Speed Kills: The Complex Links Between Transport, Lack of Time and Urban Health

Road safety experts understand the contribution of speed to the severity and frequency of road crashes. Yet, the impact of speed on health is far more subtle and pervasive than simply its effect on road safety. The emphasis in urban areas on ...

Volcanic ash as a source of nutrients: How the Hunga Tonga eruption affected ecosystems in the South Pacific

The eruption of Hunga Tonga-Hunga Ha'apai (HTHH) in January 2022 ejected about 2.9 billion tons of volcanic material into the atmosphere and across the South Pacific. In early 2022, a scientific expedition (GEOTRACES GP21) investigated the impact of this monumental event on the biogeochemistry of the South Pacific Gyre (SPG) surface waters.

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Viral shedding and environmental dispersion of two clade 2.3.4.4b H5 high pathogenicity avian influenza viruses in experimentally infected mule ducks: implications for environmental sampling - Veterinary Research

High pathogenicity avian influenza viruses (HPAIVs) have caused major epizootics in recent years, with devastating consequences for poultry and wildlife worldwide. Domestic and wild ducks can be highly susceptible to HPAIVs, and infection leads to efficient viral replication and massive shedding (i.e., high titres for an extended time), contributing to widespread viral dissemination. Importantly, ducks are known to shed high amounts of virus in the earliest phase of infection, but the dynamics and impact of environmental contamination on the epidemiology of HPAIV outbreaks are poorly understood. In this study, we monitored mule ducks experimentally infected with two H5N8 clade 2.3.4.4b goose/Guangdong HPAIVs sampled in France in 2016–2017 and 2020–2021 epizootics. We investigated viral shedding dynamics in the oropharynx, cloaca, conjunctiva, and feathers; bird-to-bird viral transmission; and the role of the environment in viral spread and as a source of samples for early detection and surveillance. Our findings showed that viral shedding started before the onset of clinical signs, i.e., as early as 1 day post-inoculation (dpi) or post-contact exposure, peaked at 4 dpi, and lasted for up to 14 dpi. The detection of viral RNA in aerosols, dust, and water samples mirrored viral shedding dynamics, and viral isolation from these environmental samples was successful throughout the experiment. Our results confirm that mule ducks can shed high HPAIV titres through the four excretion routes tested (oropharyngeal, cloacal, conjunctival, and feather) while being asymptomatic and that environmental sampling could be a non-invasive tool for early viral RNA detection in HPAIV-infected farms.