In my opinion, AWARENESS among the masses about the different aspects of this deadly diseases can contribute tremendously.

Both IEC and treatment are equally important but both have different indications. IEC is most important tool to reduce or contain the spread of the infection in  spouses, sexual partners aor the community while treatment has special indication only in those who are already infected. Virus can not be killed by IEC, one needs effective treatment. 

Is there any evidence of IEC working? Be nice to know since I have not seen any.

On the other hand treatment is a well documented means of reducing transmission.

In addition to what the other contributors have said, Mother to Child transmission  prevention strategies  is known to work . It does not provide a 100 percent prevention but it goes a long way. May you kindly see the link: https://aidsinfo.nih.gov/education-materials/fact-sheets/20/50/preventing-mother-to-child-transmission-of-hiv

It should be borne in mind that this method should be utilised together with other methods.

Both are important though treatment is being given a lot of emphasis e.g pre-exposure prophylaxis and the screen and treat approach 

Strategies which enhance the sexual discipline, encourage the early screening for general population, treat all confirmed seropositive patients and integrate nutritional programs are likely to combat efficiently HIV/AIDS.

HIV/AIDS Educational Intervention Programs including Peer education in the area of HIV/AIDS prevention has become promising and effective methods in controlling the infection.

The both strategies IEC and treatment are complementary to prevent HIV/AIDS.

Treatment is part of prevention for any disease especially for infectious diseases like HIV / AIDS. This is because, by treatment, one reduces the reservoir of the infection and thus to a large extent, protects the general population. Treatment also reduces suffering, improves quality of life of victims thus increases compliance with primary preventive measures.

By the way, the concept of prevention is viewed holistically as primordial, primary, secondary and tertiary prevention levels. Treatment belongs to the secondary level of prevention while IEC belongs to the primary level.

Therefore, both strategies are key to the control of the HIV /AIDS scourge. The current emphasis on treatment should continue but health promotion (ABC) and other primary /secondary prevention activities like PMTCT, PEP should be scaled up to reduce the rate of new infections.

In line with the UNAIDS 90-90-90 goal, that 90% of PLHIV will know their HIV status, 90% of PLHIV who know their status will be placed on long-life saving antiretroviral therapy, and 90 of PLHIV on ART will achieve viral suppression: this suggests the combination of a package of minimum HIV preventive and treatment interventions targeted at the general population and key populations (Female Sex Workers, MSMs and PWID) in a series cascade system or HIV continum of care in other to achieve epidemic control. On the other hand, current WHO recommendation of "test and start" or "start and treat" suggests the use of "HIV Treatment services as Prevention". 

The best strategies to prevent & control HIV/ AIDS are IEC activities and Treatment of it.  It is good to use a willing HIV/AIDS patient to help with the IEC activities. Many HIV/AIDS patients do not disclose their status to sex-partners, in that respect treatment itself is a preventive strategy. 

IEC a fortiori on sex trannsmission, early screening, safe health care, effective nutrition and treatment are likely to prevent and control HIV/AIDS effectively.

For me it is quite logical that we focus more on the treatment aspect since the prevention and control ways haven't yet reached their full efficiency due to many factors most of them related to culture, education, environment, economy...We should take into consideration also that the prevention and control techniques are made to limit an infection independently of its nature and not to eradicate it. Adding to that the huge number of already infected people, it is obvious that treatment of this disease is the best strategy to prevent it.  

as to me it is difficult to decide whether IEC or treatment  as The appropriate mix and distribution of prevention and treatment interventions depends on the stage of the epidemic in a given country and the context in which it occurs. so it depends on presence of definitive data 

The problems with HIV/AID transmission is multi factoral, hence no one strategy will solve the problems. IEC activities is a very good strategy for non infected to remain safe and for the infected to play safe and be careful. However, treatment too is very important and still very relevant for viral suppression for the positive people and to keep their partner safe from getting infected. 

Thanks for sharing  beautiful and informative answers for the  above cited question. 

Information, education, and communication. This intervention includes education on HIV/AIDS and condom use through pamphlets, brochures, and other promotional materials in classroom or clinic settings or through the radio, television, or press. In general, discerning the effectiveness of IEC alone is difficult, because IEC is often included in condom promotion and distribution interventions. Here we consider the effectiveness of IEC in concert with condom promotion and distribution. Of all available prevention interventions, providing information and education about HIV/AIDS is perhaps the most difficult to assess for cost-effectiveness. Numerous studies have shown that information alone is typically insufficient to change risk behavior. Accurate information, however, is indisputably the basis for informed policy discourse—a vital ingredient in the fight against fear-based stigma and discrimination. In the absence of studies to guide the level of investment in IEC, the only reasonable alternative seems to be to implement IEC on the basis of data derived from relative levels of knowledge and understanding in the population. For example, if only 25 percent of the sexually active population were able to describe how HIV is transmitted and prevented, clearly more IEC would be needed, but if 75 percent of the population understood the basic facts about HIV/AIDS, the need for additional funding would be diminished.

Athlone Hospital in Lobatse, Botswana, used a novel 'CLINICAL' intervention to address a 'VILLAGE' public health concern. It was all about HIV/AIDS Education (AIDucation) in clinical colour pictures. Simply put, ABUSING medical illustrations intended for healthcare workers (paramedics, nurses, doctors) to empower the schools, colleges, universities, churches, mosques, civil society, uniformed forces, trade unions, clubs, traditional birth attendants, traditional doctors and sangomas. 

Folks wanted to "SEE AIDS" to believe that the "INVISIBLE INFECTION" was real. What better way than Teaching aids At Low Cost (TALC) clinical slides that were compiled by the late Prof David Morley - President of TALC; and the powerful doctors - Dr Cathy Vaughan and Wendy Holmes of Australia. They are Botswana's AIDucation foundation!

What began as a village AIDucation dream in 1992 in Botswana is now an annual part of the London School of Hygiene & Tropical Medicine's Postgraduate Courses for medical doctors, project managers, nurses and others on the AIDS' Modules / Course, as from 2005.

Attached a 2004 SAFAIDS Article that tells the Botswana Story of Picturing AIDS. "Seeing is believing...a picture is worth a thousand words...we remember more of what we see than what we hear or read."

The first set of TALC slides on basic virology and transmission, in a summarised version attached. It was all about story-telling to raise HIV / AIDS awareness...

I think that this is a multifactorial problem, and when we need emergency measures, the treatment seems to solve the problem of those already infected and reduce the risk of potential sexual contacts, however it is important to plan a sustained IEC strategy  to prevent future cases in the long run. Combining strategies makes more sense, and in some areas it is urgent to issue laws to give rights and voice to women who otherwise won`t avoid infection from their partners given some opressive laws of subjection to their male partners.

There is plethora of information on it. No single measure is adequate. Combination is always effective. Hence, both IEC, preventive measures such as sentinel surveillance, condom promotion etc. as well as curative services - all are necessary for control of HIV/AIDS

A fresh approach to this problem is needed. One of the largest meta-analyses was carried out by Albarracin et al. (2005). A category of studies concerns interventions to increase condom use.  The most effective interventions were those that contained attitudinal arguments, educational information, behavioural skill arguments, and skills training. Active interventions were found to be significantly more effective than passive interventions.