This study aimed to assess the direct impact of male circumcision on the likelihood of contracting HIV among men in Zambia following fifteen years of implementing the VMMC policy in the country. Utilising data from the observational designed 2018 ZDHS, the study proposed a causal pathway linking VMMC to the risk of HIV infection, whilst accounting for baseline and knowledge-related factors as confounding variables. The study assumed this pathway to be mediated by factors associated with sexual behaviour and STI-related factors. The investigation employed IPTW with ATT and ATE weights to estimate the causal effect of male circumcision on risk of HIV infection among men in Zambia.
The study found a reduction in the risk of infection among men who underwent male circumcision, although the decrease was small (1.7%). Notably, the research identified risky sexual behavior indicators for HIV infection among men, such as inconsistent condom use, early sexual debut, and having multiple sexual partners (25). Only a small proportion of participants reported consistent condom use (11.3%) and sexual debut after the age of 20 (12.7%). Some men in the study acknowledged having multiple sexual partners. Additionally, the study found presence of sexually transmitted infections (STIs) among men, which is another risk factor for HIV infection (26). Further, some participants reported having had an STI in the 12 months preceding the 2018 ZDHS.
The preventive impact of circumcision on the risk of HIV infection among men in Zambia was found to be comparatively smaller, in contrast to the more substantial findings reported by Ashengo et al. (2014), Gray et al. (2007), and Auvert et al. (2005). These studies observed a minimum protective effect of 50% (7–10, 27), in settings similar to Zambia. This result aligns with a study in Zambia which reported that circumcised men exhibited a similar level of HIV infection as uncircumcised men (12). The presence of risky sexual behaviour factors among men may account for the limited impact of male circumcision on the risk of HIV infections. Risky sexual behaviour factors appeared to be more prevalent in circumcised men than in uncircumcised men, a consistent observation with another study that reported that circumcised men in Zambia tended to exhibit somewhat riskier sexual behaviour patterns than their uncircumcised counterparts (12). This trend is also reflected in a study by a study in Ghana, which reported that circumcised men were more likely to engage in multiple sexual partnerships compared to uncircumcised men (28). This result suggests low perceptions of personal risk to contracting HIV among circumcised men.
The presence of STIs among circumcised men may diminish the protective effect of circumcision against HIV infection as they are a predisposing factor (29, 30). The observed higher proportion of STIs among circumcised men and those who tested positive for HIV implies a potential inverse effect of male circumcision on the risk of HIV infection among these men, thereby raising critical questions regarding the effectiveness of circumcision as an intervention. Men who underwent VMMC were advised to avoid engaging in risky sexual behaviours. Counselling emphasised that circumcision did not provide 100% protection against HIV and encouraged the adoption of additional prevention strategies, including maintaining fidelity to a single partner and consistently using condoms correctly (13). However, the findings of this study indicate that the male circumcision intervention, coupled with the preventive counselling messages delivered before the procedure, is not achieving the intended outcomes among circumcised men in Zambia. Some circumcised men in Zambia may be engaging in heightened sexual risk behaviours, potentially influenced by a false sense of invincibility against HIV infection due to circumcision. This phenomenon is commonly referred to as “sexual behaviour risk compensation” and has been observed in various countries and communities, although it has been debunked in others (31). Furthermore, it is conceivable that men engaging in risky behaviour are the ones more opting for circumcision with the belief that it offers protection, being aware of the inherent risks associated with their behaviour.
Sexual behaviour risk compensation is an important concept to consider when implementing HIV prevention strategies, as unintended consequences of risk compensation could affect the effectiveness of interventions. Studying and understanding risk compensation helps design and implement interventions that effectively reduce transmission and consider potential behavioural changes in the population. Intervention strategists in Zambia must investigate whether sexual behaviour risk compensation linked to VMMC is occurring and impeding the intended causal impact of the intervention. Such an assessment is essential as questions persist regarding the effectiveness of male circumcision in reducing HIV infections.
This study had an inherent limitation as it relied on secondary data extracted from the 2018 ZDHS. The original intent of this dataset did not align with addressing the aim of determining the causal impact of VMMC on the risk of HIV infection among men in Zambia. As a result, potentially unaccounted-for confounders and mediators in the study may exist. Nevertheless, the 2018 ZDHS dataset contained a comprehensive set of variables that effectively captured the confounders and mediators pertinent to the link between VMMC and the risk of HIV infection. In relation to these variables, the implementation of IPTW on the 2018 ZDHS successfully generated comparable groups of circumcised and uncircumcised individuals and, therefore, as outlined by Zabor et al. 2020 (22), effectively adjusted for potential confounders and mediators that might have been overlooked.
Another potential limitation arose from the study's assumption that men undergoing circumcision were HIV-negative at the time of the procedure. While this assumption cannot be subject to statistical testing, a significant majority of the men in Zambia included in this study opted for circumcision at healthcare facilities or under the care of trained medical professionals. In such environments, HIV-positive individuals were not recommended to undergo circumcision then since the procedure was designed to mitigate the risk of infection with the virus (23). Exceptions were made only if the person had a concurrent medical condition at the time of the circumcision request, for which the procedure served as a therapeutic measure.