MONDAY, Dec. 31 (HealthDay News) -- With millions of Americans watching and waiting, the U.S. Supreme Court largely upheld the Obama Administration's health care reform legislation, making the survival of "Obamacare" this year's top health news story.

President Barack Obama's election to a second term also solidified the 2010 Affordable Care Act as a fact in American life, with new Congressional moves against the package now deemed unlikely.

But it was the Supreme Court's 5-to-4 decision in June that "cleared the way for implementation [of reform] to proceed," Karen Pollitz, a senior fellow with the Kaiser Family Foundation in Washington, D.C., told HealthDayat the time. The U.S. Congressional Budget Office estimates that the rolls of the uninsured will decline by up to 33 million people by 2016 -- about a 50 percent reduction -- thanks to the legislation.

Perhaps the biggest surprise to legal scholars was that the controversial "individual mandate" -- which requires adults to purchase health insurance or face a penalty -- was upheld by the court, which found it to be a tax. The mandate is now poised to go into effect in 2014, along with other key provisions.

Still, it's not all clear sailing for the Affordable Care Act: As of mid-December, half of the states in the nation had said "no" to the creation of state-based health insurance exchanges, forcing the federal government to implement these key elements of health care reform.

Other health news grabbed headlines in 2012. Perhaps the most disturbing: An outbreak of deadly fungal meningitis linked to tainted steroid injections that began in the summer and by Dec. 17 had sickened 620 and killed 39 people across 19 states.

The steroid shots -- aimed at helping patients with back pain -- were distributed by the New England Compounding Center, a Massachusetts-based "compounding pharmacy."

The scandal focused national attention on these types of pharmacies, largely unregulated firms that combine, mix or alter ingredients to create drugs to meet the specific needs of individual patients. On Dec. 20, health officials from 50 states met with U.S. Food and Drug Administration representatives to discuss proposed regulation to help prevent such a tragedy from happening again.

In cancer news, perhaps the biggest headline was the decision by experts from the U.S. Preventive Services Task Force against the routine use of the prostate-specific antigen (PSA) blood test for prostate cancer. Long the standard of cancer diagnosis, numerous studies had suggested that the test might actually do more harm than good, spotting too many slow-growing cancers that would never cause harm, and thereby pushing men toward needless worry and treatment.

"I am hoping this [recommendation] shuts down mass screenings, where men are only told that this will help them, which is stretching the truth," Dr. Otis Brawley, chief medical officer at the American Cancer Society, told HealthDaywhen the decision was announced in May.

The year also saw sobering news on the ongoing U.S. obesity epidemic and its link to diabetes. In August, the U.S. Centers for Disease Control and Prevention reported that in 12 states nearly one-third of adults are now obese, bolstering a government-appointed panel's recommendation in June that doctors now routinely screen all adults for obesity.

Americans' widening waistlines could have a devastating impact on public health. One report released by the CDC in November found that rates of obesity-linked type 2 diabetes doubledin 18 states between 1995 and 2010, while in 42 states the rate jumped by at least 50 percent. And in six states and Puerto Rico, one in every 10 adults now has diabetes. "The diabetic epidemic has gone hand-in-hand with the increases in obesity," lead researcher Linda Geiss, a CDC statistician, told HealthDayat the time.

The situation for children may be just as dire: Another CDC report released in November predicted that the rate of type 2 diabetes among American kids could quadruple by 2050.

Among other top health news for 2012:

• A major West Nile virus outbreak. One of the most severe outbreaks of mosquito-borne West Nile virus ever to hit the United States centered on Texas, which was home to a full third of cases. Final 2012 figures from the CDC, posted on Dec. 11, estimated a total of nearly 5,400 cases, including 243 deaths.
• Mixed results on multivitamins' effectiveness.Is the multivitamin that millions of Americans take each day actually helping them? If cancer prevention is the aim, there was (modestly) encouraging news -- an 8 percent decline in cancer deaths for users versus nonusers. But the same team of American researchers found no such effect when it came to cardiovascular health.
• Psychiatrists' diagnostic "Bible" gets revised.For the first time since 1994, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disordersgot a major overhaul. Among the most noteworthy (and controversial) moves: Asperger's syndrome, which formerly had its own designation, is now folded within "autism spectrum disorders"; a new entry for "disruptive mood dysregulation disorder" in kids, which critics say "medicalizes" temper tantrums; and "hypersexual disorder" (known to the lay public as sex addiction) was notadded to the DSM-V.
• Autism incidence keeps rising.There was more bad news on the autism front: In March, the CDC estimated the prevalence of the disorder at one in every 88 children, up from one in 110 in 2010. Cases were also five times more common in boys than girls, the agency found. While changes in how autism is spotted and reported may have played a role in the new tally, the other factors behind the surge remain unclear, experts said.
• More good news regarding HIV/AIDS.This year saw two major milestones in HIV care. In July, the FDA approved OraQuick, the first at-home HIV test, which enables people to privately assess their infection status within 20 minutes. The same month the FDA gave the nod to Truvada, the first pill aimed at preventing HIV transmission to uninfected, high-risk people.
• Two new diet drugs gain approval. The first new weight-loss drugs to hit U.S. drug stores in 13 years were approved by the FDA in 2012. In June, Belviq was approved for obese adults with high blood pressure, and the diet drug Qsymia was approved for those with a similar patient profile a month later.