In 2009, pandemic influenza A (H1N1) virus (H1N1 09) started to spread quickly in many countries. It causes respiratory infection with signs and symptoms of common infectious agents. Thus, clinicians sometimes may miss the H1N1 patient. Clinical laboratory tests are important for the diagnosis of the H1N1 infection. There are several tests available, however, the rapid test and direct fluorescence antigen test are unable to rule out the influenza virus infection and viral culture test is time consuming. Therefore, nucleic acid amplification techniques based on reverse transcription polymerase chain reaction assays are regarded as a specific diagnosis to confirm the influenza virus infection. Although the nucleic acid-based techniques are highly sensitive and specific, the high mutation rate of the influenza RNA-dependent RNA polymerase could limit the utility of the techniques. In addition, their use depends on the availability, cost and throughput of the diagnostic techniques. To overcome these drawbacks, evaluation and development of the techniques should be continued. This review provides an overview of various techniques for specific diagnosis of influenza infection.
Disease Outbreaks/prevention & control ; Drug Resistance, Viral ; Fluorescent Antibody Technique, Direct/methods ; Humans ; Influenza A Virus, H1N1 Subtype/drug effects/*genetics ; Influenza, Human/*diagnosis/drug therapy ; Polymerase Chain Reaction/methods ; Sensitivity and Specificity ; Time Factors

BACKGROUND: We intended to evaluate the diagnostic usefulness of a multiplex reverse transcriptase- PCR (mRT-PCR) assay kit under dual priming oligonucleotide system (DPO) for the childhood acute respiratory tract infections. METHODS: Two hundred nasopharyngeal aspirates were taken from children < or = 5 yr old admitted due to acute respiratory infections in 2004. Direct fluorescent antibody (FA) assays were performed with fresh specimens; then, mRT-PCRs for the detection of 12 respiratory viruses (Seeplex RV detection kit, SeeGene, Seoul, Korea) were tested with frozen specimens. RESULTS: FA assays for five common respiratory viruses showed positive results in 66 patients (33.0%), while mRT-PCR detected causative viruses in 112 patients (56.0%), including 16 co-infected cases (8.0%). A total of 129 viruses were identified: respiratory syncytial virus A/B (38.0%/7.8%), influenza virus A/B (10.1%/5.4%), parainfluenza virus 1/2/3 (7.0%/3.1%/7.8%), coronavirus 229E or NL63 (6.2%), human metapneumovirus (4.7%), adenovirus (4.7%), rhinovirus (3.9%), and coronavirus OC43 (1.6%). CONCLUSIONS: DPO-based mRT-PCR was found as a sensitive tool for the detection of the viruses that cause childhood respiratory infections. Clinical significances of the agents detected by mRTPCR need further evaluations.
Child, Preschool ; DNA, Viral/analysis ; Fluorescent Antibody Technique, Direct ; Humans ; Infant ; Infant, Newborn ; Oligonucleotide Probes ; Reproducibility of Results ; Respiratory Tract Infections/*diagnosis/epidemiology/virology ; Reverse Transcriptase Polymerase Chain Reaction/*methods ; Virus Diseases/*diagnosis/epidemiology/virology ; Viruses/genetics/*isolation & purification

PURPOSE: Behcet's disease (BD) is a disease of unknown etiology, which has multisystemic involvement. This multisystemic involvement might be the clue for an autoimmune pathogenesis. In order to evaluate an autoimmune pathogenesis, we examined immunoreactans depositions in the skin of BD patients. MATERIALS AND METHODS: The skin samples of 108 BD patients (28 perilesional skin, 44 positive pathergy test site, 22 negative pathergy test site, 14 normal skin) were examined for the depositions of immunoglobulin (Ig)M, IgG, IgA, complement 3 (C3), and fibrinogen (F) using direct immunofluorescence (DIF). The data were statistically compared to the DIF of 36 systemic lupus erythematosus (SLE) patients and 20 healthy controls using chi-square Fisher exact test. RESULTS: Highly significant immunoreactans depositions were obtained in BD (deposition rates: IgM 70.3%, IgG 0%, IgA 20.3%, C3 62.9%, F 83.3%). The comparison with SLE revealed no differences in IgM, IgA, and C3. However, IgG deposition was higher in SLE while F deposition was higher in BD. In both BD and SLE, the Ig depositions were highly significant when the data were compared with the healthy controls. CONCLUSION: The significant deposition of immunoreactans in BD, especially in the negative pathergy and the normal skin sites, were observed. This study is the first controlled study revealing positive Ig depositions in BD, and it is expected to help us to reconsider the autoimmune pathogenesis in BD.
Adolescent ; Adult ; Aged ; Behcet Syndrome/*metabolism ; Case-Control Studies ; Female ; Fluorescent Antibody Technique, Direct/*methods ; Humans ; Immunoglobulin A/metabolism ; Immunoglobulin G/metabolism ; Immunoglobulin M/metabolism ; Male ; Middle Aged ; Skin/metabolism/pathology ; Young Adult

PURPOSE: Behcet's disease (BD) is a disease of unknown etiology, which has multisystemic involvement. This multisystemic involvement might be the clue for an autoimmune pathogenesis. In order to evaluate an autoimmune pathogenesis, we examined immunoreactans depositions in the skin of BD patients. MATERIALS AND METHODS: The skin samples of 108 BD patients (28 perilesional skin, 44 positive pathergy test site, 22 negative pathergy test site, 14 normal skin) were examined for the depositions of immunoglobulin (Ig)M, IgG, IgA, complement 3 (C3), and fibrinogen (F) using direct immunofluorescence (DIF). The data were statistically compared to the DIF of 36 systemic lupus erythematosus (SLE) patients and 20 healthy controls using chi-square Fisher exact test. RESULTS: Highly significant immunoreactans depositions were obtained in BD (deposition rates: IgM 70.3%, IgG 0%, IgA 20.3%, C3 62.9%, F 83.3%). The comparison with SLE revealed no differences in IgM, IgA, and C3. However, IgG deposition was higher in SLE while F deposition was higher in BD. In both BD and SLE, the Ig depositions were highly significant when the data were compared with the healthy controls. CONCLUSION: The significant deposition of immunoreactans in BD, especially in the negative pathergy and the normal skin sites, were observed. This study is the first controlled study revealing positive Ig depositions in BD, and it is expected to help us to reconsider the autoimmune pathogenesis in BD.
Adolescent ; Adult ; Aged ; Behcet Syndrome/*metabolism ; Case-Control Studies ; Female ; Fluorescent Antibody Technique, Direct/*methods ; Humans ; Immunoglobulin A/metabolism ; Immunoglobulin G/metabolism ; Immunoglobulin M/metabolism ; Male ; Middle Aged ; Skin/metabolism/pathology ; Young Adult

OBJECTIVEEvaluation of the direct rapid immumohistochemical test (DRIT) for laboratory surveillance of rabies.

METHODS72 brain specimens of domestic dogs or patients collected from Guizhou, Guangxi, Hunan, Anhui, Jiangsu and Yunnan provinces were detected by conventional methods including Direct Fluorescent-antibody Assay (DFA) and Reverse Transcription Polymerase Chain Reaction (RT-PCR), and by DRIT which was newly developed in the Rabies Section of the Centers for Disease Control and Prevention in the United States. The sensitivity and specificity of DRIT were evaluated by compare of the three results. By analysis of the index including cost of experiment, technique requirement and so on, the advancement and applicability of DRIT were discussed.

RESULTSCompared with DFA and RT-PCR, DRIT will be more applicable for laboratories with limited funds and weak techniques because of its lower cost needed and simpler techniques required while its sensitivity and specificity are equal to the other two methods.

CONCLUSIONDRIT is more valuable in rabies diagnosis and more applicable for extension and popularization in rabies laboratory surveillance in local CDC.

Animals ; Brain ; virology ; China ; epidemiology ; Dog Diseases ; diagnosis ; epidemiology ; virology ; Dogs ; Fluorescent Antibody Technique, Direct ; methods ; Humans ; Molecular Sequence Data ; Prevalence ; Rabies ; diagnosis ; epidemiology ; veterinary ; virology ; Rabies virus ; genetics ; immunology ; isolation & purification

In order to develop tools for an early serodiagnosis of Plasmodium falciparum infection, we evaluated the usefulness of P. falciparum liver stage antigen-3 (LSA-3) as a serodiagnostic antigen. A portion of LSA-3 gene was cloned, and its recombinant protein (rLSA-3) was expressed in Escherichia coli and purified by column chromatography. The purified rLSA-3 and 120 test blood/serum samples collected from inhabitants in malaria-endemic areas of Mandalay, Myanmar were used for this study. In microscopic examinations of blood samples, P. falciparum positive rate was 39.1% (47/120) in thin smear trials, and 33.3% (40/120) in thick smear trials. Although the positive rate associated with the rLSA-3 (30.8%) was lower than that of the blood stage antigens (70.8%), rLSA-3 based enzyme-linked immunosorbent assay could detect 12 seropositive cases (10.0%), in which blood stage antigens were not detected. These results indicate that the LSA-3 is a useful antigen for an early serodiagnosis of P. falciparum infection.
Recombinant Proteins/biosynthesis/genetics/*immunology ; Plasmodium vivax/isolation & purification ; Plasmodium falciparum/*immunology ; Molecular Sequence Data ; Malaria, Falciparum/blood/*diagnosis ; Humans ; Genes, Protozoan/genetics/immunology ; Fluorescent Antibody Technique, Direct/methods ; Escherichia coli/genetics ; Enzyme-Linked Immunosorbent Assay/methods ; Early Diagnosis ; DNA, Protozoan/chemistry ; DNA Primers/chemistry ; Cloning, Molecular/methods ; Base Sequence ; Antigens, Protozoan/biosynthesis/chemistry/genetics/*immunology ; Animals ; Amino Acid Sequence

OBJECTIVETo establish a rapid and reliable loop-mediated isothermal amplification (LAMP) method for detecting adenoviruses (ADV)in respiratory samples collected from children with acute respiratory infections.

METHODAccording to the sequences of hexon genes of common adenovirus serotypes (Ad3, Ad7, and Ad14) downloaded from GenBank, primers were designed and LAMP method for detecting adenovirus DNA was developed. Sensitivity of the LAMP method was evaluated by using constructed recombinant plasmid DNA with gene fragment from hexon of ADV3, and specificity was tested through cross-reaction with other viruses. Then 11 ADV strains isolated from clinical specimens using tissue cultures were tested by LAMP method. A total of 108 nasopharyngeal aspirates from hospitalized patients with acute respiratory infections which had been tested by direct immunofluorescence assay (DFA), including 36 for ADV positive and 72 for ADV negative, were tested by both LAMP method and multiplex nested PCR.

RESULTAnalysis for sensitivity indicated that this LAMP method can detect 1.9×10(2)copies/ml of DNA, and no amplification was shown in DNA or cDNA of other viruses, which revealed that the specificity of the LAMP method is high. For 108 specimens which had been tested by DFA, 34 out of the 36 ADV positive specimens showed positive signal within 90 minutes using LAMP. Five out of 72 negative specimens by DFA were positive using LAMP; 39 out of the 41 ADV positive specimens by multiplex nested PCR showed positive signal using LAMP, including 19 for Ad3 and 20 for Ad7; 67 negative specimens confirmed by multiplex nested PCR showed negative signal using LAMP. The total consistency rate of DFA and LAMP method for detecting ADV was 93.5%, and the total coincidence rate of multiplex nested PCR and LAMP method for detecting ADV was 98.1%.

CONCLUSIONA new, sensitive, accurate and rapid method for detecting human adenovirus from nasopharyngeal aspirates by LAMP was developed, which should be a potential method for rapid detection of ADV from respiratory tract of children in clinical diagnosis of ADV infection.

Acute Disease ; Adenoviridae Infections ; diagnosis ; virology ; Adenoviruses, Human ; classification ; isolation & purification ; Child ; Child, Preschool ; DNA Primers ; DNA, Viral ; isolation & purification ; Fluorescent Antibody Technique, Direct ; Humans ; Molecular Diagnostic Techniques ; methods ; Nucleic Acid Amplification Techniques ; methods ; Polymerase Chain Reaction ; Reproducibility of Results ; Respiratory Tract Infections ; diagnosis ; virology ; Sensitivity and Specificity ; Sequence Analysis, DNA