BACILLUS PERTUSSIS 459 
Pathogenesis. — .-hm//a/. — Klimenk()^ and Fninkel- produced a catar- 
rhal inflaiiiiiiation of the respiratory mucosa of monkeys and young 
dogs by intratracheal injections of B. pertussis suspended in salt solu- 
tion. A febrile reaction appeared after three to four days and several 
of the animals died within two to three weeks. The bacilli were recov- 
ered from the bronchial mucus, bronchi, and from the areas of bron- 
chopneumonia which de^'eloped in the lungs. No characteristic par- 
oxysms were induced, although Klimenko stated that sneezing and 
coughing were noticed. Wollstein^ has pointed out a possible source 
of error in the dog experiments: she finds that those dogs which die 
after injections of B. pertussis succumb to canine distempter; the 
lesions of the respiratory tract are readily accounted for on this basis, 
and the blood of the animals fails to react specifically with the Bordet- 
Gengou bacillus. 
i/w7« or?.— There are no postmortem lesions characteristic of whoop- 
ing cough. Bronchopneumonia is the most common complication 
seen at autopsy. IMallory and Hornor,"* and IVIallory, Hornor and 
Henderson^ have advanced an interesting explanation for the parox- 
ysms of whooping cough. They find that the ciliated epithelium of 
the respiratory tract is denuded in places and the cilia plastered down 
to such an extent as to interfere with the free removal of mucus by 
the mechanical action of the bacteria. When mucus accumulates in 
sufficient amount, it is forcibly expelled by a prolonged violent parox- 
ysm of coughing. These experiments were made upon animals; the 
frequent occurrence of B. bronchosepticus or a closely-related bacillus 
in the respiratory tracts of laboratory animals, which produces similar 
lesions to those seen in canine distemper, should be borne in mind in 
interpreting these results. 
Immunity.— Whooping cough is more commonly a disease of chil- 
dren, and recovery from one attack appears to confer lifelong immunity 
as a rule. In this respect the disease appears to stand in contrast to 
influenza. Vaccines have been tried with apparent success to induce 
immunity to whooping cough.*' 
Bacteriological Identification. — 1. Morphological.— The diagnosis of 
the Bordet-Gengou bacillus by a microscopic examination of bronchial 
discharges is not satisfactory. Influenza bacilli are frequently present 
in the mucus and sputum from cases of pertussis, and no method is 
available at the present time which will distinguish with certainty 
between the two organisms. 
2. Cultural.— The isolation of the organism from bronchial mucus 
upon potato-glycerin-blood agar,^ or the Avery medium, and its ability 
to grow upon ascitic media free from hemoglobin separates the Bordet- 
Gengou organism from B. influenza^. 
1 Centralbl. f. Bakteriol., orig., 1909, 48, 64. 
2 Munch, med. Wchnschr., 1908, 55, 168.3. ' Loc. cit. 
' Jour. Med. Res., 1912, 27, 115. '• Ibid., 1912, 27, 391. 
« See Miller: Am. Jour. Pub. Health, 1921, 11, 913. 
' See also Povitsky: Jour. Infec. Dis., 1923, 32. 8. 
