770 MTCEOBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



In man, infection occurs usually by inoculation. Cases produced in 

 this way, occasionally appear among laboratory workers. 



Bad. mallei is to be regarded as purely parasitic and limited in its 

 natural activities to the animal body. ^ 



Back mallei is easily destroyed by a variety of unfavorable condi- 

 tions. It is destroyed by drying in fifteen to twenty days and is easily 

 killed by heat or antiseptics. 



All plain cases of glanders in domestic animals should be promptly 

 destroyed. Exposed horses should be tested with mallein. Those that 

 react khould be destroyed or quarantined, and contaminated premises 

 properly disinfected. 



Influenza* 

 Bacterium infiuenzm 



The natural disease appears to be limited to man. The incubation 

 period is very uncertain — ^probably very variable. 



While the clinical manifestations of infection with Bad. inJliienzcB 

 are variable the ordinary form begins with sudden severe headache accom- 

 panied by great prostration, pains and aches in the back and bones, 

 and a rapid rise in temperature. The fever lasts from three to five 

 days and leaves the patient extremely weak, and depressed in both 

 mind and body. . - 



Pfeiffer in 1892 described a. bacterium which occurred in large num- 

 bers in the purulent bronchial secretion expectorated by influenza 

 patients. The causal relationship has been quite definitely estabUshed. 



An examination of the sputum furnishes good presumptive evidence, 

 but cultivation is necessary for positive diagnosis. 



The purulent material is streaked out in a drop of sterile blood 

 upon an agar plate. 



Agglutination and complement fixation tests are valuable means for 

 identification. 



In pure cultures the bacterium is o.2;ii to 0.3^ wide by o.sm long with occasional 

 threads up to zm in length. The ends of the rod are rounded. The arrangement is 

 usually single, occasionally in pairs end to end and rarely in chains. The bacterium 

 is non-motile and does not show capsules or spores. It does not stain readily with 

 ordinary aniline dyes. It is Gram-negative. Polar staining is shown sometimes 



* Prepared by Edward Fidlar. 



