Pneumonic plague: What to know after Russian lab worker's death

A 28-year-old woman who worked at an anti-plague laboratory in Russia died Friday from an illness of undetermined origin, prompting U.S. officials to monitor reports of a suspected fatal case of pneumonic plague in the Irkutsk region. No cause of death has been confirmed, and nearly 200 contacts are under medical observation. Pneumonic plague, caused by Yersinia pestis bacteria, is the rarest but deadliest form of the disease, spreading through respiratory droplets within three to six feet and requiring treatment within 48 hours of symptoms. Antibiotics remain highly effective, and experts say there is no evidence of resistance or risk of a pandemic like COVID-19. The U.S. reports about seven plague cases annually, mostly in rural Southwest states, with deaths rare but possible, as seen in an Arizona man last July. Experts stress that the woman's death may be unrelated to her lab work, though biological weapons programs in such facilities would be a greater concern.