850 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



percentage diminishes from then on, the number of positive findings 

 in the faeces, on tLj other hand, runs in the opposite direction. 



Generally speaking, one attack confers immunity. Upon what 

 antibodies immunity and recovery depend is a matter of controversy. 



The elimination of the bacilli from the body will largely depend upon 

 the stage of the disease, since the blood, especially early in the illness, 

 practically always contains the specific organism; epistaxis is not an 

 unimportant feature as a possible means of disseminating the germs. 

 The bacilli can also escape in the faeces, urine, sputum, and vomit. 



In the control of this disease the best place to begin is at the bedside. 

 Disinfection of all excreta and of everything which comes into con- 

 tact with the patient should be rigorously carried out and in the case of 

 the faeces and urine should ideally be continued until examination can 

 be made showing absence of the organism. It has been estimated that 

 as high as 5 per cent of convalescents continue to excrete living typhoid 

 bacilli for varying periods from months to years after the disease; the 

 longest time noted has been forty-six years. 



The recognition of typhoid carriers will depend absolutely on the 

 finding of the specific germ in the faeces or urine as the case may be. 

 Where there are large numbers of suspects, the opsonic index is claimed 

 to be an aid in exclusion of the improbable ones, as well as the agglutinin 

 reaction. 



In a general way, prompt recognition of the source of infection such 

 as milk, polluted water, bacilli-carriers, etc., together with instruction 

 of the individual and the public are often effective in limiting and end- 

 ing an epidemic. 



While a great many sera have been used therapeutically with some 

 success, prophylaxis promises more where it can be widely employed as 

 in armies and navies. The artificial immunity is brought about by in- 

 jection of dead cultures. A difference of about 25 per cent has been 

 noted between the percentage of cases in vaccinated and unvaccinated 

 persons in civil life. 



In the United States Army, the establishment of compulsory anti- 

 typhoid inoculation demonstrated most remarkably favorable results 

 during the year 1913. Amongst 90,646 men, both American and native 

 troops, only three cases of typhoid fever occurred and two of these were 

 infected before enlistment; there were no deaths. When comparison was 

 made with the best results obtained in the army from sanitary measures 



