The number of Americans diagnosed with chlamydia, gonorrhea or syphilis reached a record high in 2016 for the second year in a row, with more than 2 million cases reported, according to newly released federal data. Cases of these three sexually transmitted diseases have been increasing since 2014, reversing a downward trend that began in 2006. Health officials say the rates reflect decreasing condom usage, a lack of awareness about STDs among doctors and patients and a falling number of STD clinics. As the number of women with syphilis has jumped, so has the number of babies born with syphilis passed down from their mothers. There were 632 cases of congenital syphilis nationwide last year.

Pollution bad for kidneys

Add a new potential ill to the list of problems linked to air pollution: kidney disease. Previous studies have linked high levels of the fine particulate matter known as PM 2.5 to cardiovascular disease and stroke. A new analysis, in the Journal of the American Society of Nephrology, found that increases in PM 2.5 corresponded directly with decreases in glomerular filtration rate, or GFR, a measure of kidney function. PM 2.5 particles are small enough to enter the bloodstream, where they make their way to the kidneys. The scientists calculate that "unhealthy" pollution levels lead to an annual increase of 44,793 cases of chronic kidney disease, and 2,438 cases of end-stage kidney disease requiring dialysis.

60% of teens get HPV vaccine

More than half of all American teenagers are getting vaccinated against human papillomavirus, and the rate is rising over time, according to a new report from the Centers for Disease Control and Prevention. Sixty percent of adolescents received one or more doses of the HPV vaccine in 2016, an increase of 4 percentage points from 2015, researchers found. About a decade ago, the figure was less than 30 percent. The vaccine protects against strains of HPV that can cause cancers of the cervix, penis, anus and back of the throat. Nearly 32,000 people get cancer from the virus each year, and about 90 percent of those cases could be prevented with the vaccine, according to the CDC.