Twelve Americans, seven states, one hospital in Tijuana

VIM-producing carbapenem-resistant Pseudomonas aeruginosa is an emerging
US public health threat: **high levels of antibiotic resistance and the
potential for rapid spread within health care facilities.**

Between 18 September and 19 November 2018, CDC received 31 reports of
it. **Six (19%) were in US patients who had recently had invasive medical
procedures in Mexico** — a pattern nobody was looking for, in a fifth of the
cases.

Finding the rest

On 19 November 2018 CDC posted an Epi-X alert and notified the
Emerging Infections Network and medical professional societies, with a case
definition: **VIM-CRPA isolated from a patient who had an invasive procedure in
Mexico in the preceding month.**

By 18 January 2019: 12 cases in seven states — four in Utah, three in
Washington, one each in Arizona, Arkansas, Oregon, Texas and West Virginia —
with specimens collected from November 2015 through December 2018.

Three years of cases, found in two months, because somebody asked the right
question of every state at once. Spread one or two per state, these were not an
outbreak to anyone; they were isolated resistant infections.

Who they were

Eleven of the twelve were medical tourists who had bariatric surgery.
Median age 39 (range 29–62); of the seven whose sex was reported, **six were
women.** The twelfth had **endoscopic retrograde cholangiopancreatography after
falling ill while travelling.**

Patients named five hospitals in Tijuana. Eight had been to one of them —
facility A.

What happened next

Median 11 days from procedure to specimen (range 7–22), so the infection
declared itself after the patient was home. Cultures came from **the incision
site (eight), blood (one) and an intra-abdominal abscess (one).**

Six were hospitalised in the United States. **The patient with the
bloodstream infection died.**

After CDC's notification, **Mexico's Secretariat of Health carried out an
on-site infection control assessment at facility A in December 2018 and
identified numerous infection control breaches.** CDC posted **a travel notice
from January to May 2019**, recommending against surgery there until the
outbreak was over.

The structural problem

A patient has surgery in one country and falls ill in another. The hospital
that caused the infection never learns of it; the hospital that treats it has no
reason to connect it to eleven other cases in six other states.

Only a system that can ask every state the same question at the same time makes
that visible — which is the whole point of the alert networks used here, and
why the case definition included where the procedure happened rather than
only what grew in the culture.

Source: Centers for Disease Control and Prevention, MMWR.