ETIDIOH - NEW

LETTER Highly pathogenic avian influenza (HPAI) viruses of genotype B3.13 were first reported in dairy cattle in March 2024 and, by 4 March 2025, had infected at least 989 cattle herds in 17 states in the US ( https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/hpai-confirmed-cases-livestock ; accessed on March 24, 2025). Importantly, spillover infections of poultry and mammalian species , including cats and humans , have occurred ( https://www.cdc.gov/bird-flu/situation-summary/index.html ; accessed on 4 March 2025). Texas reported several infected herds in the spring (1) and early summer of 2024 but saw fewer outbreaks during the second half of 2024, with reported outbreaks in July and December (2). Since September 2024, almost all reported outbreaks of genotype B3.13 viruses in dairy cattle have occurred in California . Here, we characterized self-submitted samples from a farm in Texas that experienced an outbreak in December 2024. This farm ha...

Abstract Measles outbreaks continue to pose significant public health challenges globally despite the availability of effective vaccines. In this study, we evaluated wastewater-based surveillance for detection of measles virus during an ongoing outbreak in Texas . Weekly wastewater samples collected from two Texas cities between January 2 and March 17, 2025 were analyzed using multiple RT-PCR assays targeting the nucleoprotein and matrix genes of the measles virus. Viral RNA was detected in multiple days from both cities , with City A showing positives from January 13 and City B from January 6, both predating the first confirmed case in the state on January 23. Sequencing of PCR amplicons confirmed the specificity of detection and phylogenetic analysis using global and U.S. measles genome databases further validated that the viral RNA belonged to the currently circulating genotype D8 . Our findings demonstrate that wastewater surveillance can provide early evidence of measles virus cir...

Abstract The current outbreak of highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype clade 2.3.4.4b in dairy cattle in the United States has affected nearly 900 dairy farms and resulted in at least 39 human infections, putting health authorities and the scientific community on high alert. Here we characterize the virus growth properties and host-pathogen interactions of an isolate obtained from a sick dairy cow in Texas in vitro and in vivo and compare it to an older HPAI isolate. Despite so far being associated with mild disease in human patients, the cattle H5N1 virus showed superior growth capability and rapid replication kinetics in a panel of human lung cell lines in vitro . In vivo, cattle H5N1 exhibited more intense pathogenicity in mice , with rapid lung pathology and high virus titers in the brain , accompanied by high mortality after challenge via different inoculation routes. Additionally, the cattle H5N1 demonstrated efficient antagonism of overexpressed RI...

Abstract Highly pathogenic avian influenza viruses (HPAIV) pose a serious public health concern . In March 2024, a first-time outbreak of HPAIV H5N1 in dairy cattle herds was reported in the United States (US). Since then, the virus has continued to spread in cattle herds and spilt over into humans . We recently showed that the first human isolate reported in the US in Texas (HPhTX) from a dairy worker in an affected cattle farm has enhanced replication kinetics and pathogenicity in mice compared to a closely related bovine isolate (HPbTX). However, the molecular determinants of differential pathogenicity have not yet been identified. Herein, we show that HPhTX has enhanced polymerase activity , compared with HPbTX, in human cells and that the polymerase basic 2 (PB2) protein is the main factor responsible for this difference. Through single and combined site-directed mutagenesis and swapping the three amino acids different between HPhTX and HPbTX, we found that PB2 mutation E627K is t...

The Texas Department of State Health Services is reporting the first death from measles in the ongoing outbreak in the South Plains and Panhandle regions.  The school-aged child who was not vaccinated was hospitalized in Lubbock last week and tested positive for measles. As of Feb. 25, 124 cases of measles have been confirmed in the outbreak since late January. Most of the cases are in children . Eighteen people have been hospitalized over the course of the outbreak. Measles is a highly contagious respiratory illness , which can cause life-threatening illness to anyone who is not protected against the virus. During a measles outbreak, about one in five people who get sick will need hospital care and one in 20 will develop pneumonia. Rarely, measles can lead to swelling of the brain and death. It can also cause pregnancy complications, such as premature birth and babies with low birth weight. Measles can be transmitted by direct contact with infectious droplets or by airborne spread...

ABSTRACT The host range of HPAIV H5N1 was recently expanded to include ruminants , particularly dairy cattle in the United States (US). Shortly after, human H5N1 infection was reported in a dairy worker in Texas following exposure to infected cattle. Herein, we rescued the cattle-origin influenza A/bovine/Texas/24-029328-02/2024(H5N1, rHPbTX) and A/Texas/37/2024(H5N1, rHPhTX) viruses, identified in dairy cattle and human, respectively, and their low pathogenic forms , rLPbTX and rLPhTX, with monobasic HA cleavage sites . Intriguingly, rHPhTX replicated more efficiently than rHPbTX in mammalian and avian cells . Still, variations in the PA and NA proteins didn’t affect their antiviral susceptibility to PA and NA inhibitors. Unlike rHPbTX and rLPbTX, both rHPhTX and rLPhTX exhibited higher pathogenicity and efficient replication in infected C57BL/6J mice . The lungs of rHPhTX-infected mice produced higher inflammatory cytokines/chemokines than rHPbTX-infected mice. Our results highlight ...