Antistreptolysin O and antideoxyribonuclease B titres in blood donors and in patients with features of nonsuppurative sequelae of group A streptococcus infection in Tanzania.

Antistreptolysin O (ASO) and antideoxyribonuclease B (ADN B) titres were determined on sera from blood donors in Dar es Salaam, Tanzania and from Bergen, Norway and were compared with titres in patients with features of postgroup A streptococcal diseases in Dar es Salaam. The upper limit of normal ASO titres in Dar es Salaam was 200 mu/ml and for ADN B it was 300 u/ml while in Bergen the upper limit of normal ASO titre was 250 u/ml and that of ADN B was 100 u/ml. Titres of ASO in Dar es Salaam and Bergen were consistent with those from sub-Saharan Africa and from other continents. Upper limit of normal ADN B titres in adults in Dar es Salaam were higher than those in Bergen probably due to higher frequencies of group A streptococcal skin infections in Dar es Salaam than in Bergen. Patients with features of postgroup A streptococcal diseases in Dar es Salaam had antibody titres above the upper limits of normal in 32.8% of the patients for ASO and in 45.9% for ADN B. ASO and ADN B titres or ASO and any other reliable test for antibody to group A streptococcus should be utilised together in providing strong evidence of recent infection with the group A streptococcus or of postgroup A streptococcal disease.