Clinical Studies on the Pathophysiology of Bubonic and Pneumonic Plague: Some Observations of Typhoid Fever

In 22 Vietnamese patients with fever and bubo, Yersinia pestis infection was diagnosed by positive culture or serologic response. All strains of Y. pestis except one isolated from these patients were susceptible to most antimicrobial drugs tested, including trimethoprim. Common clinical features were tachycardia, hypotension, and leukocytosis. Blood cultures from febrile patients in Saigon yielded Salmonella typhi in eight cases. Four isolates were sensitive to all antibiotics and four isolates were highly resistant to chloramphenicol, tetracycline, streptomycin, and sulphadiazine. While receiving chloramphenicol the patients with drug-resistant S. typhi had prolonged febrile courses, and one patient died. The multiple drug resistance was associated with three distinct Vi-phage types and could be transferred from three of the isolates to recipient Escherichia coli organisms.