PARATYPHOID INFECTIONS 435 



Paratyphoid Fevers 1 



The name " para-colon " bacillus was given by Gilbert in 1895 

 to races of bacilli intermediate in type between the typhoid 

 bacillus and the colon bacillus, and this designation was also 

 applied by Widal and Nobecourt to a bacillus isolated by them 

 from an abscess in the neighbourhood of the thyroid. The name 

 " paratyphoid " bacillus appears first to have been used by 

 Archard and Bensaude in 1896, and was reintroduced by Schott* 

 m tiller in 1901. 



Paratyphoid fevers are diseases which clinically 

 simulate typhoid fever and are infections caused, not by 

 the typhoid bacillus, but chiefly by organisms belonging 

 to the Para typhoid- Gartner group of bacilli. While the 

 term is generally reserved for infections due to the para- 

 typhoid bacilli, if the definition be based on clinical 

 similarity there is no reason why other typhoid-like 

 infections due to organisms of the typhoid-colon group 

 should not be included under it ; these will be referred to 

 at the end of this section. The disease is generally milder 

 than typhoid fever, arid the mortality is only 1-4 per 

 cent. Some 3-6 per cent, of the cases notified as ' : typhoid 

 fever " are probably cases of paratyphoid infection. 

 Paratyphoid infections may occur in epidemics, may be 

 spread by drinking-water, by " carriers," and in other 

 ways, like typhoid fever, and occur in all parts of the 

 world. 



Paratyphoid fever (sensu stricto) is generally caused by 

 one of two paratyphoid bacilli, known respectively as 

 para A and para B, which are ve:y similar morphologi- 

 cally and culturally. Both these bacilli are morpho- 

 logically like the typhoid bacillus and are actively motile, 

 but they ferment glucose with the production both of 



1 See Torrens and Whittington, Brit. Med. Journ., 1915, vol. ii. 

 p. 697; Bainbridge and O'Brien, Journ. of Hygiene, vol. xi, 1911, p. 68 

 (Bibliog.). 



282 



