ABSTRACT
At present, the situation of COVID-19 epidemic prevention and control in China is gradually improving, but the situation of overseas import prevention and control remains difficult. The COVID-19 epidemic may exist for long due to the undetermined source of infection, the difficulty in completely cutting off the transmission route, and a large number of susceptible people. Therefore, prevention and control will be a long-term and arduous task, making it necessary to adhere to the principle of combining emergency response with regular prevention and control, coordinating the epidemic prevention and social-economic development in a balanced way. In retrospect, the epidemic has exposed the ambiguous positioning and unsatisfying hardware construction of hospital laboratory departments, and delayed intervention of laboratory experts in the public health treatment system of China. This paper reflects on the hospital laboratory departments′ problems during the anti-epidemic activities, and put forward suggestions to improve the future development of clinical laboratories in the national public health system.
ABSTRACT
Objective To evaluate five detection methods for the laboratory diagnosis of Clostridium difficile infection in the hospitals of USA, and explore a sensitive, specific, accuracy and rapid regimen for the early diagnosis of Clostridium difficile infection. Methods A total of 174 stool specimens submitted to the clinical microbiology laboratory for Clostridium difficile testing were separately tested by five methods including toxigenic culture (TGC), Premier Toxin A&B EIA( A/B-EIA), C. Diff Quick Chek Complete( DEIA), BD G eneOhm Cdiff assay(BD-PCR) and Laboratory-developed PCR(LD-PCR). The gold standard of TGC was used as a reference criterion, and the sensitivity, specificity, positive predictive value ( PPV )and negative predictive value (NPV) of A/B-EIA, D-EIA, BD-PCR and LD-PCR assays were determined. Results Among the 174 specimens studied, 24 were defined as true positives for Clostridium difficile infection by TGC assay, giving a positive rate of 13.8% (24/174). In comparison to the standard,the sensitivity, specificity, PPV and NPV were 62.5%, 99.3%, 93.8% and 94.3% for A/B-EIA;66.7%, 98.7%, 88.9% and 94.9% for D-EIA; 83.3%, 98.7%, 90.9% and 97.4% for BD-PCR;79.2%, 93.3%, 65.5% and 96.6% for LD-PCR. Among all tested specimens, 34 were positive by atleast one of five methods, and of which 15 were concordant by all five methods. The D-EIA results were divided into three groups depending on results of GDH and (or) toxins A/B: 18 were positive for both GDH and toxins A/B, 23 were positive for only GDH, and 133 were negative for both GDH and toxins A/B. Of 18 positive specimens by D-EIA assay, all were concordant with results of BD-PCR assay and 16 were agreement with results of TGC assay. Twenty-two of 24 positive specimens by TGC assay were included in 41 specimens that were positive for GDH. Among eight false negative specimens by D-EIA assay, four were differentiated as positive results by BD-PCR. According to the present study, the sensitivity, specificity,PPV and NPV of a two-step detection algorithm in combination with D-EIA and BD-PCR assays were 83.3%, 98.7%, 90.9% and 97.4%, respectively. Conclusions From the point of technological evaluation, BD-PCR is preferable. A two-step detection algorithm combining D-EIA with BD-PCR is proposed for the laboratory diagnosis of Clostridium difficile infection. This algorithm has demonstrated an excellent sensitivity and specificity, as well as decreased test turnaround time and test cost.