Abstract
The clinical value of the NBT test and of leucocyte counts in the aetiological differentiation of acute throat infections was investigated. In our hands a frequency of less than 13 % NBT positive neutrophils is considered as normal and a test value above 19% as “positive”, i.e. indicating a bacterial infection. More than 19% or more than 1800 NBT positive neutrophils per mm3 blood were found in 10 of 18 patients with an infection caused by beta-haemolytic streptococci, in 1 of 2 patients with a Mycoplasma pneumoniae infection and in 1 patient with both a streptococcal and mycoplasmal infection, but in none of 19 patients with a viral infection. Since 8 of 18 patients with streptococcal throat infection had normal NBT test results, the NBT test apparently is of limited value in the early recognition of these infections. A high NBT test value would however support the diagnosis. The white blood cell and neutrophil counts were of little value in the differentiation between streptococcal and viral throat infection.