Fecal carriage of CTXM type extended-spectrum beta-lactamase-producing organisms by children and their household contacts.

OBJECTIVES: To investigate the epidemiology of fecal carriage of CTX-M type extended-spectrum beta-lactamases (ESBL)-producing organisms among children and their household contacts.

METHODS: Fecal carriage with CTX-M-producing organisms was studied in 53 children and 172 household members. Molecular methods were used to characterize the isolates.

RESULTS: The children were mostly healthy and hospitalized for relatively mild febrile illnesses. Overall, the prevalence of fecal carriage of CTX-M-producing bacteria was 43.5% (admission children, 37.7%; household children, 20.7% and household adults, 50.3%). Household colonization index (defined by number of household carriers/total number of members) was significantly higher among families with at least one individual having a history of prolonged (>3 months) out-of-town residence in the previous year (mean+/-standard deviation; yes group, 0.67+/-0.36 vs. no group, 0.39+/-0.28, P=0.009) and was inversely correlated with the living space per person (R-square=0.139, P=0.006). Among 29 households with at least two carriers of CTX-M-producing enterobacteria, six clusters of clonally related strains were shared by 15 individuals from seven households; with both intra- and inter-household transmission.

CONCLUSION: CTX-M beta-lactamases may spread extensively amongst family members in the home.