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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Most virulent dengue fever strain is -
assistant
The correct answer is  4 types of dengue virus exist. DEN1,DEN2,DEN3,DEN4,in which 2 is more virulent REF:ANANTHAN ARIYANAM of your TEXT BOOK OF MICROBIOLOGY 9EDITION PGNO.523