Ampicillin for Persistent Typhoid Excreters, including a Clinical Trial in Convalescence

Abstract

A double-blind clinical trial of ampicillin and inert capsules was carried out in 114 early convalescent typhoid excreters to assess the possible value of this drug in preventing the chronic carrier state. The dose of ampicillin was 4 g. daily for adults and the duration of treatment 10 days. Twenty-three patients were withdrawn, chiefly for clinical relapse, and six others suffered clinical relapse immediately after the trial treatment period. Of the remaining 85, 10 of the 45 in the ampicillin-treated group and 18 of the 40 in the control group excreted Salmonella typhi afterwards, the difference being of borderline significance (P<0.05). If the six clinical relapses are counted as “failures” the difference in favour of the ampicillin treatment is somewhat greater (P<0.025). Further trials timed differently and in other dosages are needed before the value of ampicillin in this context is established. Fifty-two persistent excreters completed three months’ treatment with ampicillin, 3 g. daily, and three of these excreted Salm. typhi thereafter and have become chronic carriers. Two received a further three-month course of ampicillin with probenecid, without effect. In three other persistent excreters who were intolerant of ampicillin a number of antibiotics, including cephaloridine, were unsuccessful. Although ampicillin is not always effective its use may have contributed to the low incidence in this epidemic of chronic carriers—five out of 469 confirmed cases. Its mode of action, and the possible limitations thereon, are discussed. © 1966, British Medical Journal Publishing Group. All rights reserved.