Answer the following question: Given the following context:  In 1898 and again in 1899 Norman Heathcote visited the islands and wrote a book about his experiences. During the 19th century, steamers had begun to visit Hirta, enabling the islanders to earn money from the sale of tweeds and birds' eggs but at the expense of their self-esteem as the tourists regarded them as curiosities. It is also clear that the St Kildans were not so naïve as they sometimes appeared. "For example, when they boarded a yacht they would pretend they thought all the polished brass was gold, and that the owner must be enormously wealthy". The boats brought other previously unknown diseases, especially tetanus infantum, which resulted in infant mortality rates as high as 80 percent during the late 19th century. The cnatan na gall or boat-cough, an illness that struck after the arrival of a ship off Hirta, became a regular feature of life.By the early 20th century, formal schooling had again become a feature of the islands, and in 1906 the church was extended to make a schoolhouse. The children all now learned English and their native Scottish Gaelic. Improved midwifery skills, denied to the island by John Mackay, reduced the problems of childhood tetanus. From the 1880s, trawlers fishing the north Atlantic made regular visits, bringing additional trade. Talk of an evacuation occurred in 1875 during MacKay's time as minister, but despite occasional food shortages and a flu epidemic in 1913, the population was stable at between 75 and 80, and no obvious sign existed that within a few years the millennia-old occupation of the island was to end.  answer the following question:  Where were infant mortality rates as high as 80 percent during the late 19th century?
Answer:
Hirta