Are Cockroaches Dangerous?

Yes, they can be – but it’s all relative. If you just have one or two roaches that wandered inside, it’s unlikely to be harmful. But they are still capable of spreading germs and bacteria.

If a home is badly infested with cockroaches and occupants are seeing them all the time, it’s much more likely to be a potentially dangerous situation where someone could get sick.

How Dangerous Are Cockroaches in Your Home?

It all depends on your specific situation. This guide is designed to help you determine how dangerous they are in your home by discussing health risks, which types of roaches are most concerning, and what to do about them.

• Health Risks of Roaches
• Which Roaches Are Most Dangerous?
• What to Do About Roaches

Listen Now: The Dangers of Cockroaches

What Are the Health Risks of Cockroaches?

Cockroaches are not just an unsightly nuisance; they can pose serious health risks. In addition to tracking diseases and bacteria, a cockroach infestation can aggravate both allergies and asthma in sensitive individuals.

Diseases Spread by Roaches

These illnesses are the most frequent health concerns associated with roaches in the U.S., primarily manifesting as “food poisoning.”

• Salmonellosis: Roaches pick up Salmonella bacteria from decaying organic matter. They can harbor the bacteria in their gut for a month or more, spreading it through their feces and vomit onto kitchen surfaces and food.
• E. coli Infection: Because roaches frequent sewers and bathrooms, they are common carriers of Escherichia coli. While many strains are harmless, the ones carried by roaches can cause severe abdominal cramps and diarrhea.
• Campylobacteriosis: This is one of the most common diarrheal illnesses in the U.S. Roaches serve as a reservoir for Campylobacter bacteria, contaminating food via direct contact.
• Listeriosis: Caused by Listeria monocytogenes, this is a significant public health concern in the U.S., particularly for the elderly and pregnant women. Roaches can transport these germs into food prep areas.
• Staphylococcus & Streptococcus: Roaches often carry these bacteria on their exoskeletons. While often causing minor skin infections, they can lead to more serious issues if they contaminate food or open wounds.

In other places around the world, roaches are even more dangerous. Here are some additional diseases they’re capable of carrying. For those of us in the U.S., we’re extremely fortunate that the risk of these is extremely low due to advanced modern sanitation and water treatment.

• Typhoid Fever: It comes from Salmonella typhi. Sure, roaches can carry it, but let’s be real—typhoid is super rare in the U.S. and is almost always caught while traveling abroad, not from a home infestation.
• Cholera: This is spread by Vibrio cholerae. Thanks to our awesome sewer and water systems in the U.S., there’s no way a roach could pick up enough contamination to actually spread this disease.
• Dysentery: Usually caused by Shigella or certain parasites. Roaches could spread this in really gross, crowded places, but in the U.S., most small outbreaks are connected to people-to-person contact or some bad commercial food.
• Leprosy (Hansen’s Disease): Roaches are suspected to carry the Mycobacterium leprae bacteria. But honestly, leprosy is incredibly rare here, and most people’s bodies naturally fight off the bacteria anyway.
• Plague: Roaches can technically carry the Yersinia pestis bacterium in a lab setting, but there hasn’t been a single documented case of roaches causing a plague outbreak in the U.S. (It’s usually spread by fleas on rodents).

Roaches Can Also Trigger Allergies and Cause Asthma

The good news is you probably won’t catch plague from roaches. The bad news is that allergies and asthma are very real problems for many people in the southeastern United States due to cockroaches.

Unlike an infection that you might get over in a week, roach-induced respiratory issues can be chronic.

Why Do Cockroaches Cause Allergies and Asthma?

Roaches are constantly contaminating their environment in the form of:

• Saliva: This gets left behind on food particles and surfaces, dries, and microscopic allergens become airborne and breathed in.
• Feces: Similarly, their pepper-like droppings dry out and crumble into microscopic airborne particles.
• Exoskeleton: Roaches “molt” as they grow; these discarded shells break down into potent allergenic dust.

What Are the Symptoms of Cockroach Allergies?

If you are sensitive, exposure to cockroach allergens can give symptoms similar to hay fever or a dust mite allergy.

• Common symptoms include itchy eyes, scratchy throat, skin rashes, and persistent sneezing or a runny nose.
• Symptoms can last all year. Unlike pollen, which is seasonal, roach allergens stay in carpets and air ducts year-round.

Do Cockroaches Cause Asthma or Trigger It?

Both. This is a severe and often overlooked danger of cockroaches, especially for kids and the elderly.

• People with asthma should try to avoid areas with severe roach infestations – it can potentially trigger or exacerbate an attack.
• Young children exposed to high levels of cockroach allergens at a young age have also been shown to be more likely to develop asthma.

You don’t have to touch a roach to have an allergic reaction; you just have to breathe the air in a room where they live.

Which Roaches Are Most Dangerous?

Most roaches bring some risk of contamination, but certainly the most alarming to find in your home are German cockroaches. German cockroaches are the small, light brown roaches that you’ll often see in large numbers. If you’re interested in learning more, check out our article about German cockroaches and how they differ from American cockroaches.

How Dangerous Are German Cockroaches?