Can Foodborne Illnesses Be Airborne? An Examination of Salmonella and Campylobacter

When it comes to foodborne illnesses, the primary modes of transmission are well understood. However, there has been some speculation about whether certain pathogens, such as Salmonella and Campylobacter, can actually be spread through the air. This article explores whether these bacteria can indeed be airborne and whether this could lead to illness being transmitted through inhalation. Additionally, the article examines why our noses are a reliable indicator of whether food is safe to eat, and how various infectious diseases spread through different means.

Salmonella and Campylobacter Transmission

Both Salmonella and Campylobacter are typically spread via the fecal-oral route. This means that either direct contact (e.g., an infected food worker not washing their hands after using the toilet) or indirect contact (e.g., cross-contamination of food) can lead to these pathogens entering the food chain. For example, potato salad might become contaminated by an infected food animal.

The transmission of these bacteria primarily occurs through ingestion, making it unlikely that they would penetrate the respiratory system even if inhaled in large quantities. For Salmonella and Campylobacter to cause illness via inhalation, they would need to enter the upper or lower respiratory tract, which is highly improbable without a mechanism for ingestion.

General Spread of Foodborne Illnesses

Unlike some airborne pathogens such as SARS-CoV-2 (the virus causing COVID-19) and Influenza, which can spread via particulate droplets from coughs and sneezes, foodborne illnesses are not typically spread this way. The traditional methods of transmission for foodborne illnesses are ingestion of contaminated food or water.

To address concerns about the spread of foodborne illnesses, humans have relied on their natural senses, specifically sight and smell, to determine whether food is safe to eat. For example, if an egg yolk is runny or smells strongly of sulfur, it is typically discarded. In contrast, if it appears clean and whole with no odor, the “Best By” date is not strictly adhered to.

The Role of Our Noses

Noses have evolved over millions of years to serve a crucial function in food safety. Our olfactory senses have been honed to detect the presence of harmful substances and to signal potential dangers. This biological mechanism is why a foul smell should be a warning sign rather than a cause for illness—all the more so when dealing with infectious agents that are unlikely to be airborne.

Historically, our noses have played a critical role in navigating the dangers of life, especially in wartime or disaster zones. For instance, after the 2010 earthquake in Haiti, the intense smell of decaying human bodies was a primary warning sign. In such situations, masks or bandanas were worn not just to protect against infectious agents, but to manage the unbearable odor.

However, in general, a foul smell should not cause illness. Instead, it should be a warning signal that something is not right with the food. While some diseases can be spread through the air, the airborne transmission of Salmonella and Campylobacter is not a significant concern for food safety.

Other Examples of Airborne Pathogens

There are a few respiratory illnesses that are indeed spread through the air. SARS-CoV-2 and Influenza, for instance, can spread through droplets expelled during coughing and sneezing. These diseases highlight the importance of wearing masks and staying at home to prevent the spread of these highly airborne pathogens.

The distinction between foodborne illnesses and airborne respiratory illnesses is crucial for maintaining food safety standards. By relying on our senses and understanding the mechanisms of disease transmission, we can better detect and prevent foodborne illnesses, ensuring the safety of the food we consume.

Interestingly, the human ability to smell has also evolved to enhance our enjoyment of life, with people often making jokes about why farts smell—even if deaf people can still enjoy the sound. This playful aspect of human biology complements the serious responsibility we have in maintaining food safety standards.