The Pan American Health Organization, part of the United Nations, has declared that measles, a highly contagious viral illness, has been eliminated in all of the countries of North, South and Central America, plus the Caribbean region.

The United States officially eliminated measles in 2000.

But that doesn't mean measles cases in the U.S. have vanished. It just means that, at least for now, measles cases originating in the Americas aren't expected. In 2015, there were 189 measles cases in the U.S., many tied to an outbreak that started at Disneyland. That outbreak was linked to a visitor from a country where measles are still problematic.

It's possible measles can make a comeback in the Americas or become endemic if vaccines rates for the disease drop too low. Health experts say countries should strive to have at least 95 percent of their population vaccinated to maintain overall protection.

Leave No Stone Unrolled

Kidney stones are small, hard deposits of mineral and acid salts that form in the kidneys. In most cases, they are passed through the urinary tract and out of the body without permanent damage, but the experience can be quite painful.

The usual prescription is lots of water and some pain medication, but a new study, published in the Journal of the American Osteopathic Association, suggests roller coasters might help. Researchers tucked a small, model kidney filled with stones in a backpack and took it on 20 rides on the Big Thunder Mountain Railroad roller coaster at Walt Disney World in Orlando, Florida. They found that each ride prompted the passage of between 4 and 24 stones.

The most effective rides — if not the most thrilling — were those at the back of the coaster, with a passage rate of 24 of 36.

Body of Knowledge

There's enough iron in your body to make a nail three inches long.

Get Me That, Stat!

The World Health Organization sets standards for air quality. In a new report, it estimates 92 percent of the world's population is living in regions where air quality is below healthful standards. Roughly 3 million people worldwide die each year due to causes linked to outdoor air pollution; nearly 90 percent of these deaths occur in low- and middle-income nations.

Counts

2.8: Number of cancer caregivers, in millions, in United States

32.9: Number of hours, on average, they spent providing care each week

62: Percentage of that time spent on daily living activities, such as bathing and feeding

Source: National Cancer Institute

Doc Talk

Acute gravity attack: the patient fell over

Phobia of the Week

Amychophobia: fear of scratches or being scratched

Never Say Diet

The world's speed-eating record for pickled whole beef tongue is 3 pounds, 3 ounces in 12 minutes, held by Dominic Cardo. It's not known if, after the contest, Cardo was able to hold his tongue.

Observation

"All who drink of this remedy recover in a short time, except those whom it does not help, who all die. Therefore, it is obvious that it fails only in incurable cases."

—Aelius Galenus (129AD-199AD) Better known as Galen ofPergamon, a Greek physician and surgeon in ancient Rome and one of the earliest medical researchers

Medical History

This week in 1984, Baby Fae became the first newborn recipient of a cross-species heart transplant when Leonard L. Bailey, a heart surgeon at Loma Linda University Medical Center in California transplanted a walnut-sized young baboon heart. Fae had been born prematurely 12 days earlier with hypoplastic left-heart syndrome, a lethal underdevelopment of the left side of the heart. Bailey suggested the experimental xenotransplant. Previous attempts with adults had provided less than four days of life at most, but Bailey thought the infant's underdeveloped immune system might be less likely to reject alien tissue and a new drug, cyclosporine, would help. Baby Fae lived 20 days before complications caused her death.

Sum body

8 Things That Can Happen to Your Skin During Pregnancy

1. Stretch marks (almost 90 percent of women experience them)

2. "Mask of pregnancy" are dark, splotchy spots that appear on face, usually forehead and cheeks.

3. "Pregnancy glow" is caused by hormones boosting blood circulation, causing the face to appear brighter. Also oilier, as glands shift into overdrive, which may make face shinier too

4. Acne

5. Varicose and "spider" veins, both due to increased blood circulation

6. Dry, itchy abdomen

7. Linea nigra, a dark line that runs from navel to public bone. It's always been there, but pregnancy darkens it, making it more noticeable

8. Freckling, darkening of moles and other pigmentation

Med School

Q: What percentage of your total oxygen consumption is used by your brain?

a) 3

b) 5

c) 10

d) 20

A: d) 20. The average adult human brain represents roughly 2 percent of body weight, but consumes 20 percent of oxygen inhaled.

Epitaphs

The Body of B. Franklin, printer

Like the Cover of an old Book

Its Contents torn out

And stripped of its Lettering & gilding

Lies here food for worms

For, it will as he believed appear once more

In a new and more elegant edition

Corrected and improved by the Author

— American founding father Benjamin Franklin (1706-

1790)