Clinical application of seven experimental methods in tuberculosis diagnosis

Objective To compare the application value of sputum smear,sputum float-concentrated,L-J sputum culture,BACTCEC MGIT960systemic culture,polymerase chain reaction(PCR),simutanenous amplificationg and testing(SAT)and antibody IgG to Mycobacterium tuberculosis(TB-Ab)in clinical diagnosis of tuberculosis(TB).Methods Sputum samples from 672tuberculosis patients and 62healthy persons from our hospital were detected by sputum smear,sputum float-concentrated,L-J sputum culture,BAC-TCEC MGIT960systemic culture,PCR,SAT and TB-Ab.Results Totally 672tuberculosis patients were submitted with a total positive rate of 17.0%(115/676)in sputum smear,25.6%(173/676)in sputum float-concentrated,32.2%(218/676)in L-J sputum culture,45.7%(309/676)in BACTCEC MGIT960systemic culture,90.1%(609/676)in PCR,96.4%(652/676)in SAT and 65.4%(442/676)in TB-Ab.In 62healthy persons,only PCR and TB-Ab were submitted with positive rate of 8.1%,12.9%respectively.Smear-negative specimens of positive rate by L-J sputum culture tuberculosis,TB-Ab and SAT combined detection were higher than that of single detection method.Conclusion Sputum smear is simple,fast and cheap,but the positive rate is low.Sputum smear is the leading role of basic-level hospitals for a long period of time.L-J sputum culture to bacteria identification and drug sensitive tests are still indispensable method,but the cycle is long.Mycobacterium tuberculosis is simple,convenient.It is still an important means of laboratory diagnosis of TB,but cannot distinguish between infection and disease.PCR is fast,sensitive and has a good diagnostic value,but the equipment of PCR is expensive.PCR requires high technology and is polluted easily.The SAT is fast,sensitive,too.STA that requires less cost and lower technique than PCR will help the diagnosis of tuberculosis.Joint detection helps improve diagnosis rate and meets the clinical needs.