In the present study, HIV seroprevalence among male patients with anal disease was between 6.3/10000 and 16.2/10000, which was nearly 30 times higher than that of male patients with nonanal disease at a colorectal hospital. This indicates a strong association between anal disease and HIV infection in male patients. Over the past 11 years (Figure 1), HIV seroprevalence in male patients with anal disease has decreased, although the status of HSV-2 seroprevalencehas remained at a level similar to that in the general male population.
According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), HIV seroprevalence in Korea is at a low epidemic level of between 1/10,000 and 4/10,000 [12, 13]. However, the number of HIV-infected individuals in Korea has continued to rise and isexpected to increase further, for two main reasons. First, the HIV epidemic pattern in Korea is similar to that observed in the early 1980s when HIV became a global pandemic. More specifically, the epidemic pattern of HIV in Korea closely follows the pattern of the early epidemiological stages of the virus when HIV was spread mainly through sexual contact, especially between men . Second, in many of the recently identified cases, the infections were discovered long after onset. This means that the infected individuals may have unknowingly transmitted the virus to other people . Moreover, an increasing number of HIV cases are detected during health checkups and treatment of other conditions . Therefore, the role of private health-care institutions has become important in both HIV treatment and diagnosis.
In a prior study that examined HIV seroprevalence during 2002 and 2007, based on data collected from colorectal hospitals across the country, HIV seroprevalence was between 2.2/10,000 and 3.9/10,000, which was about two or three times higher than that of all hospital patients [13, 15]. This study analyzed the characteristics of HIV seroprevalence among patients in a colorectal hospital according to variables including sex, age and presence of anal disease. The results showed that most of the cases of HIV were in patients who also had anal disease. Overall, HIV seroprevalence in patients with anal disease was ≈ 10/10000. In Korea, HIV seroprevalence was highest among sexual partners of HIV-infected individuals (>1,000/10,000), followed by people who applied voluntarily for HIV testing because they wanted to know their status (>20/10,000), and people who underwent additional HIV tests when their doctor suspected HIV infection during treatment (>10/10,000) [11, 16]. This study showed that male patients with anal disease were similar to those referred by their doctor and were assumed to be a high-risk group.
In addition, male patients in whom HIV infection was detected at the colorectal hospital tended to be younger than the general HIV-infected male population, and HIV seroprevalence increased significantly with younger age. For specific identification of high HIV seroprevalence in the group aged <20 years, we divided into groups aged <10 years, 10–14 years and 15–19 years. From 2001 to 2011, 1,061 male patients aged 15–19 years were treated and underwent HIV testing at the hospital. Ten HIV infections were found in the group aged 15–19 years.
In Korea, the HIV-infected young men aged 15–19 years accounted for 2.4% of the total number of HIV-infected men as of 2011. Sixty percent of these were infected through homosexual contacts, which is higher than the overall percentage infected through homosexual contact (43%) . In the present study, male patients aged 15–19 years comprised 3.7% of the total number of male patients with HIV and anal disease. This produced a higher annual HIV seroprevalence than for any other group nationwide in Korea.
A survey of male sexual behavior in Korea showed that sexual activity began around age 16 years , and only 10–20% used condoms . A survey of homosexual behavior in Korea showed that 60% of participants had a homosexual feeling before age 18 years . It is expected that the group aged 15–19 years is a group at high risk for STI.
Approximately 70% of HIV-infected individuals in the present study contracted the virus through homosexual contact, according to the HIV database of KCDC. In Korea, HIV infection was detected in many people who visited HIV testing and consulting centers for homosexual people (HIV-positive rate of 5.5%) . However, the proportion of homosexual men who tested for HIV over the past year in Korea was lower than that in other countries including Japan, China and the United States . Moreover, nearly half of all homosexual men in Korea said that they had never tested for HIV . Therefore, the present study shows that ensuring that colorectal surgeons can easily identify lesions associated with HIV infection in male patients with anal disease is important for preventing misdiagnosis or delayed diagnosis of HIV infection and stopping its spread.
HSV-2 can often cause acute infection or remain inactive until it is triggered by a decline in the immune system. HSV-2 is the cause of >90% of anorectal infections and frequently the source of proctitis in homosexual men . In homosexual men living in San Francisco, the seroprevalence of HSV-2, HIV and HSV-2/HIV was 26.1%, 18.6% and 12.0%, respectively . In male infected with HIV by sexual contacts in Korea in 2003, HSV-2 seroprevalence (23.9–69.2%) was higher than that in the general male population (6.8–26.0%) . In the present study, 20% of HIV-infected individuals were found to have HSV-2. Moreover, HSV-2 seroprevalence in male patients with anal disease was similar to that in the general male population.
The present study had the following limitations. First, there is limited scope to generalize the findings of the study, because the estimates of HIV seroprevalence were based on data obtained from a single colorectal hospital located in Seoul. However, the study did show the trends, status, and characteristics of HIV seroprevalence among male patients with anal disease. Second, although the estimated HSV-2 seroprevalence in male patients with anal disease was flawed because the results were based on data from a single hospital during a limited period, the estimate is important because it is believed to be the first such study in Korea. Finally, we don’t have data on sexual behavior to find out the reason of high HIV seroprevalence among male patients with anal disease. And, HSV-2 seroprevalence was low in male patients with anal disease, which differed from other studies [25, 26]. It will be necessary to establish the relationship between the study results and the epidemiological characteristics of the study subjects in Korea.