Pest-Related Illnesses, Diseases & Viruses
Understand the illnesses, infections, diseases, viruses, allergic reactions and other health risks that can be associated with common pests found in homes, businesses, farms and outdoor environments across the UK.
Start typing for suggestions. Choose one, or press Search to jump to the first match. Use ↑ and ↓ to select, Enter to go, and Escape to close.
Understanding illnesses and diseases associated with pests
Pests can affect health in several different ways. Some can contaminate food or surfaces, some can expose people to bacteria or viruses through urine, droppings or nesting material, while others can bite, sting or trigger respiratory and allergic reactions.
The actual health risk varies considerably. A pest being capable of carrying an organism does not mean that every infestation will result in disease. Risk depends on the species involved, the pathogen, geography, environmental conditions and the way a person has been exposed.
This knowledge base has therefore been designed to explain the relationship between common pests and human health without unnecessarily alarming homeowners, landlords, businesses, facilities managers or agricultural premises.
This resource is provided for general educational information about pest-related health risks. It is not a diagnosis or a substitute for advice from a GP, NHS 111, pharmacist or other qualified healthcare professional. If you are unwell following possible exposure to a pest, tell the healthcare professional about the exposure.
Diseases, illnesses and infections associated with pests
Some diseases have a well-established association with particular pests, animals or vectors. Others are uncommon in the UK, geographically restricted or more frequently associated with overseas travel. The information below should therefore always be considered alongside the particular pest and circumstances involved.
45 health topics. Search by condition, pest or exposure, then select a result to jump to its entry. Travel-related conditions and wider animal-hygiene concerns are labelled or explained individually; their inclusion does not mean they are routinely spread by UK household pests.
Leptospirosis & Weil’s disease
A bacterial infection associated particularly with exposure to urine from infected animals, including rats and other rodents. Severe leptospirosis, often referred to as Weil’s disease, can affect organs including the kidneys and liver.
Back to search ↑Hantavirus
Hantaviruses are a group of viruses carried by rodents including rats and mice. Human exposure can occur through contact with infected rodent urine, droppings or contaminated environments.
Back to search ↑Salmonella & salmonellosis
Salmonella bacteria can cause gastrointestinal illness. Rodents, flies, cockroaches and some birds may contribute to contamination of food, equipment and surfaces where adequate hygiene and pest controls are not maintained.
Back to search ↑Rat-bite fever
A bacterial infection associated with exposure to infected rodents, particularly through bites or scratches, although contaminated materials may also present a route of exposure.
Back to search ↑Tularaemia
Tularaemia is a bacterial zoonotic infection caused by Francisella tularensis. Internationally it can be associated with infected wildlife, including rodents and rabbits, as well as tick bites and environmental exposure. It is not considered established in the UK and human cases are exceptionally unusual.
Back to search ↑Lymphocytic choriomeningitis
Lymphocytic choriomeningitis virus, often shortened to LCMV, is associated particularly with infected rodents. Human infection is uncommon but forms part of the wider range of potential rodent-related health risks.
Back to search ↑Lyme disease
Lyme disease is a bacterial infection transmitted through the bite of an infected tick. Tick exposure is therefore an important health consideration in woodland, heathland, grassland and other outdoor environments.
Back to search ↑Tick-borne encephalitis
Tick-borne encephalitis, or TBE, is a viral infection transmitted by infected ticks. Infected ticks occur in parts of Europe, including parts of the UK, although the risk of acquiring TBE in the UK remains very low.
Back to search ↑Babesiosis
Babesiosis is an infection caused by microscopic Babesia parasites that affect red blood cells and can be transmitted through the bite of an infected tick. UK-acquired human infection is rare, although Babesia organisms have been detected in ticks collected through UK surveillance.
Back to search ↑Anaplasmosis
Human granulocytic anaplasmosis is a bacterial tick-borne infection caused by Anaplasma phagocytophilum. The organism has been identified in UK ticks, although recognised human disease remains uncommon and the public-health significance in the UK continues to be monitored.
Back to search ↑Alpha-gal syndrome
Alpha-gal syndrome is a rare tick-associated allergic condition rather than an infection. Following a tick bite, some people can become sensitised to alpha-gal, a molecule found in mammalian products, potentially causing delayed allergic reactions to foods such as red meat and other animal-derived products.
Back to search ↑Psittacosis & ornithosis
Psittacosis is a bacterial infection primarily associated with birds. Pigeons and other wild or captive birds can carry the organism, making contaminated bird droppings and nesting areas an important occupational and environmental consideration.
Back to search ↑Cryptococcosis
Cryptococcosis is a fungal infection caused by Cryptococcus species found in the environment. Cryptococcus neoformans is associated with soil and bird droppings, including environments contaminated by pigeon fouling. Infection generally occurs by inhaling microscopic fungal spores rather than directly from the bird itself.
Back to search ↑Histoplasmosis
Histoplasmosis is a fungal infection associated with breathing in spores from Histoplasma in contaminated environmental material. The fungus can grow particularly well in soil or material enriched with large quantities of bird or bat droppings, although geographic risk varies considerably and infection is much more common in some parts of the world than the UK.
Back to search ↑Campylobacter & campylobacteriosis
Campylobacter bacteria are an important cause of gastrointestinal illness. Pest activity can increase hygiene concerns where insects or rodents travel between contaminated material, waste and food preparation or storage areas.
Back to search ↑E. coli & food contamination
Certain strains of Escherichia coli can cause serious gastrointestinal illness. Flies, cockroaches and rodents can increase the risk of cross-contamination where they move between waste, faecal material and food-handling environments.
Back to search ↑Flea-borne diseases
Fleas can act as vectors for a number of infections internationally, including diseases associated with infected rodents. Many serious flea-borne infections are uncommon or not normally acquired in the UK, but remain relevant when considering travel and global pest-health risks.
Back to search ↑Flea-borne typhus & murine typhus
Flea-borne typhus, also known as murine or endemic typhus, is caused by Rickettsia typhi. Infection is associated with infected fleas and their faeces, particularly in environments where fleas and animal hosts such as rodents occur together. UK cases are principally a travel-related consideration.
Back to search ↑Plague
Plague is a serious bacterial infection caused by Yersinia pestis. In parts of the world where the organism circulates naturally among wild rodents, people may become infected through bites from infected fleas or through contact with infected animals. Plague is not endemic to the modern UK.
Back to search ↑Dipylidium tapeworm infection
Dipylidium caninum is a tapeworm commonly associated with dogs and cats that uses fleas as an intermediate host. Human infection is uncommon and usually occurs after accidentally swallowing an infected flea, making effective flea control particularly important where pets and young children share an environment.
Back to search ↑Scabies
A contagious skin infestation caused by microscopic mites. Scabies mites are different from common household dust mites and scabies should not be approached as an ordinary property pest infestation.
Back to search ↑Pest allergies & asthma
Cockroach debris, droppings and certain mite allergens can contribute to allergic symptoms in susceptible people. Established infestations may be particularly significant where occupants already experience asthma or respiratory allergies.
Back to search ↑Insect bites & skin reactions
Bites from fleas, bed bugs, mites and other arthropods can cause redness, itching, inflammation and localised reactions. Excessive scratching can also damage the skin and increase the possibility of secondary infection.
Back to search ↑Secondary skin infections
Persistent scratching following bites can break the skin and potentially allow bacterial infection to develop. Recognising and resolving the underlying biting-pest problem can therefore form part of reducing repeated exposure.
Back to search ↑Anaphylaxis & severe sting reactions
Wasp, hornet and bee stings usually cause a local reaction, but susceptible people can experience a severe systemic allergic reaction known as anaphylaxis. This is a medical emergency requiring urgent treatment.
Back to search ↑Avian influenza (bird flu)
Avian influenza viruses mainly infect birds. Human infection is rare and is associated with close contact with infected birds or contaminated material. Avoid touching sick or dead wild birds. If you become unwell after relevant bird contact, seek medical advice and describe the exposure.
Back to search ↑West Nile virus
West Nile virus circulates between birds and mosquitoes and can reach people through an infected mosquito bite. Most infections cause no symptoms, but a small proportion cause serious neurological illness. The virus has been detected in UK mosquitoes; UKHSA monitors the risk. It is not spread by simply being near birds.
Back to search ↑Dengue fever
Dengue is a viral infection transmitted by infected mosquitoes in affected countries. It can cause fever, headache and muscle or joint pain, and occasionally severe illness. For UK residents, it is principally a travel-related risk. Mosquitoes that transmit dengue commonly bite during the day.
Back to search ↑Chikungunya
Chikungunya virus is spread by infected Aedes mosquitoes. Illness commonly involves fever and joint pain, which can sometimes persist after the initial infection. It is a travel-related consideration for people visiting affected areas, including some places with outbreaks in Europe.
Back to search ↑Zika virus
Zika virus is mainly transmitted by infected mosquitoes in affected countries and can also spread through sexual contact. Infection is often mild or symptom-free, but can seriously affect a developing baby during pregnancy. Seek current travel-health advice if pregnant or planning a pregnancy.
Back to search ↑Malaria
Malaria is caused by Plasmodium parasites transmitted by infected mosquitoes. It is a serious travel-related infection and can become life-threatening. Seek urgent medical advice for fever or flu-like illness during or after visiting a malaria-risk area, and explain where you travelled, even if you took malaria-prevention tablets.
Back to search ↑Yellow fever
Yellow fever is a mosquito-borne viral infection found in parts of Africa and South America. It can cause serious illness, including liver damage and jaundice. It is not a routine UK pest risk. Travel advice may include vaccination and measures to prevent mosquito bites.
Back to search ↑Japanese encephalitis
Japanese encephalitis is a mosquito-borne viral infection found mainly in parts of Asia. Most infections cause no symptoms, but some cause serious inflammation of the brain. Risk depends on destination, activities and length of stay; a travel-health professional can advise about bite prevention and vaccination.
Back to search ↑Rabies & bat lyssaviruses
Rabies viruses can spread through bites, scratches or infected saliva contacting broken skin or mucous membranes. Some UK bats carry related lyssaviruses. Get medical help immediately after a bat bite or scratch in the UK, or a potentially risky animal exposure abroad. Do not wait for symptoms.
Back to search ↑Lassa fever
Lassa fever is a viral infection associated with specific wild rodents in parts of West Africa. Exposure can occur through food, surfaces or dust contaminated with infected rodent urine or droppings. UK cases are extremely rare and linked to overseas exposure or associated contact; ordinary UK rat activity does not imply a Lassa fever risk.
Back to search ↑Toxocariasis (roundworm infection)
Toxocariasis can follow accidentally swallowing roundworm eggs from soil or material contaminated by infected dog, cat or fox faeces. Infection is uncommon, but larvae can sometimes affect organs or the eyes. This is an environmental hygiene concern, particularly where contaminated soil is handled; it is not spread by an insect bite.
Back to search ↑Toxoplasmosis
Toxoplasmosis is caused by the parasite Toxoplasma gondii. Exposure can occur through undercooked meat or accidentally swallowing the parasite from soil or material contaminated with infected cat faeces. Infection is particularly important during pregnancy and for people with weakened immune systems. It is an animal and food-hygiene issue, not a typical insect-borne disease.
Back to search ↑Cryptosporidiosis
Cryptosporidium parasites can cause watery diarrhoea and stomach cramps. Infection follows swallowing the parasite from contaminated water, food, hands or surfaces, including after contact with infected farm animals. This is a broader animal and environmental hygiene risk; a pest sighting alone does not identify the source of an infection.
UKHSA: Cryptosporidium public advice
Back to search ↑Giardiasis
Giardiasis is an intestinal infection caused by Giardia parasites. It spreads when the parasite is swallowed, commonly through contaminated water or contact with an infected person. Symptoms can include diarrhoea, cramps and bloating. Good water and hand hygiene matter; household pest activity by itself is not evidence of the cause.
Back to search ↑Q fever
Q fever is a bacterial infection mainly associated with infected livestock, including sheep, cattle and goats. People can become infected by breathing in contaminated material or through contact with animal birth products and waste. It is primarily a farm and occupational exposure concern rather than a typical household pest-borne illness.
Back to search ↑Cat-scratch disease
Cat-scratch disease is caused by Bartonella henselae bacteria. Fleas help maintain infection among cats; people usually become infected after a cat scratch contaminated with flea faeces. Fever and swollen, tender lymph nodes can develop. Direct transmission to people by a flea bite has not been established.
Back to search ↑Bird mite dermatitis
Mites associated with birds and nesting material may bite people, causing itchy, irritated skin. This is a bite reaction and differs from scabies: bird mites do not burrow into human skin. Identifying the mite and the source of exposure is useful, because skin marks alone cannot reliably identify the pest.
Back to search ↑Leishmaniasis
Leishmaniasis is caused by parasites transmitted through the bites of infected sand flies in affected regions. Different forms can cause skin sores or affect internal organs. It is relevant to overseas exposure and travel; ordinary houseflies are not the vectors for this infection.
Back to search ↑Chagas disease
Chagas disease is caused by Trypanosoma cruzi. In affected parts of the Americas, infection can occur when faeces from infected triatomine bugs enter a bite wound, the eyes or the mouth. These insects are also called kissing bugs and are different from bed bugs. Other routes, including transmission during pregnancy, are possible.
Back to search ↑Spotted fever rickettsioses
This group includes African tick-bite fever, Mediterranean spotted fever and Rocky Mountain spotted fever. Infected ticks transmit the bacteria, and risk depends on the species and country. Fever, rash or a dark scab at a bite site after overseas tick exposure warrants prompt medical advice and a clear travel history.
Back to search ↑Pests and the health risks associated with them
Different pests create different health considerations. The following overview can help you find the relevant Shire Pest Solutions pest-control page and understand some of the potential health concerns associated with each pest.
| Pest | Potential health concern | Useful link |
|---|---|---|
| Rats | Rat urine, droppings, bites and contaminated environments can be associated with infections including leptospirosis, rat-bite fever and certain hantaviruses. | Rat control |
| Mice | Potential contamination of food and surfaces, together with exposure to rodent urine, droppings and nesting material. Rodents can also be associated with infections including LCMV and particular hantaviruses. | Mouse control |
| Fleas | Bites commonly cause itching, inflammation and skin irritation. Fleas can also act as disease vectors in certain geographic and epidemiological settings. | Flea control |
| Flies | Flies can mechanically transfer microorganisms between waste, faecal material, contaminated environments, food and food-contact surfaces. | Fly control |
| Cockroaches | Cockroach allergens can contribute to allergies and asthma, while their movement through contaminated environments can create significant food-hygiene concerns. | Cockroach control |
| Pigeons & pest birds | Accumulated droppings and nesting material can create hygiene and occupational exposure concerns. Some birds can carry organisms associated with infections including psittacosis and Salmonella. | Pigeon control |
| Wasps | The principal health concern is stinging rather than transmission of infectious disease. Some people can experience severe allergic reactions including anaphylaxis. | Wasp control |
| Bed bugs | Bites can cause itching, irritation, loss of sleep and significant distress. Scratching may damage skin and lead to secondary infection. Bed bugs have not been established as important human disease vectors. | Bed bug control |
| Mites | Health effects depend heavily on species. Some mites bite, some can trigger allergic symptoms, while scabies mites are responsible for a specific contagious skin infestation. | Mite control |
| Ticks | Ticks can act as vectors for infection. Lyme disease is the principal recognised tick-borne infection in the UK, while tick-borne encephalitis is also present at a very low risk level. | Ask Shire Pest Solutions |
| Ants | Most UK household ants are primarily a nuisance, although infestations within kitchens, restaurants, healthcare premises and other sensitive environments can create contamination concerns. | Ant control |
| Hornets | The principal human health concern is stinging, particularly for people who are allergic to insect venom or who receive multiple stings. | Hornet control |
| Mosquitoes | Bites can irritate the skin. Disease risks depend on the country and species; many serious mosquito-borne infections are primarily travel-related concerns for UK residents. | West Nile virus Malaria Dengue |
| Foxes & animal fouling | Faecally contaminated soil can present parasite and hygiene risks. Prevent hand-to-mouth exposure and seek advice about safe management of contaminated areas. | Toxocariasis |
How can pests spread illness?
There is no single mechanism by which pests affect human health. Understanding the route of exposure is often more useful than simply knowing that a pest is associated with a particular disease.
Contaminated food and surfaces
Rodents, flies, cockroaches and some pest birds can move between waste, drains, contaminated materials and places where food is prepared, stored or consumed. This creates opportunities for microorganisms to reach food or food-contact surfaces.
Urine, droppings and nesting material
Rodent infestations deserve particular attention because infectious organisms can be associated with rodent urine, faeces, saliva and contaminated nesting material. Accumulations of bird droppings can also create environmental and occupational health concerns.
Avoid unnecessarily disturbing dry rodent waste, bird droppings or contaminated nesting material, particularly where large accumulations are present.
Bites and stings
Bites from fleas, bed bugs, mites, ticks and certain other arthropods can produce itching, inflammation and skin reactions. Wasps and hornets can sting, while severe allergic reactions are an important emergency consideration for susceptible people.
Vector-borne infection
Some arthropods can transmit pathogens while feeding on humans or animals. Ticks are a particularly relevant UK example because infected ticks can transmit Lyme disease. Fleas are important disease vectors in some parts of the world, although many serious flea-borne infections are uncommon in the UK.
Airborne contaminated material
Certain infections may be associated with inhaling contaminated material. This is one reason why heavily contaminated rodent nesting areas or accumulations of bird droppings should be approached carefully rather than aggressively swept or disturbed without suitable precautions.
Allergens and pest debris
Not every pest-related health effect is an infection. Pest debris, shed material, droppings and microscopic particles associated with cockroaches and some mites can contribute to allergic or respiratory symptoms in susceptible individuals.
How to reduce pest-related health risks
Remove food sources
Store food in sealed containers, clean food preparation areas promptly, clear spills and crumbs and keep internal and external waste securely contained.
Reduce access
Inspect gaps around doors, pipes, vents, roofing, drains, loading areas and other potential pest entry routes. Proofing can be an important part of preventing recurring infestations.
Deal with contamination safely
Do not unnecessarily disturb rodent droppings, contaminated nesting material or large accumulations of bird fouling. Appropriate cleaning, hygiene and protective procedures should be used.
Protect food areas
Commercial kitchens, food-storage areas and hospitality environments should maintain robust pest-monitoring, waste-management and cleaning procedures to reduce cross-contamination risks.
Check for ticks
After spending time in areas where ticks may be present, check exposed skin and clothing and remove attached ticks safely and promptly.
Act early
Early pest identification can make treatment simpler and reduce the opportunity for an infestation to spread, reproduce or create increasing contamination within a property.
When should you seek medical advice?
Contact a healthcare professional if you develop symptoms after a known or suspected exposure to an infected animal, pest, contaminated water, droppings, nesting material or other contaminated environment, particularly if you become significantly unwell.
Tell the healthcare professional about the exposure. Information such as contact with rats or mice, bird droppings, bites, stings, tick exposure, travel, animal contact or exposure to contaminated water may be clinically relevant.
Following a tick bite, seek appropriate medical advice if you develop symptoms such as an expanding circular or oval rash or become unwell.
Call 999 for signs of a severe allergic reaction following an insect sting, such as difficulty breathing, swelling of the tongue or throat, or collapse.
Pest-control companies can address the environmental pest problem, but they do not diagnose or treat human disease.
Frequently asked questions about pests and disease
Can pests make humans ill?
Some pests can contribute to human health risks, but the level and type of risk varies considerably between species. Rodents can be associated with certain infections, while flies and cockroaches can contribute to contamination. Biting and stinging pests may cause skin or allergic reactions.
Can rats and mice spread disease?
Yes. Rodents can carry organisms capable of causing human infection. Examples include leptospirosis, hantaviruses, rat-bite fever and lymphocytic choriomeningitis virus. Potential routes of exposure include urine, droppings, saliva, contaminated material, bites and scratches.
Can mouse droppings make you ill?
Rodent droppings can contribute to health risks because rodents may carry infectious organisms. Avoid directly handling or unnecessarily disturbing droppings and contaminated nesting material, particularly in heavily infested areas.
Can pigeon droppings cause health problems?
Large accumulations of bird droppings and nesting material can create hygiene and occupational health concerns. Birds including pigeons may carry certain organisms capable of causing human infection, so significant contamination should be managed appropriately.
What is psittacosis?
Psittacosis is a bacterial infection associated with birds. Although often associated with pet birds, pigeons and other bird species can also carry the organism. Exposure can be associated with contaminated droppings, respiratory secretions and bird-related environments.
Do bed bugs carry disease?
Bed bugs are a significant nuisance and their bites can cause itching, irritation, sleep disruption and distress. They have not been established as important human disease transmitters. Scratching bites can, however, damage the skin and potentially contribute to secondary infection.
Can fleas make people ill?
Flea bites commonly cause itching and skin irritation. Fleas can also transmit certain pathogens in particular geographic settings. The diseases associated with fleas vary according to location, flea species and animal hosts.
Can ticks spread disease in the UK?
Yes. Infected ticks can transmit Lyme disease in the UK. Tick-borne encephalitis virus has also been identified in parts of the UK, although the risk of acquiring tick-borne encephalitis domestically remains very low.
Can flies spread disease?
Flies can transfer microorganisms mechanically between contaminated materials, waste, food and food-contact surfaces. This is particularly important in food, hospitality, agricultural and healthcare environments.
Can cockroaches cause health problems?
Yes. Cockroach allergens can contribute to allergic symptoms and asthma in susceptible people. Cockroaches can also create food-hygiene concerns by moving through contaminated environments and onto food or food-contact surfaces.
Can pest bites become infected?
Bites frequently cause itching and irritation. Repeated or vigorous scratching can damage the skin, potentially increasing the risk of a secondary bacterial skin infection.
Can wasp or hornet stings be dangerous?
Most stings cause pain and a localised reaction. However, some people can experience a severe allergic reaction known as anaphylaxis. Symptoms affecting breathing, the throat, tongue or circulation require emergency medical attention.
Does seeing a rat mean I will get Weil’s disease?
No. The presence of rats does not mean that infection will occur. Disease risk depends on whether relevant organisms are present and whether a person experiences an appropriate route of exposure. Nevertheless, an established rat infestation should be addressed promptly.
Should I contact a pest controller or a doctor?
Contact a pest controller for the infestation, proofing, contamination or environmental pest problem. Contact a GP, NHS 111 or emergency medical services when you are concerned about symptoms or illness. The two services address different aspects of the issue.
Concerned about pests in your home or business?
Shire Pest Solutions provides professional pest control across Oxfordshire, West Berkshire and surrounding areas, including Didcot, Wallingford, Wantage, Abingdon and nearby towns and villages.
Medical information and sources
The additional topic summaries link to NHS, UKHSA, CDC and other public-health guidance. Geographic risks can change; check the linked sources for current advice, especially before travelling. Useful general references include:
- UKHSA: animal-associated infections and transmission routes
- NHS: insect bites and stings
- UKHSA: tick-borne encephalitis
- CDC: vector-borne diseases A–Z
Shire Pest Solutions provides pest-control, pest-prevention and bird-control services alongside general pest-health education. This page does not provide medical diagnosis or treatment advice.
Additional topic sources checked: .
Recent Comments