Reference | Study | Key findings relevant to antimicrobial resistance | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Typea | subjects | country | time period | bacterial target | relevant study outcomes | sample size | controls | comments | ||
GRADE level: Controlled trial | ||||||||||
n/a | ||||||||||
GRADE level: observational trial | ||||||||||
[121] | Cohort | Patients with Salmonella infections | US | 1996–2001 | Salmonella | Frequency of hospitalization and bloodstream infection | n = 1415 patients (FoodNet) and n = 7370 isolates (NARMS) | Patients infected with susceptible Salmonella strains | Two analyses were performed, one of Salmonella isolates collected through NARMS, and one of patients with NARMS Salmonella isolates and corresponding FoodNet interviews | Resistant isolates were more likely associated with bloodstream infections than susceptible isolates (for example, for serotype Typhimurium, 3% of patients infected with susceptible isolates had bloodstream infections, compared to 6% of patients infected with resistant strains); patients infected with resistant isolates were more likely to be hospitalized because of bloodstream infection than those infected with susceptible isolates; among hospitalized patients, those infected with resistant isolates had longer stays than those infected with susceptible isolates; |
[122] | Cohort | Patients with Salmonella infections (bloodstream and GI infection) | US | 2006–2008 | Salmonella | Clinical outcomes | n = 875 patients | Patients infected with susceptible Salmonella strains |  | Bloodstream infections and hospitalizations more likely among patients with resistant than susceptible isolates |
[123] | Cohort | Patients infected with Salmonella | US | 1989–1990 | Salmonella | Infection and hospitalization |  | Patients infected with susceptible Salmonella strains | Results were compared to similar study conducted in 1979–1980 | Patients with resistant infections were more likely to be hospitalized than those with susceptible infections; recent antimicrobial treatment as well as age and race were significant predictors of resistance |
[124] | Cohort | Patients with Salmonella infections | Canada | 1999–2000 | Salmonella Typhimurium | Risk of hospitalization | n = 440 patients | Patients infected with susceptible Salmonella strains |  | Hospitalization was more likely in patients infected with resistant than susceptible strains; an estimated 57–72% of hospitalizations were attributable to resistance patterns |
[125] | Cohort | Patients infected with Salmonella Typhimurium | Denmark | 1995–1999 | Salmonella Typhimurium | Death rates | N = 2047 | 10 random controls (matched by age, sex and county of residence); comparison between susceptible and resistant infections | Subjects were followed for up to 2 years after entering the study | Patients with susceptible Salmonella Typhimurium infection were 2.3 times more likely to die during the study period than the general population; patients with most resistant strains were 4.8 times (95% CI: 2.2–10.2) more likely; patients infected with quinolone-resistant isolates were 10.3 times more likely to die than the general population. |
[126] | Cohort | Patients with Campylobacter infections | Denmark |  | Campylobacter (quinolone and erythromycin-resistant) | Risk of invasive illness and death within up to 90 days of sample receipt | n = 3471 patients | Patients infected with susceptible Campylobacter isolates |  | Patients infected with quinolone-resistant Campylobacter strains had a 6-fold increased risk of invasive illness or death within 30 days of sample collection compared with patients infected with susceptible isolates; infection with erythromycin-resistant Campylobacter strains was associated with >5-fold higher risk within 90 days compared to infections with susceptible strains |
[127] | Meta-analysis of cohort studies | Studies of patients with bloodstream infection due to Staph. aureus | multiple countries | 1980–2000 | Staphylococcus aureus, MRSA | Mortality rates due to infections with methicillin susceptible and resistant Staphylococcus aureus | n = 3963 patients in n = 31 studies | Patients infected with methicillin susceptible strain | Results pooled with random effects model | Increased mortality associated with MRSA infections compared to methicillin –susceptible strains (OR: 1.93; 95% CI – 1.52 – 2.42) |
GRADE level: other | ||||||||||
[128] | Outbreak analysis | Outbreaks of patients infected with Salmonella | US | 1984–2002 | Salmonella | Hospitalization due to infection with susceptible or resistant Salmonella strains | n = 23,206 patients in n = 32 outbreaks | Outbreaks with susceptible Salmonella strains |  | The median proportion hospitalized for each type of outbreak caused by resistant strains was 26%, 2.5 times higher than the median proportion hospitalized for outbreaks caused by pan-susceptible strains |