Lassa Fever: An Old World Arenavirus A brief summary of lassa fever, its history, pathology and effects on the indigenous populations. Also, lassa fever in the context of newly emerging diseases. LASSA FEVER On January 12, 1969, a missionary nun, working in the small town of Lassa, Nigeria, began complaining of a backache. Thinking she had merely pulled a muscle, she ignored the pain and went on about her business. After a week, however, the nurse had a throat so sore and so filled with ulcers, she couldn't swallow. Thinking she was suffering from one of the many bacterial diseases end