In their recent research letter entitled ‘The contribution of HIV-discordant relationships to new HIV infections in Rakai, Uganda’, Gray et al. [1] argue that targeting HIV testing and counseling efforts to HIV serodiscordant couples will have limited impact for HIV prevention. We disagree with this argument for several reasons. Gray et al. [1] underestimate the true contribution to overall HIV incidence from serodiscordant couples in two ways. First, they focus only on study participants identified as both married and serodiscordant. Yet approximately one-third of married couples had a partner of unknown HIV status (36 and 33% in the pre- and post-antiretroviral therapy (ART) intervals, respectively). It is likely that some of these couples were in fact HIV serodiscordant. Likewise, among those who were not currently married, some were likely in long-term serodiscordant relationships. Thus, the number of infections that occurred among serodiscordant couples is unknown but likely higher than could be reported with the available data. Second, although the authors state that acceptance of couples counseling has been low in their cohort, it is unclear from the letter what proportion of the couples identified as serodiscordant in the database were actually aware of their serodiscordant status or had received couples HIV testing and counseling (CHTC). Thus, the contribution of serodiscordant couples to new HIV infections may have been low because of mutual disclosure of HIV status or other effective interventions that reduce sexual risk behaviors and transmission [2–7]. In the current analysis, the authors report HIV incidence among discordant couples before and after ART availability (an ecologic measure). However, in a previous analysis of data from this cohort, they categorized discordant couples before and after ART initiation (a couple-level measure) [3]. If the authors had data on ART use among discordant couples, why not use these data in the research letter? This question is especially pertinent as data from the previous report showed that ART initiation was associated with both lower HIV incidence among discordant couples and with increased consistent condom use. Those data would support using CHTC as a way to identify additional discordant couples and link them to prevention and treatment services in order to reduce HIV transmission to the uninfected partner. Note that CHTC does not target discordant couples as stated by Gray and colleagues but rather seeks to identify discordant couples by providing HIV testing and counseling to persons in, or planning to be in, a sexual relationship, and allowing them to learn their HIV status together. In addition to reduced sexual risk behaviors among discordant couples, CHTC has benefits for preventing mother-to-child HIV transmission [8]. Nevertheless, CHTC is not a stand-alone intervention but instead is a first step in a continuum of effective prevention and treatment strategies. These strategies include linking HIV-positive individuals into care and treatment services; offering circumcision to HIV-negative men; and ensuring both partners have access to sexual risk reduction counseling and condoms [9,10], and prevention of mother-to-child HIV transmission services, including ART prophylaxis, family planning, and safer pregnancy counseling. Furthermore, if as Gray and colleagues suggest, a number of infections in discordant couples come from outside partners, these prevention interventions offer an opportunity to address this potential risk and discuss partner reduction and condom use with outside partners. In their conclusion, the authors state that there is merit to HIV testing and counseling, including of couples, but that prevention efforts need to address the broader population and embrace specific interventions. We agree. In combination with other proven interventions, CHTC has the potential to contribute to reductions in population-level HIV incidence in generalized epidemics and should be viewed as facilitating access to the continuum of effective prevention, care, and treatment strategies. Acknowledgements Conflicts of interest There are no conflicts of interest.