Complex sentence: Typhus was also common in prisons, where it was known as'Aryotitus fever' and often occurred when prisoners were frequently huddled together in dark, filthy rooms where lice spread easily.
Split into simpler sentences: Typhus was also common in prisons, where it was known as'Aryotitus fever.' It often occurred when prisoners were crowded together into dark, filthy rooms where lice spread easily.