European Relapsing Fever 233 



European Relapsing Fever There is widely distributed in Europe 

 a type of relapsing fever which is caused by Spiroch&ta recurrentis. 

 It has long been supposed that this disease is spread by the bed-bug 

 and there is some experimental evidence to show that it may be 

 conveyed by these insects. 



In 1897, Tictin found that he could infect monkeys by inoculating 

 the contents of bed-bffgs which had fed upon a patient within forty- 

 eight hours. Nuttall, in 1907, in one experiment succeeded in trans- 

 mitting Spiroch&ta recurrentis from mouse to mouse by bites of bed- 

 bugs. The bugs, thirty-five in number, were transferred at short 

 intervals from one mouse to another, not being allowed to take a 

 full meal on the first, or infected mouse. 



On the other hand, there is much clinical evidence to show that 

 the European relapsing fever like various other types of the disease 

 is transmitted from man to man by head and body lice (Pediculus 

 humanus and Pediculus corporis). 



Interesting supplementary evidence is that of Bayon's observa- 

 tions ( 1 9 1 2 ) , in Moscow. ' ' Having visited the big municipal night hos- 

 pitals at Moscow I soon noticed that they were kept with such scrupu- 

 lous cleanliness, disinfected so lavishly, the beds of iron, the floor cement- 

 ed, that it was not possible for bed-bugs to thrive to any extent on 

 the premises. The people sleeping there were allowed, however, 

 to sleep in their own clothes. The introduction of these model homes 

 had not had any effect on the incidence of relapsing fever, for the 

 places were still hot-beds of the fever during winter. On the other 

 hand, though I changed my rooms several times, I found bugs in 

 every successive lodging, and I was told in Moscow, this can hardly 

 be avoided. Yet no foreigner, or Russian of the better class, ever 

 catches relapsing fever. To this may be added the fact that when 

 I asked for clothes-lice and promised to pay a kopec for two, the 

 attendants from the night hostel brought me next morning a small 

 ounce bottle crammed with Pediculus capitis (= P. humanus), and 

 Pediculus vestimentorum (= P. corporis) collected off the sleepers. 

 If relapsing fever were transmitted by bed-bugs, it would be much 

 more disseminated than it is at present in Moscow." 



Direct experimental evidence of the agency of lice in transmitting 

 relapsing fever is especially clear in the case of a type of the disease 

 prevalent in parts of North Africa. We shall consider this evidence 

 later. 



