<prompt> Scarlet fever is caused byStreptococcus agalactieStreptococcus pyogenesStreptococcus pneumoniaeStreptococcus equisimilus  <response>: Ans. is b i.e., Streptococcus pyogenes Infections caused by streptococcus pvogenes Respiratory infections Sore throat is the most common of streptocococcal disease . It may be localised as tonsillitis as in older children and adults or it may involve the pharynx more diffusely pharyngitis as in younger children. Otitis media 