Impact of the 2009 influenza A(H1N1) pandemic wave on the pattern of hibernal respiratory virus epidemics, France, 2009.

International audienceThis short report based on clinical surveillance and laboratory data describes the circulation of rhinoviruses, influenza viruses and respiratory syncytial viruses (RSV) in France during the 2009-10 season compared with the previous winter season. The delayed circulation of RSV observed in 2009-10 compared with 2008-09 suggests that the early circulation of the 2009 pandemic influenza A(H1N1) viruses had an impact on the RSV epidemic

Placental lesions and SARS-Cov-2 infection: Diffuse placenta damage associated to poor fetal outcome

International audienceINTRODUCTION: Pregnant women with covid-19 are more likely to experience preterm birth. The virus seems to be associated with a wide range of placental lesions, none of them specific. METHOD: We collected cases of Covid-19 maternal infection during pregnancy associated with poor pregnancy outcomes, for which we received the placenta. We studied clinical data and described pathological findings of placenta and post-mortem examination of fetuses. We performed an immunohistochemical study and RT-PCR of SARS-Cov-2 on placenta samples. RESULTS: We report 5 cases of poor fetal outcome, 3 fetal deaths and 2 extreme premature neonates, one with growth restriction, without clinical and biological sign of SARS-Cov-2 infection. All placenta presented massive perivillous fibrin deposition and large intervillous thrombi associated with strong SARS-Cov-2 expression in trophoblast and SARS-CoV-2 PCR positivity in amniotic fluid or on placenta samples. Chronic histiocytic intervillositis was present in 4/5 cases. Placental ultrasound was abnormal and the sFLT1-PIGF ratio was increased in one case. Timing between mothers' infection and the poor fetal outcome was ≤10 days in 4 cases. The massive placental damage are directly induced by the virus whose receptors are expressed on trophoblast, leading to trophoblast necrosis and massive inflammation in villous chamber, in a similar way it occurs in diffuse alveolar damage in adults infected by SARS-Cov-2. DISCUSSION: SARS-Cov-2 can be associated to a rare set of placental lesions which can lead to fetal demise, preterm birth, or growth restriction. Stronger surveillance of mothers infected by SARS-Cov-2 is required

Oseltamivir-zanamivir bitherapy compared to oseltamivir monotherapy in the treatment of pandemic 2009 influenza A(H1N1) influenza virus infections

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Serosurveillance study on transmission of H5N1 virus during a 2006 avian influenza epidemic

In 2006 an outbreak of avian influenza A(H5N1) in Turkey caused 12 human infections, including four deaths. We conducted a serological survey to determine the extent of subclinical infection caused by the outbreak. Single serum samples were collected from five individuals with avian influenza whose nasopharyngeal swabs tested positive for H5 RNA by polymerase chain reaction, 28 family contacts of the cases, 95 poultry cullers, 75 individuals known to have had contact with diseased chickens and 81 individuals living in the region with no known contact with infected chickens and/or patients. Paired serum samples were collected from 97 healthcare workers. All sera were tested for the presence of neutralizing antibodies by enzyme-linked immunoassay, haemagglutination inhibition and microneutralization assays. Only one serum sample, from a parent of an avian influenza patient, tested positive for H5N1 by microneutralization assay. This survey shows that there was minimal subclinical H5N1 infection among contacts of human cases and infected poultry in Turkey in 2006. Further, the low rate of subclinical infection following contact with diseased poultry gave further support to the reported low infectivity of the virus