Serum folate in viral and mycoplasmal infections.

The concentration of serum folate in 260 patients with viral and mycoplasmal infections was determined (305 samples). In 60% the serum folate concentrations were found to be below 3 micrograms/l. The incidence of low serum folate varied slightly. According to the infections diagnosed, low values were: for influenza A 50% (50 patients), influenza B 42% (45 patients), human parvovirus 67% (76 patients), rubella 62% (13 patients), infectious mononucleosis 60% (15 patients), Mycoplasma pneumoniae 73% (45 patients). For a group of undiagnosed rashes it was 81% (16 patients). The cause of low concentrations of serum folate in these patients is discussed.