Why Is HIV/AIDS a Surprising Killer Among Seniors?

National HIV/AIDS Day and Aging Awareness Day fall on the same date — and for good reason. According to the Centers for Disease Control and Prevention, HIV/AIDS diagnoses are surprisingly common among seniors, and older adults with the illness face a special set of challenges.

Related: 18 Myths About Seniors and Sex

Many seniors consider themselves to be low-risk for contracting HIV/AIDS, but the CDC says 327,00 Americans ages 50 and older were living with diagnosed HIV at the end of 2016. That's a full 45 percent of all cases in the United States. Risk factors do not decrease with age, and although the disease was long associated with high mortality, the population of Americans living with HIV/AIDS is graying.

Increasing divorce rates, changes in sexual attitudes, and the introduction of drugs such as Viagra have made older Americans more likely to remain sexually active longer than in previous generations. Since they are not concerned with the risk of pregnancy, seniors may also be less likely to use condoms, which are critical in preventing sexual transmission of the disease, the National Institute on Aging notes.

Many older Americans suffer from ailments that produce symptoms similar to those associated with HIV/AIDS. Health care providers are less likely to test older patients for HIV, and elderly patients and their caregivers often mistake common symptoms with the aches, pains, weight loss, and fatigue of normal aging, the CDC says. AIDS-related dementia can be misdiagnosed as Alzheimer's or Parkinson's.

Older Americans tend to visit doctors more frequently, but are less likely to discuss their sex lives or drug use with them, the CDC says. As a result, seniors may be less informed about the illness and its causes and more concerned with social stigma surrounding the illness, especially if they already feel lonely or isolated.

HIV/AIDS disproportionately affects gay and bisexual men in the larger patient population, and that doesn't change with age. HIV/AIDS diagnoses among people 50 and older remained stable in the United States between 2012 and 2016. But for people 50 and older, male-to-male sexual contact was the transmission category for 67 percent of all new diagnoses.

The effectiveness of the immune system, which HIV/AIDS attacks, declines with age. Therefore, antiretroviral treatments may not enable immune systems to recover as quickly or as thoroughly as they do in younger patients who get the same medication, the U.S. Department of Health and Human Services says.

HIV/AIDS also makes it more likely the patient will develop other serious ailments later in life, according to Aging in Stride. Both the virus itself and the powerful cocktails of medication used to treat it can increase the likelihood of developing some types of cancer, kidney disease, heart disease, or dementia. It can also worsen existing conditions such as hypertension, diabetes, osteoporosis, and arthritis.

Since HIV/AIDS often goes unnoticed, older Americans are far more likely than younger people to be diagnosed only when the illness has already entered its late stages. In those cases, patients miss out on crucial treatment time and suffer more immune system damage. Forty percent of Americans diagnosed at age 50 or older get a late-stage diagnosis.

It's important for seniors with prescriptions for common age-related ailments to take special care with managing HIV/AIDS symptoms. Government health agencies remind that antiretroviral treatments can trigger unintended, sometimes dangerous reactions with other drugs.

Because they didn't know they were infected, didn't have the means, or simply didn't expect to live long enough to have to worry about it, many patients did not plan for financially managing HIV/AIDS in retirement after being diagnosed. But there are special rules and benefits in the Social Security, Medicare, and Medicaid programs that apply specifically to people aging with HIV/AIDS.

It's true that thousands of older Americans contract HIV every year, but the increasing number of senior cases largely comes from good news: Starting in the 1990s, major advancements in treatment have allowed many patients to reach old age, which otherwise would not have been possible.