As of Oct. 2, no additional cases have been confirmed, according to Collin County health officials. The possible exposure at a Frisco elementary school has been ruled out.
Typhoid fever is spread through contaminated food and water, according to the Centers for Disease Control and Prevention. It is not common in the United States, but it is in developing countries. About 300 people, most of them travelers, get typhoid fever in the United states each year, according to the CDC.
Symptoms include high fever, stomach pain, weakness, headache and loss of appetite. Travelers can protect themselves by getting a typhoid vaccine, only eating fully cooked food and drinking bottled or disinfected water.