Introduction

Despite the tremendous progress in the global response to the HIV epidemic, we have not yet been able to fully control the spread of HIV infection [1]. Since the start of the epidemic over 30 years ago, around 75 million have become infected with HIV and nearly 36 million have died of AIDS. The HIV epidemic has become one of the greatest pandemics in modern times with disastrous socioeconomic and demographic consequences [2]. The unprecedented scale of multisectoral approach and coordinated global efforts to respond to this epidemic can serve as a model of response to other global health threats such as chronic diseases [2].

HIV was introduced much later in East Asia than in the rest of the world, but the pattern of spread differed from that described in other regions [3]. According to the latest UNAIDS estimates, there were 35.3 million people worldwide living with HIV infection in 2012, of whom 880,000 resided in East Asia [1]. Unlike the global downward trend, the number of estimated newly infections among all ages and among children increased 19 % and 50 %, respectively, in East Asia since 2001. Similarly, the estimated number of AIDS-related deaths increased from 18,000 in 2001 to 41,000 in 2012. The estimated HIV prevalence in East Asia is still low (0.1 %) compared to other regions, notably sub-Saharan Africa (4.7 %), North America (0.5 %), or neighboring countries in South and Southeast Asia (0.3 %) [1]. However, given the large population in China (1.3 billion, 2012) [4], even low prevalence translates into large numbers of people affected. Since China is the hardest hit in this region, not surprisingly the HIV epidemic of other countries or areas in East Asia is usually overlooked when referring to Asia at large. Therefore, we would like to describe the trends or patterns of the HIV epidemics over the last 30 years in People’s Republic of China (China), Taiwan, Japan, Republic of Korea (South Korea), Hong Kong, and Mongolia.

China

China is by far the largest country in East Asia and most populous in the world [4]. Although the national estimated prevalence of HIV infection remains low at 0.058 % [5], China alone accounts for 89 % of the estimated people living with HIV (PLHIV) in East Asia [1]. It was estimated that by the end of 2011 there were 780,000 PLHIV, of whom 154,000 were living with AIDS. Although, the annual incidence of HIV infection has remained stable at a low level in recent years, the patterns of transmission have evolved over time [5, 6••]. HIV prevalence varies greatly among different sub-populations and shows clear regional disparities [6••]; six out of 31 provinces reported 75.8 % of the cumulative national total of HIV/AIDS cases [5].

China’s HIV epidemic began in rural areas and then spread to urban areas. The first case of AIDS was reported in 1985 in a tourist from the United States [7]. The following years other isolated cases were reported in foreigners and Chinese traveling overseas and hemophiliac patients infected through imported contaminated blood products [8]. The first outbreak of HIV infection, however, was reported in 1989 among injecting drug users (IDUs) in Yunnan Province close to the so-called “Golden Triangle”, an opium producing area of South East Asia. From there, HIV spread steadily along major drug trafficking routes and from IDUs into the general population through sexual contact [9]. As it rapidly spread among injecting drug users (IDUs), HIV also spread among female sex workers (FSWs). Subsequent sexual transmission to their male clients and other sexual partners led to further spread of HIV.

Around the mid-1990s a second major outbreak of HIV infection occurred among commercial blood/plasma donors in rural communities in the east-central provinces due to unhygienic practices [10, 11]. As soon as the problem became apparent in the early 2000s, the Chinese government took strong action to prevent further spread closing blood collection stations, issuing new regulations, conducting mass HIV screenings, and providing free treatment (National Free Antiretroviral Treatment Program) [12]. There are no accurate data reported on the number of people infected, but in 2005 the Ministry of Health and UNAIDS/WHO estimated it to be 55,000 [13, 14]. Former commercial blood/plasma donors were primarily poor farmers with almost no IDU or commercial sex work in their communities. A recent study revealed that the HIV epidemic in former plasma donors was not widespread but rather centered in Henan Province and surrounded provinces [11]. By 2004, 43 % of the cumulative reported HIV cases were IDUs and 26.8 % former commercial plasma donors [15].

As the HIV epidemic among IDUs has fallen (less so in China’s southwest region), HIV incidence has stabilized since 2005 [6••] probably because of significant progress toward implementing and enhancing harm-reduction programs countrywide [6••, 16]. The proportion of newly reported HIV cases who acquired the infection through IDU has decreased from 34.1 % in 2006 to 16.9 % in 2011 (Table 2) [17]. In contrast, the proportion of new HIV cases resulting from sexual transmission increased from 33.1 % in 2006 to 76.3 % in 2011, during which time cases of MSM increased from 2.5 % to 13.7 % [17]. The HIV epidemic is rapidly expanding among MSM (Fig. 1). A national epidemiological survey including over 47,000 MSM was conducted between 2008 and 2009 in 61 major cities of China [18••]. This survey reported an overall HIV prevalence of 4.9 %, with the highest HIV prevalence of 13.2 % in the southwest region. More recent estimates suggest that HIV prevalence among MSM has reached 6.3 % in 2012, up from 5.7 % in 2010 and 2 % in 2007 [17, 19]. HIV incidence among MSM has tripled from 0.39 in 2000 to 0.98 per 100 person-years in 2010 nationwide, especially rapidly in large cities such as Shanghai, Beijing, Tianjin, Chongqing, and Chengdu [6••]. In addition, previous studies have reported high prevalence of syphilis among MSM, ranging from 9.5 % to 17.5 % [18••, 20, 21], inconsistent condom use with male partners, multiple sexual partnerships including bisexual behaviors, low testing rates, and prevalent stigma and discrimination [18••, 20, 22, 23, 24•]. These data suggest the increasing potential of HIV infection spreading into the broader population [6••].

Fig. 1
figure 1

Changing trend of the annual number of HIV cases by main routes of transmission in China1, Taiwan, Japan, South Korea2, Hong Kong and Mongolia (1984 – 2012) 1Annual number of HIV cases for 1984 to 2005 were not available 2Data for 2012 could not be included

Full size image

Despite increasing heterosexual HIV transmission in China, the national HIV prevalence among FSWs has decreased from 0.46 % in 2000 to 0.26 % in 2011 [6••, 19], remaining low except for southwest China where it was 1.57 % in 2010 [6••]. Similarly, HIV prevalence among sexually transmitted infection (STI) clinic attendees and pregnant women have been maintained at a low level [5]. Recent studies suggest that non-commercial heterosexual contact in the general population may play an important role [25, 26]. The prevalence of multiple sexual partnerships among adult women increased from 8.1 % in 2000 to 29.6 % in 2006 [26]. Other factors that may contribute to further expansion are the high prevalence of syphilis among different populations, characteristics of commercial sex work (e.g., migrants, highly mobile, engaged for short time), and low condom use [27, 28]. Moreover, in provinces with high HIV prevalence among IDUs HIV prevalence is also high among FSWs and MSM, suggesting interactions between these groups [6••].

Since the beginning of the twenty-first century China has taken bold steps to control the HIV epidemic and has made great progress [29]. However, many challenges still remain particularly addressing the needs of Chinese MSM [6••, 29, 30].

Taiwan

The first AIDS case in Taiwan was identified in 1984 in an American in transit [31]. In the 1980s, similar to what happened in Japan and Hong Kong but on a smaller scale, at least 53 Taiwanese hemophiliacs were infected with HIV through contaminated blood products from the United States, 37 of them had died [31–34]. The government banned the use of unheated blood products in 1985 and no more HIV cases among hemophiliacs have been reported since 1997 [35]. By 2012, a total of 25,081 people had been reported as infected with HIV (24,239 Taiwanese and 842 foreigners), of whom 9828 had developed AIDS (9725 Taiwanese and 103 foreigners) (Table 1) [36]. Of Taiwanese nationals infected with HIV in 2012, the male-to-female ratio was 30:1 [37]. Despite international growing advocacy to remove “HIV-related restrictions on entry, stay and residency” for PLHIV, Taiwan still keeps its policy to deport foreigners on the grounds of HIV status [38].

Table 1 Annual reported number of HIV and AIDS cases in China, Taiwan, Japan, South Korea, Hong Kong, and Mongolia (1984 - 2012)
Full size table

The HIV epidemic in Taiwan is concentrated in high-risk populations. HIV prevalence among drug users was estimated to be 6.9 %; much higher among IDUs compared to non-IDUs (25.5 % vs. 0.5 %) [39]. Among MSM, HIV prevalence varies between 8.1-10.7 % [40•, 41]. However, the predominant mode of HIV transmission has changed over time (Fig. 1). Until 2003, sexual transmission accounted for the largest proportion of new infections, predominantly sex between men which accounted for 61.5 % that year [35]. In the following year the epidemic started to increase exponentially with the major route of infection shifting from unprotected sex to sharing needles and solvents to dilute heroin [42]. In 2005, the number of new HIV infections peaked at 3380, a 122 % increase over the previous year [37]. The total number of HIV cases attributable to IDU grew from 173 (3 % of all cases) until 2003 to 3215 (32 %) by 2005, a 19-fold increase in two years. Molecular epidemiological studies revealed that the HIV strain responsible for this outbreak may have originated in Yunnan Province, China [43, 44]. In response, the government took swift measures in 2005, which included harm-reduction programs such as needle and syringe exchange program (NSEP) and substitution treatment. After the introduction of these programs, all newly reported cases attributable to IDU fell from a high of 72 % in 2005 to only 3.6 % in 2012 [37]. Even though the HIV epidemic among IDUs is largely controlled, a survey in 2008 found that only 21 % of IDUs in methadone maintenance treatment programs were using condoms always/frequently in the last 6 months and almost all (93 %) were infected with hepatitis C virus (HCV) [45]. In Taiwan, co-infection of HIV/HCV among IDUs has received increased attention. The prevalence of HCV infection among HIV-infected IDUs increased from 65.5 % before 2002 to 98.6 % in 2006 [46]. A multicenter cohort study in the Asia Pacific region revealed that patients co-infected with HIV/HBV or HIV/HCV had significantly worse survival rates compared to HIV-infected patients [47]. Thus, the importance of preventing HCV infection among IDU population cannot be underestimated in harm reduction programs.

Since 2008, the epidemic took a turn and the spread of HIV among MSM has re-emerged as a major threat. The proportion of new HIV cases attributed to sex between men increased from 23.3 % in 2006, 59.3 % in 2008 to 77.2 % in 2012 [35]. Bathhouses are reported as the most common venue for unprotected sex [48]. HIV incidence among MSM in gay bathhouses increased from 7.8 % in 2004 to 15 % in 2007 [40•]. Over the same period, the prevalence of active syphilis among this population remained high but stable, from 31.8 % to 23.0 %. Of concern is that one fourth of attendees reported unprotected anal sex (UAS) at the last visit to the bathhouse. A recent online survey revealed that 72.4 % of MSM used the Internet as a main way to seek sexual partners, of these, 73.9 % had sex with partners they found online [41]. However, prevention programs targeting MSM are not implemented effectively in Taiwan because homosexuality is highly stigmatized and many MSM do not “come out” [31].

An increasing concern is young people who are becoming infected. Those aged 20-29 represent the highest number of total HIV cases, accounting for 40 % through 2012 [34]. According to a study among college students, only 48.5 % know that HIV can be spread through infected semen [49]. Regarding other risk populations, no updated information was available in English.

Japan

Japan has East Asia’s second largest population after China, with 127 million [4]. The first officially reported case of AIDS was in 1985, a homosexual Japanese man who had been living in New York. However, the first outbreak of the epidemic occurred among approximately 2000 recipients of contaminated blood products from the United States (most of them hemophiliacs) [33]. Until the mid-1990s they accounted for approximately 55 % of HIV and AIDS cases [50]. After the introduction of heat-treated blood products in 1985, the proportion of infections through this route declined amid a gradual increase in cases due to sexual contact. Prostitution is illegal in Japan, but the adult entertainment industry is well-established nonetheless. In the early 1990s many women from other Asian countries arrived in Japan as commercial sex workers (CSWs). A peak in the number of foreign women infected with HIV, most of them infected outside Japan, was observed between 1991 and 1994, but fell markedly thereafter [50]. Currently, the male-to-female ratio is 16:1 and 12:1 for HIV and AIDS cases respectively, with the epidemic among women and non-Japanese contained at a low level.

As of the end of 2012, 14,706 HIV and 6719 AIDS cases were reported to the national HIV/AIDS surveillance system (Table 1) [51]. Though the prevalence of HIV in the general population still remains very low (0.018 %) [52], the HIV epidemic has been disproportionally concentrated in a particular subpopulation, men who have sex with men (MSM). In a preliminary study the cumulative number of reported HIV/AIDS cases infected through sex between men through 2008 was estimated to be 8.82 per 1000 of estimated MSM population aged 20 to 59; 68 times greater than non-MSM [53]. However, in large cities such as Tokyo and Nagoya, HIV prevalence among MSM who visited free HIV testing sites has been calculated to be 5.7 % and 4.5 %, respectively [54]. The number of newly reported HIV cases of MSM more than doubled from 314 in 2001 to 724 in 2012 (Fig. 1). In 2012, 74 % (683/920) of Japanese male HIV cases were through this route, of which 67 % (460/683) were aged 20 to 39 [55]. Since the peak in 2008, the number of Japanese MSM HIV cases in this age group has been declining. However, it is of great concern that teenage cases are on the rise since 2005 [55]. Evidence suggests that high proportions of MSM engage in risky behaviors such as UAS, illicit drug use, and sex with multiple partners [56, 57]. Without new interventions it has been projected that HIV prevalence among MSM could reach 10.4 % in 2040 [58••].

The number of AIDS cases reported in Japan is considerably lower than in other industrialized countries. However, newly reported AIDS cases (without prior diagnosis of HIV infection) continue to increase since the beginning of the epidemic, especially the cases of homosexual contact, contrary to other developed countries, where a clear downward trend has been observed since the introduction of antiretroviral therapy (ART) in the mid-1990s [59]. Despite availability of ART, social awareness and public perception about HIV infection remain extremely low [60] as well as the number of people who use the free HIV testing service at public health centers in Japan [55]. Thus, systematic efforts and strategy to raise awareness and improve access to HIV testing should be strongly encouraged, particularly among MSM population.

Regarding other routes of transmission, infection through injecting drug use (IDU) is very limited, representing 0.4 % and 0.7 % of the HIV and AIDS cases through 2012. Finally, transmission from mother to child accounts for only 0.2 % and 0.3 % of the HIV and AIDS cases in the same period [55].

South Korea

Since the first case in 1985, the number of HIV-infected South Koreans reported through 2012 was 9410, of whom 7788 were currently living with HIV (Table 1) [61]. Available statistics do not distinguish cases of HIV infection from cases with AIDS. As of 2011, the Korean Centers for Disease Control and Prevention estimated the HIV prevalence rate to be 14.1 per 100,000 population [62]. Other studies estimated the HIV prevalence in hospitals to be 1.3 per 10,000 individuals (2008) [63] and in public health centers to be 4.4 per 10,000 individuals (2009) [64•]. Although HIV prevalence is very low, the number of newly reported HIV cases increased sharply since 2000, from 219 to 868 in 2012 [62].

The main route of transmission since the beginning of the HIV epidemic has been sexual contact, mostly affecting the male population (93.1 % of cumulative cases) [61]. Even though, the male-to-female ratio of newly reported cases decreased from 17:1 in 2007 to 14:1 in 2012 [61], a recent study projected a widening to 19:1 by 2017 [65]. Heterosexual and homosexual contact accounted for 34.2 % and 24.6 % of newly reported HIV cases among South Koreans in 2011 (Table 2) [66]. However, it is reasonable to speculate that the rate of homosexual transmission may be much higher given the high gender imbalance and low prevalence among women and FSWs [67, 68]. Data from the Korea HIV/AIDS Cohort indicated homosexual contact was a major transmission route of recently identified infected individuals [69]. Latest studies among MSM found the prevalence of HIV ranged between 2.7 % and 6.5 % [70, 71]. In addition, high prevalence of self-reported STIs in the last year (10.7 %) and current syphilis (20.4 %) were found in this population. Over 50 % of MSM reported being drunk while having sex, having bisexual relationships, multiple sexual partners, and inconsistent condom use with male and female partners [71, 72]. Therefore, MSM may serve as a bridge for the transmission of HIV to the population at large.

Table 2 Newly reported HIV and AIDS cases by route of transmission in China, Taiwan, Japan, South Korea, Hong Kong, and Mongolia
Full size table

Transmission through IDU is rare in Korea. Until 2012, there were only four HIV/AIDS cases due to IDU, all among men. Some authors speculate this could be due to the low prevalence of illicit drug use, and sterile needles and syringes being available over the counter [68]. However, a recent study found high prevalence of hepatitis B, C, and ever-sharing injecting equipment among IDUs [73]. CSWs and migrant workers constitute other vulnerable groups. CSW is illegal and there is no official report on the number of CSWs infected with HIV [68]. However, studies have shown very low prevalence in this population [67, 68]. As of 2012, there had been 1042 foreigners infected with HIV (71 % male), the majority from Asia and Africa [66]. Foreigners account for only 3 % of the total population, but represent 10 % of the cumulative HIV/AIDS cases. Also, among HIV test-takers in public health centers, foreigners showed a higher HIV prevalence than Koreans (6.8 vs 4.2 per 10,000 HIV-tested individuals) [64•].

In recent years, greater attention has been placed on the need to promote timely testing [74•, 75, 76]. The proportion of late presenters has increased since 1999 after abolition of a government policy of mass mandatory screening [75]. Despite the significant improvement of survival since the introduction of HAART there was a high risk of early mortality in the period 2002-2011 probably due to late diagnosis and late presentation to care [74•, 75].

Finally, similar to other countries in Asia, homosexuality is heavily stigmatized in South Korea and many do not “come out” [77]. Also, unsafe sex behaviors even with high risk partners [78], misconceptions about HIV transmission, and negative attitudes toward PLHIV are still prevalent [79]. Thus, it is necessary to monitor and implement appropriate strategies to prevent further spread of the epidemic in South Korea.

Hong Kong

Hong Kong is a Special Administrative Region of China since 1997. With a population of 7.2 million and the vast majority being ethnic Chinese, Hong Kong is one of the most densely populated areas in the world [4]. In contrast to mainland China, HIV epidemic has remained at a relatively low level, both among the general and high risk populations. HIV prevalence among blood donors, STI clinic attendees, pregnant women, and methadone clinic patients was 0.001 %, 0.172 %, 0.01 %, and 0.489 %, respectively in 2009 [80]. Since the first HIV case was reported in 1984, a total of 5783 HIV cases (3500 Chinese and 1725 foreigners) and 1353 AIDS cases (980 Chinese and 287 foreigners) have been reported through 2012 (Table 1) [81]. The number of new HIV reports hit a record high of 513 cases in 2012, a 17 % increase from the previous year, of which 50.7 % were through homosexual or bisexual contact. The male-to-female ratio increased from 2.6:1 in 2010 to 3.5:1 in 2012, further increasing male predominance. Overall, young male adult Chinese are the group that is most affected [82].

Sixty four hemophilia patients were the first sub-group to be infected through contaminated blood. They were infected prior to 1985, before a safe heat treated alternative and test for HIV became available [32]. Subsequently, most infections have been from sexual contact, with infections through IDU less common. Over the years, sexual transmission has remained the predominant route of infection. In the 1980s the largest percentage of new infections was through sex between men. In 1987, 57.6 % of the new cases were attributable to homosexual or bisexual contact, whereas only 9.1 % were thought to be from heterosexual contact. Then, in the 1990s until mid-2000s the situation reversed and heterosexual transmission surpassed that of homosexual or bisexual contact. In 2000, 62.8 % of new HIV infections were reported to be through heterosexual contact compared to 15.8 % through homosexual or bisexual contact. However, the situation has reversed again since 2004 when a sharp increase in the HIV cases of MSM became apparent, while heterosexual transmission remained relatively stable [62] (Fig. 1). It is also plausible that there are surveillance differences over time that may underreport MSM activity if interviewing is less probing, i.e., some men may report heterosexual risk when male-to-male sexual activity is the true risk factor.

Similar to other parts of the world, MSM in Hong Kong are seeking sex partners through the Internet [83]. Over half of MSM recently diagnosed with HIV infection found sex partners through the Internet in the year prior to their infection [83]. Another study revealed a high proportion of MSM in Hong Kong seeking cross-border sex and having UAS with multiple types and number of male sex partners in Shenzhen, China where high prevalence of HIV and syphilis was reported among MSM [84]. In the last six months, 62.1 % of MSM in Hong Kong had had sex with male CSWs, 84.6 % with male non-regular partners, and 31.3 % with male regular partners in Shenzhen [84]. Prevalence of UAS with these types of partners was 29.8 %, 27.9 %, and 78.7 %, respectively. Prior to 2005 there were only two non-governmental organizations which ran condom distribution and outreach testing programs for MSM in saunas and bars [85]. MSM have been identified as the pressing priority for action in the five year AIDS Strategies from the Advisory Council on AIDS.

Unlike the remarkable spread of HIV among IDUs in mainland China and Taiwan, the HIV epidemic among drug users in Hong Kong remained low. Before the start of the HIV epidemic, methadone maintenance treatment (1976) and the STI clinic services of the Department of Health (1970s) were widely accessible in Hong Kong [86]. Both programs provided preventive interventions, free condoms, and treatment for drug users and patients with STIs. It has been argued that they played key roles in protecting people at elevated risk for contracting HIV [86, 87]. Also, the prevalence of HIV among methadone clinic attendees remained at a consistently low level of 0.2-0.5 % from 2004 to 2010 [88]. HIV infection among IDUs has contributed to only 1.4 % (7/513) of all cases in 2012, a marked decrease from 58 cases in 2006. Nevertheless, the potential risk of an upsurge among this population cannot be disregarded as significant proportions engage in unsafe behaviors [89, 90].

HIV prevalence among FSWs was low, 0.2 % between 2005 and 2007 [91]. However, cross-border (from Hong Kong to mainland China) FSW is common [92]. With increasing population mobility and growing HIV epidemics in neighboring countries, sub-populations with elevated risk of infection need to be closely monitored.

Mongolia

Mongolia is a landlocked country located in Northeast Asia, bordered by the Russian Federation (Russia) to the north and China to the south, two countries with rapidly expanding HIV epidemics. With a small population of 2.8 million, more than 1 million are registered residents of Ulaanbaatar city, the capital and largest city [4]. Mongolia has the smallest HIV epidemic in the region, prevalence in the general population is less than 0.1 % [1, 93] despite high prevalence of other STIs among different population groups [94–96]. Between 1992 and 2004 only five cases of HIV were reported [97], two of whom were AIDS cases (personal communication with UNAIDS Mongolia) (Table 1). However, the number of HIV and AIDS cases has been increasing sharply in recent years. A total of 126 cases were reported by the end of 2012, more than 60 % of them within the last 4 years and 91 % of cases identified in Ulaanbaatar [97]. According to official statistics 17 died by the end of 2012 [97]. The sharp increase in HIV cases could be a response to an increasing incidence of HIV and improved HIV surveillance system [97–100]. Epidemic estimates (by Spectrum) show that at the end of 2013, the number of PLHIV stood at 655. Of these, 73.3 % were MSM (personal communication with UNAIDS Mongolia).

To date, all cases for which route of transmission is known have been attributed to sexual contact, predominantly MSM (Fig. 1). Until 2011, 80 % of HIV cases were males, 82.5 % of them MSM [93]. This is probably an underestimation given that data on sexual orientation was not collected until 2007. Among the female cases, 52 % were CSWs. There are no reported cases of HIV transmission related to blood or vertical transmission. Unlike the neighboring countries of Russia and China, no cases have been found among IDUs in Mongolia [93, 101].

A series of second generation surveillance surveys (SGSS) have been the main source of information in Mongolia over the past decade. MSM and FSWs are currently the population most at risk. The prevalence among MSM during the 2005, 2007, 2009, and 2011 SGSS was 0.0 %, 0.85 %, 1.80 %, and 7.5 %, respectively [98–100]. The sharp increase in HIV prevalence has been argued to be an artifact possibly due to changes in the cases included for estimations (only new HIV cases vs. new and previously identified cases), sampling strategies (convenience vs. response driven sampling [RDS]), sample sizes (88 in 2005 compared to 200 in 2011), and improvements in surveillance [93, 102••]. However, 7.5 % HIV prevalence rate found in the last round of SGSS may be comparable to 6.3 % self-reported HIV prevalence observed during a survey among MSM in Ulaanbaatar in 2011 using RDS [103•]. There is evidence suggesting risky behaviors among MSM [95, 102••, 103•, 104]. Furthermore, low HIV-related knowledge regarding the risks associated with same-sex practices, low exposure to prevention programs (33.6 %), and high misconception about HIV transmission have been reported [102••, 103•]. It should also be noted that there is very limited research on MSM done to date (no data available from outside the capital city) [105], high levels of discrimination, including violence, and low societal acceptance of MSM [106].

Even though previous SGSS did not find HIV infection among FSWs, overall prevalence of syphilis in this population was consistently high ranging from 17.4 % in 2005 to 27.8 % in 2011. High risk sexual behaviors are still common among FSWs and many have misconceptions about HIV transmission [102•]. The illegal character of sex work coupled with high rates of poverty and unemployment may lead increasing numbers of women into sex work for survival [107]. Little is known about other vulnerable groups such as, IDUs, mobile populations, and clients of FSWs. Low impact behavioral interventions should be considered since they can achieve considerable reductions of HIV and STI risk in such a low resource setting [108•].

Conclusion

Although the HIV epidemic reached East Asia relatively late, it expanded region wide driven by the epidemic in China. Because of the timely and effective measures, great progress has been achieved in the control of the HIV epidemic. However, in most of the countries or areas of the region the greatest concern is the growing epidemic among MSM population that has been neglected for many years. Large-scale prevention needs to be tailored to this subpopulation with careful monitoring and evaluation, addressing appropriately the issues of discrimination and stigmatization. Governments need to have strong commitments because the potential consequences of inaction are huge and could have disastrous implications.