Human Carrier of the Psittacosis Virus

Abstract

A 36-yr.-old biochemist contracted a severe psittacosis infection; the agent was demonstrated in the blood and in the sputum. After recovery, a productive cough persisted and annual re-examination of the serum invariably yielded positive psittacosis complement fixation in titers varying between 1:128 and 1:1256. In the 8 yrs. after infection, the psittacosis agent was repeatedly isolated from 24-hr. specimens of sputum, before and after treatment with penicillin. Isolation was accomplished with antibiotics which inhibited the concomitant bacterial flora highly virulent for mice. In the 10th yr. after infection, the viral agent continued to be present in the respiratory secretions. Careful epidemio-logic inquiries fail to indicate that the carrier was or is infective. The infective agent behaves in pathogenicity tests like the original strain. The endotoxin is not neutralized by the antitoxin generated in rooster by the Louisiana and San Francisco pneumonitis agents. However, the carrier strain antitoxin has a broad neutralization spectrum. A protective antiserum prepd. on roosters inactivates significant units of only the meningo-pneumonitis virus. The mouse pneumonitis (Bar Harbor), meningopneumonitis and ornithosis (pigeon 207) antiserums neutralize varying quantities of infective units of the carrier strain. Intracerebral cross-protection tests of mice infected by the subcut. route in part confirm the neutralization tests. In guinea pigs the carrier strain induces considerable resistance against the Louisiana pneumonitis agent.