Hello You mentioned that your son is taking DOLO 650 mg ( paracetamol ) 6 hourly and fever subsides whenever he takes dolo . Your son is also taking ceftriazone 1 gm twice in day from 15 days . Tested Widal positive and this cefteriazone is most potent and effective drug for typhoid fever . However there are so many side effects of dolo as liver damage , G I upset and very rare blood dyscrasias ( as after prolong use but in your son case already he took it for 15 day and this is prolong use). However , there are so many drugs for typhoid fever , but I prescribe my patient ciprofloxacin 500 mg twice in day for 14 days . Alternatively azithromycin 1 gm once in day for 5 day. But in my opinion please get in X RAY chest , blood for c b c , E S R ( if 100 mm 1st hour , consider about some chronic infectious disease including T B ). Also get in blood for Hepatitis A , B C E . In my opinion consult another physician and rule out any infectious disease. Good luck.