- These are deaths resulting from hospital-acquired infections caused by antibiotic-resistant bacteria.
- Experts attribute this to the misuse of these medications and explain how the situation could improve.
Note: Clarín – Emilia Vexler
The overuse of antibiotics not only drives antimicrobial resistance in hospitals and clinics across Argentina (
), but also gives rise to a bacterium that is not multidrug-resistant but is “opportunistic,” which also (
) affects those hospitalized for several days and is particularly harmful to older adults. (
) What might simply be typical diarrhea “from taking too many medications” is actually a serious
problem associated with clinical care in the country, an effect of this difficult-to-treat pathogen, which survives on surfaces in healthcare facilities for months. It is called Clostridioides difficile.
It can cause outbreaks within the same hospital, but it can also lead to intestinal infections even after discharge
or following a course of strong antibiotics.
In patients over the age of 65, this risk increases significantly. For them, the likelihood of becoming infected while in the hospital
rises to 51%. When persistent colitis and fever progress to inflammation of the colon, it can lead to peritonitis, sepsis, intestinal perforation, toxic megacolon, and death.
“The infection occurs due to the use—and, often, the misuse—of antibiotics, which disrupts the balance of the gut microbiota, allowing this bacterium to multiply uncontrollably and release toxins that inflame the colon. It is transmitted primarily via the fecal-oral route, in hospital settings or nursing homes. There are 50–75 cases per 100,000 inhabitants, with high morbidity and significant costs for the healthcare system,” explains Gonzalo Pérez Marc, a physician and principal investigator at Equipo Ciencia, to Clarín.
"These are not intestinal infections caused by antimicrobial resistance," he clarifies, "but they are related to that global health threat, since both are a consequence of the indiscriminate use of antibiotics; they thrive in the same medical setting and are equally serious for the same patients."
Data on the prevalence and significance of this bacterium are scarce and inconsistent.
“Most laboratory-based epidemiological studies express incidence as a proportion of the total number of stool samples and calculate it using different denominators,” noted Laura Barcán, who, in response to the pandemic and the surge in hospitalizations, published the “Recommendations for the Diagnosis, Treatment, and Prevention of Clostridioides difficile Infections.”
While there is a battle being waged in intensive care units to prevent secondary infections caused by bacteria in the environment, another equally intense battle is taking place in laboratories. And Argentina is playing a major role in an international study aimed at preventing these hospital-acquired infections in older adults.
Specifically, a vaccine. The first one to prevent severe Clostridioides difficile disease.
“It would be a vital tool for addressing this public health problem. In a way, this vaccine helps prevent the consequences of that indiscriminate use of antibiotics and the existence of a diminished gut microbiota,” explains Pérez Marc, a scientist who worked alongside Fernando Polack on the clinical trial of Pfizer’s COVID vaccine during the pandemic. He is now involved in this new project being carried out by the same U.S. laboratory worldwide and also in Argentina.
Promising Results The study, which is in Phase 3, is being conducted at the Equipo Ciencia Research Center, at Fundación Huésped, at the SMG Barrio Parque Center, the Sanatorio Sagrado Corazón (OSECAC) in Buenos Aires, at the Instituto Médico Platense in La Plata, at ICSAL in Salta, at the Clínica del Sol in Córdoba, at the Clínica de Cuyo in Mendoza, and at the Clínica del Niño y la Familia in Mar del Plata.
“This vaccine has the unique distinction of having already demonstrated high efficacy in preventing
severe disease in another study that was originally conducted for a different purpose. It indirectly demonstrated
what we are now trying to show again as our primary objective,” the doctor notes.
That trial, called Clover, was published in *Clinical Infectious Diseases* in late 2024 and found that the
vaccine “reduced the duration of symptoms among those who required medical care and antibiotic treatment, highlighting its potential to reduce the healthcare burden associated with this infection,” the paper states.
“The vaccine has proven safe in Phase 2 and Phase 3 studies involving more than 17,000 volunteers across 23 countries. A similar study is now being repeated with a focus on preventing severe disease. This vaccine trial aims precisely to get ahead of the problem, prevent infection, and reduce hospitalizations, generating evidence that could transform the way we address these diseases in the future,” Pérez Marc concludes.
The current trial will enroll approximately 30,000 additional volunteers worldwide, and nearly one-fifth of them will be Argentin
s.
The vaccine is administered in two doses, six months apart, and the follow-up period for the volunteers—who must be over 65, have been hospitalized in the past year, attend multiple medical appointments, and have recently taken antibiotics—lasts about three years, in order to evaluate clinical outcomes.
