In 1831 the colonial authorities built a quarantine hospital for immigrants on Grosse Isle, 30 miles downstream from Quebec. Disease was the immigrant's worst peril. The years in which Quebec received the greatest number of immigrants, were also plague years. In 1832, Asian cholera, which had spread to Britain from Central Europe, was brought by immigrants to Quebec where one person in 28, including the members of local population, died. In 1847 the famine Irish carried typhus and the disease frequently erupted in the filthy conditions between the decks. Before a ship reached Quebec, it was boarded by a medical officer, and if he found any fever-ridden passengers, everyone was put into quarantine at Grosse Isle. If an immigrant survived the crossing, there was a good chance he would contract the disease on Grosse Isle. Of the 89,738 immigrants who sailed to Quebec in 1847, 5,293 died in passage and almost 5,000 in quarantine.
