One of the most important lessons that has emerged over the years is that a safe and supportive environment is a crucial element of effective HIV prevention. Countless intervention studies and grassroots initiatives have shown that even when individuals are well aware of the dangers of AIDS, are motivated to avoid HIV infection, and know full well how to avoid HIV infection, factors in the immediate and wider environment play an important role in determining whether or not they can protect themselves. Some of these factors are restrictive laws and policies, economic constraints, social and cultural pressures, lack of availability and poor accessibility to health services.

This means that along with carefully tailored actions directed at the level of the individual (for instance, providing individuals with the information they need, motivating them to take the necessary steps to protect themselves, and strengthening their abilities to deal with challenging everyday situations through ‘life-skills' training), a complementary set of carefully tailored actions is required at the level of the environment (to overcome the environmental factors that hinder individuals' abilities to protect themselves).

The involvement of communities in their own health care is neither a new concept nor a new practice. Twenty years ago, the Declaration of Alma Ata called for international commitment to involving the communities in the design, choice and delivery of their own health care. Today, the concept of community involvement is receiving even greater interest and support than  before. In developed and developing countries alike, families and communities everywhere are realising that they must assume greater responsibility for their own health and welfare, and that everything possible must be done to develop and strengthen their capacity.

Communities also play a crucial role in HIV prevention. In the absence of a vaccine, people must be informed about how HIV is transmitted and encouraged to protect themselves and their loved ones. They can do this by adopting safe behaviours, such as abstinence, mutual fidelity, or the consistent use of condoms. Ignorance and prejudice can best be vanquished by facts and understanding through neighbourhood support systems, schools, religious associations, professional groups or family networks. Even when national and international campaigns inform people about HIV/AIDS, many people do not see the potential consequences of their behaviour until they receive the same message disseminated by their own community or peer group.

The most effective messengers are enlightened insiders: people within a community who are trusted by those needing information and support. Community members know who is in most need, are aware of cultural sensitivities, and speak the same language  in every sense of the phrase. At another level, individuals can be educated and motivated to change their sexual behaviour, but experience has shown that this process is helped if the change in individual lifestyle is backed up by community commitment to safer sex and to other protective measures. Leaders and other influential community members can thus play a pivotal role in helping people in their communities learn and understand about AIDS.

Moving beyond improving knowledge and understanding, what is it that leaders and other ‘influentials' can play when community members are unable to take the actions needed to avoid HIV (even if they want to) for reasons beyond their control? With the support and encouragement from outside organizations, they may be able to make a real difference. For example, tribal elders may be able to convince their followers to modify long-held customs and traditions that increase the risk of people getting HIV. Sometimes however, tackling these problems may be beyond the capacity of the community. For example, because of lack of work opportunities in a poverty stricken rural area, young women may be forced to migrate to towns and cities nearby to enter sex work. In such a situation, the direct involvement of many different government bodies and NGOs will be required for any meaningful change to be brought about.

In most situations, helping overcome environmental factors that hinder the ability of community to avoid HIV (and STDs) will require a combination of actions that produce (useful but limited) results in the short term, alongside actions that will have more far-reaching results in the long term. For example, laws are often difficult to change; it involves a slow process which can take months or even years. Other useful actions could be taken simultaneously, such as explaining to the officials who enforce the laws why laws that make it difficult for sex workers, drug users and others to protect themselves increase the likelihood that others in the community could get HIV.

Similarly, improving girls' and women's access to education and vocational training and removing obstacles to their ability to earn money will help empower future generations of women. Meanwhile, actions to enable the present generation of women to protect themselves are urgently needed. Literacy programmes and revolving credit schemes are helping countless women around the world to take greater control over their lives. Another promising approach is stimulating and supporting collective action. Many organizations are tapping into the power of collective action by bringing people together in small groups to discuss how HIV/AIDS could (or already does) affect their lives and decide what actions they could take individually and collectively to deal with it. The support of the group can give the strength and confidence people need to bring about changes in their situation, both within their personal situation and within their communities.

In sum, community action must be nurtured and supported over time; it will not just happen.

Fortunately, this has changed over the years, and now there is a stated  as well as a demonstrated  commitment in many countries to empower individuals and communities to take the necessary steps to promote their own health. In a real sense the pendulum has swung from one end to the other. Fifteen years ago, so-called experts told communities what they should do; today the same experts are telling communities that both the problem and the key to its solution lie in their hands. In some places this has been interpreted as a ploy for the authorities to forsake their legitimate responsibilities. If the past approach was ill advised and inappropriate, so is the current one. Both public health professionals and community members have useful contributions to make to sexual health promotion, and both have important roles to play in a partnership of equals.

Venkatraman Chandra-Mouli, World Health Organization, Department of Child and Adolescent Health and Development, CH1211 Geneva,27, Switzerland; Tel: +4122791.4814; Fax: +4122791.4853; e-mail: chandramouliv@who.ch