Efficacy of nalidixic acid in the treatment of acute bloody diarrhea.

Of sixty four children (mean age 20.1 +/- 1.2 mo) with acute bloody diarrhea and high fever, 47 had infection with non-typhoidal Salmonella (NTS) (20), Shigella (15) and enteropathogenic E. coli (EPEC) (12) and were treated with nalidixic acid (NA). The mean duration (h) of presence of macroscopic blood in the stool following institution of treatment was significantly shorter (p less than 0.05) in those with EPEC (11.5 +/- 4.9) as compared to NTS (30.4 +/- 15.4) or Shigella groups (22.9 +/- 15.6). The number of children having less than or equal to 50% reduction in stool frequency within 72 h was: NTS (17); Shigella (14); EPEC (10). Negative stool cultures on day 5 were obtained in all patients with Shigella and EPEC and 16 (80%) of those with NTS. Two patients with NTS and one with EPEC failed to respond to NA.