Complex sentence: Trichinosis can be fatal depending on the severity of the infection; death can occur 4--6 weeks after the infection, and is usually caused by myocarditis, encephalitis, or pneumonia.
Split into simpler sentences: Trichinosis can be fatal depending on the severity of the infection; death can occur 4--6 weeks after the infection. Death is usually caused by myocarditis, encephalitis, or pneumonia.