<human>:  How did the Spanish Flu and Cholera spread?
<bot>: The Spanish flu spread by aerosols, and cholera spread by water. The Spanish flu was caused by the H1N1 virus, which is a type of influenza. The H1N1 virus is a type of influenza that can infect humans and other animals. In humans, the virus causes flu-like symptoms, such as fever, coughing, sore throat, muscle aches, fatigue, headache, chills, nausea, vomiting, diarrhea, and sometimes pneumonia. The Spanish flu is estimated to have killed between 50 and 100 million people worldwide.