My patient, a young boy of 12 years presented with cough, fever with chills since last 3 days. On history, there was rise in temperature with cold and chills especially during the night. The temperature raised every evening too. History says the boy visited Tirupati when there was Cyclone in Tamilnadu.

I have put him on symptomatic treatment. What could be the diagnosis? Please guide me for any further investigations to be done or if specific antibiotics are to be given. Please suggest.