Tuberculosis infected the author's sister and their school. It is a serious disease that kills over 2 million people per year. Left untreated, each infected person can spread it to 10-15 others through the air. However, tuberculosis can be easily detected through skin tests or x-rays and cured with 9 months of proper medication treatment to stop its spread. The author urges people to get tested if exposed and complete treatment if infected to help eliminate this preventable disease.