Covid navy ship outbreak: 90% of crew infected with Delta variant – How we can mitigate this risk
Recent studies have shown that the Delta variant of concern (VOC) has a higher transmissibility rate compared to the original variant. A case study on a navy ship illustrates the dangers of large populations becoming infected with the Delta VOC in a short space of time, with 90% of the navy soldiers on the ship testing positive within a period of just 25 days1. Clearly, Covid-19 is airborne.
The study cites the spread of aerosols in confined spaces as a major factor in the rapid outbreak. When the infected soldiers exhaled, the smallest particles in their breath (aerosols) could have remained airborne for a few hours. These aerosols can travel several metres, especially inside due to air currents. If ventilation is inadequate, the risk of infection is accelerated. Furthermore, many ships have recirculated ventilation systems, which mean that viral particles can spread throughout the entire ship, as was the case with the super spreader event on The Diamond Princess in 2020.
The Delta VOC represents a serious threat, even among the healthy, with 6% of the infected soldiers requiring hospitalisation and 2% of the soldiers becoming seriously or moderately ill.
Rhys Thomas, Chief Medical Officer at PP-L Biosafety says, “The Delta VOC is very concerning as it has the power to infect more people, with each infected person spreading the virus to over twice as many people as that of previous variants2. There is also data that suggests that the Delta variant can cause more severe illness than previous variants leading to a higher risk of hospitalisation and sadly also a higher risk of death.2” Rhys added with a final thought on the likelihood of new variants that might develop this winter that are even more infectious and may possess vaccine escape properties.
Paul Waldeck, Chief Technical Officer at PP-L adds, “It is clear that this risk needs to be mitigated, in order to protect against this viral threat. Crowded indoor spaces such as nightclubs, pubs, concerts and indoor events have the possibility of becoming ‘super spreader’ events if the aerosol build-up is not controlled. With daily positive cases still high in the UK, the chances of an infected person unknowingly exhaling virus-laden breath in a crowded space are still high.”
If adequate ventilation cannot be maintained, which is usually the case in crowded indoor spaces, the Health and Safety Executive recommend the use of high-efficiency filters and ultraviolet-based devices in order to reduce airborne transmission of aerosols3. PP-L offer a range of high-quality infection mitigation devices, as well as in-duct solutions for HVAC systems, which utilise these recommended technologies. Our mission is to make organisations safer, more resilient, and ready for whatever the future may bring.