A Psittacosis Outbreak among English Office Workers with Little or No Contact with Birds, August 2015

Abstract

Introduction:On 14th August 2015 an office manager informed Public Health England of five employees known to have been diagnosed with pneumonia over the previous three weeks. We investigated to establish whether an outbreak occurred and to identify and control the source of infection.Methods:We undertook case finding for self-reported pneumonia cases at local businesses (July-August 2015). Clinical samples from a hospitalised case were tested for common respiratory pathogens, but returned negative results. Further testing confirmed Chlamydia psittaci infection in this case (serology and PCR). We subsequently undertook C. psittaci testing for all cases, redefining them as confirmed (C. psittaci PCR or high antibody titre via serology) or probable (inconclusive C. psittaci serology). Twenty-eight day exposure histories informed descriptive epidemiological analysis. We conducted an environmental investigation at the office to identify potential sources of exposure.Results:We identified six office workers with pneumonia; four met case definitions (three confirmed, one probable) with symptom onset between 29th July and 4th August 2015. Workplace was the only epidemiological link and only one case reported limited, indirect bird contact. Environmental investigations identified pigeons roosting near the office which were being fed by workers (none cases).Discussion:This was a probable outbreak of psittacosis with no direct bird-to-human contact reported. Cases recovered after receiving appropriate antibiotics. Feeding of pigeons was stopped. A deep clean of office ventilation systems was conducted and workers were advised to avoid bird contact. We hypothesised that indirect environmental exposure to infected pigeons was to the source of this outbreak. This work provides evidence that health professionals should consider psittacosis in the differential diagnosis of cases of severe or atypical respiratory illness even without overt bird contact.

Metagenomic next-generation sequencing in the diagnosis of severe pneumonias caused by Chlamydia psittaci

“…Chlamydia psittaci is responsible for less than 5% of community-acquired pneumonia [3,4]. Several outbreaks of C. psittaci infections in humans have occurred in different countries over the past 20 years, with a case fatality rate of less than 1% [5,6]. Chlamydia psittaci enters the body mainly through the respiratory tract by inhaling aerosolised bacteria when exposed to infected secretions, droppings, or feathers [6].…”

Detection of Chlamydia psittaci in both blood and bronchoalveolar lavage fluid using metagenomic next-generation sequencing

“…The main route of infection in humans is inhalation of aerosols from contaminated animal excreta through the respiratory tract. [ 1 ] C psittaci may cause severe diseases in people who have come into contact with birds. The C psittaci infection in humans may lead to severe conditions and complications, including sepsis and multiple organ failure.…”

Prevalence and Zoonotic Potential of Avian Chlamydia in Croatia

“…Other onset of the symptoms have scarcely been reported [27][28][29][30] . Main source of the disease are infected birds, rarely other animals [31][32] . Human to human transmission is extremely rare [33] .…”