The indirect haemagglutination test in dysentery caused by Shigella sonnei and Shigella flexneri.

The examination of cultures of stools is mostly used in establishing the diagnosis of bacillary dysentery. Agglutination, the most frequently used serological investigation, does not give reliable results and is therefore not generally used. The bacteriological examination of stools fails in a certain percentage of cases, irrespective of the mode of culture used. Particularly troublesome are examinations of stools in patients treated with antibiotics, for then the stools are usually negative. Patients with negative culture results are admitted to hospital and discharged with a vague diagnosis of gastro-enteritis or entero-colitis. This fact, however, can be very important epidemiologically, especially in children living in collective groups or persons employed in handling food. Recent work, especially that of Neter and Walker (1954), Neter, Westphal, Luderitz, and Gorzynski (1956a), and Neter, Gorzynski, Gino, Westphal, and Luderitz (1956b), demonstrated the value of the haemagglutination technique in the diagnosis of enteric infections, so it was decided to use this method in the investigation of bacillary dysentery.