Thank you for your query.
Strep infection and pertussis
do not cause such muscle aches and pains so as to immobilize anyone. I suggest that you discuss the issue with the treating doctor and request for viral markers for chickenguniya infection. Chickenguniya is known to cause severe muscular pain
I hope I have answered your query to your satisfaction.
Wishing your son an early recovery.
Rajiv K Khandelwal