This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'A patient has arthralgia, a rash, lymphadenopathy, pneumonia but no fever. Which of the following diseases is most likely based on these symptoms? \nSelect and explain. \nA. Dengue fever, B. St. Louis encephalitis, C. Infectious mononucleosis, D. Hepatitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dengue (breakbone fever) is caused by a group B togavirus that is transmitted by mosquitoes. The clinical syndrome usually consists of a mild systemic disease characterized by severe joint and muscle pain, headache, fever, lymphadenopathy, and a maculopapular rash. Hemorrhagic dengue, a more severe syndrome, may be prominent during some epidemics; shock and occasionally death result.', 'role': 'assistant'}]