Can cockroaches make you sick? Yes, but probably not in the way you'd guess. The best-documented harm isn't a disease they hand you. It's the allergens in their droppings, saliva and shed skins, which build up in house dust and can cause allergy symptoms and make asthma worse, especially in children. Roaches also carry germs such as E. coli and Salmonella, but the science on how often that makes people sick is less settled than most pest control websites admit. Here's what the research shows, the symptoms to watch for, who is most at risk, and why killing a few roaches isn't enough to make a home healthier.
Allergens and asthma are the main hazard. Cockroach allergen was detected in an estimated 63% of U.S. homes in a national survey. Children who are both allergic to it and exposed to high levels were hospitalized for asthma about 3.4 times as often as other asthmatic children.
They also carry germs such as E. coli and Salmonella on their bodies and in their droppings, so they can contaminate food. How often that actually makes people sick is, in a 2020 review's words, "poorly understood." And an NC State study in Raleigh found that only eliminating an infestation clears the allergens. Partial control leaves them high.
Cockroach Health Hazards at a Glance
| Hazard | How strong the evidence is | Who it matters most for |
|---|---|---|
| Allergens (droppings, saliva, shed skins, dead bodies) | Strong. Measured in homes nationwide and tied to allergy symptoms | Anyone allergic to cockroaches |
| Asthma attacks | Strong, for children who are both sensitized and exposed | Children and adults with asthma |
| Endotoxins from cockroach droppings | Newer. Measured in Raleigh homes in 2025, linked to inflammation | People with asthma or allergies |
| Bacteria on food and surfaces | Germs are well documented on cockroaches. Proof they cause illness in homes is limited | Young children, older adults, people with weak immune systems |
| Pesticide exposure from DIY treatment | Measured. Bug bombs left kitchen residue far above baseline | Everyone in the home, especially kids and pets |
Cockroach Allergens: The Biggest Risk
The EPA lists cockroaches as an asthma trigger: proteins in their droppings, saliva and body parts cause allergic reactions, and cockroaches are especially common in crowded cities and the South. UC IPM adds that allergen levels track the number of cockroaches. More roaches means more allergen.
- How common: the National Survey of Lead and Allergens in Housing detected cockroach allergen in an estimated 63% of U.S. homes, and in about 84% of high-rise apartment living rooms. Most of those homes were below the levels linked to symptoms, which is why the size of the infestation matters.
- How many people react: in national survey data, about 10% of U.S. children and teens (ages 6 to 19) tested in 2005 to 2006 were sensitized to cockroach, down from 23% in the early-1990s survey.
- Typical symptoms: sneezing, a runny or stuffy nose, itchy eyes and coughing that don't follow pollen seasons and are often worse at home or in bed. On Reddit, one apartment renter described two years of allergy symptoms "when sleeping and in my apartment in general" before suspecting cockroaches.
An allergist can confirm cockroach allergy with a skin prick or blood test.
Cockroach Sickness Symptoms
Most of the sickness cockroaches cause is allergic. The Asthma and Allergy Foundation of America (AAFA) lists the typical cockroach allergy symptoms:
- Sneezing, a runny or stuffy nose, and postnasal drip
- Itchy, red or watery eyes, and an itchy nose, mouth or throat
- Cough
- Itchy skin or a skin rash
- Ear and sinus infections
If the allergy triggers asthma, AAFA adds shortness of breath, chest tightness or pain, wheezing, and waking at night with asthma symptoms. The American College of Allergy, Asthma and Immunology notes that cockroach allergy symptoms often become chronic, lasting beyond typical seasonal allergies, because the allergen stays in the home all year. An allergist can confirm it with a skin or blood test.
Stomach illness from food that roaches have contaminated is possible, but it's much harder to trace back to cockroaches, as the research below explains. If someone in your home has ongoing allergy or asthma symptoms and you have roaches, tell their doctor.
The Asthma Link, With the Detail That Matters
The key study is the National Cooperative Inner-City Asthma Study, published in the New England Journal of Medicine in 1997. Among 476 children with asthma, those who were both allergic to cockroach allergen and exposed to high levels in their bedroom were hospitalized for asthma 0.37 times a year, compared with 0.11 for the other children. That's about 3.4 times as often. They also had more unscheduled doctor visits, more wheezing days and more missed school.
The detail most articles drop: both conditions were needed. Being allergic without high exposure, or exposed without being allergic, didn't produce the effect. So cockroaches aren't an asthma risk for everyone, but for an allergic child with asthma living with an infestation, they're a serious one.
The Newer Finding: Endotoxins in Cockroach Droppings
In 2025, NC State researchers led by Coby Schal studied apartments in Raleigh, North Carolina. Cockroach droppings were full of endotoxins, bacterial compounds that can provoke allergic and inflammatory reactions when inhaled. Females excreted about 2,900 endotoxin units per milligram of droppings, roughly twice the 1,400 from males. Infested homes had high levels of both allergen and endotoxin in their dust.
Homes where the cockroaches were eliminated saw their allergens disappear in most cases and endotoxins drop significantly. Untreated homes stayed high. Schal's summary: "Small decreases in cockroaches don't lower allergen levels because the remaining live cockroaches deposit more allergens."
What Diseases Do Cockroaches Carry?
Cockroaches aren't like mosquitoes or ticks, which inject germs when they bite. They're mechanical carriers: they pick up microbes in drains, garbage and sewage, then leave them on food, dishes and counters through their legs, droppings and regurgitated food.
- A 2020 review in Environmental Health Insights found that about a quarter of the microorganisms isolated from cockroaches are food-borne pathogens, including E. coli O157:H7, Staphylococcus aureus, Bacillus cereus, Shigella, Salmonella Typhi and rotavirus.
- A 2025 systematic review of cockroaches collected in hospitals worldwide found E. coli in 22 studies and Pseudomonas aeruginosa in 11, many of them antibiotic-resistant.
Now the honest part. The same 2020 review says the role of cockroaches in human infections "is poorly understood and has been an issue of debate for several years." The 2025 review describes a "potential risk," mainly in hospitals in developing countries. Cockroaches clearly can contaminate food. How often a home infestation actually causes food poisoning hasn't been well measured. The sensible response is to treat any food or surface they've been on as contaminated, not to panic about every sighting.
For the allergy symptoms to watch for, see cockroach sickness symptoms above.
Do cockroaches urinate?
Not the way mammals do. Cockroaches don't produce separate urine. Their nitrogen waste leaves the body with their droppings, mainly as ammonia, and they store uric acid inside their bodies instead of excreting it. Research published in Science found uric acid isn't a major part of cockroach droppings at all. What they leave behind is droppings, which look like pepper or coffee grounds from German cockroaches, plus smears and the brownish stains of regurgitated food in heavy infestations.
Who Is Most at Risk
- Children with asthma or allergies, especially those already sensitized to cockroach. This is the group the strongest research is about.
- Adults with allergic asthma or year-round "indoor allergies" that are worse at home.
- Babies and toddlers, who spend time on floors where allergen-laden dust settles and put things in their mouths.
- Older adults and people with weakened immune systems, who are more vulnerable to food-borne germs.
- People in apartments and multi-unit buildings, where infestations spread between units and allergen levels run highest.
Why DIY Treatment Can Make the Health Risk Worse
Since partial control leaves allergens high, a treatment that kills some roaches but not the colony doesn't do much for your health. Recent research shows why store-bought products often stall at that point:
- Bug bombs: an NC State study found total-release foggers failed to reduce cockroach populations in infested homes and left pesticide residue on kitchen surfaces averaging 603 times higher than before. That adds a pesticide exposure without fixing the allergen problem.
- Consumer sprays: a 2024 University of Kentucky study found common pyrethroid sprays killed roaches sprayed directly but had little lasting effect on treated surfaces, with some taking up to 5 days of continuous contact to kill. The authors expect them to "add little to no value" to cockroach control. UC IPM notes German cockroaches have become resistant to many insecticides in common sprays.
- Store-bought baits: a 2025 follow-up found consumer baits that worked in the lab were inconsistent in real homes, and one brand of bait station never produced a decline. Professional gel baits performed better.
In apartments, a neighbor's bug bomb can become your problem. Under a Solutions Pest & Lawn video on German cockroaches (about 990,000 views), one commenter, with 44 likes, wrote that when they moved in, the neighbors had bombed, which "sent them scattering." That's one renter's account, not a study, but it matches the NC State result: foggers didn't reduce cockroach numbers, so the survivors keep breeding and shedding allergen wherever they settle.
Professional German cockroach treatment relies on gel baits placed in the cracks where roaches hide, insect growth regulators to stop the next generation, and follow-up visits until the population is gone, not just reduced. Each German cockroach egg case holds about 30 young (UC IPM), which is why stopping halfway lets the colony rebuild. Our cockroach control service works this way, and our guide to heavy roach infestations covers what full treatment involves.
After the Roaches Are Gone: Clearing the Allergens
Allergens outlast the roaches. In a randomized trial in low-income apartments, cockroach bait plus resident education and professional cleaning cut allergen on kitchen floors by 96% within six months, and by about 83% to 84% in living rooms and bedrooms. Even that aggressive cleanup didn't remove all of it. A commentary on the study by allergist Peyton Eggleston noted that residual allergen can take more than six months of cleaning to clear. On Reddit, one person described the same thing: after the roaches were gone, allergens "were still in the structure, in the cabinets, behind the cabinets."
- Confirm the infestation is eliminated, not just reduced, with monitoring traps over several weeks.
- Vacuum with a HEPA vacuum, especially along baseboards, under appliances and inside cabinets.
- Wipe hard surfaces with a damp cloth and detergent rather than dry dusting, which puts allergen in the air.
- Wash bedding and soft furnishings in hot water. Bedding picks up allergen too.
- Replace shelf liners, cardboard and heavily stained materials, and change HVAC filters.
Keeping Them From Coming Back
German cockroaches usually arrive in boxes, grocery bags, used appliances and secondhand furniture, or from a neighboring unit. Store food and pet food in sealed containers, fix leaks and drips, cut back clutter and cardboard, and seal gaps around pipes under sinks. For more, see how to keep cockroaches away for good.
Key Takeaways
- Allergens are the main hazard. Detected in about 63% of U.S. homes, and highest where infestations are heavy.
- Asthma risk is serious for children who are both allergic and exposed: about 3.4 times the hospitalization rate.
- Cockroaches carry food-borne germs, but how often they cause illness at home isn't well measured.
- They don't urinate. Waste leaves with their droppings.
- Only elimination clears allergens. NC State found partial control leaves levels high.
- Skip bug bombs and sprays. They add pesticide exposure without clearing the colony.
Sources: Asthma and Allergy Foundation of America, "Cockroach Allergy"; American College of Allergy, Asthma and Immunology, "Cockroach Allergy"; U.S. EPA, Asthma Triggers: Gain Control; R. D. Cohn, S. J. Arbes Jr. et al., "National Prevalence and Exposure Risk for Cockroach Allergen in U.S. Households", Environmental Health Perspectives 114:522 (2006); D. L. Rosenstreich et al., "The Role of Cockroach Allergy and Exposure to Cockroach Allergen in Causing Morbidity among Inner-City Children with Asthma", New England Journal of Medicine 336:1356 (1997); E. C. McGowan, R. Peng, P. M. Salo, D. C. Zeldin and C. A. Keet, "Cockroach, Dust Mite, and Shrimp Sensitization Correlations in the National Health and Nutrition Examination Survey", Annals of Allergy, Asthma & Immunology 122:536 (2019); M. L. Kakumanu, Z. C. DeVries, R. G. Santangelo, J. Siegel and C. Schal, "Indoor allergens and endotoxins in relation to cockroach infestations in low-income urban homes", Journal of Allergy and Clinical Immunology: Global 5:100571 (2026), and NC State news release (2025); E. S. Donkor, "Cockroaches and Food-borne Pathogens", Environmental Health Insights (2020); Crespo et al., "Pathogens of Medical Importance Identified in Hospital-Collected Cockroaches: A Systematic Review", Microorganisms 13:337 (2025); S. J. Arbes Jr. et al., "Abatement of cockroach allergen (Bla g 1) in low-income, urban housing: A randomized controlled trial", Journal of Allergy and Clinical Immunology 112:339 (2003); D. A. Mullins and D. G. Cochran, "Nitrogen Excretion in Cockroaches: Uric Acid Is Not a Major Product", Science 177:699 (1972); P. A. Eggleston, commentary on cockroach allergen abatement, Journal of Allergy and Clinical Immunology (2003); Z. C. DeVries et al., "Exposure risks and ineffectiveness of total release foggers (TRFs) used for cockroach control in residential settings", BMC Public Health (2019); J. M. Gordon et al., "Common consumer residual insecticides lack efficacy against insecticide-susceptible and resistant populations of the German cockroach", Journal of Economic Entomology 117:2051 (2024); J. M. Gordon et al., "Laboratory and in-home evaluations of consumer- and professional-grade cockroach baits", Journal of Economic Entomology 118:826 (2025); UC IPM, Pest Notes: Cockroaches; Solutions Pest & Lawn, "How to Get Rid of German Cockroaches (4 Simple Steps)", YouTube; homeowner and renter accounts from Reddit (via Google search excerpts) and YouTube comments.
Frequently Asked Questions
Yes. The best-documented way is allergy: cockroach droppings, saliva and shed skins contain allergens that can cause sneezing, congestion, coughing, rashes and asthma attacks, especially in children who are both allergic and exposed. Roaches also carry germs such as E. coli and Salmonella and can contaminate food, though how often that makes people sick is poorly understood.
The Asthma and Allergy Foundation of America lists sneezing, runny or stuffy nose, itchy or watery eyes, itchy nose or throat, cough, itchy skin or rash, and ear or sinus infections. If it triggers asthma, symptoms include shortness of breath, chest tightness, wheezing and waking at night. Symptoms often last year-round.
An infestation raises allergen levels in house dust, which is what drives allergy and asthma symptoms in sensitive people. An NC State study found that only eliminating the infestation brought allergen levels down; partial control left them high. Roaches can also contaminate food and surfaces with germs.
Yes. The strongest evidence is for allergens and asthma, especially in children who are allergic and exposed to high levels. Roaches also carry germs on their bodies and in their droppings and can contaminate food, though a direct link to infections in people hasn't been firmly established.
They leave allergens that build up in dust, contaminate food and surfaces with germs from drains and garbage, and breed quickly indoors. NC State research also found their droppings carry endotoxins, bacterial compounds linked to inflammation.
Cockroaches have been found carrying food-borne pathogens including E. coli, Salmonella, Shigella, Staphylococcus aureus, Bacillus cereus and rotavirus, and Pseudomonas aeruginosa in hospital studies. They spread germs mechanically on their bodies and droppings rather than by biting.
Cockroach allergen is an established asthma trigger. In a major NEJM study, asthmatic children who were both allergic to cockroach and exposed to high levels were hospitalized about 3.4 times as often as other asthmatic children. Both conditions were needed for the effect.
A national survey detected cockroach allergen in an estimated 63% of U.S. homes and about 84% of high-rise apartment living rooms. Most homes were below the levels linked to symptoms. Levels rise with the size of the infestation.
No. Cockroaches don't produce separate urine. Their nitrogen waste leaves with their droppings, mostly as ammonia, and they store uric acid inside their bodies. What you find is droppings, smears and stains.
A few American cockroaches wandering in from outside are a low risk. An indoor German cockroach infestation is a real health concern, especially for anyone with asthma or allergies, small children, older adults or people with weak immune systems. It should be eliminated, not just reduced.
Slowly. In a randomized trial, bait plus professional cleaning cut kitchen-floor allergen 96% in six months, but residual allergen can take longer than that to clear. HEPA vacuuming, damp wiping and washing bedding speed it up.
Not much. NC State researchers in Raleigh found that small decreases in cockroaches don't lower allergen levels because the survivors keep depositing allergens. Homes where cockroaches were eliminated saw allergens disappear in most cases.
They're not effective and they add exposure. An NC State study found bug bombs didn't reduce cockroach populations and left pesticide residue on kitchen surfaces averaging 603 times higher than before treatment. Gel baits worked better.
Photo credits: Clemson University, USDA Cooperative Extension Slide Series, CC BY 3.0 US, via Wikimedia Commons; Gary Alpert, CC BY 2.5, via Wikimedia Commons.