Secular trend of nosocomial pneumonia in an university hospital in Zhengzhou / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the secular trend of infection rate, risk factor exposure rates for nosocomial pneumonia (NP), and to evaluate the nosocomial infection surveillance and control programs efficacy in an university hospital from 1993 to 2000.</p><p><b>METHODS</b>All 126 665 hospitalized patients from 1993 to 2000 were studied for NP. The independent risk factors for NP were analyzed by using case-control study method and logistic regression technique. The time-specific rates for NP and risk factor exposure were calculated annually.</p><p><b>RESULTS</b>The infection rates for NP were decreased by 50% from 1.20% in 1993 to 0.60% in 2000. The logistic regression analysis showed that the independent risk factors for NP were immunosuppressive therapy (OR = 2.72), chemotherapy (OR = 2.17), cancer (OR = 1.45), chronic obstructive pulmonary disease (COPD, OR = 1.88), ICU (OR = 3.18), coma (OR = 3.26), tracheotomy (OR = 14.95), hemodialysis (OR = 5.12), bone or lumbar puncture (OR = 1.82). The time-trends for exposure rates of COPD and bone or lumbar puncture were slightly decreased, however those for the others and the synthetic risk factors were not changed significantly.</p><p><b>CONCLUSION</b>The infection rates for NP were significantly decreased in the case of no change for exposure rates of risk factors for NP, this suggests that the nosocomial infection surveillance and control programs were effective for lowering infection rate for NP in this hospital.</p>

Study on the molecular mechanism of quinolone resistance in Shigellae spp / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the resistance and its mechanism of Shigellae spp. to quinolones.</p><p><b>METHODS</b>Seventy-three clinical isolates were collected. Susceptibility tests of pipemidic adcid (PI), ofloxacin (OFL), norfloxacin (NOR), and ciprofloxacin (CIP) were performed in all clinical isolates and Shigella 51573. The N-terminal coding region of gyrA and parC were amplified by polymerase chain reaction (PCR) respectively. Restriction fragment length polymorphism (RFLP) was applied to all PCR procucts of gyrA and parC, and single strand conformational polymorphism analysis (SSCP) was also applied to PCR procucts of parC.</p><p><b>RESULTS</b>The resistance rates for all the Shigella spp. to PI, CIP, NOR and OFL were 79.5%, 60.3%, 41.1% and 36.9%. Sixty-seven strains (91.8%) were quinolone-reduced-sensitive isolates, in which 61 strains (91%) were found carrying mutations in gyrA with 5 strains (7.5%) found carrying mutations in parC. No mutation was found in 6 quinolone-sensitive isolates or Shigella 51573.</p><p><b>CONCLUSION</b>The Shigella spp. had high resistance rates to quinolones. The target gene mutations which were mainly found in gyrA and secondarily in parC, played an important role in the quinolone-resistance in Shigella spp.</p>