People who are temporarily or consistently homeless are at increased risk for infectious diseases, including hepatitis B and hepatitis C, because of poor living conditions, poor access to health care, high prevalence of drug use, sexual contact with multiple partners, and sharing of personal-hygiene equipment, such as razors (Badiaga et al., 2008; Boyce et al., 2009). The prevalence of HIV, HBV, and HCV among drug-involved street sex workers in Miami, Florida, was 22.4%, 53.4%, and 29.7%, respectively; and 42% of participants were homeless (Inciardi et al., 2006). Homeless adolescents and runaways are at particular risk because they are less likely than their peers to be vaccinated for HBV and to have access to health care and are more likely to engage in risky behaviors, such as drug use and sex work (Sneller et al., 2008).
The current literature suggests that public-health programs for the homeless should address issues related to unsafe sex, drug abuse, homelessness, and other lifestyle factors that contribute to adverse health outcomes. Reaching that population is difficult, and appropriate street-based and shelter-based interventions are potentially effective in doing so. Collaboration among providers of services to the homeless will be needed to provide counseling, education, testing, and such interventions as condom distribution, syringe-access programs, and vaccination against HBV (Badiaga et al., 2008; Boyce et al., 2009; Inciardi et al., 2006; Rosenheck et al., 2003; Roy et al., 2007; Sneller et al., 2008). All homeless persons should be offered the hepatitis B vaccine. A study of vaccination of homeless adults found that reducing HBV-related disease through vaccinations in this population is cost-effective and is associated with substantial improvements in quality of life (Greengold et al., 2009).
Community-based mobile services, such as the use of mobile health vans, can mitigate some access issues. Programs that use mobile health-care vans have been successful in providing HIV prevention and testing services to at-risk people who might not seek health-care services in other settings. Street outreach programs have been successful in reaching marginalized populations in HIV/AIDS prevention programs (Valentine and Wright-De Aguero, 1996). Kahn et al. (2003) found that mobile vans are a feasible approach to community-based STD screening and treatment, are accepted by the community, and are capable of identifying people who have STDs. A study of polysubstance abuse and HIV/STD risk behaviors in men who have sex with men used a mobile van as the service access point and found that polysubstance users had high rates of uninsurance (21%) and that 96%