Factors influencing serum antibody responses in streptococcal pyoderma

Factors influencing serum antibody responses to streptococcal pyoderma were analyzed as part of a prospective investigation of the epidemiology of this disease. Studies were carried out in a well-defined rural southern population among whom pyoderma is highly endemic. Seventy-five black children, ages 2 to 6, enrolled in Project Headstart centers in Holmes County, Miss., were observed during July, Aug., and Sept., 1970. Each child had weekly cultures of skin lesions (if present) and throat; serum samples were obtained at the beginning and end of the 13-week study. Fifty-eight (77 per cent) of the 75 students had bacteriologically confirmed streptococcal pyoderma at some time during the study period. None developed acute glomerulonephritis. Subjects with pyoderma experienced statistically significant rises in mean log titers of antihyaluronidase (AH) and antideoxyribonuclease B (ADNase B) but not of antistreptolysin O (ASO). Although both ADNase B and AH tests were useful, the former appeared to be the more sensitive of the two in reflecting streptococcal skin infection. The magnitude of the immune response to streptococcal pyoderma was influenced both by initial serum antibody level and by persistence of infection. Differences in the immunologic response to streptococcal infections of throat and skin have immediate implications for the diagnostic laboratory and may in the future shed light upon the pathogenesis of nonsuppurative streptococcal sequels.