The Linkage of Illicit Drug Use / Alcohol Use and HIV Infection in Young Adults

1.1. Introduction to Substance Abuse and HIV Infection among Young Adults

The time span determining young adulthood is imprecise being a function of psychosocial development and physical development which varies region to region and culture to culture. Studies have identified the age range to be between 16 - 40 years of age for young adulthood (1-3). For the purpose of addressing substance use and substance use disorders in the context of Human Immunodeficiency Virus (HIV) infection during young adulthood, the age range of 16 - 30 years has been selected to reflect a time when life goals are formulated, along with meeting the challenges of independently facing a diverse, global and rapidly changing environment. This time frame, based on social norms, is the period of sexual debut (average age of first sex in 44 countries is 18.4 years) (4) and the consequences of first exposure to legal drugs, such as alcohol. Exposure to alcohol in childhood or early adolescent and binge drinking in late adolescence confer an increased venerability to alcohol dependence as young adults (5, 6). In the United States, national surveys show that approximately 70% of young adult consume alcohol and research studies show that young adults drink the most in their late teens to mid-twenties in age (7-9). With regard to illicit drug use and young adults, prescription drug abuse is reported high in national surveys of developed countries with approximately 6% of young adults reporting nonmedical use of prescription drugs in the last month (10). One in six urban young adults attending partying venues have been reported to combine illicit drug use with prescription drug abuse (11). Of those abusing prescription drugs, 66% used the prescription drug with at least one illicit drug in common combination with marijuana, cocaine, ecstasy and psychotropic drugs. Illicit drug use that is most identified with an elevated risk of HIV transmission, either through injection drug practices or high-risk sexual behavior, are opioids, amphetamines and cocaine (12). An estimate of global use of these illicit drugs can be found in the World Drug Report where it is reported that between 3.5 and 7.0% of the global population (ages 15 - 64) has used an illicit drug in the previous year (13). It is also estimated that 10% of these individuals exhibit symptoms of a substance use disorder, indicating an uncontrolled use and abuse of the illicit drug. These latter individuals are at highest risk for either injection or sexual behaviors that place the illicit drug user at elevated risk for HIV transmission. Thus for young adults, data from studies and national surveys show a convergence of the consequences of the initiation of drug and alcohol use along with a time of sexual debut, linking the young adult period with an elevated risk of HIV infection.

2.1. Etiology of HIV Prevalence Prior to Young Adulthood Linked to Substance Abuse

While young adulthood is a time of high-risk for the transmission of HIV due to drug and alcohol use in the context of sexual activity, the prevalence of HIV infection in young adults comprises both infection prior to and during young adulthood. Prior to young adulthood, HIV infection can result from Mother To Child Transmission (MTCT) or infection during adolescents due to high-risk activities. For MTCT, numerous studies (14-17) have documented that maternal use of cocaine and other illicit drugs results in a greater than three-fold higher risk for vertical transmission of HIV. This increased risk of transmission is evident for drug-using pregnant women who receive anti-retroviral therapy during pregnancy to reduce the risk of vertical transmission (18). Infants born with HIV infection have an excellent survival rate when provided anti-retroviral treatment under WHO treatment guidelines (19). However, infants born with HIV infection have more factors associated with failure to thrive, and as they progress through childhood, adolescence and young adulthood experience poorer health and lower quality of life (20, 21). These individuals, living with HIV, as they progress to young adulthood, have a higher risk of prescription drug abuse, as well as, illicit drug and alcohol use due to both increase chronic health issues, as well as, the stigma and discrimination of growing up with HIV infection (22). In addition, research has shown a genetic component to addiction where allelic phenotypes of genes related to both the brain and nervous system contribute to the onset of problematic drug and alcohol use, particularly in young adulthood (23). Thus, the perfect storm forms comprising neonatal exposure to drugs and alcohol combined with genetic risk, chronic health conditions early in life, and poor quality of life into young adulthood, a time of onset for abuse of drugs and alcohol.

Another important risk factor for illicit drug and alcohol use, for individuals living with HIV and without HIV, is growing up in a drug-using household (24). Household and family substance use coupled with the stigma and discrimination of HIV infection provides a high-risk environment for the early initiation of illicit drug and alcohol use, along with sexual debut in adolescence or young adulthood. Growing up without the knowledge of HIV infection is also an issue. Young adults with perinatal HIV infection, who receive a late diagnosis of HIV infection in their teens or early twenties, face a life changing event during a time of developmental and emotional immaturity. Without significant support, these individuals are at-high risk for not only illicit drug and alcohol abuse and addiction, but also suicide and mental health disorders, such as major depression. Unfortunately, it is not uncommon in both resource rich and resource limited countries for young adults, with perinatal HIV infection and who receive limited health care services early in life, to be diagnosed with HIV infection in late adolescence or early young adulthood (25).

The early initiation of drug and/or alcohol use during adolescence, the developmental stage prior to young adulthood, is a high-risk behavior for the acquisition of HIV infection. The early initiation of drug and/or alcohol use in adolescence results in increased sexual risk-taking with the potential exposure to HIV infection (26). So, what protects from and promotes the early initiation of drug and/or alcohol use? Positive protective factors include a good adolescent-school relationship, as well as, good family- adolescent relationship which includes: positive parenting, parental involvement, family cohesion, family communication, parental monitoring of peers, and parent-adolescent communication (27). Promotional factors for drug and alcohol use include household drug and/or alcohol use, adolescent disengagement from school, poor family relationship and poverty.

With regard to household drug/alcohol use, adolescents perinatally exposed to illicit drug use have a two fold increase risk in the use of drugs or alcohol by age 15, as well as, an increased risk of early sexual debut (28, 29). In a low income setting, minority adolescents who were early initiators of sexual activity also reported substance use and illicit drug selling (30). Also, in this setting, youth who reported continuous involvement in drug use also reported intense sexual involvement as compared to sexual experimentation. A highest-risk group for substance use and HIV transmission are homeless street youth. In both high income settings and low-income settings, street youth report daily use of alcohol and illicit drugs, as well as, high-risk sexual activities, including survival sex (31, 32). The circumstance of social estrangement is an important situation in the lack of access and receipt of health services for substance use disorders and HIV infection (33). Socially estranged adolescents are frequently involved with the criminal justice system and are a population that has been shown to have repeated sexually transmitted diseases (34). Behaviors that place these youth at high-risk for HIV infection include binge-drinking, risky sexual encounters while intoxicated, intravenous drug use, and frequent incarceration (35-38). A history of arrest and detention has been shown to be a marker for both adolescent HIV infection risk and substance abuse (39).

Since illegal behaviors have been shown as a marker for substance abuse and HIV infection risk, behavior screening of adolescents and young adults is an important tool for health care providers. Adolescent and young adults, who are key populations (people who inject drugs, men who have sex with men, sex workers and transgendered individuals), face laws and community practices that criminalize the behaviors. The criminalization places them at high risk for HIV infection, sustained violence and discrimination for their behaviors, and impeded access to drug and HIV-related prevention, care and treatment (40). These individuals along with homeless young adults living on the street experience more unprotected sex, sexually transmitted infections, HIV infection, unintended pregnancies, violence, mental health disorders and substance use disorders than young adults in the general population (41). The result is a marginalized population of young adults with the triple diagnosis of HIV infection, substance use disorder and mental health disorders who are estranged from needed medical care and treatment.

HIV infection is an epidemic among adolescent girls and young women in many parts of the world (42). In Eastern and Southern Africa, young girls account for 80% of all new HIV infections and HIV/AIDS is the leading cause of death for girls aged 15 - 19. The vulnerability to HIV results from gender inequality, lack of economic opportunity, intergenerational and transactional sex, stigma and discrimination due to sexual violence, forced marriage, trafficking and sex work. In Southwest Asia, roughly one-in-three trafficked women were determined to be living with HIV when provided health services (43). Those trafficked into sex work have also shown to be high consumers of drugs and alcohol (44). Thus, for young women, the convergence of young age, sexual activity and drug or alcohol use presents a high-risk for HIV-infection and other social consequences (45).

2.2. Linking Young Adults, Substance Use/Substance Use Disorders and Prevalence of HIV Infection

Currently, there are roughly 1.6 billion young people 12 - 24 years of age and, thus, young adults represent roughly one-quarter of the global population (46, 47). With regard to HIV infection, young people aged 15 - 24 account for 42% of new HIV infections and roughly 4 million of these young adults are living with HIV live in sub-Saharan Africa (46). AIDS is the number one cause of death for young adults in Africa. Young women in sub-Saharan Africa account for 58% of the young adults living with HIV (47). Africa has one of the highest alcohol per capita consumption levels in young adults at 19.5 liters per person, as well as, emerging regional drug abuse epidemics with heroin abuse along the coast in Eastern Africa, stimulant use in Southern and Western Africa (48, 49). Local situations vary with a high variability of multiples substances including local brews and spirts “gongo” as well as cannabis ‘bhang” or other locally grown plants. Youths start using substances between the ages of 10 and 15 years and graduate to more potent substances as young adults (50).

In Central Asia and Eastern Europe, the HIV epidemic is driven by injection drug use and focused in key populations (51). Recent studies have shown that young adults who were homeless were most likely to be living with HIV and injecting illicit drugs (52, 53). Studies have shown that key populations who initiate drug use as young adults may have a 20-fold risk for HIV infection and less likely to seek HIV services (54). In Central Asia and Eastern Europe, there are an estimated 3.7 million people who inject drugs, nearly one-quarter of the global total (55).

In the United States, young adults are the only age group to experience a rise in new HIV infection with nearly 40% of new infections occurring between the ages of 13 - 29 (56). Men who have sex with men account for 72% of HIV infections in people under the age of 25. Also in the United States, there is a rapid onset of substance use disorders for young adults under the age of 20 with one-in-three young adults reporting lifetime alcohol use and 24% reporting illicit drug use- mostly marijuana or prescription drug abuse (57).

Elsewhere, in Asian countries, numerous studies have shown that for key populations the risk for HIV infection is substantial, but becomes even greater with alcohol or injection drug use (58-61). In South America, cocaine is the drug of choice. Studies have shown young adult crack cocaine users have health and economic marginalization, an elevated risk for HIV infection and compromised health along with poor health services utilization (62-64). In the Dominican Republic, a recent study has addressed alcohol use in young adults in the context of risk for HIV infection (65). This study notes that 18% of AIDS cases occur in young adults between the ages of 15 - 24, with 29% of young adults reporting sexual debut before the age of 15. These sexually active young adults are drug and alcohol experienced with one-in-three reporting binge drinking prior to the age of 12. Hazardous chronic alcohol use is common with 25% of girls and 35% of boys reporting heavy episodic drinking.

Thus from Europe, Asia, Africa and the Americas globally the link between substance use/substance use disorders and HIV infection in young adults is evident. The link is both bidirectional and multifaceted with multiple components. The bidirectional nature of the link is the sequential exposure to either the HIV virus or illicit drugs or alcohol. The common direction is initial exposure to illicit drugs and alcohol followed by exposure to the HIV virus through high-risk sexual encounters or high-risk injection drug practices. Alternatively, young adults who acquire HIV infection through vertical transmission can initiate illicit drug or alcohol use early in life in adolescence or as young adults. In addition, in a less common scenario, young adults could be exposed to both the HIV virus and illicit drugs or alcohol in utero during pregnancy by women living with HIV who are using /addicted to drugs or alcohol during the pregnancy. The components of the linkage between substance use/substance use disorders and HIV infection in young adults comprise social, economic, familial, educational, legal, and human rights issues. These issues describe the young adult subpopulations (see Table 1) with risk factors as noted above in the etiology of exposure to the HIV and illicit drugs and alcohol. Regardless of the timing of the exposure to illicit drugs and alcohol, young adults who have hazardous levels of consumption or who are dependent on illicit drugs or alcohol, need to seek medical care through comprehensive substance abuse treatment programs.

3.1. Comprehensive Substance Abuse Treatment Programs Targeting Young Adults to Impact Global Health

Young adults should routinely seek medical care from health care providers who are familiar with and have experience in providing primary care to individuals through their developmental stage in life. In seeking care and treatment for substance use/ substance use disorders in young adulthood, health care providers who are familiar with the stages of substance use progression and patterns of adolescent drug and alcohol use can provide evidence-based interventions to reduce hazardous levels of consumption, such as screening and brief interventions (66). Based on the level of abuse, an individual treatment plan should be developed as part of the assessment and intake process (67). If the young adult is not ready for treatment, then the healthcare provider should engage the young adult with motivational interviewing techniques with the goal of reducing consumption levels (68, 69). For young adults seeking or entering treatment, comprehensive treatment programs that provide services beyond treatment of the substance use disorder are effective evidence-based programs (70-72). These programs address the health needs of the young adults and through case management and other interventions, as well as, family issues and support, educational, legal/criminal justice and economic issues, including the stigma and discrimination associated with addiction. These programs also provide peer recovery support for the young adults as part of the reintegration effort with social change (73).

The effective treatment for substance use disorders for young adults is important since access and adherence to anti-retroviral medication regimens leads to a normal and productive life span. Substance use disorders interrupt normal life progression through biological changes in the immune system, increased poor nutrition and health, changes in socio-economic status, increased drug-related mortality, reduced access and uptake of medical care, as well as, poor adherence to medication regimens (74-77). Treatment of substance use disorders in young adults, in addition to relapse prevention interventions and recovery support services results in a reduction of young adults lost to follow-up in HIV care and treatment and a reduction in HIV transmission (78-80).

3.2. The Challenges of Linking Substance Abusing Young Adults to HIV Care and Treatment

Numerous studies have identified the substantial challenges in linking and retaining adults living with HIV to HIV care and treatment (81-83). These studies have identified patient, clinical and societal challenges that include: remote clinic locations, lack of transportation, fear of disclosing status, stigma, long clinic wait times, clinic staff shortages, fear of drug side effects, need to take time off from work and poverty. These challenges result in a cycling of adults in and out of care, particularly for men and young adults. Interventions to promote linkage though the clinical care cascade comprise health system interventions, such as integration of services; decentralization, task-shifting, use of technology; patient convenience and accessibility, such as point of care services, home based care and treatment, case management, use of first line medications; behavioral interventions and peer support, such as patient referral and education, patient navigators, improved communication; and incentives, such as food support or cash incentives (81, 83).

Focusing on substance abusing young adults, three additional challenges can be identified:(a) transitioning from adolescent care to adult care for those individuals who are living with HIV prior to reaching young adulthood and who were in care, (b) accessing HIV care and treatment from HIV testing with the dual comorbidities of AUDs and HIV infection and (c) out-of-care young adults disengaged from medical care. For all of these challenges, providing a young adult friendly venue that integrates comprehensive services for substance abuse and HIV care and treatment provides the optimal opportunity for engagement and retention in care with good clinical outcomes (84).

For transitioning youth into adult HIV care, optimal care includes a formal plan for the transition from pediatrics/adolescent/ family care to adult care, as well as, a formal written policy on transfer (85, 86). The plan should be individualized for each youth based on specific developmental milestones addressing cognitive development, mental health, medication adherence, sexuality, reproductive and gender issues, stigma and discrimination, peer support, socioeconomic status and payment for services. A recent study (87) pilot tested a formal transfer protocol to assist the transition to adult care. Using the “Movin Out” transitioning protocol approximately half the youth were able to transition to adult care. Reasons for not transitioning were relocation, attrition, lost to follow-up and transfer to another service. Interestingly, substance abusing youth were successful in transitioning to adult care using this protocol (87).

For substance abusing young adults diagnosed with HIV, accessing HIV care and treatment can be challenging. These individuals can face health system challenges, as well as, social and individual challenges (88, 89). These challenges include stigma, long waits for services, patient provider relationships, system navigation for health services and social services, and lack of family and peer support. Overcoming these barrier to HIV care are critical since patients in HIV treatment that also are retained in care report better treatment outcomes (89). Interventions that promote linkage to HIV care and treatment include utilizing care coordinators to promote linkage and utilization of care, providing information and education on HIV care, providing motivational counseling, utilizing care navigators, providing coordinated services with good patient provider communication along with social services (88-90).

For substance abusing young adults out of care the priority is to initiate the Test and Treat algorithm (91). Thus, in outreach efforts to these key populations, testing for HIV infection with concomitant initiation of care and treatment is paramount. Studies have shown community-based HIV testing with facilitated linkage to care and treatment resulted in access to care and initiation of anti-retroviral treatment (92). Home-based testing, mobile testing and self-testing were found to be accepted and facilitated access to care and entry into treatment for young adults (92, 93). Subsequent to the initiation of HIV care and treatment, young adults can be further stabilized with entry into comprehensive substance abuse treatment. Thus, interventions have been identified that address the challenges encountered by substance abusing young adults in accessing and receiving HIV care and treatment.