Infection, autoimmune disease linked to depression

Former Executive Editor, Harvard Health

Depression, bipolar disorder, and other mental health problems arise when something goes wrong with brain function. What causes that malfunction is an open question. A new study from Denmark suggests that a serious infection or autoimmune disease could trigger a mood disorder. How might an infection or autoimmune disorder lead to a mood or other mental health disorder? Infection causes localized and body-wide inflammation. Inflammation generates substances called cytokines that have been shown to change how brain cells communicate. In autoimmune diseases, the body’s defense system attacks healthy tissues rather than threatening invaders. It’s possible that in some cases the wayward immune reaction could target brain cells and other nerve cells throughout the body.

Tattoos and infection: Think before you ink

Former Executive Editor, Harvard Health

A report in this week’s Journal of the American Medical Association describes an outbreak of tattoo-related infections in four states: New York, Washington, Iowa, and Colorado. All involved Mycobacterium bacteria. Infection with these fast-growing bugs can cause problems ranging from a mild rash around the tattoo site to severe abscesses that require surgery and several months of antibiotic therapy. This isn’t the first such report. An outbreak in Ohio, Kentucky, and Vermont involved methicillin-resistant Staphylococcus aureus (sometimes known as MRSA), a hard-to-treat bug that can cause substantial damage to the skin and the rest of the body. Tattoo-related infections have three main sources: unsterile practices by the tattoo artist and his or shop, the ink used for tattooing, and poor after-care. Don’t hesitate to ask a tattoo artist directly what the shop’s sterilization processes are. And follow instructions afterward for caring for the tattoo.

Threat level high for West Nile infection

Howard LeWine, M.D.

Chief Medical Editor, Harvard Health Publishing

The United States is in the midst of the largest outbreak of West Nile virus since that virus was first discovered here in 1999. So far this year, more than 1,100 cases of human West Nile infection have been reported, about half of them in Texas, and at least 40 people have died from the virus. More cases are expected, since West Nile virus infections generally peak in late August and September. The virus is transmitted to humans by mosquitoes. Mosquitoes pick it up by feeding on birds carrying the virus. Very rarely, West Nile virus infection occurs due to transfusion of infected blood. It can’t spread from human to human by casual contact. None of the antiviral drugs currently available kill West Nile virus. And no vaccine is available. Prevention is best: stay inside when mosquitoes are most likely to bite, and use insect repellant when outside.