Work package 3

Infections and Antimicrobial Resistance

Leader: Prof. Diederik van de Beek
Academic Medical Center Amsterdam (AMC)


To assess the types and frequencies of infections in all included patients and to compare the prevalence of resistant bacteriae between patients allocated to treatment with antibiotics (ceftriaxone) and patients without antibiotics.

Assess the number of patients with infection and the type of these infections

Assess the total use of antibiotics

Asses and monitor the occurrence of overgrowth of specific bacteria (Clostridium difficile) due to antibiotic use

Monitor antibiotic resistance in pathogens causing infections in of patients with stroke

Description of tasks

One of the treatments under investigation in PRECIOUS is the antibiotic ceftriaxone to prevent infections after stroke. The AMC is a key leader in neurological infections, including infections complicating stroke.

The team at AMC assessed the total number of patients diagnosed with one or more infection(s) during hospital admission, as well as the total number of infections. Infection was assessed in two ways. Firstly, infections were diagnosed in the hospital as judged by the treating physician. Secondly, infections were diagnosed according to strict international criteria by an expert panel at the AMC. Infection rates were compared between patients who received the antibiotic ceftriaxone and the patients who don’t. In addition, use of antibiotics other than the antibiotic therapy in PRECIOUS will be recorded by the local investigator.

A potential risk of using antibiotics on a large scale is the development of antibiotic resistance. The use of preventive
antibiotics has potential side effects. On an individual level, increased use of antibiotics may induce a bacterial
overgrowth syndrome by antibiotic-resistant pathogens. Therefore, monitoring of the effect of preventive antibiotics
on the occurrence of an overgrowth infection with C. difficile or infection with ceftriaxone-resistant
microorganism was essential. To monitor antibiotic resistance and overgrowth of antibiotic-resistant pathogens all cultured causative pathogens of all patients included in PRECIOUS with infections were analysed. 

In addition to the risk of the development of bacterial resistance, treatment with antibiotics could lead to overgrowth of bacteria which are not killed by the antibiotic treatment. An example is the overgrowth of the bacteria Clostridium Difficile, which can cause diarrhea. Overgrowth of Clostridium Difficile was diagnosed by the treating physician. Case definition of this infection is diarrhea plus a positive C. Difficile toxin test. The diagnosis will be reviewed by the expert panel at AMC. In previous studies, only a few (<1%) patients developed overgrowth of this bacteria. The occurrence of Clostridium Difficile overgrowth was compared between patients treated with ceftriaxone and those in the control group.

PRECIOUS: List of Work Packages

WP 1: Trial Management

WP 2: Outcome Adjudication

WP 3: Infections and Antimicrobial Resistance

WP 4: Monitoring

WP 5: Health Economics

WP 6: Safety Monitoring

WP 7: Statistical Analysis

WP 8: Dissemination, Exploitation and Communication

WP 9: Project Management