Infectious Diseases 2019

Infectious Diseases 2019

USA: Psittacosis outbreak among workers at chicken slaughter plants

Emerging Infectious Diseases Vol. 25, No. 11, November 2019 17 October, 2019

During August–October, 2018, an outbreak of severe respiratory illness was reported among poultry slaughter plant workers in Virginia and Georgia, USA. Psittacosis results from inhalation of aerosolized droppings or respiratory secretions of birds infected with Chlamydia psittaci. During 2008–2017, a total of 60 cases of psittacosis, a nationally notifiable disease in the United States, were reported to the National Notifiable Diseases Surveillance System. The most recent large poultry-associated outbreaks in the United States were reported 3 decades ago and were linked to turkeys. During August 31 - September 4, 2018, the Virginia Department of Health (VDH) received reports of 10 persons, all workers at the same chicken slaughter plant, hospitalized with fever, headache, cough, and radiographic evidence of pneumonia. Lower respiratory tract specimens from 3 hospitalized workers were positive for C. psittaci by real-time PCR. The Virginia plant suspended operations on September 8. On September 12, the Georgia Department of Public Health (GDPH) was notified that 3 employees of a Georgia chicken slaughter plant owned by the same company were hospitalized with pneumonia. C. psittaci was detected in sputum samples from all 3 patients. The Georgia plant suspended operations on September 15. After plant closures, VDH and GDPH staff inspected the respective plants, which both slaughter only chickens, and collected environmental samples to test for C. psittaci. Environmental samples were tested for chlamydial species by using real-time PCR, followed by high-resolution melt analysis, at the University of Georgia Infectious Disease Laboratory.
At the Virginia plant, 50 cases (including 5 confirmed) were identified; 30 cases (including 8 confirmed) were identified at the Georgia plant. Genotype D of C. psittaci was identified in patient specimens; this genotype is most often found in poultry. Bird evisceration was the most common job duty or title (reported by 53% of ill workers).
C. psittaci was not detected in any of the environmental samples from the Virginia (n = 62) and Georgia (n = 46) plants.