Most investigations on infectious diseases or chemotherapy have been reported by teaching hospitals, such as university hospital, but the first step of treatment of infectious deseases occurs in outpatients clinics in general practice settings or small hospitals. Such institutions treat many newly diagnosed infectious desease patients, and their situations may be valuable for the investigators. I have investigated infections diseases and chemotherapy through clinical experience working at a community hospital from 1975 to 1994 and began making diagnose in 1995 as a general ENT practitioner. In 1979 I reported that major causative pathogens of pediatric acute otitis media were Streptococcus pneumoniae and Haemophilus in fluenzae, not Staphylococcus aureus. In 1988, I encountered the first case of acute otitis media caused by PISP and I discussed the clinical significance of PISP infections with co-investigators. Since 1998, we have been reporting that infectious disease caused by PISP have spread to adults without underlying diseases, mainly to young mothers in their 30 s, and their children are being diagnosed with otitis media & sinusitis caused by PISP as a result of intrafamilial cross contamination. In comparison with 2000 and 2002 susceptibility of Streptococcus pyogenes erythromycin and azithromycin has decreased, with MIC90 valves increasing from 0.1μg/mL to 6.25μg/mL. I have some doubts about the administration of fl uoroquinolones to patients with tonsillitis caused by S. pyogenes. Penicillins should be the first line treatment.