As a matter of fact it takes considerable time and laboratory skill to carry out reliable cultural and serological tests.
From a practical standpoint we can use the therapeutic polyvalent serum for agglutination and any organism recovered on the plate made from the faeces which agglutinates in 1 to 50 or 1 to 100 may be considered as diagnostic of bacillary as against amoebic dysentery. Often one does not see a case of dysentery until late in the disease and then, provided the condition is serious and the diagnosis points to a bacillary infection it would be better to inject the curative serum rather than await laboratory confirmation.
Prophylaxis and Treatment
Prophylaxis.—The ease with which water-closet seats may be contaminated should make us pay great attention to their disinfection during an outbreak of bacillary dysentery. The same applies to the bedclothes of such patients sent out for laundering.
Great care should be given to the washing of one’s hands prior to eating. The greatest care must be taken with rectal tubes when used for treatment. It is better to make an invariable rule to confine the use of a single tube to a single patient, as the rubber tubes are difficult to disinfect other than by boiling and such treatment, especially in the tropics, soon ruins the tube. For disinfecting tubes a 5% solution of liquor cresolis compositus is good. The tubes should be thoroughly washed of the disinfectant before using again. For disinfection of faeces one can use an equal portion of the above disinfectant to a similar amount of stool leaving the disinfectant to act on the stool at least one hour before emptying the receptacle. Soiled clothes should be disinfected in a 2½% solution of the compound cresol solution. Flies must be kept in mind and water and milk supplies boiled. The carrier is of as great importance here as in typhoid or cholera, especially when assisting in preparing food.
Vaccination.—Vaccination against dysentery does not seem to have made much headway owing to the very severe reactions following injections of killed cultures of the Shiga bacillus. By injecting such bacilli treated with an immune serum (sensitized) the reaction is less severe.
Dean reports the value of treating the emulsion of organisms with an equal amount of 1 to 1000 eusol. Gibson treated a suspension of dead organisms with an equal amount of serum, mixing in the syringe at the time of injection. Although this method was used during the war its immunizing value was not settled.
The question of the best method of preparing vaccines for prophylactic use is still unsettled. The greatest difficulty has been experienced in making vaccines of the Shiga bacillus on account of the great toxicity of such preparations.
The serum alone is used almost exclusively for curative rather than prophylactic purposes.