Clinical Characteristics And Pathogenic Bacteria Analysis Of Staphylococcal Bloodstream Infection In 70 Patients With Secondary Immunodeficiency

Objectives To understand the clinical characteristics of staphylococcal bloodstream infection in patients with secondary immunodeficiency,as well as the distribution and drug resistance of Staphylococcus aureus(SAU) and coagulase negative Staphylococcus(CNS),and provide a reference for clinical diagnosis and treatment.Methods A total of 101 patients with Staphylococcus isolated from blood sample were retrospectively reviewed in our hospital.The patients were classified into a group with secondary immunodeficiency and another group with normal immune function as control group.Collect general information of patients(including gender, age, occupancy departments, hospital days, etc.), underlying diseases, risk factors for infection, the clinical features, treatment and clinical outcomes, etc. according to the design of the questionnaire.Register blood routine including white blood cell count, neutrophil count and lymphocyte count.Simultaneously register CRP, ESR, blood culture and sensitivity results.Results 1. All the 70 patients with staphylococcal bloodstream infection and secondary immunodeficiency had various degree of fever except 2 cases(temperature<36 degrees Celsius).Chills and shiver were reported in 30.0% of the patients,and migratory lesions in 15.5% of the patients.Lungs were the most common site of infection.About 11.4% of the patients complicated with septic shock.The case mortality was 17.1%.The incidence of septic shock and mortality in the patients with secondary immunodeficiency were higher than in the control group, but the difference was not statistically significant(P=0.050,P=0.054).2. Comparison of two groups on risk factors for infection,arteriovenous catheterization(21.4%: 3.2%, P = 0.021), glucocorticoid application(58.6%: 19.4%, P = 0.000) and the application of cytotoxic drugs(12.9%: 0%, P = 0.036) difference was statistically significant.3. A total of 70 strains of Staphylococcus were identified in the patients with secondary immunodeficiency,including 41(58.6%) strains of SAU, of which 18(43.9%) strains were MRSA,CNS 29(41.4%) strains,of which 24(82.8%) strains were MRCNS.In the control group,26(83.9%) strains of SAU were identified,of which 11(42.3%) strains were MRSA,and all the 5(16.1%) strains of CNS were identified as MRCNS.The incidence of CNS infection in the patients with secondary immunodeficiency was significantly different from that in the control group(P=0.013).4. All the MRS strains were Multidrug-Resistant Organism(MDRO) except one strain of Staphylococcus intermedius.The staphylococcal strains isolated from the patients with secondary immunodeficiency showed high rate of resistance to penicillin(100%),clindamycin(73.0%),erythromycin(90.0%) and gentamycin(61.0%).No strain was found resistant to tigecycline,linezolid or vancomycin.The resistance rate did not show significant difference between the patients with or without secondary immunodeficiency.Conclusions The clinical characteristics of staphylococcal bloodstream infection in the patients with secondary immunodeficiency are similar to the patients without secondary immunodeficiency,except higher incidence of septic shock and death,but the incidence of CNS infection is relatively higher.MDRO is more prevalent.Antimicrobial agents should be prescribed in clinical practice according to disease conditions and the result of antimicrobial susceptibility testing.