The laboratory should be advised that the organism is suspected in order to process the sample correctly. Beta hemolysis on sheep blood agar is less intense than with GAS and may be overlooked in cultures with heavy growth of normal bacterial flora. The rash may be scarlitinaform but circumoral pallor is absent. Invasive infections including septicemia, brain and tonsillar abscess, meningitis, osteomyelitis and pneumonia have been reported. Skin infection with chronic ulceration, paronychia and wound infections also occur.
Humans are the only reservoirs of infection.
The incubation period is unknown. Erythromycin is the drug of choice but no prospective trials have been performed. The organism is also sensitive to clindmycin, azithromycin, ciprofloxacin and tetracycline in vitro. Environmental spread is generally from person to person. The organism occurs intracellularly which may account for failure of penicillin therapy.