcomes for men who have sex with men (MSM) and heterosexuals included partners: at risk, notifiable, notified, tested and diagnosed with STI/HIV.

Results Of all index patients newly diagnosed with HIV/STI (N = 388) for whom PN was indicated, 312 MSM, 35 heterosexual men and 41 women reported respectively 2042, 126 and 82 partners at risk (6.5, 3.6 and 2.0 partners per index). Proportions of notifiable partners differed significantly by sexual preference (MSM: 46%, heterosexual men: 63%, women: 87%, p < 0.001). Proportions of notified partners (of those notifiable) were lowest for heterosexual men (77% versus 92% for MSM and 83% for women, p < 0.001). STI positivity rates among partners were high for all groups: 33%–50%.

Conclusions The major challenge in PN among MSM remains the large proportion of unnotifiable (anonymous) partners, whereas among heterosexuals a higher percentage partners were lost during the actual notification process. Therefore, newly developed interventions, e.g.anonymous internet-based PN or PN training, should be tailored to specific risk-groups.