Updated

A man is cured of AIDS. A salmonella outbreak is hard to pinpoint, and a stem cell breakthrough that could lead to cures for some of the most confounding illnesses are just a few of the top health stories and medical breakthroughs of the past year.

Click here to view the Top 10 stories of 2008 in a photo essay or scroll down and follow the links to the stories themselves.

In chronological order, the top stories are ...

1. April – August 2008: A Salmonella Outbreak Starts With Tomatoes and Ends With Peppers

Nothing dumbfounded government health agencies more than the widespread salmonella outbreak that began with an announcement on April 10, and ended on Aug. 29 with officials admitting that the true source of the outbreak may never be found.

Health officials initially believed the outbreak was due to tainted tomatoes, but months later traced it to jalapeño and serrano peppers. The outbreak sickened at least 1,440 people in 43 states. Texas was the hardest-hit state, accounting for nearly 40 percent of all confirmed cases.

The joint investigation by the CDC and Food and Drug Administration found strong evidence that jalapeño peppers were a major carrier of the outbreak bacteria, and that serrano peppers were also to blame. The salmonella strain was traced back to a jalapeno pepper at a produce distribution center in Texas that received peppers from Mexico. But FDA investigators struck out when they performed tests at the farm in Mexico where they believed the pepper had been grown.

2. June 23: First Non-Invasive Down Syndrome Test

Researchers in Hong Kong say they've developed an accurate blood test for Down syndrome. Using blood from the expectant mother, the test was found to diagnose 90 percent of Down syndrome cases in a small trial. It also correctly identified 97 percent of fetuses that did not have the condition.

If its accuracy can be improved and validated in larger patient trials, which scientists believe should take three to five years to complete, it would transform prenatal testing for the disease. Currently, Down syndrome testing requires the use of amniocentesis or chorionic villus sampling (CVS), which involves inserting a needle into the womb of a pregnant woman to remove amniotic fluid surrounding the fetus, or a small piece of the placenta. In addition to being invasive, the procedure may also cause a miscarriage.

3. June 24: Five-in-1 Vaccine for Children

The FDA approved a single vaccine (Pantacel) for active immunization against diphtheria, tetanus, pertussis, poliomyelitis, and Haemophilus influenzae type b. The vaccine combo means children get fewer shots and parents spend less money on vaccinations.

The Centers for Disease Control and Prevention recommend 23 vaccine injections for kids by the time they turn 2 years old. Using Pantacel would reduce the number of shots required by the age of 7 so children would need just 16 shots.

4. July 10: Measles Makes a Comeback Thanks to the measle, mumps and rubella vaccination, measles have been on the decline for several decades. But, in 2008, the disease made a resurgence infecting at least 127 people in 15 states. It was the biggest outbreak in the United States in more than 10 years, the CDC reported

Cases started springing up in May, when more than 70 people in a dozen states became ill. According to federal healthofficials, most of the patients were not vaccinated against the highly contagious virus.

5. July 29: World’s First Double Arm Tranplant A German farmer, who lost both arms in a farming accident, received the world's first complete double arm transplant. Doctors spent 15 hours on July 25-26 grafting the donor arms onto the body of 54-year-old Karl Merk.

At a news conference July 29, doctors said it could take up to two years before Merk learned to use his new hands.

6. and 7. August and November: Stem Cells Breakthroughs

Aug. 7: Harvard Scientists Create Stems Cells

The stem cells were created for 10 genetic disorders, which will allow researchers to watch the diseases develop in a lab dish and could speed up efforts to find treatments for some of the most perplexing diseases such as treatments for Parkinson's and Huntington's diseases and Down syndrome.

Nov. 19: Woman Receives Windpipe Transplant Grown From Stem Cells

Doctors created a new windpipe for a woman using tissue grown from her own stem cells —eliminating the need for anti-rejection drugs.

"This technique has great promise," said Dr. Eric Genden, who did a similar transplant in 2005 at Mount Sinai Hospital in New York.

The transplant was given to Claudia Castillo, a 30-year-old Colombian mother of two who suffered from tuberculosis for years. After her left lung collapsed, Castillo needed regular hospital visits to clear her airways and was unable to take care of her children. The operation used both donor and recipient tissue. Only a handful of windpipe, or trachea, transplants have ever been done.

8. Nov. 13: Bone Marrow Transplant May Have Cured AIDS Patient

The doctors of a man who suffered from AIDS said he's been cured of the disease 20 months after receiving a targeted bone marrow transplant normally used to fight leukemia.

While researchers — and the doctors themselves — caution that the case might be no more than a fluke, others say it may inspire a greater interest in gene therapy to fight the disease that claims 2 million lives each year. The virus has infected 33 million people worldwide.

Dr. Gero Huetter said his 42-year-old patient, an American living in Berlin who was not identified, had been infected with the AIDS virus for more than a decade. But 20 months after undergoing a transplant of genetically selected bone marrow, he no longer shows signs of carrying the virus.

9. December 2: China Says 6 Children Have Died and 300,000 Sickened by Tainted Milk

Milk powder fed to infants in China was found to be tainted with the industrial chemical melamine in September and ultimately killed six infants and left 300,000 sickened with symptoms that ranged from kidney stones to severe kidney damage.

The same chemical was later found in discounted baby formula and chocolate made in China and sold in the U.S. No U.S. illnesses were reported.

10. Dec. 16: Cleveland Clinic Announces It Completed the First U.S. Face Transplant

Reconstructive surgeon Dr. Maria Siemionow and a team of other specialists replaced 80 percent of a woman's face with that of a female cadaver a couple of weeks ago in a bold and controversial operation certain to stoke the debate over the ethics of such surgery. The woman, who was not named, was said to be so severely disfigured that she risked her life for the procedure.

Only the woman's upper eyelids, forehead, lower lip and chin were left. It is the first facial transplant known to have included bones, along with muscle, skin, blood vessels and nerves. The woman received a nose, most of the sinuses around the nose, the upper jaw and even some teeth.

The Associated Press contributed to this report.