Practitioners and campaigners in the fight against HIV and AIDS in the Netherlands say they are \"cautiously optimistic\", even while curbing the epidemic in the gay community and other high-risk groups remain a top priority. As December 1 marks 30 years of the global fight against AIDS, the number of new HIV/AIDS cases has been stabilizing in the Netherlands, according to experts interviewed by Xinhua in Amsterdam. Problem areas persist, however. About five to ten percent of the homosexual community in the country is infected with the disease, according to Prof. Roel Coutinho, director of the Dutch Center for Infectious Disease Control. \"The gay community is the highest-risk group in the Netherlands. Almost everyone knows someone with HIV,\" he said. According to a report published last week by the Dutch HIV Monitoring Foundation, up to 98 percent of HIV/AIDS cases in the country were caused by sexual activity, over half of which were men having sex with men (MSM). About two percent were caused by drug use. However, the increase in the number of new HIV diagnoses among MSM has stabilized to an estimated 750 cases a year, according to the data of recent years, presumably reflecting improved awareness and more people getting tested regularly. \"In gay communities, an estimated 80 percent of them have a good knowledge about HIV, compared to about 40 percent a few years ago,\" says Ton Coenen, director of the Amsterdam-based SOA AIDS organization. Meanwhile, immigrant groups mainly from Africa continue to pose a threat to anti-AIDS efforts in the Netherlands. Currently, illegal immigrants do not have proper access to HIV treatment in the country. \"Immigrants are the largest group of unregistered patients and also the most difficult group to handle because many immigrants are reluctant to get tested or treated due to social stigma or financial constraints,\" said Prof. Frank de Wolf, founding director of the HIV monitoring foundation and medical microbiologist with the University of Amsterdam. The main focus in western European countries such as the Netherlands is stemming the transmission of HIV/AIDS through sexual activity. In eastern Europe, however, authorities are far more bothered by transmission through drug usage due to its popularity and lack of knowledge. Experts said in general, youth in the the Netherlands have an above-average level of knowledge about sex and AIDS issues. Perhaps not surprisingly, the country\'s teenage pregnancy levels remain among the lowest in Europe. \"It is largely a conservative country, despite the image we have abroad. The well-educated population here understand how serious AIDS can be,\" Prof. Coutinho added.