It was two days after the young Yemeni man was released from surgery that the doctors first noticed the smell. The bullet that wounded the leg of the 22-year-old college student had shattered bone and torn a hole in the soft tissue. Now, the wound was emitting a distinct smell, described in the medical literature as \u201coffensive.\u201d It strongly suggested infection, perhaps life-threatening, and the wound was not getting better.\r\nRealizing that normal antibiotics were not working, the doctors at a trauma center run by Doctors Without Borders sent a blood culture for analysis to their new microbiology lab, the only one of its kind in the region. The tests found a bacterium, Acinetobacter baumannii, resistant to most standard antibiotics. Nobody knows how the student \u2014 who was identified using his initials, A. S., to preserve his privacy \u2014 acquired the drug-resistant infection, but it is so common in Yemen that it could have come from the bullet itself or the sand on the ground when he fell, said Dr. Nagwan Mansoor, the chief physician in Doctors Without Borders\u2019s antibiotic stewardship program.\r\nDoctors started the gunshot victim on a program of specialized antibiotics, medicines rarely used because of their potentially dangerous side effects. He required numerous surgeries, seven in all. What would normally have been a five-day stay became three weeks, during which the man was put into isolation to prevent him from infecting other patients. When his family came to visit, they could not touch him without wearing protective clothing.\r\nA. S. survived. \u201cWe captured the patient from the mouth of death,\u201d said Dr. Mansoor. But A. S. was lucky: Most hospitals in Yemen do not have the capacity or protocols in place to detect and treat drug-resistant infections; if he had been anywhere else, he would have lost his leg, or died.\r\nThe Saudi-led bombing campaign in Yemen has produced thousands of casualties and created vast numbers of refugees. But the real cost may not become apparent for years to come. After years of bombardment that has crippled the food supply, destroyed basic infrastructure and disrupted medical care, Yemen has become a breeding ground for antibiotic-resistant disease, with potentially catastrophic consequences \u2014 and not just for Yemen.\r\nWhen penicillin was first widely introduced in 1942, it was a revolution in medicine. Infections that used to kill no longer did. Similar breakthroughs followed, but the threat of microbes developing resistance to these wonder drugs has been a concern from the beginning. Until recently, the threat of drug-resistant disease was largely theoretical, a generalized fear rooted in a few isolated cases.\r\nIt\u2019s happening now in Yemen. The conflict is taking on aspects of warfare once found only in history books, when the real toll of a military campaign is not the immediate damage from weapons, but the long-term and far greater impact of disease that spread in the chaos of armed conflict. \u201cIt\u2019s a huge burden on the health system that can barely take care of primary health care,\u201d said Ana Leticia Nery, the medical coordinator for Doctors Without Borders in Yemen, which has long been the poorest country in the Middle East. More than 60 percent of the patients admitted to the medical organization\u2019s hospital in Aden have antibiotic-resistant bacteria in their systems.\r\nThe widespread prevalence of multidrug-resistant infections has nearly quadrupled the amount of time patients must spend in a field hospital to recover from war wounds. This extra time, plus the specialized antibiotics a patient requires to overcome a drug-resistant infection, means far fewer patients can be treated than the norm, and the care is much more expensive and difficult.\r\nSimilar problems are reported to be occurring through the war-torn regions of the Middle East, including Iraq and Syria, and countries with extensive refugee populations, like Jordan. \u201cThere is a scary, scary prevalence of multidrug resistance we see in the Middle East,\u201d Dr. Nery said.