RtANSMISSION "i Dl 



Transmission. Whatever tin- organi-m may be, tin- f;i(t i-, now 

 established tli;it typhus i it led by human licC, Niiollr. ( 



;ind Conseil. working in northern Africa conveyed tin- d 



by the injection Of lmm;m l)lood to a < hinipan/.rr ; thru from the 

 chimpan/ce to a maca<|iie nionkry; ami. by mran> ol" liuinan body lit C, 

 from this animal to other monkeys. I)rs. I\i< k< 1 Wilder 



prrt'ormetl similar exj)erimrnts in Mexico City (1910) with similar 

 results. They found that monkeys kept free from Ike r< -n. 

 healthy, hut contracted t he disease after inoculation hy means of body 

 lire which had fed on t he blood of typhus pat ient s. They showed also 

 the strong probability that infection is transmitted through the eggs 

 to the next generation of lice, which through this indirect infection can 

 cause typhus in monkeys and presumably in man also. It has been 

 found that both the body louse (Pediculus corporis) and the head louse 

 ( I\ (-a pills) transmit typhus, but bedbugs and fleas are not implicated. 

 The brilliant work of Dr. H. T. Ricketts was cut short by his death, 

 in K)io, from typhus contracted during his experiments. 



Control. A typhus patient is harmless as a source of contagion in 

 the absence of human lice, the agents of transmission. Lice, as is well 

 known, crawl readily from man. to man in crowded quarters, and inhabit 

 the clothing as well as the body, particularly the underclothing, the 

 seams of which may contain the eggs in immense numbers. Eradica- 

 tion of lousiness means freedom from typhus. During the World W r ar, 

 Great Britain, France and Germany were successful in protecting their 

 armies from the ravages of typhus by the use of methods, often elabo- 

 rate, directed against the lice, or "cooties." These methods, which 

 are generally known, consisted of (i) the thorough cleansing of the 

 surface of the human body; (2) the disinfection of clothing and other 

 belongings, and of the living quarters, by various physical or chemical 

 processes. 



RELAPSING FEVER 



Relapsing or recurrent fever is less fatal than typhus, but like the 

 latter is conveyed by lice (though not exclusively) and accompanies 

 war. The disease has often raged in Europe; the last epidemic, early 

 in the recent war, being exceptionally severe in Serbia. 



The cause of relapsing fever is the genus Spirochata, of which 

 ditterent species produce various types of the disease in different parts 

 of the world. 



