An antibiotic-resistant strain of Klebsiella pneumoniae has killed a seventh patient at the NIH Clinical Center in Bethesda, Maryland, the Washington Post reports.

Since the outbreak began in August 2011, the bacteria have infected 19 patients at the federal hospital, which only sees the sickest of the sick patients. Eleven of these patients died. Six of those deaths were directly attributed to the bacteria.

The hospital implemented strict infection control measures that included replacing plumbing where the bacteria lived, building a wall to isolate infected patients, and hiring hand-washing monitors. The measures appeared to work. For six months, no patients were diagnosed with Klebsiella pneumoniae until this most recent case — a boy with a compromised immune system — was diagnosed in July.

Source: Washington Post