DISEASES CAUSED OR CARRIED BY MITES AND TICKS 411 



being chiefly involved. The patient suffers from severe occipital headache 

 with considerable rigidity of the muscles of the nape of the neck, so that 

 the head may be turned to one side as in torticollis. The superficial 

 glands in the groin and axilla are found to be enlarged and acutely pain- 

 ful. The acute neck s^'mptoms begin to subside from the eighth to tenth 

 day and recovery takes place spontaneously, but the glandular enlarge- 

 ment persists a month or more after recovery. The glands become hard 

 and painless. 



AUSTRALIAN HUMAN TICK PARALYSIS is caused by either 

 Ixodes ricinus (Linnaeus) Latreille or Ixodes liolocyclus Neumann and 

 is very similar to the American tick paralysis. Eaton considers tliat there 

 are three possibilities as the cause of the paral^'sis : pre-f ormation of the 

 poison by the tick, development of the infective organism in the blood, or 

 liberation mechanically or biologically (by bacterial introduction) at the 

 site of the bite, of some poison subsequently absorbed. 



DISEASES CARRIED BY MITES AND TICKS 



Ticks and mites are the carriers of many diseases. 



DISEASES CAUSED BY PLANT ORGANISMS 



There are undoubtedly many cases of SEPTICEMIA due to the intro- 

 duction of plant organisms at the site of the bite of the tick. These are 

 most likely to be streptococcal and staphylococcal infections. For in- 

 stance, the bite of Argas reflexus (Fabricius) Latreille has been known 

 to give rise to FURUNCULOSIS caused by Staphylococcus pyogenes 

 (Nuttall, Warburton, Cooper, and Robinson, 1908). Ixodes ricinus 

 (Linnaeus) Latreille may also carry infections of Staphylococcus 

 pyogenes (Nuttall, Warburton, Cooper, and Robinson, 1911). 



Demodex folliculorum Simon, the blackhead mite, causes an irritation 

 giving rise to papules which become infected with Bacillus necrophorus. 



Jarvis has just published an article in which he claims that EPIZOO- 

 TIC LYMPHANGITIS is an inoculable disease through the agency of 

 tlie ticks of the genus Amblyomma. The disease is characterized by sup- 

 puration, ulceration, and necrosis. He believes that the lesions are caused 

 by a variety of micro-organisms including the Priesz-Nocard organism, 

 the Cryptococcus farciminosus, the Bacillus necrophagus, and Staphylo- 

 cocci, and that these organisms are introduced through the agency of the 

 mouth parts of the ticks which are very long and pierce the whole integu- 

 ment, reaching the subcutaneous layers where the bacteria can easily set 

 up lesions. 



Hadwen has just published an article in which he shows that ticks play 



