while the disease is usually caused by a bite, it can also occur from close contact with rodents or ingestion of contaminated food or water. the latter is known as haverhill fever. the disease typically presents with chills and fever accompanied by headache, vomiting, and muscle pain. a rash and arthritis develop 2–4 days after the initial onset. less commonly the infection can cause pneumonitis, endocarditis or meningitis. as these symptoms are common to many febrile diseases, this is often classified as a fever of unknown origin (fuo). if untreated, death will occur in approximately 10% of cases.