The value of early diagnostic screens for the diagnosis of influenza A, B and Mycoplasma pneumoniae infections.

BACKGROUND: Rapid diagnosis of influenza virus and Mycoplasma pneumoniae infections is of importance for therapeutic intervention. It was the aim of the study to evaluate screening tests for influenza A (Flu A), B (Flu B), and Mycoplasma pneumoniae (M. pneumoniae) infections in young patients admitted to the hospital. METHODS: 522 children and juvenile patients were admitted to the hospital because of symptoms suspecting Flu A, B or M. pneumoniae infections. Gold Immunochromatography Assays were used to screen for Flu A and Flu B and rapid identification culturing with subsequent polymerase chain reaction (PCR) was carried out at admission for identification of M. pneumoniae infections. Diagnoses were based upon seroconversion during the clinical course. RESULTS: In the current study, 26% of 522 patients were shown to be infected with Flu A and 77% had positive screens using the Gold Immunochromatography Assays. 19% of 522 patients were infected with Flu B as diagnosed by seroconversion and 89% were detected by the screen. The rapid identification culture showed that 169 of 522 patients were M. pneumoniae positive. The positive samples based on rapid identification showed negative and poor concordance with PCR tests. The consistency test between the two screening methods mentioned above showed higher kappa value in the children group than infant group. CONCLUSIONS: The results are in agreement with literature and indicate that in juvenile patients and children the screening efficiency was limited. PCR assays may be applied prior to evaluation of antibody titres in the case of M. pneumoniae infections confirming previous results. The pronounced effect of age on the outcome has to be taken into account for evaluation of the screening methods.

The evaluation of colloidal gold immunochromatographic assay (GICA) for rapid diagnosis of influenza A disease.

BACKGROUND: A low cost colloidal gold immunochromatographic assay (GICA) for rapid detection of influenza A virus was developed. The assay was evaluated in this study. METHODS: Six hundred and twenty-six patients were enrolled. All patients contributed two pharyngeal swabs, one used for colloidal gold immunochromatographic rapid assay for influenza A virus immediately after the collection of specimen and one used for real-time reverse transcriptase polymerase chain reaction (RT-PCR) test or virus culture at the Centers for Disease Control and Prevention (CDC) influenza network laboratory. RESULT: In reference to viral culture, GICA influenza A test demonstrated a sensitivity of 64%, a specificity of 95% and an overall accuracy of 93%. Consistency between the GICA test and virus culture assay is moderate, with Kappa being 0.46. In reference to RT-PCR, GICA test demonstrated considerable high sensitivity (74%) and specificity (86%), with Kappa value being 0.61 and overall accuracy of 81%. There was no significant difference between GICA test and virus culture/RT-PCR on the detected positive rates of influenza A cases. CONCLUSIONS: GICA is a reliable, rapid, convenient and inexpensive test for the screening and diagnosis of influenza A disease. Given its lower cost than other rapid tests, the GICA test has the great potential in the management of influenza A disease in resource-poor countries.

Evaluation of the commercial rapid Mycoplasma pneumoniae medium method using the medium PCR and serum antibody test.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is a major cause of respiratory tract infection. There is no specific and simple diagnosis test for the clinic treatment. In this study, we evaluated the effectiveness of a recently developed commercial rapid M. pneumoniae medium testing method. METHODS: There were 132 patients with acute respiratory tract infection enrolled in this study. All of the patients' throat swabs were taken in the morning after admission and determined using the rapid identification culture test for M. pneumoniae. In addition the M. pneumoniae polymerase chain reaction (PCR) test and routine bacterial and fungal microorganism culture test were used to identify the organisms following culture. In addition, serum from each patient was tested for M. pneumoniae using the passive particle agglutination test. RESULTS: The rapid identification culture procedure indicated that 41 patients were M. pneumoniae positive, only 6 patients were M. pneumoniae positive based on PCR, and all of the positive cultures had fungus contamination. There were only 26 of the 41 patients whose serum M. pneumoniae tested positive. Passive particle agglutination test shows 38.6% of the patients were M. pneumoniae positive (51 out of 132). Compared with the passive particle agglutination test, the specificity, sensitivity of rapid M. pneumoniae identification culture method are 81.48% and 50.98%. CONCLUSIONS: The rapid identification of M. pneumoniae culture test is easy to perform and provides results fast, but has poor concordance with the M. pneumoniae PCR and serum M. pneumoniae antibody test due to the high fungus contamination. This commercial rapid M. pneumoniae medium method needs improvement for clinical use.

Hippocampal protein kinase C family members in spatial memory retrieval in the mouse.

Although a few individual members of the protein kinase C (PKC) family were studied in spatial memory no systematic approach was carried out to concomitantly determine all described PKC family members in spatial memory of the mouse. It was therefore the aim of the current study to link hippocampal PKCs to memory retrieval in the Morris water maze (MWM). CD1 mice were trained (n=9) or untrained (n=9) in the MWM, hippocampi were taken 6h following the test for memory retrieval and PKCs were determined in mouse hippocampi by immunoblotting. The trained animals learned the spatial memory task and kept memory at the probe trial. PKCs alpha and epsilon were comparable between groups while PKCs beta, delta, gamma (two forms, i.e. two bands on Western blotting), zeta (2 forms) were higher in trained mice and theta (2 forms) were lower in trained mice. PKC gamma (1 form) was significantly correlating with the time spent in the target quadrant (r=0.7933; P=0.0188). Changes of hippocampal levels of PKCs beta, delta, gamma, zeta and theta were paralleling memory retrieval of the MWM task but correlations revealed that spatial memory retrieval was only linked to one form of PKC gamma. Results are also in agreement with a recent publication showing that PKM zeta is not required for memory formation. These findings may be relevant for the interpretation of previous work and the design of future work on the protein kinase C family in spatial memory of the mouse.

Evaluation of a rapid detection influenza virus a antigens kit using paired serum antibody test.

PURPOSE: To evaluate the feasibility for gold immunochromatographic assay (GICA) in rapid detection of influenza virus A infection. MATERIALS AND METHODS: Seventy-three patients were enrolled. All patients contributed nasopharyngeal secretions and paired serum samples. Nasopharyngeal secretions was used for colloidal gold immunochromatographic rapid assay for influenza A virus immediately after the collection of specimen. Paired serum samples were used for the hemagglutination inhibition assay at the Centers for Disease Control and Prevention influenza network laboratory in Beijing. RESULTS: Compare GICA test to hemagglutination inhibition (HI) assay, the Kappa value was 0.402 and the p value in the paired χ² test was higher than 0.05. Therefore, the difference was not statistically significant. The sensitivity of GICA was 50.0% and the specificity was 90.2%, and the negative predictive value was 90.2%. CONCLUSION: The sensitivity for Influenza A antigen detection by using GICA is relatively low, the specificity is relatively satisfactory.

Screening for influenza viruses in 7804 patients with influenza-like symptoms.

OBJECTIVE: To screen a large number of patients with influenza-like symptoms by using the gold-immunochromatographic assay kit. METHODS: All patients with influenza-like symptoms visiting the outpatient department of the General Hospital of Beijing Military Region, Beijing, China between May 2009 and January 2010 were enrolled in the study. Nasopharyngeal swabs were collected immediately after the patient visited, then a gold-immunochromatographic assay was performed for screening of influenza A and B viruses according to the kit protocol. RESULTS: Among the 7804 patients enrolled in this study, 202 patients were influenza virus-positive; the positive cases accounted for 2.6% of all cases detected. Among the 202 influenza virus-positive patients, 171 patients were influenza virus A-positive, 24 were influenza virus B-positive, and 7 were co-infected with influenza virus A and B. More than 57% of the virus-positive patients were younger than 30 years old. Symptoms such as fever, sore throat, nasal congestion, sneezing, runny nose, and joint pain were more frequently observed in influenza virus A-positive patients than in influenza virus B-positive and influenza virus-negative patients. CONCLUSION: The gold immunochromatographic assay kit is very useful for screening a large number of patients with influenza-like symptoms. A higher number of influenza virus A-positive patients have sore throat, nasal congestion, sneezing, runny nose, and joint pain than influenza virus B-positive and influenza virus-negative patients.