404 GLANDERS, ANTHRAX, PYOCYANEUS 
a negative reaction. It should be borne in mind that mallein interferes 
with serological tests, hence the latter should be made before the injec- 
tion of mallein. 
Pathogenesis— J??'i?«a/. — Cattle appear to be immune to glanders; 
swine are but slightly susceptible; cats, sheep, goats, field mice and 
guinea-pigs are susceptible, but white mice are refractory. 
Acute glanders in horses and asses begins after an incubation period 
of from three to six days with an abrupt rise of temperature and a 
viscid, purulent nasal discharge. The nasal mucosa, at first deeply 
congested, becomes ulcerated; the regional lymph glands enlarge 
and may suppurate. The lungs become involved and death usually 
occurs within six to fourteen days; occasionally the animal lives 
several weeks. The onset of the chronic form is somewhat more insid- 
ious, and the symptoms are less violent. There is usually a nasal 
discharge which may be blood-streaked, and the superficial glands 
of the neck are palpable. The cutaneous lymph glands, and usually 
the lymph channels as well, become generally enlarged, and they may 
break down and suppurate. The disease may run a very mild course, 
hardly noticeable, and frequently terminates in a cure after months 
or years. 
The injection of material from ulcers, nasal secretion, or lymph 
glands into male guinea-pigs leads, usually within two or three days, 
to a characteristic lesion, unless the material is grossly contaminated 
with other organisms, namely, a purulent orchitis; the testicle enlarges 
until it cannot be retracted, and the inflammation spreads from the 
tunica vaginalis to the epididymis. The peritoneum is inflamed, and 
if the organism is not very virulent there is joint involvement and 
gradual emaciation and death. This is known as the Straus reaction. 
Ihmian.— The essential lesion in man is similar to that in the horse— 
a granulomatous nodule made up chiefly of epitheloid cells and man}' 
lymphoid cells. The bacilli occur in the nodules in large numbers as 
a rule. The nodules occur chiefly in the nasal mucosa, or in cutaneous 
infections under the skin. They break down readily, causing ulceration 
or abscess formation. A crop of papules, which soon break down, 
appears on the face, around joints, and frequently upon the arms. 
The disease terminates fatally in about 65 to 70 per cent of all cases. 
Immunity and Immunization.— Recovery from an attack of glanders 
does not appear to confer immunity to subsequent infection, and 
attempts to induce immunity in susceptible animals by vaccines, by 
the use of mallein, or by sera have been unsuccessful. Specific agglu- 
tinins and precipitins are present in the blood serimi of infected animals 
and a diagnosis can be made by the method of complement-fixation. 
The latter procedure, important in horses and other domestic animals, 
has not been tried very extensively in man, partly because of the 
comparative rarity of cases. 
Bacteriological Diagnosis. — 1. Microscopic Ea-aviination.— 'Material 
from the purulent discharges of the nose or scrapings from cutaneous 
