The Study Of Early Diagnosis Value And Clinical Significance Of Fluorescence Quantitative Polymerase Chain Reaction Test For Early Detecting Value And Clinical Significance Mycoplasma Pneumonia Infection.

ObjectiveMycoplasma pneumoniae is a common cause of community-acquired pneumonia and lower-respiratory-tract infections. It is reported to cause 6 to 20% of community-acquired pneumonia (CAP) and lower-respiratory-tract infections (LRTI)in children . The incidence of M. pneumoniae with CAP and LRT1 ranges from 1 to 30%, depending on the population studied and the diagnostic test used Diagnosis has traditionally been obtained by serological diagnosis, but increasingly, molecular techniques have been applied.. M. pneumoniae is difficult to grow in cultures; therefore, clinical diagnosis relies mainly on serology and, Serological methods lack sufficient sensitivity in the acute phase of the disease. An accurate diagnosis with convalescent-phase samples is often made many days after the onset of disease Sensitivity and specificity values are between 55 and 100%, depending on the serological method used and the patient population tested in recent years, clinical diagnosis relies mainly on molecular techniques. It is important to establish M. pneumoniae as the pathogen by laboratory diagnosis, as the clinical presentation is not significantly different from that seen with other pathogens causing CAP. Since the organism is not sensitive toβ-lactam antibiotics, which are often used for empirical treatment of LRTI, a rapid diagnostic method is required for the prescription of effective antibiotics (7). PCR has been shown to offer the potential of increased sensitivity and rapidity compared to other diagnostic tests. For the diagnosis of M. pneumoniae infections, therefore, nucleic acid amplification techniques have been introduced in many diagnostic laboratories as a valuable test.Fluorescence quantitative polymerase chain reaction Test(FQ-PCR) is a new development of nucleic acid detection technology.It integrated high sensitive of PCR and high specificity of DNA hybridization probe and high exact quantitation of spectrum technical.It give a fast consequence within 2 hours,Which can promptly to provid clinic and quantitate for pathogeny. Moreover,It have no post- management as common PCR,Compared to traditional PCR it cut down the happen of pollution markedly.The study purpose is investigate the fluorescence quantitative polymerase chain reaction Test for early Diagnosis value and clinical significance of children Mycoplasma Pneumonia infectation.Especially for infant and low-immunopotency who produce little antibody.Target and Methods一. Choosing target for study(一) Target for studyThe 122 out- patient of below- respiratory infection in our respiratory clinic from 2006.10-2007.3.Man:64,Female:58.age from 2 months to 14 years. <3 years 53 people, 3-6years 41 people ,≥6years 28 people. Sex Ratio have no significant difference.(二) control group20 people, unimpaired child during the same period in our hospital.age angd sex have no significance difference with experiment group.二. Method(一) The main instrument and reductantSLAN Fluorescence quantitative polymerase chain analysator, superclean bench, hydroextractor, vibration organ,MP -DNA kit. Computer,freezer.(二) specimen collectthe cotton pledget clean and polish throat paries posterior, Therefore quake in 1-ml SPSS ,maintain in zero -20 degree.collect VB within the day or the second day of visit.(三) diagnosis standardthe second antibody step up exceed 4 times or the first titre≥1: 160 as MP infection(四) Detection1,Take out of specimen and defrost to get out DNA.2,Take out of kit and rewarming the room temperature.3,Start SLAN.(五) statistics analysisInterclass masculine rate compare with X~2 detection,Use SPSS10.0 software, P<0.05 have statistics difference.Results一. The positive rate of Swab FQ-PCR Compare with particalagglutinate methodThe sensitive of FQ-PCR is 86.67%,Specificity is 91.30%, positive predictive value is 76.47%, negative predictive value is 97.67%,coincidence is 90.16%,have no significance difference.二. The positive rate of Swab FQ-PCR Compare with The firsttitre < 1:160There are 110 positive example in 122 person,and 18 were confirmed positive by the second antibody detection,FQ-PCR detect 16 in the 18 example,the coincidence of two method is 90.90%,so FQ-PCR can be the early diagnosis method.especially in the early stage when the first titre < 1:160.三. The comparion of different age groupNo matter the two methords in the group of≥6years the positive rate is the most highest, FQ-PCR,have higher positive rate in patients≤3 years.四. The detection of common children groupThere has 1 people positive in 20 Control groupConclusion1. two methods have good coincidence,so FQ-PCR have higher sensitivity and specificity.2. FQ-PCR have good coincidence with the second antibody detection,so it have early diagnosis value.3. FQ-PCR have higher diagnosis value than particle agglutination in infant.