Results of the 1st external quality assurance for SARS new coronavirus diagnostic PCR and serology : talk

Background The detection of the new Coranavirus (CoV) causing agent of the severe acute respiratory syndrome (SARS) for diagnostic purposes is still a critical step in prevention of secondary hospital infections. In this respect the PCR for SARS diagnostic is the fastest and most sensitive method and was published very early after the description of the new pathogen by different groups. To evaluate the quality and sensitivity of the SARS PCR performed in diagnostic laboratories all over the world an external quality assurance (EQA) for SARS PCR was initiated by the WHO, the European Network for Diagnostics of "Imported" Viral Diseases (ENIVD) and the Robert Koch-Institut. Methods Therefore 10 samples of inactivated SARS CoV strains isolated in Frankfurt and Hong Kong in different dilutions and negative controls were prepared. The freeze dried samples were send by mail to 62 different laboratories, in 37 countries in Europe and Israel (35), Asia (11), The Americas (11), Australia and New Zealand (4) and Africa (1). The results were returned by email or fax 1 week (13), 2 weeks (14), 3 weeks (6) and later (29) after receiving the material which does not mimic at all the possible speed of this fast method. But this was not considered in the evaluation of these first SARS EQA. Results 44 laboratories showed good or excellent results (26 = 100%, 18 = 90%) and even the 14 laboratories which archived only 80% (10) or 70% (4) correct results are mostly lacking sensitivity. The results of the other 4 laboratories show basic problems in regard to sensitivity, specificity and consistency of results and must be overcome as soon as possible. 4 laboratories seem to have problems with the specificity finding a positive signal in negative samples. The different methods used for preparation of the SARS CoV genome and diagnostic PCR test procedure used by the participating laboratories will be discussed in more detail in the presentation. Conclusion However, in contrast to previous EQAs for Ebola, Lassa and Orthopoxviruses the quality of PCR results was rather good which might be caused by the early publication and distribution of well developed PCR methods. An EQA for evaluation of SARS specific serology is still ongoing, first results will be available beginning of April 2004

Respiratory Infections during SARS Outbreak, Hong Kong, 2003

The effect of community hygienic measures during the outbreak of severe acute respiratory syndrome in Hong Kong was studied by comparing the proportion of positive specimens of various respiratory viruses in 2003 with those from 1998 to 2002. Community hygienic measures significantly reduced the incidence of various respiratory viral infections

A HIV-1 heterosexual transmission chain in Guangzhou, China: a molecular epidemiological study

<p>Abstract</p> <p>Background</p> <p>We conducted molecular analyses to confirm four clustering HIV-1 infections (Patient A, B, C & D) in Guangzhou, China. These cases were identified by epidemiological investigation and suspected to acquire the infection through a common heterosexual transmission chain.</p> <p>Methods</p> <p><it>Env C2V3V4 </it>region, <it>gag p17/p24 </it>junction and partial <it>pol </it>gene of HIV-1 genome from serum specimens of these infected cases were amplified by reverse transcription polymerase chain reaction (RT-PCR) and nucleotide sequenced.</p> <p>Results</p> <p>Phylogenetic analyses indicated that their viral nucleotide sequences were significantly clustered together (bootstrap value is 99%, 98% and 100% in <it>env</it>, <it>gag </it>and <it>pol </it>tree respectively). Evolutionary distance analysis indicated that their genetic diversities of <it>env</it>, <it>gag </it>and <it>pol </it>genes were significantly lower than non-clustered controls, as measured by unpaired <it>t</it>-test (<it>env </it>gene comparison: <it>p </it>< 0.005; <it>gag </it>gene comparison: <it>p </it>< 0.005; <it>pol </it>gene comparison: <it>p </it>< 0.005).</p> <p>Conclusion</p> <p>Epidemiological results and molecular analyses consistently illustrated these four cases represented a transmission chain which dispersed in the locality through heterosexual contact involving commercial sex worker.</p

Oseltamivir- and Amantadine-Resistant Influenza Viruses A (H1N1)

Surveillance of amantadine and oseltamivir resistance among influenza viruses was begun in Hong Kong in 2006. In 2008, while both A/Brisbane/59/2007-like and A/Hong Kong/2652/2006-like viruses (H1N1) were cocirculating, we detected amantadine and oseltamivir resistance among A/Hong Kong/2652/2006-like viruses (H1N1), caused by genetic reassortment or spontaneous mutation

Influenza A H5N1 Detection

We developed a sensitive and rapid real-time reverse transcription-polymerase chain reaction (RT-PCR) assay to detect influenza A H5N1 virus in clinical samples. This assay was evaluated with samples from H5N1-infected patients and demonstrated greater sensitivity and faster turnaround time than nested RT-PCR

Low Frequency of Poultry-to-Human H5N1 Transmission, Southern Cambodia, 2005

Transmission is low despite extensive human contact with poultry

Coronavirus-positive Nasopharyngeal Aspirate as Predictor for Severe Acute Respiratory Syndrome Mortality

Severe acute respiratory syndrome (SARS) has caused a major epidemic worldwide. A novel coronavirus is deemed to be the causative agent. Early diagnosis can be made with reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal aspirate samples. We compared symptoms of 156 SARS-positive and 62 SARS-negative patients in Hong Kong; SARS was confirmed by RT-PCR. The RT-PCR–positive patients had significantly more shortness of breath, a lower lymphocyte count, and a lower lactate dehydrogenase level; they were also more likely to have bilateral and multifocal chest radiograph involvement, to be admitted to intensive care, to need mechanical ventilation, and to have higher mortality rates. By multivariate analysis, positive RT-PCR on nasopharyngeal aspirate samples was an independent predictor of death within 30 days