War kills, injures and traumatizes in many ways. Many are unable to access a hospital for treatment. Those who do often find wards overcrowded, with soldiers and civilians suffering from infected wounds, malnutrition or the constant stress of living in a conflict zone.
But another threat is increasingly looming: antimicrobial-resistant infections, which pose an additional risk to their health.
Globally, antimicrobial resistance (AMR) is already responsible for around 5 million deaths per year, a figure that is constantly increasing.
“In the chaos of war, where health workers are overwhelmed by the number of wounded and lack resources, broad-spectrum antibiotics are sometimes administered urgently to stabilize patients, although this increases the risk of antimicrobial resistance.”
– Dr. Ezra Barzilay, National Director of the U.S. Centers for Disease Control and Prevention (CDC) Office in Ukraine
Although the misuse of antibiotics in medicine and agriculture is a major factor, the role of armed conflict in the spread of resistant infections is increasingly recognized.
As hopes for a world without war fade, public health experts are wondering how to counter this threat.
Drug-resistant infections
Antimicrobial resistance occurs when bacteria, fungi or viruses undergo mutations that allow them to survive drugs intended to eradicate them.
The threat could undo decades of medical progress, making routine care riskier and infections harder to treat.
Wars exacerbate this problem in several ways. First, battlefield wounds are often dirty, contaminated with dirt or other substances, increasing the risk of infection.
Additionally, the weapons and explosives used can introduce heavy metals into wounds, forcing microbes to adapt to survive.
“Infections do not stop at borders, regardless of conflict, and hospitals in Europe or Japan that have received Ukrainian patients have reported the presence of bacteria with unprecedented or extremely resistant resistance profiles.”
– Dr. Ezra Barzilay, National Director of the U.S. Centers for Disease Control and Prevention (CDC) Office in Ukraine
Bombings and fighting often cause large numbers of casualties in a short period of time, requiring urgent care. However, the destruction of health infrastructure – from hospitals under attack to power cuts – reduces treatment capacity.
“We usually prefer to treat these wounds with antibiotics,” says Dr. Ezra Barzilay, country director of the U.S. Centers for Disease Control and Prevention (CDC) office in Ukraine. “But to limit the risk of resistance, the choice of drugs, as well as their frequency and timing, must be carefully considered.”
In mass emergency situations, this often becomes unfeasible. Furthermore, ensuring strict hygiene of hands, surfaces and medical equipment can be difficult.
“In the chaos of war, where health workers are overwhelmed by the number of wounded and lack resources, broad-spectrum antibiotics are sometimes administered urgently to stabilize patients, although this increases the risk of antimicrobial resistance,” Barzilay adds.
Adapt to survive
Although broad-spectrum antibiotics are often effective, they have risks. They can promote the transmission of resistance genes between microbes, allow already resistant bacteria to multiply, and by eliminating both harmful and beneficial microbes, they leave space for resistant organisms to proliferate in wounds or organs.
In situations where access to care is restricted, these resistant infections can easily spread from one patient to another.
The war also contributes to their geographical spread. The shortage of beds sometimes forces the transfer of wounded people to other regions, where hospitals are already overwhelmed, which makes it more difficult to rigorously apply infection prevention and control measures.
Ideally, people with resistant infections should be isolated, but in these settings this is often not possible. Sometimes the facilities to screen for these infections are also lacking.
The conflict in Ukraine
The situation is particularly worrying in Ukraine, where antimicrobial stewardship by health workers was already poor before the war, leading to high rates of antibiotic resistance in the population.
These high baseline levels, combined with the massive influx of injured people and transfers of patients to other regions or countries, have created a “perfect storm” for the spread of resistant infections, according to Dr. Barzilay.
Several studies have documented an increase in resistance among Ukrainian soldiers and civilian patients since the beginning of the conflict.
A study of 141 patients requiring emergency surgery for burns, fractures or shrapnel wounds found that at least half of the bacterial samples were resistant to an antibiotic, and 6% – all Klebsiella pneumoniaea bacteria that causes many hospital pneumonias – were resistant to all treatments tested.
“A severe shortage of caregivers is straining an already overworked workforce, which is focused primarily on emergency interventions rather than preventing infections and antimicrobial resistance.”
– Dr. Krystel Moussally of the Middle East medical unit of Médecins Sans Frontières
Other studies have revealed alarming levels of antibiotic-resistant bacteria among refugees and injured Ukrainians, including strains carrying the New Delhi metallo-β-lactamase enzyme and the OXA-48 mutation, two mechanisms that confer resistance to a wide range of commonly used antibiotics.
“It is clear that antimicrobial resistance has worsened since the start of the war and is progressing rapidly,” says Dr Barzilay.
“Infections do not stop at borders, regardless of conflict, and hospitals in Europe or Japan that have received Ukrainian patients have reported the presence of bacteria with unprecedented or extremely resistant resistance profiles.”
For example, a recent study in Germany found an increase in cases of Klebsiella pneumoniae carriers of New Delhi metallo-β-lactamase or OXA-48 mutation among Ukrainian refugees and soldiers.
The case of Iraqibacter
This phenomenon is not limited to Ukraine. Antoine Abou Fayed of the American University of Beirut and his team reviewed studies showing the emergence of resistant bacteria in Iraq, particularly following the 2003-2011 war and conflicts with the Islamic State.
One of these pathogens is Acinetobacter baumanniia bacterium that causes hospital infections of the blood, urinary tract, lungs and wounds. “Its growing resistance is now a global concern, to the point that it is called ‘Iraqibacter’ because of its meteoric rise as a resistant pathogen in Iraqi hospitals,” says Abou Fayed.
Gaza is also a hotbed of concern. In late 2023, Dr. Krystel Moussally of Médecins Sans Frontières and her colleagues warned in an article in Lanceton the increase in antibiotic resistance in the region, aggravated by the ongoing conflict.
They pointed out that the destruction of hospitals and the collapse of health systems mean that contaminated wounds are often not operated on in time to prevent infections. “A severe shortage of health workers is exhausting an already overworked workforce, which is focused primarily on emergency interventions rather than on preventing infections and antimicrobial resistance,” Moussally said.
She adds that critical shortages of essential medical equipment and antibiotics, combined with chaos and collapsing laboratory infrastructure, make responsible antimicrobial stewardship nearly impossible.
Infection control
What can be done to address this problem? In Ukraine, CDC is working with the Ministry of Health, local authorities, and international partners to strengthen laboratory detection, improve clinical care, and implement infection control measures in several regions of the country.
“We equip central labs with state-of-the-art equipment and train teams to integrate it into their daily routine,” says Dr. Barzilay. “We also work with our partners to improve patient flow management in hospitals, creating these invisible barriers that limit the spread of infections between patients.”
He adds: “We also work at the policy level to ensure that good practices in the use of antibiotics are disseminated and applied throughout the health system, both civilian and military.”
The World Health Organization (WHO) considers antimicrobial resistance to be one of the greatest threats to public health and global development. While health workers cannot prevent wars, these efforts could at least mitigate some of the disastrous consequences they bring.
