Related Experiment Videos
Community outbreak of psittacosis in a rural Australian town
J Williams1, G Tallis, C Dalton
1Infectious Diseases Unit, Department of Human Services, Victoria, Australia.
Background:
Health authorities in Victoria, Australia were notified of three men from a rural town with atypical pneumonia, admitted to hospital over 8 days. Initial serological testing suggested Chlamydia psittaci as the cause. We did a case-control study to find risk factors for psittacosis.
Methods:
We searched for cases of pneumonia or severe flu-like illness through family physicians and the regional hospital. We selected three controls per case from the region's electoral roll. We collected blood for serological tests and administered questionnaires to all cases and controls.
Findings:
We found 16 cases of psittacosis and one died. Most cases were clustered within a small geographical area, with a median age of 58 years (range 23-76), 15 (94%) of whom were male. Keeping, handling, or feeding domestic or wild birds was not associated with illness. Cases spent a median of 17.5 h per week in their garden, compared with a median of 5.2 h for controls (p=0.04) and were more likely to have mowed lawns during the 3 weeks before onset of illness than controls (odds ratio 4.81 [95% CI 1.08-33.37]).
Interpretation:
We showed that psittacosis outbreaks are not limited to direct contact with birds and pose new challenges for disease control. Modifications may be needed to work outdoors to decrease the risk of psittacosis.
Insights
Psittacosis, a pneumonia caused by Chlamydia psittaci, was linked to gardening and mowing lawns, not direct bird contact. These findings highlight new challenges for controlling this avian disease.
Area of Science:
- Infectious Diseases
- Epidemiology
- Public Health
Background:
- Atypical pneumonia cases in Victoria, Australia, prompted an investigation into potential causes.
- Initial serological tests indicated Chlamydia psittaci as the likely causative agent for the observed pneumonia cases.
Purpose of the Study:
- To conduct a case-control study to identify risk factors associated with psittacosis.
- To understand the transmission dynamics of psittacosis beyond direct avian contact.
Main Methods:
- Case ascertainment through physicians and regional hospital for pneumonia or severe flu-like illness.
- Selection of three controls per case from the electoral roll for comparison.
- Data collection via serological blood tests and structured questionnaires for cases and controls.
Main Results:
- Sixteen cases of psittacosis were identified, with one fatality.
- The majority of cases (94%) were male, with a median age of 58.
- Significant risk factors included increased time spent gardening (median 17.5 hours/week) and mowing lawns in the preceding 3 weeks (OR 4.81).
Conclusions:
- Psittacosis outbreaks can occur without direct contact with birds, presenting novel disease control challenges.
- Outdoor work modifications, particularly gardening and lawn mowing, may be necessary to reduce psittacosis transmission risk.