Thirty studies were identified that examined interventions directed towards general populations most at risk of becoming infected with HIV, of which 21 were interventions directed towards sex workers, 5 towards injecting drug users and 4 towards men who have sex with men. There were 16 studies from Asia, 8 from Africa, and 6 from Latin America.
Studies of interventions with sex workers included several peer-reviewed articles with data measured both pre-intervention and post-intervention, with or without control groups. Studies from the Asia-Pacific region included interventions in China (32), India (33-35), Indonesia (36-38), Papua New Guinea (39) and Thailand (40-42). In Africa, studies from Benin (12), Cote d'Ivoire (43), Ghana (44), Kenya (45, 46), Sierra Leone (47) and the Democratic Republic of the Congo (48) were identified. In Latin America, three studies were identified, one each from Bolivia, Honduras and Peru (22, 49, 50). In addition, projects in Bangladesh, India and Papua New Guinea were documented in the UNAIDS case study Female sex worker HIV prevention projects (51).
All of the interventions had information and education components, and most offered services either by providing free condoms (12 studies) or free STI treatment (6 studies). The majority of programmes were type 4 interventions. They operated in specially designed facilities (either STI clinics or community centres) where the education sessions or STI treatment took place, and they engaged in outreach activities to attract clients to their facilities. A few of the interventions had only outreach activities, although these sometimes included training peer educators at their workplaces.
The best documented intervention to reduce HIV transmission among sex workers is the Thai government's "100% condom" programme (40). After proving successful in Thailand, a similar approach was adopted by several other Asian countries. Additional strategies have been tested in different locations, mainly in Asia , including peer education, outreach education, group education and the involvement of employers. Other measures tested widely included distributing condoms and providing HIV counselling and testing and STI treatment. All programmes used more than one method to reduce HIV incidence, and therefore it was not possible to tease out the impact of specific interventions.
Other evaluation studies of interventions targeting sex workers in Asian countries that showed positive changes in behaviour and knowledge included: peer education (increased AIDS and STI knowledge and decreased prevalence of gonorrhoea, P = 0.05) (37) and combined educational activities and STI treatment (increased knowledge about AIDS and STIs, P < 0.001; increased condom use, P = 0.01; and decreased prevalence of trichomoniasis, P < 0.001) (38).
In Côte d'Ivoire a randomized controlled trial among female sex workers was conducted with 542 women who were given either a basic or intensive intervention (more frequent visits) consisting of information and education, free condoms and STI treatment (type 4 interventions). Outcomes were measured for 225 women (42%) through self-reported behaviour and testing for STIs. When baseline data were compared with post-intervention data, the intervention was found to be significantly associated with increases in condom use (from 40% to 82%) and decreases in the prevalence of gonorrhoea (from 14% to 5%) and trichomoniasis (from 24% to 11%). In terms of HIV incidence, rates were lower among those who participated in the intensive programme than among those in the basic programme, although these differences were not statistically significant (43).
A longitudinal study of an intervention in the United Republic of Tanzania involving 600 women at increased risk of becoming infected provided information sessions every 3 months on HIV and STIs and reproductive health, voluntary HIV counselling and testing, and clinical health check-ups including syndromic management ofSTIs. This intervention reduced HIV incidence from 13.9/100 person-years to 5.0/100 person-years over three consecutive 9-month periods; the reduction was attributed to the combination of information and services, which describe a type 4 intervention (52).
Although the study in the United Republic of Tanzania demonstrated that interventions aimed at improving STI treatment can be successful in reducing HIV incidence among sex workers, monthly oral administration of 1g of azithromycin among Kenyan sex workers in a randomized placebo-controlled trial did not have this effect (46). Two studies - in Benin and Bolivia - tried to assess the impact of interventions through serial cross-sectional surveys (12, 22). Although both studies reported significant reductions in STI prevalence that were achieved through treatment and educational activities, the research design is severely limited because it does not provide information on any of the outcome measures for consecutive visits made by the same person, only for the group of sex workers as a whole. It also failed to document the level of participation in the programmes. The findings can at most, therefore, show time trends for STI prevalence among a group of sex workers.
The vast majority of interventions for injecting drug users concentrate on making drug injecting safer (that is, they use a harm reduction approach). A key component of this approach is needle and syringe exchange programmes, in which sterile injecting equipment is provided or exchanged for used equipment. Two evaluations of type 4 intervention exchange programmes were found in Asia. An evaluation in Nepal interviewed 586 clients of a programme during a 4-year period and found that the median number of times participants shared needles decreased from 14 to 2, and the median number of people they shared injecting equipment with was reduced from 2 to 1 (53). An evaluation of an exchange intervention in Thailand reported significant reductions in risk-taking behaviours, despite difficulties encountered by young injecting drug users in accessing the programme (54).
Two type 2 outreach education interventions for adult injecting drug users were also identified. The first was based in Chennai, India, and targeted men aged 18 years and older. An outreach team recruited injecting drug users and provided various interventions at street level, including the distribution of bleach. These combined interventions brought about safer injecting behaviours (P = 0.01) without affecting sexual risk behaviour (55). The second intervention took place in Puerto Rico where outreach workers provided information on HIV prevention to indigenous adults who were injecting drug users. This intervention was associated with significant improvements in knowledge of HIV and a reduction in risky injecting behaviours (56).
A WHO multisite study that looked at injecting drug users and took place in two cities in Brazil and one city in Thailand as well as nine cities in developed countries (57), showed that the behavioural changes that occurred were similar in Bangkok and the cities in developed countries but different from those in the Brazilian cities. The frequency of consistent condom use with casual partners was lowest in Rio de Janeiro, whereas in Bangkok it was reported to be higher than in most of the cities in developed countries. This highlights the challenge of comparing results from studies conducted in different developing countries and between developed and developing countries.
In addition to the data from developing countries, evidence of successful HIV interventions aimed at injecting drug users is available from a number of literature reviews (58). Consecutive HIV prevalence data from injecting drug users in cities in the United States with and without needle-exchange programmes were reviewed (59); there was significant evidence of a 5.8% decrease in seroprevalence among injecting drug users in the 29 cities that had needle-exchange programmes compared with a 5.9% increase among drug users in the 52 cities without such programmes (P = 0.004) (59). A Cochrane systematic review assessed the effect of oral substitution treatment for opioid-dependent injecting drug users on rates of HIV infection and high-risk behaviours and found significant associations between treatment and reductions in illicit opioid use, injecting use and the sharing of injecting equipment. Reductions in risk behaviours related to drug use also translated into reductions in the prevalence of HIV infection (60). In general, these were type 4 interventions.
Four interventions targeting men who have sex with men were identified from Brazil (61), India and Morocco (both mentioned in Tawil) (21) and Puerto Rico (62). The intervention in Morocco included 600 men and the intervention in India included 3 000 men reached through peer outreach programmes focusing on safer sex messages, condom distribution and providing STI care at a drop-in centre (a type 4 intervention). Increased safer sex practices were reported in post-intervention analyses at both sites, with these effects being statistically significant in India but not in Morocco. The two interventions in Latin America identified participants though peer referral and focused on peer education. The study in Brazil had a pre-intervention versus post-intervention design and included 227 men who have sex with men, who had a mean age of 29 years; in this study men were assigned either to an intensive series of safer sex workshops or a series of health education lectures. There were no significant differences in health outcomes between the two interventions, although comparisons between baseline and post-intervention surveys showed statistically significant increases in knowledge and awareness and decreases in self-reported risk behaviours. These differences were found to have been sustained at a 6-month follow-up survey.
In addition to these studies from developing countries, a meta-analysis of HIV behavioural interventions aimed at reducing sexual risk behaviour among this group of men included 33 studies from different parts of the world (63). It described significant decreases in the prevalence of unprotected anal intercourse (OR = 0.8, 95% CI = 0.7-0.9) and number of sexual partners (OR = 0.85, 95% CI = 0.6-0.9) as well as a significant increase in condom use during anal intercourse (OR = 1.6, 95% CI = 1.2-2.2). In this meta-analysis, successful programmes were those that were based on a theoretical model, included training in interpersonal skills, incorporated several delivery methods and were delivered over multiple sessions spanning a minimum of 3 weeks (63), thus providing evidence for the effectiveness of type 4 interventions.
Was this article helpful?