252 ■ APPLIED BACTERIOLOGY 



SCARLET FEVER. 



A streptococcus described by Klein is probably the specific cause of 

 scarlet fever — Occurrence and distribution of the disease — Mortality 

 greatest in young children — Conveyance of the disease by milk — 

 Number of epidemics caused by mUk infection — Difficulty of 

 exercising sanitary control owing to the nature of the infective 

 material — Pathogenesis — Epidemics — Successful treatment of oases 

 with Marmorek's antistreptococcic serum. 



A large number of organisms have been described in 

 connection with scarlet fever by different observers, but the 

 organism discovered by Klein, and called by him the 

 Streptococcus scarlatince, would appear from the evidence 

 forthcoming to be the specific organism of the disease. 

 He found it in the desquamating particles of skin, in the 

 blood and the sputa of patients. It is non-motile, aerobic 

 or anaerobic ; does not form spores ; is killed by drying 

 and by exposure to sunlight in the presence of oxygen. 

 The organisms were isolated by smearing sloped gelatine 

 tubes with the infected blood. 



Occurrence and Distribution. — The disease is scattered 

 throughout Europe, but is more prevalent in the northern 

 portions, and rarer in Asia. Epidemics occur at intervals, 

 exhibiting a remarkably regular quinquennial recurrence. 

 In epidemics the mortality is generally low — namely, about 

 3'0 per cent. — but it has on some occasions risen to 30"0 

 per cent. The mortality is greatest in October and 

 November, and least in March, while almost the precise 

 reverse is experienced in New York. 



One attack is usually protective. The mortality is 

 greatest at the age of three, and above this age rapidly 

 diminishes. It is therefore wise to keep children as far 

 as possible from infection in their earlier years, as later 



