Dissertation committee:
Βασιλική Μπενέτου, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Παγώνα Λάγιου, Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Παναγιώτα Τουλούμη, Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Δημήτριος Παρασκευής, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Βασιλική - Αναστασία Σύψα, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Μαρία Καντζανού, Επίκουρη Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Γκίκας Μαγιορκίνης, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Summary:
Introduction: Despite great advances in HIV prevention and treatment, HIV infection remains a major global public health issue associated with serious morbidities, high health care and treatment costs and a significant number of deaths. Since a safe and effective vaccine is not available yet, the use of other evidence-based methods and interventions is considered essential in order to contain the epidemic. Worldwide, the predominant mode of HIV transmission is through sexual intercourse and, as a result, condoms remain the key preventing tool against HIV infection. Even though several previous studies have supported condom effectiveness for HIV prevention, new evidence has appeared (including data from a very large number of HIV serodiscordant heterosexual couples), while there was also a need to perform further subgroup investigation, and to take into consideration the current availability of sound meta-analytic techniques.
Sharing of contaminated injecting equipment among people who inject drugs is another potential mode of HIV transmission, something that becomes more important in times of outbreaks like that among PWID that occurred in 2011, in Athens, Greece. Apart from the early and intense implementation of harm reduction programs (including NSP and OST programs) that have been proved effective in limiting HIV spread among PWID, knowledge about acute/recent HIV infection could also play an important role, given that correct knowledge about recent infection and its disproportionate large contribution to HIV transmission could lead to avoidance of high risk behaviors, maintenance of positive attitude towards recently HIV-infected people, recognition of acute HIV infection symptoms and, consequently, to early HIV detection and treatment. However, despite the critical role of recent HIV infection in onward HIV transmission, there is still a gap in the literature regarding research, both quantitative and qualitative, on people’s knowledge, beliefs, and attitudes toward recent HIV infection.
The aim of the present research was:
• to produce updated and more precise estimates of condom effectiveness in reducing the risk of HIV transmission among HIV serodiscordant heterosexual couples and to investigate factors that potentially influence its effectiveness (using meta-analytic techniques),
• to measure knowledge about recent HIV infection and normative beliefs and attitudes towards persons with recent HIV infection among a sample of PWID, during a period of high HIV incidence in that group [analyzing data from novel interventions that were implemented during the outbreak among PWID, in Athens: specifically, a multi-wave, respondent-driven sampling (RDS) program (ARISTOTLE) and a social network-based contact tracing approach (Transmission Reduction Intervention Project – TRIP)].
Results: Concerning condom effectiveness, 25 observational studies were identified by a comprehensive search in Medline, Scopus, and the ISI Web of Science database, involving a large number of HIV serodiscordant heterosexual couples (n=10,676). The meta-analysis showed that the risk of HIV transmission was considerably lower among couples that were always using condoms compared to never users (RR: 0.29, 95% CI: 0.20–0.43), or to those that were not consistently using condoms (RR: 0.23, 95% CI: 0.13-0.40). The protective effect of consistent condom use was slightly higher when the male rather than the female partner was infected [RR (always use - never use): 0.29 (95% CI: 0.17–0.51) vs 0.38 (95% CI: 0.18–0.80), respectively, and RR (always use-inconsistent use): 0.31 (95% CI: 0.20–0.48) vs 0.44 (95% CI: 0.24–0.80), respectively] and was extremely high in Asian settings (RR: 0.06, 95% CI: 0.01–0.46). The meta-analysis of adjusted for potential confounders estimates yielded similar findings.
As far as knowledge/attitudes/normative beliefs about recent HIV infection are concerned, the present analysis includes data from the fifth round (19 September 2013 – 16 December 2013) of ARISTOTLE, as this was the first round in which ARISTOTLE’s questionnaire included items from the TRIP questionnaire regarding participants’ knowledge of recent infection; their normative beliefs about reactions of people in their networks to persons with recent infection; and their own attitudes towards recently infected individuals. Univariable analyses were done using chi-squared tests and t-tests, while multivariable methods included logistic regression models. All statistical analyses were conducted in Stata v. 14 (Stata Corp., USA)].
In total, 1,407 PWID (mean age (SD): 36.3 (7.9) years old; males: 81.9%) participated in that round, most of whom were Greeks (87.6%), while 34.8% reported that they were currently homeless or had been homeless in the past 12 months, and more than half had primary or middle/secondary school education. The HIV prevalence was 14.6% and was significantly (p<0.001) higher among the homeless (23.6%).
61.5% of the participants correctly stated that the likelihood of HIV transmission is higher during the first six months of HIV infection, with knowledge being significantly better (p<0.05) among PWID with stable accommodation (63.5%), of Greek origin (65.1%), and HIV-infected (72.3%).
In total, 58.4% of the participants believed that most people in their networks would react to a friend with recent HIV infection in a positive/neutral manner, while that proportion was lower among those with only primary school education (46.5%) and higher among participants with stable accommodation and among HIV seropositives [60.3% and 65%, respectively (p<0.05)]. The majority disagreed with the statement that they would avoid any contact with a recently infected person in his/her first month/s of HIV infection (87.4%) and with physically removing a recently HIV-infected person from the neighborhood (90%). Over 80% of participants, and even higher (p<0.05) proportions of those diagnosed with HIV, agreed that a person with recent HIV infection should get appropriate medical care and assistance so as to cope with his/her anxiety and fear, and avoid engagement in risky practice.
Participants who knew that people with recent HIV infection were more likely to transmit the virus in the first six months of their infection were 3.5 times (95% CI: 2,737, 4,357) more likely to believe that people in their network would become closer with a person with recent infection or that their relationship with the recently infected individual would not change. PWID who were knowledgeable of recent HIV infection were between 50% and 100% more likely to disagree with statements such as that one should avoid all contact or sex and drug use with a person with recent HIV infection or that recent infected persons should be removed from the neighborhood. Moreover, they were twice as likely to agree with the statement that an HIV+ person is less likely to transmit HIV when h/she is on combination ART.
Conclusion: Combining the existing published bodies of observational data, it can be inferred that condoms, when used in a consistent manner, are 71–77% effective in reducing HIV incidence in cohorts of negative partners of HIV discordant heterosexual couples. The protection offered by condoms seems to be larger in some geographic settings, raising issues of social, cultural, and biological or methodological differences that need to be studied further.
PWID in Athens, Greece proved quite knowledgeable, on average, of the role of recent HIV infection in HIV transmission, although efforts are needed to improve knowledge rates, especially among migrants and people with lower education levels. Normative beliefs and attitudes were deemed positive overall for the TRIP sample, as participants were more likely to report that they would respond to recently infected people with help and solidarity, rather than stigma and hostility. This was especially true among those who were aware of the increased risk of HIV transmission during the period of recent HIV infection. Although further research is needed to confirm these findings in other geographical or epidemiological settings, it seems that interventions to improve knowledge of the importance of recent HIV infection in HIV transmission, and especially among high-risk groups, could play an important role in preventing HIV transmission.
