Pox, plague and pestilence

"More than 1.6 million convicts and immigrants travelled by sea to Australia in the 19th century. Some never arrived. They were victims of shipwreck or, more commonly, sickness. Most sickness and death at sea in the first half of the 19th century resulted from infectious diseases and deficiency disorders such as scurvy. Contributing factors were the severely restricted diet, poor sanitation and lack of personal hygiene on board ship. Living conditions were harsh by modern standards. Immigrants and convicts had to spend three or four months in the confined spaces of a small and uncomfortable sailing ship!"