Adenosine deaminase activity in typhoid fever.

Serum adenosine deaminase (ADA) activity was determined in 41 patients of typhoid fever and 15 normal controls. The mean ADA activity was significantly raised in typhoid fever patients as compared to controls (p < 0.001). The peak enzymatic activity was observed in the first week of illness. Complicated patients had lower mean ADA activity at diagnosis as compared to uncomplicated group and they showed a rise in enzyme level during defervescence, repeated in a few cases. A significant correlation between serum ADA activity and lymphocyte percentage was found (r = 0.4245, p < 0.001). It is concluded that ADA activity in typhoid fever patients not only indicates immunity but also has a prognostic value.