Roberts found a bone marrow match in her sister, Sally-Ann. Twenty-one days after undergoing a bone marrow transplant, Roberts was discharged from the hospital in October.

"I know it is your prayers and warm thoughts that have gotten me this far," she wrote in a post on "GMA's" website to her fans. "Each day I get stronger and stronger ... (E)ven in some dark moment, of which there are still a few, I now see that light at the end of the tunnel. This too really shall pass."

6. Hantavirus at Yosemite

Warnings were sent to Yosemite National Park visitors from 39 other countries in September after a potentially deadly hantavirus sickened some visitors to the park.

In all, eight people were infected and three died. Most became ill after staying at the park's popular Curry Village "tent cabins."

The carriers of hantavirus are deer mice, cotton mice, rice rats and white-footed mice, according to the CDC. The virus can be present in the rodents' urine, droppings and saliva, and is spread to people when they breathe in air contaminated with the virus. The virus is not communicable from person to person.

7. Former Rep. Jesse Jackson Jr. and bipolar disorder

Jackson, a congressman from Illinois, look a leave of absence in June to be treated for what his office initially called a "mood disorder."

In August, the Mayo Clinic said he was responding well to treatment for bipolar II disorder. The disorder, less severe than bipolar I, includes periods of depression alternated with hypomania, a mild form of mania that may include elevated mood and irritability. The depression periods usually last longer, the clinic said.

Despite winning re-election, Jackson -- who has been the subject of several investigations -- resigned from office in November, citing health reasons. "For the past several months, as my health has deteriorated, my ability to serve the constituents of my district has continued to diminish," he wrote in his resignation letter.

8. Spike in autism cases

The number of children with autism nationwide continues to rise, the CDC announced in March. The agency released its most recent data from 2008, showing that 1 in 88 American children has some form of autism spectrum disorder -- a 78% increase compared to a decade ago.

Boys with autism outnumber girls 5 to 1, according to the CDC, which estimates in 54 boys have autism.

More children are being diagnoses with autism because of "better diagnosis, broader diagnosis, better awareness, and roughly 50% of 'we don't know,'" Mark Roithmayr of the advocacy group Autism Speaks said at the time.

9. Actress Kathy Bates' double mastectomy

Actress Kathy Bates underwent a double mastectomy in September after being diagnosed with breast cancer in July, a publicist said.

Bates, 64, was nominated for an Emmy for her lead role in the TV drama series "Harry's Law." She is best known for winning an Academy Award for Best Actress for the 1991 movie "Misery." She battled ovarian cancer eight years ago.

"I don't miss my breasts as much as I miss Harry's Law. ;-) Thanks for all the sweet tweets. Y'all kept me going," Bates tweeted after her surgery.

10. Ex-hospital worker accused in hepatitis C infections

A man who worked as a traveling medical technician on a contract basis for hospitals in Arizona, Georgia, Kansas, Maryland, Michigan, New York and Pennsylvania was arrested in July and accused of spreading hepatitis C, sickening more than 30 people.