Extensively Drug-Resistant Carbapenemase-Producing Pseudomonas aeruginosa and Medical Tourism from the United States to Mexico, 2018-2019

Abstract

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) producing the Verona integron‒encoded metallo-β-lactamase (VIM) are highly antimicrobial drug-resistant pathogens that are uncommon in the United States. We investigated the source of VIM-CRPA among US medical tourists who underwent bariatric surgery in Tijuana, Mexico. Cases were defined as isolation of VIM-CRPA or CRPA from a patient who had an elective invasive medical procedure in Mexico during January 2018‒December 2019 and within 45 days before specimen collection. Whole-genome sequencing of isolates was performed. Thirty-eight case-patients were identified in 18 states; 31 were operated on by surgeon 1, most frequently at facility A (27/31 patients). Whole-genome sequencing identified isolates linked to surgeon 1 were closely related and distinct from isolates linked to other surgeons in Tijuana. Facility A closed in March 2019. US patients and providers should acknowledge the risk for colonization or infection after medical tourism with highly drug-resistant pathogens uncommon in the United States.

Keywords: Mexico; Pseudomonas aeruginosa; United States; antimicrobial resistance; bacteria; bariatric surgery; carbapenemase producing; extensively drug-resistant; medical tourism; outbreak.

Figure 1

Confirmed and probable cases of infection with Verona integron‒encoded, metallo-β-lactamase‒producing, carbapenem-resistant Pseudomonas aeruginosa, by state in which bacterium was identified, among US medical tourists undergoing elective invasive procedures in Tijuana, Mexico, January 2018–December 2019. Six suspected cases, from Arizona (n = 1), Georgia (n = 3), Michigan (n = 1), and Washington (n = 1) are not shown.

Figure 2

Confirmed and probable cases of infection with Verona integron‒encoded, metallo-β-lactamase‒producing, carbapenem-resistant Pseudomonas aeruginosa, by week of surgery, among US medical tourists undergoing elective invasive procedures in Tijuana, Mexico, January 2018‒December 2019. Dark blue bars show cases associated with surgery performed at facility A by surgeon 1; light green bars show cases associated with surgery at facilities D–H and J by surgeons other than surgeon 1; and light blue bars show cases associated with facilities B, C, and I by surgeon 1; and dark green bar shows a case associated with surgeon 1 and an unknown facility. A confirmed case was isolation of Verona integron‒encoded, metallo-β-lactamase‒producing, carbapenem-resistant P. aeruginosa from a patient who had an elective invasive medical procedure in Mexico during January 2018–December 2019 and within 45 days before specimen collection. A probable case was isolation of carbapenem-resistant P. aeruginosa, with an isolate unavailable for carbapenemase testing, from a patient who had an elective invasive medical procedure in Mexico during January 2018–December 2019 and within 45-days before specimen collection. No cases were identified from patients who underwent surgery before August 2018 (week 34). The peak of the outbreak encompassed epidemiologic weeks 2–5 (January 2019).

Figure 3

Whole-genome sequencing analysis and selected epidemiologic data for 22 Verona-integron-encoded metallo-β-lactamase-producing carbapenem-resistant Pseudomonas aeruginosa clinical isolates from US medical tourists who underwent surgery in Tijuana, Mexico, August 2018–December 2019. Phylogenetic tree includes an outlier isolate from Arkansas. On the right, the first group of 8 columns indicates facilities (A, B,C, E, F, G, I, and unknown), and the second group of 4 columns indicates surgeons (1, 2, 3, and unknown). Scale bar indicates nucleotide substitutions per site.

Figure 4

Whole-genome sequencing analysis and selected epidemiologic data for 21 Verona-integron-encoded metallo-β-lactamase-producing carbapenem-resistant Pseudomonas aeruginosa clinical isolates from US medical tourists who underwent surgery in Tijuana, Mexico, August 2018–December 2019. Phylogenetic tree excludes an outlier isolate from Arkansas. On the right, the first group of 8 columns indicates facilities (A, B,C, E, F, G, I, and unknown), and the second group of 4 columns indicates surgeons (1, 2, 3, and unknown). Scale bar indicates nucleotide substitutions per site.