Can rats get sick from humans

Understanding Zoonotic Diseases

What are Zoonotic Diseases?

Zoonotic diseases are infections that can be transmitted between animals and humans. «Zoonotic disease» refers to any pathogen—viral, bacterial, parasitic, or fungal—that naturally moves from a vertebrate host to a human host, or vice versa.

Transmission occurs through direct contact with bodily fluids, bites, scratches, or inhalation of contaminated aerosols. Indirect routes include consumption of contaminated food, water, or exposure to environmental reservoirs such as rodent droppings.

Rats serve as reservoirs for several zoonoses, demonstrating the bidirectional potential of disease spread. Pathogens maintained in rat populations can reach humans, and human‑origin pathogens can infect rats under certain conditions.

Examples of rat‑associated zoonotic agents:

Leptospira spp. (leptospirosis) – transmitted via urine‑contaminated water.
Hantavirus – spread through inhalation of aerosolized rodent excreta.
Salmonella enterica – acquired from contaminated food or surfaces.
Rat‑bite fever (Streptobacillus moniliformis) – introduced through bite wounds.
Lymphocytic choriomeningitis virus – transmitted by aerosol or direct contact.

Continuous surveillance of rodent health and strict hygiene practices reduce the risk of cross‑species infection. Monitoring disease prevalence in rat colonies provides early warning for potential human exposure.

How are Zoonotic Diseases Transmitted?

Direct Contact

Direct contact between humans and rats provides a pathway for the transfer of infectious agents. Pathogens that can move from people to rodents typically require physical interaction such as handling, biting, or exposure to contaminated wounds.

Common agents documented in human‑to‑rat transmission include:

Staphylococcus aureus strains, especially methicillin‑resistant variants, transmitted through skin lesions or contaminated surfaces.
Salmonella spp., spread via fecal material transferred to the animal’s fur or paws.
Mycobacterium tuberculosis complex, transferred when rats inhale aerosolized droplets from infected persons or receive contaminated secretions.
Certain respiratory viruses (e.g., influenza A) that can infect rats after direct exposure to nasal or oral secretions.

Preventive actions focus on minimizing direct interaction and maintaining strict hygiene. Protective gloves and disposable clothing should be used when handling rats in laboratory or pest‑control settings. Wounds on either party must be cleaned promptly; disinfection of surfaces and tools reduces the risk of cross‑contamination. Regular health monitoring of both humans and rodents enables early detection of emerging infections.

Indirect Contact

Indirect contact refers to exposure of rodents to infectious agents without a direct physical interaction with an infected person. Pathogens may persist on objects, food, water, or in the environment long enough to be acquired by a rat that later contacts the contaminated source.

Common routes of indirect transmission include:

Contaminated feed or water containers that have been handled by a sick individual;
Surfaces such as cages, bedding, or laboratory benches exposed to respiratory droplets;
Airflow systems that convey aerosolized particles from a human‑occupied area to rodent housing;
Waste material or litter that contains viable microorganisms shed by a person.

The likelihood of infection depends on pathogen stability outside the host, environmental conditions, and the duration between contamination and rodent contact. Some viruses and bacteria retain infectivity for hours to days on inert surfaces, making indirect exposure a plausible risk factor.

Mitigation strategies focus on strict hygiene protocols: routine disinfection of feeding equipment, separation of human and rodent workspaces, use of HEPA filtration for shared ventilation, and proper disposal of waste. Regular monitoring of environmental contamination levels supports early detection of potential transmission events.

Vectors

Vectors are organisms or particles that transport pathogenic agents between hosts. In the case of potential transmission from humans to rats, vectors facilitate indirect exposure when direct contact is limited.

Common vectors implicated in human‑to‑rat disease transfer include:

Fleas that feed on both species, capable of carrying bacteria such as Yersinia pestis.
Mites that can harbor viruses and survive on rodent fur after contact with infected humans.
Airborne droplets that settle on surfaces, later ingested by rats during grooming.
Contaminated feed or water contaminated by human waste, acting as a mechanical vector for enteric pathogens.

Evidence of vector‑mediated transmission remains limited; documented cases involve primarily zoonotic agents moving from rodents to humans. Surveillance of vector populations and hygiene control reduce the risk of reverse transmission.

Human-to-Rat Disease Transmission Potential

Diseases Humans Can Transmit to Rats

Influenza

Influenza viruses primarily infect mammals with respiratory epithelium that expresses sialic‑acid receptors compatible with viral hemagglutinin. Laboratory studies demonstrate that several rat strains support replication of human‑derived influenza A subtypes when inoculated intranasally, confirming physiological susceptibility. Natural infection, however, requires exposure to sufficient viral load, which is uncommon in typical human‑rat interactions because humans excrete virus mainly through coughing and sneezing, while rats usually encounter contaminated surfaces rather than aerosolized particles.

Evidence from field investigations indicates sporadic detection of influenza RNA in wild‑caught rats living in densely populated urban areas. Positive samples often correlate with high community incidence of seasonal flu, suggesting that environmental contamination can lead to transient carriage. Viral isolation from rat lung tissue confirms active infection rather than passive contamination, implying that rats can serve as incidental hosts under conditions of intense human outbreak.

Key considerations for assessing risk:

Rat species with close proximity to human dwellings exhibit higher detection rates.
Viral shedding from infected rats is limited to low titres, reducing likelihood of onward transmission to humans or other animals.
Biosecurity measures that limit rodent access to food storage and waste diminish exposure opportunities.

Current consensus among virologists holds that rats are not a significant reservoir for human influenza, yet they may acquire the virus temporarily during severe epidemics. Monitoring rodent populations in outbreak zones provides additional data for understanding cross‑species transmission dynamics.

Common Cold Viruses

Rats are occasionally exposed to human respiratory pathogens when sharing laboratory facilities, pet environments, or urban settings. The viruses that cause the common cold in humans belong primarily to the rhinovirus, coronavirus, and adenovirus families. These agents replicate in the nasal epithelium of humans, producing mild upper‑respiratory symptoms.

Evidence for cross‑species infection is limited. Experimental studies have shown that certain human rhinovirus strains can attach to rodent cellular receptors, yet productive infection rarely occurs. Conversely, some human coronaviruses, such as OC‑43, have demonstrated low‑level replication in murine models, suggesting a potential, albeit inefficient, transmission route.

Key factors influencing the likelihood of rats acquiring a cold‑type infection:

Presence of compatible cellular receptors on rat respiratory epithelium.
Viral load in the environment, especially in enclosed spaces.
Absence of innate immune barriers that normally block heterologous viruses.

Overall, natural infection of rats by human cold viruses is uncommon. Most reported cases involve laboratory‑controlled exposure rather than spontaneous transmission. Preventive measures, including proper sanitation and separation of human and rodent housing, reduce the already low risk of interspecies spread.

Other Respiratory Pathogens

Human‑to‑rat transmission of respiratory microorganisms extends beyond influenza and coronaviruses. Several additional agents have been documented to cause disease in laboratory and pet rats.

• Streptococcus pneumoniae – colonises the upper airway; aerosol exposure can lead to pneumonia and pleuritis.
• Haemophilus influenzae – rare in rodents, but experimental infection demonstrates bronchopneumonia after intranasal inoculation.
• Adenoviruses (e.g., rat adenovirus type 2) – transmitted through respiratory droplets; produces rhinitis and interstitial pneumonia.
• Rhinoviruses – human strains occasionally replicate in rodent epithelium, causing transient nasal discharge.
• Mycoplasma spp. (non‑pneumoniae) – acquired from contaminated personnel; results in bronchial inflammation.

Transmission occurs primarily via inhalation of infectious aerosols generated by coughing, sneezing, or speaking. Indirect spread is possible through contaminated bedding, feed, or handling equipment. Close proximity of rats to infected caregivers increases risk.

Clinical signs in affected rats include nasal discharge, sneezing, increased respiratory rate, and audible wheezing. Severe cases may progress to dyspnoea, lethargy, and weight loss. Pathological examination often reveals pulmonary consolidation and inflammatory infiltrates.

Diagnostic confirmation relies on culture of respiratory secretions, polymerase‑chain‑reaction assays targeting pathogen‑specific genes, and histopathological evaluation of lung tissue. Preventive strategies comprise routine health monitoring of personnel, use of personal protective equipment during handling, regular disinfection of cages, and isolation of newly introduced animals pending screening.

Understanding the spectrum of respiratory pathogens transmissible from humans to rats informs biosecurity protocols and reduces the incidence of zoonotic respiratory disease in laboratory and domestic rodent colonies.

Factors Influencing Transmission

Close Proximity

Close proximity describes situations in which rats and people occupy the same limited space, share food sources, or contact the same surfaces. Urban apartments, laboratories, and waste‑handling facilities often create such conditions.

Transmission pathways that become active at short distances include:

Respiratory droplets expelled during coughing or sneezing, which can settle on rodent fur or bedding.
Direct contact with saliva, blood, or mucous membranes when humans handle rats or when rats gnaw at contaminated objects.
Ingestion of food or water contaminated with human pathogens, such as norovirus, influenza A, or certain bacterial strains.

Research documents reverse zoonotic events where human‑origin viruses have infected laboratory and wild rats. Molecular analysis confirmed human‑derived influenza A virus in wild populations living near densely populated neighborhoods. Similar findings report bacterial infections, such as methicillin‑resistant Staphylococcus aureus, in rats captured in hospitals and veterinary clinics.

Mitigation strategies focus on reducing shared space and limiting exposure:

Implement physical barriers that separate rodent habitats from human activity zones.
Enforce strict hand‑washing and equipment‑disinfection protocols for personnel handling rodents.
Store food and waste in sealed containers to prevent rodent access.
Conduct routine health screening of both humans and rats in environments where contact is unavoidable.

These measures decrease the likelihood that diseases originating in people will spread to rats sharing the same environment.

Immune System Status

Rats possess a robust innate immune system that includes physical barriers, phagocytic cells, and complement proteins. These components provide immediate defense against invading microorganisms, regardless of the source of exposure.

Adaptive immunity in rats features T‑cell–mediated responses and antibody production. The repertoire of immunoglobulin classes mirrors that of other mammals, enabling recognition of a wide array of antigens introduced by contact with human carriers.

Documented instances demonstrate that rats can acquire pathogens typically associated with humans. Examples include transmission of Staphylococcus aureus strains resistant to methicillin and infection by respiratory viruses such as influenza A. Laboratory studies have confirmed replication of human‑derived viral particles in rat respiratory tissue, confirming cross‑species susceptibility.

Factors that modify immune status in rats encompass:

Nutritional deficiency, which reduces leukocyte activity.
Chronic stress, leading to elevated cortisol and suppressed cytokine production.
Co‑habitation density, increasing exposure to contaminated surfaces.
Age‑related immunosenescence, diminishing vaccine response.

These variables influence the probability that a rat will become ill after exposure to human pathogens. Immunocompromised individuals within rat populations exhibit higher rates of infection, suggesting that immune competence directly affects transmission outcomes.

Understanding rat immune dynamics informs public‑health strategies. Monitoring rodent health in environments with high human disease prevalence can serve as an early warning system for zoonotic cycles. Control measures that reduce stressors and improve nutrition may lower the risk of rats acting as reservoirs for human‑origin illnesses. «Rats share many immunological pathways with humans», underscoring the relevance of their immune status in assessing cross‑species disease potential.

Environmental Conditions

Rats sharing habitats with humans encounter pathogens when environmental factors favor survival and transfer of infectious agents. Close physical proximity, especially in densely populated dwellings, creates direct routes for microbes through contaminated surfaces, food, or water.

Key conditions influencing interspecies disease transmission include:

High humidity levels that prolong viral stability on surfaces.
Warm temperatures that accelerate bacterial growth in waste accumulations.
Poor sanitation resulting in accumulation of organic debris, providing breeding grounds for parasites.
Inadequate ventilation that concentrates aerosolized particles in confined spaces.
Overcrowding of rodent populations, which intensifies contact rates and stress‑induced immunosuppression.

Mitigation strategies focus on controlling these variables: maintaining dry, well‑ventilated environments; implementing rigorous waste management; limiting rodent access to food sources; and reducing population density through humane control measures. Such environmental management reduces the likelihood that rats acquire illnesses originating from human carriers.

Preventing Cross-Species Transmission

Hygiene Practices for Pet Owners

Handwashing

Hand hygiene directly lowers the probability that humans transmit infectious agents to rats. When people handle rodents, feed them, or clean cages, microorganisms present on the skin can be deposited onto the animal’s fur, eyes, nose or open wounds, creating a pathway for disease transmission.

Effective handwashing should be performed before and after any contact with rats, after handling waste, and after touching surfaces that may be contaminated. The procedure includes:

Wetting hands with clean water.
Applying enough soap to create a lather.
Scrubbing all hand surfaces for at least 20 seconds, covering palms, backs of hands, between fingers and under nails.
Rinsing thoroughly under running water.
Drying with a disposable towel or air dryer.

«Proper handwashing prevents the transfer of pathogens such as Salmonella, Leptospira and hantavirus from humans to rodents». In laboratory settings, veterinary clinics, and households with pet rats, strict adherence to these steps reduces the risk of illness in the animals and limits the potential for reverse zoonotic events.

Cleaning Enclosures

Cleaning the enclosure is essential to limit the possibility of disease transfer from humans to pet rats. Regular removal of waste, uneaten food, and soiled bedding eliminates reservoirs where pathogens can survive and multiply.

Key steps for effective cleaning:

Remove all bedding, toys, and accessories before washing.
Rinse the cage with hot water to dislodge organic material.
Apply a disinfectant proven safe for rodents, such as a diluted quaternary ammonium solution, following the manufacturer’s contact time.
Rinse thoroughly with clean water to prevent chemical residues.
Dry all components completely before re‑adding fresh bedding and enrichment items.

Disinfectants must be selected for efficacy against bacteria, viruses, and fungi commonly carried by humans, while being non‑toxic to rats. Products containing bleach or phenols are unsuitable because residues can cause respiratory irritation. Veterinary guidelines recommend using a 0.1 % solution of hydrogen peroxide or a veterinary‑approved enzymatic cleaner.

Handler hygiene complements enclosure sanitation. Before and after each cleaning session, wash hands with soap and water for at least 20 seconds. Wearing disposable gloves prevents direct skin contact with potential contaminants. Changing clothing after handling sick individuals reduces the risk of introducing external pathogens into the cage environment.

Consistent application of these procedures creates a barrier that minimizes the chance of rats acquiring infections originating from human carriers. «Proper enclosure maintenance protects both animal health and owner welfare».

Veterinary Care and Rat Health

Regular Check-ups

Regular veterinary examinations are essential for monitoring the health of laboratory and pet rodents, especially when close contact with humans raises the possibility of cross‑species infection. Veterinarians assess physical condition, respiratory function, and gastrointestinal health, detecting pathogens that could be transferred from caretakers.

Key components of a systematic health assessment include:

Physical inspection of fur, eyes, and ears for signs of irritation or lesions.
Measurement of body weight to identify sudden loss or gain, which may indicate disease.
Auscultation of heart and lung sounds to reveal respiratory disturbances.
Collection of fecal samples for microbiological analysis, targeting bacteria and parasites commonly associated with human carriers.
Blood work to evaluate immune response and detect viral agents that can move between species.

Scheduling recommendations:

Initial examination within two weeks of acquisition.
Follow‑up visits every three months for stable colonies, with quarterly blood testing.
Additional checks after any known exposure to ill personnel, after introduction of new animals, or when environmental conditions change.

Preventive actions linked to regular check‑ups:

Implementation of quarantine protocols for newly introduced rodents.
Enforcement of strict hand‑washing and personal protective equipment use by handlers.
Documentation of health records to trace potential transmission events.

Consistent veterinary monitoring reduces the risk of unnoticed infections, safeguards research integrity, and protects the welfare of animals that share environments with humans.

Recognizing Symptoms of Illness in Rats

Rats that contract infections from people often display clear clinical signs. Recognizing these signs enables prompt veterinary intervention and reduces the risk of further spread.

• Reduced food and water intake, leading to noticeable weight loss.
• Lethargy or decreased activity, with rats spending more time motionless in corners.
• Abnormal grooming behavior: excessive scratching, loss of fur, or a dull, unkempt coat.
• Respiratory disturbances, such as sneezing, nasal discharge, or labored breathing.
• Ocular or nasal secretions that appear watery or purulent.
• Diarrhea or changes in stool consistency, sometimes accompanied by blood.
• Unexplained aggression or sudden temperament shifts, indicating discomfort or pain.

Additional observations can aid diagnosis. A temperature rise above the normal range (≈38 °C) suggests fever. Palpable abdominal tenderness may indicate internal infection. Sudden onset of these symptoms, especially after close contact with ill humans, warrants immediate veterinary assessment.

Early detection relies on routine health monitoring. Regular weighing, visual inspection of coat condition, and observation of feeding patterns provide baseline data against which deviations become evident. Prompt treatment improves recovery odds and limits potential transmission between species.

Limiting Exposure

Sick Humans and Pet Rats

Pet rats share close contact with owners, creating opportunities for pathogen exchange. Human respiratory viruses such as influenza and SARS‑CoV‑2 have been detected in laboratory‑bred rodents after deliberate exposure, demonstrating that mammals can acquire viral particles from infected people. Bacterial agents, including Staphylococcus aureus and Streptococcus pyogenes, may colonize the skin and nasal passages of rats exposed to contaminated hands or clothing. Parasitic infections, for example, the protozoan Giardia duodenalis, have been reported in pet rodents whose owners carry the cysts and fail to maintain strict hygiene.

Key considerations for owners:

Wash hands thoroughly before handling rats and after contact with sick individuals.
Avoid feeding rats food that has been in direct contact with a sick person’s saliva or respiratory secretions.
Isolate the pet in a separate cage if the owner is experiencing an active infection.
Seek veterinary assessment promptly when the rat shows signs of illness, such as lethargy, respiratory distress, or abnormal feces.

Veterinary literature emphasizes that cross‑species transmission is less common than reverse zoonosis, yet documented cases confirm that humans can transmit certain pathogens to their pet rats. Maintaining rigorous hygiene and monitoring animal health reduce the risk of such events.

Wild Rodent Control

Human pathogens can infect wild rats when close contact occurs in urban or agricultural settings. Evidence shows that respiratory viruses, gastrointestinal bacteria, and blood‑borne agents transferred from people to rodents may establish temporary or persistent infections, potentially altering rodent health and increasing the risk of reverse zoonosis.

Effective wild rodent control relies on integrated measures that reduce opportunities for interspecies transmission. Key components include:

Habitat modification to eliminate shelter and food sources near human dwellings.
Mechanical trapping combined with targeted baiting, employing anticoagulant or non‑chemical traps to minimize non‑target mortality.
Environmental sanitation, such as regular waste removal and sealing of building entry points, to prevent rodent ingress.
Monitoring programs that track rodent population density, health status, and pathogen prevalence using live‑capture sampling and laboratory diagnostics.

Sustained surveillance and rapid response to detected infections protect both public health and rodent populations. Coordination among municipal authorities, pest‑management professionals, and veterinary laboratories ensures timely implementation of control actions and reduces the likelihood of disease spread from humans to wild rodents.

Specific Diseases and Their Risks

Respiratory Infections

Symptoms in Rats

Rats can acquire infections transmitted by humans, and clinical manifestations often appear rapidly. Observation of behavior and physical condition provides the primary means of detection.

Reduced activity or lethargy
Loss of appetite and weight decline
Nasal discharge, sneezing, or coughing
Watery eyes or ocular irritation
Diarrhea or abnormal stool consistency
Skin lesions, alopecia, or crusted fur
Fever, detectable by rectal temperature elevation
Neurological signs such as tremors, ataxia, or seizures

Severity varies with pathogen type and individual health status. Prompt veterinary evaluation is essential to confirm diagnosis, initiate treatment, and prevent further spread within rodent colonies. Continuous monitoring of colony health reduces the risk of unnoticed transmission.

Prevention Strategies

Rats can acquire pathogens from humans through direct contact, contaminated food, or shared environments. Preventing such transmission requires strict control of interaction points and rigorous hygiene practices.

Maintain separate feeding stations; store rat food in sealed containers to avoid contamination by human saliva or respiratory droplets.
Implement daily disinfection of cages, tunnels, and equipment with agents effective against bacterial and viral agents known to cross species barriers.
Enforce hand‑washing protocols for personnel handling rats, using antimicrobial soap and disposable gloves when exposure risk is high.
Limit access to rat habitats for individuals displaying symptoms of respiratory or gastrointestinal illness; isolate affected personnel until recovery.
Conduct regular health screening of staff, including temperature checks and symptom questionnaires, to identify potential sources of infection early.
Provide training on proper animal handling techniques, emphasizing avoidance of face‑to‑face proximity and preventing accidental bites or scratches.
Establish a quarantine period for newly introduced rats, during which they are observed for signs of illness and housed away from established colonies.

Documentation of all preventive measures, coupled with routine monitoring of both human and rodent health status, reduces the likelihood of disease transfer and supports sustainable laboratory or breeding operations.

Gastrointestinal Issues

Potential Pathogens

Human‑to‑rat transmission of disease agents is documented for several microbial groups.

• Bacterial pathogens: Staphylococcus aureus, including methicillin‑resistant strains; Streptococcus pneumoniae; Escherichia coli producing extended‑spectrum β‑lactamases.

• Viral agents: Influenza A viruses of human origin; severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) demonstrated in experimental exposure; human adenoviruses identified in laboratory‑derived rat colonies.

• Fungal organisms: Candida albicans and other opportunistic yeasts reported in rats housed with infected caretakers.

• Parasites and protozoa: Giardia lamblia and Cryptosporidium spp. transmitted through contaminated water or bedding shared with infected humans.

Transmission routes include direct contact, aerosol exposure, ingestion of contaminated food or water, and fomites such as cages and equipment. Preventive measures—strict biosecurity, personal protective equipment, and routine health monitoring—reduce the risk of reverse zoonotic events.

Dietary Considerations

Dietary habits directly affect a rodent’s susceptibility to pathogens that originate in humans. Nutrient composition, food source hygiene, and exposure to contaminated waste determine whether an animal can acquire and propagate infectious agents.

Human‑derived foods frequently contain bacteria such as Salmonella spp., Escherichia coli O157:H7, and viruses including norovirus. When rats ingest these items, gastrointestinal colonization can occur, providing a route for cross‑species infection. Raw or undercooked meat, unpasteurized dairy products, and improperly washed fruits or vegetables represent the highest risk categories.

Key dietary considerations:

Exclude raw animal tissue and unpasteurized milk from the diet.
Provide only commercially prepared rodent feed that meets nutritional standards and undergoes sterilization.
Store supplemental foods in sealed containers at temperatures that inhibit bacterial growth.
Discard any food that has been left at ambient temperature for more than two hours.
Avoid feeding scraps that have been handled without gloves or that originate from human meals containing sauces, spices, or additives known to alter gut flora.

Maintaining a controlled, pathogen‑free diet reduces the probability that a rat will contract illnesses transmitted from humans, thereby supporting both animal welfare and public‑health safety.

Rare or Emerging Concerns

Limited Evidence of Transmission

Evidence that pathogens move from people to rats remains scarce. Surveillance data rarely record human‑origin infections in wild or domestic rodents, and most reports stem from isolated incidents rather than widespread patterns.

Documented cases include:

Sporadic identification of methicillin‑resistant Staphylococcus aureus (MRSA) in laboratory rats housed near infected staff.
Occasional recovery of Salmonella serotypes linked to human carriers from pet rats presented in veterinary clinics.
Limited reports of influenza A virus RNA in rats exposed to infected caretakers under experimental conditions.

Experimental research demonstrates that certain viruses, such as hantavirus and SARS‑CoV‑2, can infect rats when high viral loads are introduced, yet natural transmission rates are low. Controlled studies show successful infection only after direct inoculation or prolonged close contact, suggesting that casual human‑rat interaction does not readily facilitate disease spread.

Key constraints on current knowledge:

Small sample sizes in field investigations.
Predominance of laboratory settings over natural habitats.
Lack of longitudinal monitoring of rodent populations exposed to infected humans.
Limited genetic analysis to differentiate human‑derived strains from endemic rodent pathogens.

Overall, the paucity of robust data supports the conclusion that human‑to‑rat transmission is possible but infrequent, and further systematic research is required to clarify risk factors and transmission mechanisms.

Conclusion on Human-to-Rat Disease Transmission

Reciprocal Risks

Rats and humans share environments that allow pathogens to move in both directions. When a human carries an infectious agent, the animal can acquire it through contaminated food, water, or direct contact, creating a reverse‑zoonotic pathway.

Staphylococcus aureus – colonises skin and nasal passages; can infect laboratory and pet rats via handling.
Influenza A (H1N1, H3N2) – transmitted through respiratory droplets; documented in rat colonies exposed to infected caretakers.
SARS‑CoV‑2 – experimental evidence shows rats become infected after exposure to infected individuals.
Methicillin‑resistant Staphylococcus (MRSA) – spread in facilities where humans and rodents coexist.

Conversely, rats act as reservoirs for agents that may affect humans. Typical examples include:

Leptospira interrogans – shed in urine; contaminates water sources accessed by people.
Hantavirus – expelled in aerosols from rodent excreta; inhalation leads to severe respiratory disease.
Salmonella spp. – carried in the gastrointestinal tract; transferred to food handling surfaces.

Mitigation relies on hygiene, barrier methods, and monitoring. Regular disinfection of surfaces, use of personal protective equipment during rodent handling, and routine health screening of both humans and rodents reduce bidirectional transmission. Controlling rodent populations in residential and occupational settings further limits exposure opportunities.

Best Practices for Responsible Pet Ownership

Rats may contract pathogens carried by humans, making preventive care essential for owners. Maintaining a barrier between human illness and rodent health reduces the likelihood of cross‑species infection.

Implement strict hand‑washing before and after handling the animal.
Isolate new rats for a minimum of two weeks to monitor for signs of disease.
Provide a clean, well‑ventilated enclosure; remove waste and uneaten food daily.
Schedule regular veterinary examinations focused on infectious disease screening.
Avoid direct contact when owners exhibit respiratory symptoms, fever, or gastrointestinal upset.
Use personal protective equipment, such as gloves, when cleaning cages or administering medication.

Consistent application of these measures safeguards both the pet and its caretaker, minimizing the risk of disease transmission.