Rédaction Africa Links 24 with Megan Molteni
Published on 2024-04-18 21:28:42
During the early months of the Covid-19 pandemic, the world experienced chaos in terms of shortages of essential supplies like toilet paper, canned food, and cleaning products. The focus at that time was primarily on sanitizing surfaces as the main mode of virus transmission was believed to be through contact. However, as evidence started to accumulate about the potential airborne spread of the virus, a shift in understanding was needed.
One of the key organizations guiding public health responses, the World Health Organization (WHO), initially stated that Covid-19 was not an airborne disease. It took until late 2021 for the WHO to acknowledge the airborne nature of the virus. This delayed recognition stemmed from a lack of consensus on the definitions of terms like “aerosol,” “airborne,” and “airborne transmission” among different groups of scientists and medical professionals.
To address this confusion, the WHO convened a group of experts in November 2021 to update its guidelines on disease transmission routes. After more than two years of discussions, the group published a report outlining new definitions that better reflected the current scientific understanding of how pathogens spread. The updated guidelines categorized transmission routes into those involving direct contact and those involving the air, with specific subcategories for particle size and deposition.
The adoption of these new guidelines has significant implications for infection control standards and prevention measures going forward. The inclusion of aerosol scientists and engineers in the expert group marked a departure from the traditional medical focus on droplet transmission versus airborne transmission based on particle size.
The recognition that infectious particles exist on a spectrum of sizes and can spread through the air at various distances challenges the previous binary approach to infection control measures. This shift toward a more nuanced understanding of disease transmission emphasizes the need for tailored risk assessments and prevention strategies based on the specific characteristics of the pathogen and the population at risk.
While the updated guidelines provide a more comprehensive framework for classifying transmission routes, there is still disagreement on the practical implications for infection prevention policies. Some experts argue that more proactive measures, such as airborne precautions, should be taken to counteract the risks posed by smaller infectious respiratory particles. Others point to the complexity of implementing such measures and the need for context-specific risk assessments.
Despite these challenges, the adoption of the new guidelines represents a positive step toward improving global health responses to infectious diseases. By bringing together a diverse group of experts and reaching consensus on terminology, the WHO has laid the groundwork for future research and collaboration in developing effective infection control practices.
As WHO chief scientist Jeremy Farrar emphasized, the publication of the updated guidelines marks a starting point for further scientific inquiry and collaboration. By recognizing the multidisciplinary nature of disease transmission and infection control, the global health community can better prepare for both known diseases and future outbreaks. The acknowledgment of airborne transmission as a significant factor in disease spread represents a milestone in the evolution of public health responses and underscores the importance of ongoing research and collaboration in addressing global health challenges.
