Date Published: February 27, 2019
Publisher: Public Library of Science
Author(s): Marineide Gonçalves de Melo, Ivana Varella, Pamina M. Gorbach, Eduardo Sprinz, Breno Santos, Tauí de Melo Rocha, Mariana Simon, Marcelo Almeida, Rita Lira, Maria Cristina Chaves, Zoe Baker, Tara Kerin, Karin Nielsen-Saines, Jean-Jacques Parienti.
An undetectable serum HIV-1 load is key to effectiveness of antiretroviral (ARV) therapy, which depends on adherence to treatment. We evaluated factors possibly associated with ARV adherence and virologic response in HIV-infected heterosexual individuals.
A cross-sectional study was conducted in 200 HIV-1 serodiscordant couples and 100 unpartnered individuals receiving ARV treatment at a tertiary hospital in southern Brazil. All subjects provided written informed consent, answered demographic/behavioral questionnaires through audio computer-assisted self-interviews (ACASI), and collected blood and vaginal samples for biological markers and assessment of sexually transmitted infections (STIs). HIV-negative partners were counseled and tested for HIV-1.
The study population mean age was 39.9 years, 53.6% were female, 62.5% were Caucasian, 52.6% had incomplete or complete elementary education, 63.1% resided in Porto Alegre. Demographic, behavioral and biological marker characteristics were similar between couples and single individuals. There was an association between adherence reported on ACASI and an undetectable serum viral load (P<0.0001). Logistic regression analysis demonstrated that single-tablet ARV-regimens were independently associated with adherence (OR = 2.3; 95CI%: 1.2–4.4; P = 0.011) after controlling for age, gender, education, marital status, personal income, ARV regimen, and median time of ARV use. A positive correlation between genital secretion PCR results and serum viral load was significant in the presence of STIs (r = 0.359; P = 0.017). Although HIV PCR detection in vaginal secretions was more frequent in women with detectable viremia (9/51, 17.6%), it was also present in 7 of 157 women with undetectable serum viral loads (4.5%), p = 0.005. ARV single tablet regimens are associated with adherence. Detectable HIV-1 may be present in the genital secretions of women with undetectable viremia which means there is potential for HIV transmission in adherent individuals with serologic suppression.
According to the WHO, approximately 1.7 million adults have recently become infected with HIV-1 and more than 90 percent of these infections are sexually transmitted, occurring in individuals of reproductive age. The city of Porto Alegre is the epicenter of the Brazilian HIV epidemic, with 74.0 cases per 100 thousand inhabitants, corresponding to twice the rate of the Rio Grande do Sul state and four times the Brazilian prevalence rate. Antiretroviral (ARV) therapy has significantly improved the prognosis of patients infected with HIV-1 and has decreased the association with morbidity and mortality, besides reducing sexual transmission among serodiscordant couples. Nevertheless, there are many challenges to the effective delivery of ARV, some of which are outlined in detail in the UNAIDS report of 2016.
A cross-sectional evaluation was performed in 200 couples (400 individuals) who were in a stable relationship for more than three months, and were serodiscordant for HIV-1, and in 100 single HIV-1 seropositive individuals with no partners at the time of the study. All HIV seropositive subjects had ongoing medical care and were on ARVs for three months or more at a specialized HIV care service at Hospital Nossa Senhora da Conceição in Porto Alegre, Brazil. All study subjects provided written informed consent, answered a demographic and behavioral questionnaire via ACASI and provided blood samples for viral load, CD4, STI assessments and vaginal/ genital secretions for virus load if female. All HIV-negative partners were counseled and tested for HIV-1. The study was reviewed and approved by the ethics committee/ Institutional Review Boards (IRB) of Conceicao Hospital (CEP Hospital Conceicao) and by the UCLA IRB (UCLA MIRB1).
The majority of the population studied (68.5%) consisted of HIV seropositive women (Fig 1). The mean subject age was 40 years. Most study participants lived in Porto Alegre (63.1%), were white (62.5%), female (53.6%) and had completed elementary school only (52.6%). The proportion of females and the mean age of unpartnered participants was higher than that of individuals in HIV serodiscordant relationships. Unpartnered individuals more frequently responded positively to having their own source of income, however the median monthly income was higher for couples. Demographic characteristics of the study population are shown in Table 1. Occasional alcohol intake was more frequently reported by couples. There were no reported differences between couples and unpartnered individuals regarding the use of illicit drugs, type of drugs or injectable use (Table 2).
We studied a population of serodiscordant couples and HIV unpartnered individuals at a period of time when there is universal recommendations for ARV use. During the time our study was conducted pre-exposure prophylaxis to partners of HIV-infected individuals was not the standard of care. Our main goal was to determine factors associated with adherence and adequate virologic plasma and genital suppression, both key to avoidance of HIV sexual transmission in this setting. As genital virus load can be significantly influenced by concurrent STIs we also evaluated our population for co-infections. We noted the differences between infectious markers such as blood and genital secretion viral load and contrasted findings with self-reports of adherence obtained via ACASI, taking into consideration also the presence of concurrent STIs. Few studies have compared partnered and unpartnered HIV-positive individuals in terms of ARV adherence. In one specific study, the presence of a partner was a strong predictor of adherence. In our study population however, we did not identify significant differences regarding adherence when comparing index cases in serodiscordant couples and unpartnered individuals.