numbers, maintaining a group that is highly vulnerable to physical ailment. North America's primary risk factors for illness are currently excessive alcohol use, malnutrition, obesity, tobacco use, and water sanitation. Obesity is a recent epidemic in North America. The 1990s brought a rise in the average Body Mass Index, or BMI. From the beginning and to the end of the decade, the median percent of adults who were obese rose from 12% to 20%. Alcoholism is the addiction of over-consumption of alcohol and is highly prevalent in the US. There are high incidence rates in many other world regions. Roughly 61% of American adults drank in 2007, and 21% of current drinkers consumed five or more drinks at one point in the last year. There have also been 22,073 alcohol induced deaths in the United States in the past year, about 13,000 of which were related to liver disease. Alcoholism has many risk factors ingrained in North American culture, such as heredity, stress from competition or availability. The Swine Flu (also known as H1N1) epidemic is a recent disease emerging in the early 21st century. In April 2009, during the early days of the outbreak, a molecular biologist named Dr. Henry Miller wrote in the Wall Street Journal about New York City high-school students. These students apparently brought the virus back from Mexico and infected their classmates. All six cases so far reported in Canada were connected directly or indirectly with travel to Mexico as well. Flu viruses can be directly transmitted (via droplets from sneezing or coughing) from pigs to people, and vice versa. These cross-species infections occur most commonly when people are close to large numbers of pigs, such as in barns, livestock exhibits at fairs, and slaughterhouses. The flu is transmissible from human to human, either directly or via contaminated surfaces." South America There are many diseases that affect South America, but two major conditions are malaria and Hepatitis D. Malaria affects every country in South America except Uruguay, Chile, and The Falkland Islands. Elevation is a major factor in the areas where malaria is found. The disease is spread from person to person via mosquito bites. People are typically bitten by mosquitoes at dusk and dawn. Symptoms of this disorder are: high fever, chills, sweating, headaches, body aches, weakness, vomiting and diarrhea. If left untreated, new symptoms can occur; people that are infected may experience seizures,