Abstract: Objective To explore the HIV/AIDS associated with bacterial pneumonia's clinical characteristics, etiological characteristics and chest CT imaging data,and provide guidance for clinical diagnosis and treatment.Methods The clinical data and chest CT imaging data of 105 cases of AIDS complicated with bacterial pneumonia diagnosed in Guangxi Longtan Hospital from 2014 to 2015 were retrospectively analyzed. All cases met the diagnostic criteria for community-acquired pneumonia,and other pulmonary diseases were excluded.Result sIn 83 patients, CD4⁺T was less than 50/μL（P<0.05）. Procalcitonin was elevated in 95% of patients, while leukocyte and neutrophil ratios were normal or low in 87% of patients. A total of 236 pathogenic bacteria were isolated from the sputum or alveolar lavage (BALF) specimens of 105 patients. Pathogenic bacteria samples were common in klebsiella pneumoniae, pseudomonas aeruginosa, escherichia coli and staphylococcus aureus. 61% of patients were infected with multiple bacterial species, and most of them were drug-resistant strains. There were 11 cases of two bacterial infections, 41 cases of mixed three bacterial infections, and 12 cases of patients with more than three bacterial infections. Early chest CT only showed thickening and disorder of texture, followed by focal or large infiltrating shadows. When the lesion was severe, it showed lobar pulmonary consolidation or diffuse grid-like pattern in both lungs. There was no statistically significant difference in etiology, lung lesion site distribution and chest CT images (P>0.05).Conclusion Bacterial pneumonia was associated with immune function in AIDS patients, and patients with CD4⁺T was less than 50/μL were easily associated with bacterial pneumonia, which was not significantly associated with host age. PCT examination can assist AIDS patients in the diagnosis of bacterial pneumonia. The pathogenic bacteria of AIDS complicated with bacterial pneumonia are mainly g-bacillus and staphylococcus, and a variety of pathogenic bacteria are mixed for infection, among which the majority are durg-resistant strains. There was no significant correlation between etiology and clinical manifestations, pulmonary lesion site distribution and chest CT imaging. Dynamic observation of pulmonary lesions on chest CT was helpful for diagnosis.

Key words: HIV/AIDS, Bacterial pneumonia, Etiological characteristics, Chest CT