RichardB. Hornick

Relative efficacy of blood, urine, rectal swab, bone-marrow, and rose-spot cultures for recovery of Salmonella typhi in typhoid fever.

The recovery of Salmonella typhi from blood, rectal swab, urine, bone-marrow, and rose spots was compared in 62 patients with typhoid fever, most of whom had received some antibiotic therapy before presentation. S. typhi was isolated from culture of bone-marrow in 56 patients (90%); in contrast, S. typhi was recovered from blood in only 25 (40%), from stool in 23 (37%), and urine in 4 (7%). S. typhi was isolated from 24 (63%) of 38 patients who had rose-spot cultures. If culture sites had been limited to blood, stool, and urine, the bacteriological diagnosis would have been missed in 24 patients.

CHOLERA, NON-VIBRIO CHOLERA, AND STOMACH ACID

Fasting and postprandial stomach acid production were low in 16 of 37 Bangalees convalescing from cholera or non-vibrio cholera. Gastric juice of hypochlorhydric patients did not kill cholera vibrios in vitro, whereas that from normochlorhydric patients rapidly killed vibrios in concentrations up to 10(10)/ml. To determine whether hypoacidity resulted from cholera or was a common predisposing factor, basal and betazole-hydrochloride-stimulated acid production were measured before and after cholera in a second group of patients consisting of American volunteers participating in a vaccine development programme. Cholera did not alter the stomach acid secretion of American volunteers, but low precholera basal acid production predispose to severe cholera. The results indicate that hypochlorhydria observed in convalescent Bangalee cholera patients is not caused by cholera, and must therefore have preceded it. Idiopathic tropical hypochlorhydria may be a major factor accounting for the high incidence of diarrhoea due to acid-sensitive pathogens in developing countries.

CANNABIS, HYPOCHLORHYDRIA, AND CHOLERA

In 90 volunteers participating in a vaccine-development programme consumption of beer more than 3 days a week was linked with high stomach acid output, and smoking of cannabis greater than 2 days a week was linked with low acid output. In 92 volunteers challenged with Vibrio cholerae or enterotoxigenic Escherichia coli, heavy use of cannabis was associated with more voluminous diarrhoea. Cannabis use may be an important factor predisposing to severe diarrhoea.

COMPARATIVE EFFICACY OF CHLORAMPHENICOL, AMPICILLIN, AND CO-TRIMOXAZOLE IN THE TREATMENT OF

Two clinical trials were conducted to compare the efficacy of 3 antimicrobial agents often recommended for the treatment of typhoid fever. Chloramphenicol was more effective than parenteral ampicillin or oral co-trimoxazole (trimethaprim/sulphamethoxazole) in reducing the duration of fever. Oral chloramphenicol was more effective than parenteral chloramphenicol probably because oral doses resulted in higher blood concentrations of the drug. However, parenteral chloramphenicol was given during the initial period of acute illness, without loss of efficacy.