Objectives To analyze and assess the status of detection of human immune-deficiency virus (HIV) by PCR, and to find a new screening test of HIV. Methods Using the following keywords "diagnosis tests", "AIDS", "PCR" and "HIV", we searched the Medline and CBM from 1991 to 2001. Then we assess each of diagnosis test according to the international standards. Results 567 articles were searched, in which 53 articles were chosen to assess. In these 53 articles, it was found that 47% applied comparison with Golden Standard, 25% calculated sensitivity, 23% calculated specificity, and 23% calculated predictive value, no likelihood ratio was calculated in these articles. Conclusions It was still a kind of pilot-study to apply PCR to screening detection of HIV. The design methods of study should be improved.
Abstract: Objective To analyze the characteristics of pathogens isolated from patients with lung cancer after surgery, and provide instructions for the prevention and treatment of postoperative infection. Methods A retrospective investigation of the pathogenic microbiology data of 159 patients（142 males and 17 females with average age at 61.8±9.6 years) with lung cancer after surgery in West China Hospital from January 2009 to December 2011 was performed.We got the specimen from the patients by routine methods, identified the pathogens, and conducted drug susceptibility tests in vitro. Results The pathogens were mainly isolated from sputum of the patients （90.6%, 155/171）. Canidia albicans（25.7%, 44/171）, Klebsiella pneumonia（15.2%, 26/171）, Acinetobacter calcoaceticus-A. baumannii（13.4%, 23/171）and Pseudomonas aeruginosa（8.2%, 14/171） were the predominant species. Among A. calcoaceticus-A. baumannii isolates, 39.1%（9/23） of them were multidrug resistant strains. And 23.1%（6/26）of K. pneumonia isolates produced extended spectrum beta-lactamases. P. aeruginosa isolates showed high in vitro susceptibility to the antibacterial agents. Conclusion Pathogens are mainly isolated from sputum of patients after surgery for lung cancer. Canidia albicans and gram-negative bacilli are predominant isolates and should be the major targets for the prevention and treatment of postoperative infection.
Objective To analyze the species distribution and resistance of the pathogens isolated fromblood cultures of the patients in intensive care unit ( ICU) , and provide a basis for prevention and control of bloodstream infections in critically ill patients. Methods The data of blood cultures of the patients in ICUduring January 2009 to December 2011 was investigated retrospectively.Results In the last 3 years, positive rate of blood cultures of ICU patients was 15. 4% , 15. 7% , and 17. 6% respectively. Among the isolates, Gram-positive bacteria were predominant ( 52. 3% ) , followed in order by gram-negative bacteria ( 33. 1% ) and fungi ( 14. 7% ) . Aerobe and facultative anaerobe were the predominant bacterial isolates ( 99. 7% ) . Enterococcus faeciumand Staphylococcus spp. were the most common gram-positive bacteria, and 4. 5% of E. faecium isolates were resistant to vancomycin. Rate of methicillin-resistance for S. aureus and S. epidermidis was 73. 5% and 93. 7% respectively. In terms of gram-negative bacteria, Acinetobacter calcoaceticus- A. baumannii complex were the leading species, 96. 9% of the isolates had multi-drug resistance and 14. 1% of the isolates had extra-drug resistance. Klebsiella pneumonia and Escherichia coli isolates were less frequently isolated and those producing extended spectrum beta-lactamases accou ted for 70. 3% and 80. 0% of the isolates respectively. Candida spp. was the most common fungi isolates ( 96. 7% )with an annual change of species distribution and declining susceptibility to azoles.Conclusions Gram-positive bacteria should be the major target for prevention and control of bloodstream infections in critically ill patients. Whereas, more attention should be paid to the infection caused by candida spp. and multidrug resistant gram-negative bacteria.
Objective To investigate the characteristics of the pathogens isolated from the cerebrospinal fluid (CSF) and the prognosis of the adult patients with central venous system (CNS) infection, and to provide the basis for disease treatment. Methods The clinical data and findings of the laboratory examination of the patients, who were admitted to West China Hospital of Sichuan University from January 2014 to September 2016, and suffered from CNS infection with the positive results of CSF culture, were retrospectively analyzed. The species distribution and in-vitro susceptibility of the pathogens and hospital mortality were analyzed. Results A total of 157 cases, involving 87 (55.4%) community-acquired cases and 70 (44.6%) hospital-acquired cases, were included. One hundred and fifty-eight strains of the pathogens were isolated from the CSF specimens of these patients, including 73 isolates (46.2%) of gram negative bacteria, 64 isolates (40.5%) of fungus, and 21 isolates (13.3%) of gram positive bacteria. In terms of species distribution,Cryptococcus neoformans was the predominant (62/87, 71.3%) species isolated from the patient with community-acquired infection, whileAcinetobacter calcoaceticus-A. baumannii complex (31/71, 43.7%) was the predominant specie from the patients with hospital-acquired infection. Analysis of the resistance phenotypes showed that all theC. neoformans isolates were susceptible to the antifungal agents. More than 90% ofA. calcoaceticus- A. Baumannii complex isolates were resistant to the regular antibiotics. The resistant rates ofK. pneumoniae isolates to the regular antibiotics were no more than 25%. The hospital mortality of the groups infected by gram-negative bacteria, fungi, and gram-positive bacteria were 52.3% (38/72), 32.8% (21/64), and 19.0% (4/21), respectively. There was statistical difference for the hospital mortality among these groups (P=0.006). Conclusion In our hospital,C. neoformans are the common species isolated from CSF of the patients with community-acquired CNS infection. Gram negative bacilli are commonly isolated from CSF of the hospital-acquired cases. The mortality of patients with gram negative bacilli is high.
Objective To analyze the characteristics of pathogens causing bloodstream infection (BSI) after cardiovascular surgery, and provide instructions for prevention and treatment of such kind of disease. Methods A retrospective investigation of clinical and pathogenic data of the patients suffering from BSI after cardiovascular surgery in West China Hospital of Sichuan University from January 2015 to December 2016 was performed. There were 61 patients with 36 males and 25 females at average age of 48.2±17.1 years. A percentage of 65.6% (40/61) of the underlying diseases was rheumatic heart disease. Results Sixty-five strains were isolated from the blood culture specimens of the 61 patients. Gram-positive bacteria, gram-negative bacteria and fungi isolates accounted for 56.9% (37/65), 35.4% (23/65), and 7.7% (5/65), respectively. Among these isolates, Streptococcus spp. was predominant (19/65, 29.2%), followed by Staphylococcus epidermidis (8/65, 12.3%), Staphylococcus aureus (6/65, 9.2%), Acinetobacter calcoaceticus- A. baumannii (5/65, 7.7%) and Escherichia coli (5/65, 7.7%). The resistance rate of Streptococcus spp. to erythromycin and clindamycin was 73.4% (14/19) and 63.2% (12/19), while its resistance to cefepime, vancomycin or linezolid was not observed. Staphylococcus spp. showed the resistance rate of 71.4% (10/14) to oxacillin. All of A. calcoaceticus-A. baumannii isolates were multidrug resistant (5/5, 100.0%), and 80.0% (4/5) of them were resistant to imipenem. The isolates producing extended spectrum beta-lactamase accounted for 80.0% (4/5) of E. coli. Conclusion Streptococcus spp. was the common pathogen causing BSI after cardiovascular surgery. Staphylococcus spp. and gram-negative bacilli show high resistance.
ObjectiveTo analyze the distribution and drug resistance of Enterobacteriaceae in West China Hospital of Sichuan University, to provide long-term monitoring data references for clinical practice.MethodsThe clinical information of non-repetitive Enterobacteriaceae isolates from 2006 to 2015 was collected and analyzed. All the isolates were identified by VITEK-2 Compact Automatic Microbial Identification Analyzer (Bio Merieux, France). The statistic informations were analyzed by WHONET 5.6 and iLabDataforMDR 1.03.ResultsA total of 38 487 strains of Enterobacteriaceae were isolated from 2006 to 2015, mainly including 14 862 stains of Escherichia (38.6%), 12 894 stains of Klebsiella (33.5%), 6 277 stains of Enterobacter (16.3%), 1 758 stains of Proteus (4.6%), 1 257 stains of Serratia (3.3%), 933 stains of Citrobacter (2.4%), and 506 stains of Morganella (1.3%). The top three sample types were sputum (46.9%), urine (18.7%), and secretions (11.5%). The drug resistance rate of Enterobacteriaceae showed a downward trend to most antibacterials. The average resistance rate of Enterobacteriaceae to ampicillin, ampicillin/sulbactam, and cefazolin was 85.3%, 52.6%, and 72.9%, respectively. The resistance rates to ceftriaxone, cefepime, gentamicin, and tobramycin were significantly reduced. The resistance rates to other antibiotics showed decreasing or slow increasing trends. The isolation rate of extended-spectrum β-lactamases (ESBL)-producing strains in Escherichia did not change, but the rate in Klebsiella decreased significantly. The isolation rate of multidrug-resistant organisms (MDRO) showed a slow decrease.ConclusionsThe overall antimicrobial resistance and the isolation rates of MDRO and ESBL-producing organisms showed a downward trend in investigating period. However, the carbapenem-resistant Enterobacteriaceae was rising continuously. Long-term monitoring of drug resistance is of notable value to antibiotic management policies.
ObjectiveTo investigate the diagnostic value of lateral chromatography for cryptococcal capsular polysaccharide antigen in cryptococcal infection.MethodsThe data of patients who detected cryptococcal capsular polysaccharide antigen in West China Hospital of Sichuan University in 2018 were collected. The sensitivity, specificity, positive predictive value and negative predictive value of cryptococcal capsular polysaccharide antigen detected by lateral chromatography were analyzed. The samples with positive lateral chromatography and definite clinical diagnosis were compared with the results of ink staining and fungal culture.ResultsA total of 721 cases were detected. The sensitivity, specificity, positive predictive value and negative predictive value of lateral chromatography detection were 100.00%, 99.39%, 93.93%, 100.00%, respectively. The positive rates of ink staining, fungal culture and cryptococcal capsular polysaccharide antigen for cryptococcal infection were 63.46%, 48.00% and 100.00%, respectively. Sixty-two patients were clinically diagnosed, including 45 cases of cryptococcal meningitis (72.58%), 16 cases of cryptococcal pneumonia (25.81%), and 1 case of bone cryptococcal infection (1.61%).ConclusionsLateral chromatography detection for cryptococcal capsular polysaccharide antigen shows well performing sensitivity and specificity in the diagnosis of cryptococcal infection. Considering its rapid and simple pre-operation, cryptococcal capsular polysaccharide antigen detection with lateral chromatography has good application value for early diagosis of cryptococcal infection.