To our knowledge, this study is the first to assess HIV or STI prevalence among a military population in Afghanistan, potentially a reflection of the general population, and one of few to describe STI prevalence among a nationally-derived sample
]. Findings are notable for a very low prevalence of HIV and other STIs and for a small but sizeable proportion of incoming ANA recruits having engaged in sexual and drug use risk behaviors. Lifetime condom use is quite low and, coupled with reported sexual risk behaviors, may be one focal point within force health protection efforts.
Prevalence of HIV, syphilis, and HCV are quite low, similar to those measured among other populations of varying sexual risk (with the exception of injecting drug users) in Afghanistan
]. Military recruits have been found to be an accurate general population proxy for prevalence of HIV and hepatitis C in some settings, but not others
]. Lower rates of HIV have been detected among active duty troops as compared to the general population or military applicants in countries with compulsory HIV screening and regulations barring conscription of HIV-infected individuals
]. Conversely, higher HIV prevalence has been detected among active duty troops than in general population groups, leading to the characterization of military populations as a high-risk group in some contexts
]. With regard to risk behavior, some studies speculate that military populations have higher rates of risk behaviors, potentially decreasing ability to generalize prevalence of risk behaviors to a general population of young adults or have military populations serve as a sentinel group for risk behaviors
]. The regular movement associated with postings and stress related to combat have been posited as reasons for military populations to engage in behaviors placing them at greater risk for STIs, including HIV
]. Further research is needed to determine relative risk behaviors between military and non-military populations of young adults specific to each context.
HSV-2 prevalence was also relatively low and was not directly associated with risky sexual practices, but with age, having a television, and, marginally, prior alcohol use. The association between HSV-2 and increasing age likely reflects exposure time and has been noted in other military populations
]. Television ownership was associated with both HSV-2 and sex with FSWs in this population and may represent peri-urban location and financial resources enabling purchase of sex. Higher socioeconomic status was a marker for HSV-2 infection among Chinese male migrant workers in the presence of no associated sexual behaviors
]. HSV-2 was marginally independently associated with prior alcohol use, potentially representing unsafe sexual practices while intoxicated. Prior alcohol use was also independently associated with engaging FSW services; alcohol consumption, an illicit activity in Afghanistan, may have occurred with FSWs. Data from Afghan FSWs support this possibility as, of those who used alcohol or other intoxicants (9.8%), 53.9% used these substances with their clients
]. Though HSV-2 was not associated with engaging FSW services, this activity may have been under-reported.
Reported relations with FSWs were also independently associated with prior condom use, previously living outside Afghanistan and having returned within the last year, prior incarceration, and higher number of lifetime sexual partners. Lifetime condom use was low among recruits; it is unclear whether condom use is driven by need for contraception or STI prevention. However, reported consistent condom use with FSWs and condom use at the last FSW encounter were relatively uncommon. Further, it is also unclear whether condoms used in the context of paid sex are at the behest of the client or FSW, as prior studies indicate that a majority of Afghan FSWs state they determine condom use with clients
]. Motivations surrounding condom use require greater information in this population to inform prevention efforts. Having lived outside Afghanistan and recent repatriation were both associated with engaging FSW services, as noted among other male Afghan expatriates
]. The association between incarceration and sex with FSWs is unclear but may be reflected by 30% of previous incarcerations occurring outside Afghanistan, despite being independent of living outside the country in analysis. Greater number of lifetime partners has not been directly associated with FSW patronage among military populations, but higher numbers of partners increased HIV acquisition risk in a context where HIV was largely attributed to unprotected sex with FSWs among male Thai military recruits
MSM activity was common among sexually-active recruits and was associated with hashish use, history of urethral discharge, greater number of sexual partners, younger age, and never having lived outside Afghanistan. In Afghanistan, hashish is the most commonly used intoxicant and use among males begins at a young age (18–19 years)
]. The association of MSM activity with young age, hashish use, and not having lived outside Afghanistan potentially reflects normative behaviors in certain areas of the country. Of note, though the analysis was controlled by province, province of origin was significantly associated with MSM activity. The association between MSM activity and number of sexual partners may reflect the paid nature of half of these relations and the association with prior cases of urethral discharge may reflect low condom use. Among Thai military conscripts, MSM activity was associated with hashish use, a greater number of sexual partners, and prior urethritis as compared to those reporting exclusively heterosexual contacts in the mid-1990s
]. In our study, having a current marital partner was negatively associated with both sexual risk behaviors and may reflect both limited options for sexual activity for unmarried men and potential social stigma associated with adultery in this conservative setting. By contrast, engaging in MSM activities were more likely for married male military recruits in Thailand
There are limitations to this study that must be considered. First, though participants were randomly selected during a 12-month period, approximately one-fifth originated from one province. Analyses were adjusted by province of origin to reduce this effect, but this disproportion should be considered during interpretation. The high participant number from Nangahar may be associated with two different factors: proximity to Kabul, enabling potential recruits to come to KMTC rather than recruitment through local garrisons, and instability in western Pakistan may have displaced Afghan families whose sons were employed or students in Pakistan, resulting in need for stable employment. We only obtained serum samples and cannot comment on the prevalence of STIs that typically cause genitourinary symptoms, such as N. gonorrhea or C. trachomatis. Correlations of reported genitourinary symptoms and likely presence of STIs should thus be interpreted with caution. Due to low literacy, questionnaires had to be administered by study staff, potentially reducing disclosure of sexual or drug use activities. Sex-matched study staff were trained extensively in counseling and ability to establish rapport to counter this effect. Last, certain provinces may have been under-represented, particularly provinces (Nuristan and Laghman) from which Pashayee speakers originate, as they comprised the bulk of those ineligible due to language differences.