Publications by authors named "Charles Todd Davis"
Article Synopsis
- - Since 2013, there have been 167 cases of people infected with special flu viruses from pigs in the U.S. called swine-origin influenza A.
- - Most of these viruses had a change in their genes that makes them resistant to certain medicines, but none were resistant to another type of medicine called neuraminidase inhibitors.
- - Scientists did tests to find out how well these viruses respond to treatments and discovered that one specific change in the virus made it much harder to treat with a medicine called baloxavir.
Article Synopsis
- * The CDC's National SARS-CoV-2 Strain Surveillance (NS3) program analyzed SARS-CoV-2 samples to understand the evolution of these variants and their spike mutations from May 2021 to February 2023.
- * The study found that some subvariants have significantly evaded neutralizing antibodies from post-vaccination sera, indicating a need for ongoing research to evaluate the effectiveness of current vaccines and inform future updates.
Avian influenza A(H5) virus circulation in live bird markets in Vietnam, 2017-2022.
Influenza Other Respir Viruses
December 2023
Background: Highly pathogenic avian influenza A(H5) human infections are a global concern, with many A(H5) human cases detected in Vietnam, including a case in October 2022. Using avian influenza virus surveillance from March 2017-September 2022, we described the percent of pooled samples that were positive for avian influenza A, A(H5), A(H5N1), A(H5N6), and A(H5N8) viruses in live bird markets (LBMs) in Vietnam.
Methods: Monthly at each LBM, 30 poultry oropharyngeal swab specimens and five environmental samples were collected.
In March 2021, Lao People's Democratic Republic (Laos) reported an avian influenza A(H5N6) virus infection in a 5-year-old child identified through sentinel surveillance. This was the first human A(H5N6) infection reported outside of China. A multidisciplinary investigation undertook contact tracing and enhanced human and animal surveillance in surrounding villages and live bird markets.
View Article and Find Full Text PDFMutations in the influenza virus neuraminidase (NA) that cause reduced susceptibility to the NA inhibitor (NAI) oseltamivir may occur naturally or following antiviral treatment. Currently, detection uses either a traditional NA inhibition assay or gene sequencing to identify known markers associated with reduced inhibition by oseltamivir. Both methods are laborious and require trained personnel.
View Article and Find Full Text PDFDuring November 2014-April 2015, a total of 165 case-patients with influenza virus A(H5N1) infection, including 6 clusters and 51 deaths, were identified in Egypt. Among infected persons, 99% reported poultry exposure: 19% to ill poultry and 35% to dead poultry. Only 1 person reported wearing personal protective equipment while working with poultry.
View Article and Find Full Text PDFBackground: Avian influenza A (H7N9) virus has emerged recently and continues to cause severe disease with a high mortality rate in humans prompting the development of candidate vaccine viruses. Live attenuated influenza vaccines (LAIV) are 6:2 reassortant viruses containing the HA and NA gene segments from wild type influenza viruses to induce protective immune responses and the six internal genes from Master Donor Viruses (MDV) to provide temperature sensitive, cold-adapted and attenuated phenotypes.
Methodology/principal Findings: LAIV candidate A/Anhui/1/2013(H7N9)-CDC-LV7A (abbreviated as CDC-LV7A), based on the Russian MDV, A/Leningrad/134/17/57 (H2N2), was generated by classical reassortment in eggs and retained MDV temperature-sensitive and cold-adapted phenotypes.