People receiving mental health care are up to four times more likely to be infected with HIV than the general population, according to a new study published Feb. 13 in the American Journal of Public Health from researchers at the Perelman School of Medicine at the University of Pennsylvania and other institutions who tested over 1,000 patients in care in Philadelphia and Baltimore. Of that group, several new HIV cases were detected, suggesting that not all patients are getting tested in mental health care settings, despite recommendations to do so from the CDC and the Institute of Medicine.

The study is one of the largest studies to date to estimate HIV prevalence and risk factors among persons receiving treatment in mental health settings and included researchers from the Centers for Disease Control and Prevention (CDC), as well as the University of Maryland and Columbia University Medical Center.

“These findings paint a recent picture of HIV infection rates in the community, and reinforce how important it is to identify patients and get them into appropriate infectious disease care in a timely manner while being treated for mental illness,” said lead author Michael B. Blank, PhD, associate professor in Psychiatry at the Perelman School of Medicine. “With such a high-risk group, it’s imperative to be routinely testing patients to improve care and reduce transmissions to others. Historically, though, HIV testing is often not implemented in mental health care.”

For the study, researchers provided rapid HIV testing to 1,061 individuals (621 men and 436 women) seeking treatment for symptoms, including depression, psychosis, and substance abuse, at university-based inpatient psychiatry units, intensive case-management programs, and community mental health centers from January 2009 to August 2011. About 0.3 percent of the general population is HIV infected, and CDC estimates a much higher prevalence of 1.4 percent in Philadelphia and 1.3 percent in Baltimore, since both cities are HIV epicenters.

The research team found that 4.8 percent of the mental health patients receiving care (51 individuals) were infected with HIV, which is about four times the base rate in each city and about 16 times the base rate for the United States population. Thirteen of the 51 infected patients reported that they did not know they were HIV positive, which represents an important failure in our public health system since they were already receiving ongoing mental health care. These results suggest that even in areas in the U.S. where prevalence is lower those with mental illness may be at substantially higher risk and should be routinely tested.

Results of the study also showed that persons with more severe symptoms of mental illness were at higher risk for being HIV-infected. HIV prevalence was also higher among the groups most likely to be infected in the general population, including African American, gay or bisexual men, and those infected with Hepatitis C, which is often an indicator of past injection drug use.

Previous studies have found that people with serious mental illness are at an increased risk for being infected with HIV, but many were from the 1990s and early 2000s and produced wide variations in risk, most likely because of small sample sizes, differences in sampling frames, and inadequate adjustment for confounding effects of factors associated with the disease. What’s more, the demographics of the HIV epidemic have shifted in the past decade, and the degree to which HIV prevalence among persons with mental illness has changed remains unclear.

Both CDC and the Institute of Medicine recommend routine HIV screening be conducted in all clinical settings, including mental health settings, to increase identification of those infected and strengthen access to care. However, little progress has been made toward integrating HIV testing into mental health care, said Blank.

“There are barriers to testing, be it funding, system-level barriers or access to rapid HIV testing, that need to be addressed in order to have a wider adoption,” said Blank, who also serves as the co-director of the recently-established Penn Mental Health AIDS Research Center, alongside co-author David S. Metzger, PhD, director of the HIV/AIDS Prevention Research Division at Penn Medicine, and chair of Psychiatry Dwight L. Evans, MD.

“The results of this important study highlight the need for research into integrated treatments for people with complex, co-occurring conditions like HIV and mental illness,” said Dr. Evans.

The health care system’s approach to these patients may also play a role in the health disparities that are observed in them. Mental illness and HIV often times go hand in hand; however, today’s system is not fully equipped to treat these co-morbidities in tandem. In order to achieve optimal outcomes, patients would be better served with a more integrated approach, rather than today’s fragmented one.

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