Complex sentence: Gastroenteric symptoms are often severe and include nausea, vomiting, diarrhea, and abdominal pain; cardiac arrhythmias may precede complete respiratory failure and cardiovascular collapse.
Split into simpler sentences: Gastroenteric symptoms are often severe and include nausea, vomiting, diarrhea, and abdominal pain. Cardiac arrhythmias may precede complete respiratory failure and cardiovascular collapse.