536 million: the number of people ages 15 to 49 worldwide-315 million women and 221 million men-estimated in 2003 to have herpes simplex virus type 2 infection, which causes genital herpes, as reported in the October 2008 issue of the Bulletin of the World Health Organization.

23.6 million: the number of people in the United States who have diabetes, as estimated by the American Diabetes Association. Nearly one-quarter are unaware they have it.

2.7 million: the estimated number of Americans with a history of epilepsy who have had a seizure or used antiepileptic medicine within the last five years, according to the Epilepsy Foundation.

26.1%: the percentage of all "poor" children ages two through five who had untreated dental cavities in 2001 to 2004, according to Centers for Disease Control and Prevention data. Among poor Mexican American two-to-five-year-olds, the rate was 35%.

1 in 99: the incarceration rate for U.S. adults in 2007, according to a report from the Pew Charitable Trusts' Center on the States. Most prisoners are men from racial or ethnic minority groups. Hepatitis C and the aging of the prison population in particular are increasing the health care costs associated with incarceration.

7: the number of months Hawaii's state-funded universal health care coverage for low-income children lasted. The plan covered 2,000 children for about $25.50 each per month, reported the Associated Press. But parents who had private insurance coverage for their children dropped it to take advantage of the state plan.

0: the number of fines issued as a result of the more than 38,000 complaints of violations of the Health Insurance Portability and Accountability Act (HIPAA) since the privacy rule was enacted in 2003, according to an analysis by the Des Moines Register published on August 17, 2008.