Rapid point-of-care testing for SARS-CoV-2 in a community screening setting shows low sensitivity.

OBJECTIVE: With the current SARS-CoV2 outbreak, countless tests need to be performed on potential symptomatic individuals, contacts and travellers. The gold standard is a quantitative polymerase chain reaction (qPCR)-based system taking several hours to confirm positivity. For effective public health containment measures, this time span is too long. We therefore evaluated a rapid test in a high-prevalence community setting. STUDY DESIGN: Thirty-nine randomly selected individuals at a COVID-19 screening centre were simultaneously tested via qPCR and a rapid test. Ten previously diagnosed individuals with known SARS-CoV-2 infection were also analysed. METHODS: The evaluated rapid test is an IgG/IgM-based test for SARS-CoV-2 with a time to result of 20 min. Two drops of blood are needed for the test performance. RESULTS: Of 49 individuals, 22 tested positive by repeated qPCR. In contrast, the rapid test detected only eight of those positive correctly (sensitivity: 36.4%). Of the 27 qPCR-negative individuals, 24 were detected correctly (specificity: 88.9%). CONCLUSION: Given the low sensitivity, we recommend not to rely on an antibody-based rapid test for public health measures such as community screenings.

[Transient splenial lesion in influenza A H1N1 2009 infection]. / Transiente Spleniumläsion bei Influenza-A-H1N1-09-Infektion.

Severe neurologic complications have been rarely reported during novel pandemic influenza A(H1N1) virus infections. We describe the case of an 10-year-old boy with new onset seizures and proven influenza A(H1N1) 2009 infection showing a reversible hyperintense lesion in the splenium of the corpus callosum on T2-weighted and FLAIR magnetic resonance images without contrast enhancement. Transient splenial lesions have been described in the context of virus encephalopathy and do not require specific treatment.

Detection of influenza A(H1N1)v virus by real-time RT-PCR.

Influenza A(H1N1)v virus was first identified in April 2009. A novel real-time RT-PCR for influenza A(H1N1)v virus was set up ad hoc and validated following industry-standard criteria. The lower limit of detection of the assay was 384 copies of viral RNA per ml of viral transport medium (95% confidence interval: 273-876 RNA copies/ml). Specificity was 100% as assessed on a panel of reference samples including seasonal human influenza A virus H1N1 and H3N2, highly pathogenic avian influenza A virus H5N1 and porcine influenza A virus H1N1, H1N2 and H3N2 samples. The real-time RT-PCR assay for the influenza A matrix gene recommended in 2007 by the World Health Organization was modified to work under the same reaction conditions as the influenza A(H1N1)v virus-specific test. Both assays were equally sensitive. Clinical applicability of both assays was demonstrated by screening of almost 2,000 suspected influenza (H1N1)v specimens, which included samples from the first cases of pandemic H1N1 influenza imported to Germany. Measuring influenza A(H1N1)v virus concentrations in 144 laboratory-confirmed samples yielded a median of 4.6 log RNA copies/ml. The new methodology proved its principle and might assist public health laboratories in the upcoming influenza pandemic.

Genoprevalence in human tissues of TT-virus genotype 6.

TT virus (TTV) is a newly discovered human virus of high genotypic diversity. TTV is widely distributed among humans, but the possible genotype-related differences in TTV biology are not well known. The prevalence and amount of TTV-DNA, especially of genotype 6, was determined by nested-PCR in various human tissues, and human parvovirus B19, another ssDNA virus, was used as a reference. TTV DNA was detected simultaneously in bile, peripheral blood mononuclear cells (PBMC) and plasma of 77% subjects, in 38% skin samples, in 38% synovial samples and in all (100%) adenoids, tonsils and liver samples. The relative concentrations of TTV-DNA did not vary significantly among the different samples. Genotype 6 TTV-DNA was detected in bile and plasma of one subject (3%), in skin and serum of one subject (8%) and in one liver (5%). The overall prevalence of TTV genotype 6 was 4% in subjects and 4% in sera. TTV genotype 6 was shown to occur in human tissues with no obvious tissue-type or symptom specificity. Parvovirus B19 DNA was detected overall in 38% subjects, and bile was the only sample type tested that did not persistently harbour B19 DNA.