Abstract:
Objective To investigate the epidemiological and clinical characteristics of psittacosis cases in Fuyang District of Hangzhou, Zhejiang Province, and to provide evidence for clinical diagnosis, treatment, and prevention and control of this disease.
Methods Epidemiological investigation data and clinical records of psittacosis cases residing in Fuyang District of Hangzhou from September 2020 to February 2025 were collected. Descriptive epidemiological methods were applied to analyze temporal-spatial-demographic distribution characteristics, exposure history, clinical manifestations, diagnosis, treatment and laboratory findings. Comprehensive analyses were further conducted incorporating environmental surveillance and case follow-up data.
Results Among the 16 psittacosis cases, the male-to-female ratio was 1∶1, with an incidence rate of 0.57/100 000 for both males and females. The mean age was (59.88±10.66) years old, and the highest incidence rates were in the 70‒79 years and 60‒69 years age groups, with an incidence rate of 1.41/100 000 and 1.30/100 000, respectively. Fourteen cases (87.50%) had a history of avian exposure. The predominant clinical symptoms included fever (15 cases, 93.75%), cough (11 cases, 68.75%), expectoration (9 cases, 56.25%), and fear of cold (8 cases, 50.00%). All cases showed elevated levels of C-reactive protein (CRP), and the results of chest computed tomography (CT) indicated pneumonia in every case. Neutrophil percentage was elevated in 87.50% (14/16) of cases, while lymphocyte percentage was reduced in 93.75% (15/16) of cases. The median time from onset to first medical consultation was 4.00 days, the median time from onset to confirmed diagnosis was 9.50 days, and the median time of hospitalization was 9.00 days. Compared with non-severe cases, the severe group had significantly higher neutrophil percentage, CRP levels, and longer intervals from onset to confirmed diagnosis, onset to first antibiotic administration, and duration of hospitalization. All cases recovered and were discharged, and more than 50% were treated with omadacycline following confirmed diagnosis.
Conclusion Most psittacosis cases reported definitive avian exposure history in Fuyang District of Hangzhou. Early diagnosis and treatment are critical for preventing disease progression to severe stages.