LAUSR

In September 2021, the Wyoming Department of Health (WDH) was notified of a suspected case of pneumonic plague in an adult who was admitted to a Wyoming hospital after 48 hours of worsening cough, dyspnea, and acute hemoptysis. The patient had two sick cats but no recent travel history or ill contacts. Due to compatible symptoms, no history of COVID-19 vaccination, and increased SARS-CoV-2 community transmission in Wyoming, health care providers suspected COVID-19. A provider's SARS-CoV-2 antigen test was negative 48 hours after symptom onset. The patient was hospitalized later that day with worsening symptoms and two negative SARS-CoV-2 laboratory-based nucleic acid amplification tests. Lung imaging indicated community-acquired pneumonia. A respiratory panel showed no viral pathogens in respiratory specimens. Sepsis and mechanical ventilation developed within 48 hours of admission. Azithromycin, piperacillin-tazobactam, and vancomycin treat pneumonia and sepsis. Seventy-two hours after the patient was admitted to the hospital, blood and sputum cultures did not indicate a causative pathogen. An infectious diseases specialist advised repeating a sputum culture with Gram stain and empiric ciprofloxacin due to the patient's history of exposure to sick cats. The Wyoming Public Health Laboratory identified Yersinia pestis from gram-negative bacilli. WDH reviewed medical records, worked with hospital infection preventionists, and interviewed the patient's friends, family, neighbors, and coworkers to determine PEP. Twenty-two close contacts were identified (19 healthcare workers and three personal contacts). No one got sick after receiving PEP within a week of symptom onset. The patient recovered and was discharged 35 days after hospitalization.