Household acquisition and transmission of extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae after hospital discharge of ESBL-positive index patients
Objectives: This study aimed to determine rates and risk factors of extended-spectrum b-lactamaseproducing
Enterobacteriaceae (ESBL-PE) acquisition and transmission within households after hospital
discharge of an ESBL-PE-positive index patient.
Methods: Two-year prospective cohort study in five European cities. Patients colonized with ESBLproducing
Escherichia coli (ESBL-Ec) or Klebsiella pneumoniae (ESBL-Kp), and their household contacts
were followed up for 4 months after hospital discharge of the index case. At each follow up, participants
provided a faecal sample and personal information. ESBL-PE whole-genome sequences were compared
using pairwise single nucleotide polymorphism-based analysis.
Results: We enrolled 71 index patients carrying ESBL-Ec (n ¼ 45), ESBL-Kp (n ¼ 20) or both (n ¼ 6), and
102 household contacts. The incidence of any ESBL-PE acquisition among household members initially
free of ESBL-PE was 1.9/100 participant-weeks at risk. Nineteen clonally related household transmissions
occurred (case to contact: 13; contact to case: 6), with an overall rate of 1.18 transmissions/100
participant-weeks at risk. Most of the acquisition and transmission events occurred within the first
2 months after discharge. The rate of ESBL-Kp household transmission (1.16/100 participant-weeks) was
higher than of ESBL-Ec (0.93/100 participant-weeks), whereas more acquisitions were noted for ESBL-Ec
(1.06/100 participant-weeks) compared with ESBL-Kp (0.65/100 participant-weeks). Providing assistance
for urinary and faecal excretion to the index case by household members increased the risk of ESBL-PE
transmission (adjusted prevalence ratio 4.3; 95% CI 1.3e14.1).Instituto de Salud Carlos II
