56 Typhoid Fever 



36 showed the reaction during the second week ; 45 between the seven- 

 teenth and twenty-first days of the disease; 8 not until the twenty- 

 fifth day; and 2 as late as the twenty-eighth day of the illness.* 



In addition to the 230 cases considered above, in which the clinical 

 symptoms and course were typical, the presence of the Widal reaction 

 was noted in 10 atypical cases, and lacking in the characteristic fea- 

 tures of typhoid fever. 



Delepine f found that during the first week the reaction was often 

 slow and not clear, and that to establish an assured diagnosis re-exam- 

 ination was often necessary. 



In Osier's wards in the Johns Hopkins Hospital, Block and Gwyn, 

 up to November, 1898, showed that in 151 cases the reaction was 

 present in 144. "In 4 of the negative cases the clinical course was 

 not certain. In only 46 of the last 108 cases was the reaction obtained ; 

 in only 26 cases was the reaction present before the seventh day of 

 the disease"; in 4 cases it developed on the twenty-second, twenty- 

 sixth, thirty-fifth, and forty-second days respectively. 



In rare cases the reaction may be absent. There are also cases 

 in which the reaction is missed during the primary attack, or until 

 the period of convalescence (Achard, Blumenthal), and, in still others, 

 in which it first makes its appearance in the relapse (Biggs, Park, 

 Stahl, Bell, et a/.). 



Stengel and Kneass J collected and tabulated 2392 cases of typhoid 

 in which the reaction was positive in 2283 and negative in 109; also 

 1387 non-typhoid cases, of which 22 reacted positively and 1365 nega- 

 tively. The results in these cases show 



Reactions in typhoid cases 95.5 per cent. 



No reactions in non-typhoid cases 98.4 " 



Correct results in 96.5 



Incorrect results in 3.5 " 



This table indicates a small proportion of negative results and 

 accentuates the value of the method for diagnosis. 



Our present knowledge of the paratyphoid bacillus and its ability 

 to occasion disease resembling clinical typhoid fever enables us to 

 explain these irregularities as probable infections by bacilli other 

 than the true typhoid organism. 



The reaction is not permanent. The agglutinating property of 

 the blood usually begins to diminish in the first weeks of convalescence, 

 and marked reduction in its activity is noticed in a few months. Few 

 cases continue to show it longer than one year. Widal and Sicard 

 found that it may disappear as early as the eighteenth day after con- 

 valescence. 



In a series of 30 cases that I studied some years ago, the attack 

 of typhoid fever having taken place from one month to twenty years 

 previously, I found the reaction positive in most cases up to the 

 eighth year, doubtful at the ninth year, and absent in all cases after 

 the ninth year. Musser and Swan || observed a case in which the re- 

 action remained positive for ten years. 



* These results may be misleading, as they might seem to indicate 

 that the blood of these cases was tested every day and the reaction 

 first noted on the day given. In reality the blood was sometimes not 

 examined until the day mentioned. 



f Allbutt's "System of Medicine," vol. in, p. 1147. 



J "Amer. Year-book of Med. and Surg." for 1898. 



" Compte-rendu de la Soc. de Biol.," Dec. 19, 1896, No. 33. 



|| "Jour. Amer. Med. Assoc.," Aug. 14, 1897. 



