Diseases Transmitted from Rats and Mice to Humans

Introduction to Rodent-Borne Diseases

Understanding Zoonoses

Direct vs. Indirect Transmission

Direct transmission occurs when a person acquires a pathogen through immediate contact with an infected rat or mouse. Typical routes include:

Bite or scratch that introduces saliva or tissue into the wound.
Direct exposure of mucous membranes or broken skin to rodent urine, feces, or saliva.
Inhalation of aerosolized particles generated by handling infected rodents or their bedding.

These mechanisms deliver the infectious agent without an intermediate carrier, resulting in rapid onset of disease after exposure.

Indirect transmission relies on a medium that separates the rodent host from the human recipient. Common pathways are:

Contamination of food or water supplies with rodent excreta, leading to ingestion of pathogens such as Leptospira spp. or hantaviruses.
Transfer of infectious material to surfaces, utensils, or clothing, which later contacts a person’s skin or mucosa.
Vector-mediated spread, where fleas, mites, or ticks acquire the agent from rodents and subsequently bite humans, exemplified by plague transmission via Xenopsylla fleas.

Distinguishing between these routes is essential for targeted control measures: direct exposure demands protective equipment and safe handling practices, whereas indirect exposure requires sanitation, pest control, and environmental monitoring.

Factors Influencing Disease Transmission

Rodent-borne pathogens reach humans through complex interactions that depend on ecological, biological, and social variables. High rodent population density increases contact opportunities, especially when food sources are abundant or habitat fragmentation forces rodents into human dwellings. Pathogen survival outside the host is enhanced by temperature, humidity, and shelter availability, allowing viruses, bacteria, and parasites to persist on surfaces, in grain stores, or in water supplies.

Key determinants of spillover include:

Rodent behavior: nocturnal foraging, nesting near food processing areas, and aggressive territoriality raise the likelihood of contaminating human environments.
Human activities: poor sanitation, inadequate waste management, and occupational exposure in agriculture or pest control create direct interfaces with rodent excreta.
Host susceptibility: immunocompromised individuals, children, and the elderly exhibit higher infection rates when exposed to contaminated material.
Pathogen traits: low infectious dose, resistance to desiccation, and capacity for aerosolization facilitate transmission through inhalation or ingestion.

Mitigation requires integrated pest control, environmental sanitation, and public‑health surveillance that address these interrelated factors to reduce the risk of zoonotic disease emergence.

Common Rodent-Borne Diseases

Hantavirus Pulmonary Syndrome (HPS)

Etiology and Pathogenesis

Rodent‑borne infections arise from a limited group of pathogens that exploit the close association between commensal or wild mice and rats and human environments. Primary bacterial agents include Leptospira interrogans (leptospirosis), Yersinia pestis (plague), Streptobacillus moniliformis (rat‑bite fever), and Salmonella spp. Viral agents comprise hantaviruses (hantavirus pulmonary syndrome, hemorrhagic fever with renal syndrome), lymphocytic choriomeningitis virus, and Seoul virus. Parasitic contributors consist of Hymenolepis diminuta (dwarf tapeworm) and Angiostrongylus cantonensis (rat lungworm). Transmission routes encompass contaminated water or food, inhalation of aerosolized rodent excreta, direct bite or scratch, and contact with urine‑laden surfaces.

The etiologic process begins with pathogen excretion in urine, feces, saliva, or blood, followed by environmental persistence that allows human exposure. For leptospires, the organism penetrates mucous membranes or abraded skin, disseminates via bloodstream, and colonizes renal tubules, resulting in acute febrile illness and potential renal failure. Y. pestis enters through skin breaches, multiplies in regional lymph nodes, and induces septicemia or pneumonic disease through rapid bacteremia and toxin production. Hantaviruses are inhaled as aerosolized particles; the virus binds to β‑integrin receptors on endothelial cells, increasing vascular permeability and producing pulmonary edema or renal impairment. Lymphocytic choriomeningitis virus replicates in macrophages after percutaneous exposure, spreads to the central nervous system, and provokes meningitis.

Pathogenic mechanisms share common features: evasion of innate immunity, exploitation of host cellular receptors, and induction of inflammatory cascades that damage target organs. Bacterial toxins (e.g., Yersinia’s Yop proteins) interfere with phagocytosis, while viral glycoproteins trigger cytokine storms that compromise vascular integrity. Parasites migrate through neural tissue, releasing proteolytic enzymes that cause eosinophilic meningitis.

Control of rodent‑related disease relies on interrupting the environmental reservoir, reducing human‑rodent contact, and applying targeted antimicrobial or antiviral therapy once infection is confirmed.

Symptoms and Diagnosis

Rodent‑borne infections present with diverse clinical patterns that often overlap with other febrile illnesses. Prompt recognition of characteristic signs enables targeted laboratory evaluation and reduces morbidity.

Leptospirosis – abrupt fever, severe headache, myalgia, conjunctival suffusion, jaundice, renal impairment.
Hantavirus pulmonary syndrome – prodromal fever, myalgia, gastrointestinal upset followed by rapid onset of dyspnea, non‑cardiogenic pulmonary edema, hypotension.
Plague (Yersinia pestis) – bubonic form: tender, enlarging lymph nodes (buboes), fever, chills; septicemic form: high fever, abdominal pain, bleeding; pneumonic form: cough, hemoptysis, respiratory distress.
Rat‑bite fever (Streptobacillus moniliformis) – fever, rash, arthralgia, migrating polyarthritis, occasional abdominal pain.
Murine typhus (Rickettsia typhi) – fever, headache, maculopapular rash beginning on trunk, mild respiratory symptoms.
Salmonellosis (Salmonella enterica serovars) – fever, abdominal cramps, diarrhea, occasionally bacteremia.
Lassa fever (Lassa virus, transmitted by Mastomys rodents) – fever, sore throat, chest pain, vomiting, hemorrhagic manifestations, facial swelling.

Diagnostic work‑up relies on a combination of clinical suspicion and specific laboratory techniques. Blood cultures identify bacterial pathogens in plague, rat‑bite fever, and salmonellosis. Serologic assays (ELISA, indirect immunofluorescence) detect antibodies to leptospira, hantavirus, murine typhus, and Lassa virus. Molecular methods (PCR) provide rapid confirmation for hantavirus, Lassa virus, and Yersinia pestis. Urinalysis and renal function tests assess leptospiral kidney involvement. Chest radiography evaluates pulmonary edema in hantavirus and pneumonic plague. Complete blood count and coagulation profile reveal leukocytosis, thrombocytopenia, or disseminated intravascular coagulation in severe cases.

Early identification of symptom clusters and appropriate laboratory confirmation guide antimicrobial therapy, isolation measures, and supportive care, thereby improving patient outcomes.

Treatment and Prevention

Rodent‑borne infections such as hantavirus pulmonary syndrome, leptospirosis, plague, salmonellosis, and rat‑bite fever pose significant health risks. Prompt medical intervention reduces morbidity and mortality; each pathogen requires a specific therapeutic approach.

Hantavirus: initiate supportive care in an intensive‑care setting; ribavirin may be considered in early disease.
Leptospirosis: administer doxycycline or penicillin G for 7–10 days; severe cases require intravenous ceftriaxone.
Plague: give streptomycin or gentamicin as first‑line agents; doxycycline is an alternative for milder presentations.
Salmonellosis: employ fluoroquinolones or third‑generation cephalosporins for invasive infections; uncomplicated gastroenteritis often resolves without antibiotics.
Rat‑bite fever: treat with penicillin G for 10 days; macrolides serve as alternatives for penicillin‑allergic patients.

Effective prevention relies on eliminating rodent exposure and interrupting transmission pathways.

Secure food storage and waste disposal to deny rodents access.
Seal building openings; install metal mesh on vents and gaps.
Maintain clean, dry environments; eliminate standing water and clutter.
Use snap traps or bait stations according to local regulations; avoid poison that may contaminate food chains.
Equip laboratory and field workers with gloves, masks, and eye protection when handling rodents or contaminated materials.
Conduct regular rodent‑population monitoring and apply integrated pest‑management strategies.
Educate at‑risk populations about safe handling of rodents and proper wound care after bites.

These measures, combined with early diagnosis and pathogen‑specific therapy, constitute a comprehensive strategy to mitigate the impact of rodent‑derived diseases on human health.

Leptospirosis

Causative Agent and Transmission

Rats and mice serve as reservoirs for a range of pathogens that can infect humans. The most significant agents include:

Bacteria: Leptospira spp. (leptospirosis), Yersinia pestis (plague), Salmonella spp. (salmonellosis), Streptobacillus moniliformis (rat‑bite fever).
Viruses: Hantavirus species (hantavirus pulmonary syndrome, hemorrhagic fever with renal syndrome), Lassa virus (occasionally linked to rodent exposure), Seoul virus (a hantavirus variant).
Parasites: Taenia taeniaeformis (tapeworm), Bartonella spp. (cat‑scratch disease‑like infections), Toxoplasma gondii (via contaminated rodent prey).

Transmission occurs primarily through direct contact with rodent excreta, bites, or contaminated materials. Key pathways are:

Inhalation of aerosolized urine, feces, or saliva containing pathogens such as hantaviruses.
Percutaneous exposure from bites or scratches, introducing bacteria like Streptobacillus moniliformis.
Oral ingestion of food or water contaminated with rodent droppings, leading to leptospirosis or salmonellosis.
Indirect contact with surfaces or objects (fomites) that have been tainted by rodent secretions, facilitating spread of various agents.

Understanding the specific agents and their routes of transmission is essential for targeted prevention and control measures.

Clinical Manifestations

Rodent‑borne infections present a spectrum of signs that often overlap, making clinical recognition challenging. Acute fever, chills, and malaise appear early in most cases, frequently accompanied by gastrointestinal upset such as nausea, vomiting, or diarrhea. Respiratory involvement may manifest as cough, dyspnea, or pleuritic chest pain, particularly in hantavirus pulmonary syndrome. Hemorrhagic tendencies emerge with leptospirosis, characterized by conjunctival suffusion, jaundice, and renal impairment; severe forms progress to pulmonary hemorrhage and multi‑organ failure. Neurological signs, including headache, confusion, seizures, or meningismus, are typical of Lassa‑like arenavirus infections and certain rickettsial diseases. Dermatologic clues—maculopapular rash, eschar formation, or petechiae—often accompany murine typhus or scrub typhus. Musculoskeletal pain, arthralgia, and myalgia are common across many rodent‑associated pathogens. Chronic sequelae may involve persistent renal dysfunction, pulmonary fibrosis, or neurocognitive deficits after recovery.

Management and Control

Effective control of rodent‑borne illnesses requires coordinated actions that reduce pathogen exposure, limit rodent populations, and protect vulnerable groups. A systematic approach integrates surveillance, environmental management, chemical and biological interventions, and public education.

Key elements of a control program include:

Continuous monitoring of rodent activity and pathogen prevalence in urban and rural settings.
Implementation of integrated pest management (IPM) that combines habitat modification, exclusion techniques, and targeted baiting.
Maintenance of sanitation standards: secure waste containers, prompt removal of food debris, and repair of structural defects that permit entry.
Application of approved rodenticides or anticoagulant baits under strict regulatory oversight to minimize non‑target impacts.
Deployment of biological control agents where feasible, such as predatory birds or engineered pathogens specific to rodent species.
Distribution of personal protective equipment and hygiene guidance to workers in high‑risk occupations (e.g., waste handling, grain storage).
Community outreach programs that convey risk information, safe handling practices, and reporting procedures for rodent sightings.

Implementation guidelines stress interdisciplinary coordination among public health agencies, veterinary services, environmental authorities, and local municipalities. Protocols require regular data review, adjustment of control measures based on efficacy metrics, and rapid response to outbreak signals. Documentation of interventions, dosage records, and incident reports supports accountability and facilitates continuous improvement.

Evaluation of program success relies on measurable indicators: reduction in rodent indices, decreased incidence of confirmed cases, and compliance rates with sanitation regulations. Periodic audits identify gaps, inform resource allocation, and sustain long‑term protection against rodent‑associated disease transmission.

Salmonellosis

Bacterial Strain and Reservoirs

Rats and mice harbor several bacterial strains that cause human infection. Each strain persists in a defined rodent host and environment, enabling transmission through direct contact, contaminated food, or aerosolized excreta.

Leptospira interrogans – maintained in the kidneys of various rodent species; shed in urine, contaminating water and soil.
Salmonella enterica serovar Typhimurium – colonizes the intestinal tract of commensal rodents; expelled in feces, contaminating surfaces and food supplies.
Yersinia pestis – persists in the flea‑feeding cycle of wild rats; fleas acquire the bacterium from rodent blood and transmit it to humans through bites.
Streptobacillus moniliformis – resides in the oropharynx of mice; released in saliva and secretions, entering humans via bites or handling of contaminated animals.
Bartonella henselae – detected in the blood of both rats and mice; transmitted by ectoparasites such as fleas and lice.

Reservoir characteristics determine the risk of spillover. Urban rats occupy sewers, waste dumps, and food‑storage facilities, creating persistent sources of urine and fecal contamination. Rural mice inhabit grain stores, barns, and peridomestic structures, where close proximity to humans facilitates direct contact. Ectoparasite populations—fleas, lice, and mites—bridge the gap between rodent carriers and people, especially in settings with poor sanitation. Control measures focus on reducing rodent density, limiting access to food and water sources, and managing ectoparasite infestations.

Symptoms and Complications

Rodent‑borne infections produce a range of acute signs and long‑term sequelae that can be life‑threatening if untreated.

Hantavirus pulmonary syndrome

Fever, myalgia, headache, gastrointestinal upset.
Rapid onset of dyspnea, cough, and non‑cardiogenic pulmonary edema.
Complications: acute respiratory distress syndrome, renal failure, shock, high mortality without intensive care.

Leptospirosis

Sudden fever, chills, muscle aches, conjunctival suffusion.
Nausea, vomiting, abdominal pain, jaundice.
Complications: Weil’s disease (hepatic dysfunction, renal insufficiency, hemorrhage), meningitis, pulmonary hemorrhage, myocarditis.

Rat‑bite fever (Streptobacillus moniliformis infection)

Fever, chills, arthralgia, maculopapular rash.
Polyarthritis, tenosynovitis.
Complications: endocarditis, septicemia, renal impairment.

Plague (Yersinia pestis)

Bubonic form: painful, swollen lymph nodes (buboes), fever, chills.
Septicemic form: high fever, hypotension, purpura, disseminated intravascular coagulation.
Pneumonic form: cough, hemoptysis, chest pain, rapid respiratory failure.
Complications: multi‑organ failure, secondary infections, permanent tissue damage.

Lymphocytic choriomeningitis virus

Flu‑like prodrome: fever, malaise, myalgia.
Neurological phase: meningitis, encephalitis, photophobia, seizures.
Complications: persistent neurological deficits, hearing loss, chronic fatigue.

Salmonella spp. from rodent feces

Diarrhea, abdominal cramps, fever, nausea.
Invasive disease: bacteremia, osteomyelitis, septic arthritis.
Complications: dehydration, electrolyte imbalance, relapse in immunocompromised hosts.

Early recognition of these symptom patterns and prompt antimicrobial or supportive therapy reduce the risk of severe complications and improve outcomes.

Prevention Strategies

Rodent‑borne illnesses pose a persistent public‑health threat, especially in densely populated or agricultural settings. Effective prevention requires coordinated actions that limit rodent access to humans and interrupt transmission pathways.

Secure all food sources: store in sealed containers, dispose of waste in rodent‑proof bins, and clean spills promptly.
Eliminate shelter: seal cracks in walls and foundations, trim vegetation near structures, and maintain cleared perimeters around buildings.
Implement baiting and trapping programs: use licensed rodenticides or mechanical traps according to local regulations, and monitor activity levels regularly.
Conduct routine inspections: assess premises for signs of infestation, record findings, and adjust control measures accordingly.

Personal protection focuses on minimizing direct contact with rodents and their excreta. Workers handling waste, laboratory specimens, or live animals should wear gloves, masks, and disposable gowns. Handwashing with soap or an alcohol‑based sanitizer must follow any potential exposure. Food preparation areas require strict hygiene protocols, and utensils should never be left uncovered in rodent‑prone zones.

Surveillance systems track incidence of rodent‑associated diseases, enabling rapid response to outbreaks. Laboratories should be equipped to test for common pathogens such as hantavirus, leptospira, and salmonella. Where vaccines exist—e.g., for leptospirosis—targeted immunization of high‑risk groups reduces morbidity.

Community education reinforces preventive behavior. Public campaigns should convey clear instructions on waste management, safe food storage, and reporting of rodent sightings. Schools, workplaces, and health clinics serve as distribution points for informational materials and training sessions.

Institutional policies must integrate these strategies into standard operating procedures. Regular audits verify compliance, and budget allocations ensure sustained availability of control tools and protective equipment. By maintaining rigorous environmental, personal, and organizational safeguards, the transmission of rodent‑origin diseases to humans can be substantially reduced.

Rat-Bite Fever (RBF)

Pathogens Involved

Rats and mice serve as reservoirs for a range of microorganisms that can infect humans through direct contact, bites, contaminated food, or aerosolized excreta. The most clinically relevant agents include:

Bacteria
- Leptospira spp. – cause leptospirosis; transmitted via skin abrasions or mucous membranes exposed to urine‑contaminated water.
- Salmonella enterica serovar Typhimurium – produce salmonellosis; spread through ingestion of food contaminated by rodent feces.
- Yersinia pestis – agent of plague; transmitted by flea bites that have fed on infected rodents or by handling infected carcasses.
- Streptobacillus moniliformis – responsible for rat‑bite fever; introduced through puncture wounds or scratches.
Viruses
- Hantavirus (e.g., Sin Nombre virus) – causes hantavirus pulmonary syndrome; inhalation of aerosolized urine, droppings, or saliva.
- Lassa virus – endemic in certain regions; rodent excreta may contaminate food or household surfaces.
- Lymphocytic choriomeningitis virus (LCMV) – produces meningitis; spread by inhalation of contaminated dust or direct contact with rodent secretions.
Parasites
- Toxoplasma gondii – while felids are definitive hosts, rodents act as intermediate carriers; humans acquire infection by consuming undercooked meat from infected rodents or through environmental contamination.
- Bartonella spp. – cause bartonellosis; transmitted by rodent ectoparasites such as fleas and lice.
Fungi
- Cryptococcus neoformans – encapsulated yeast; rodents disseminate spores through droppings; inhalation leads to cryptococcal meningitis, especially in immunocompromised individuals.

These pathogens represent the primary microbial threats associated with rodent exposure, each requiring specific preventive measures and clinical awareness.

Clinical Presentation

Rodent‑associated infections present a spectrum of signs that often overlap, complicating initial diagnosis.

Acute febrile illness is common across most agents, typically accompanied by headache, myalgia, and malaise. Specific patterns help differentiate etiologies:

Hantavirus pulmonary syndrome: rapid onset of high fever, cough, and shortness of breath; chest radiographs reveal bilateral infiltrates; progression to respiratory failure can occur within 48 hours.
Leptospirosis: abrupt fever, chills, conjunctival suffusion, and muscle tenderness, especially in the calves; severe cases develop jaundice, renal impairment, and hemorrhagic manifestations.
Plague (Yersinia pestis): sudden fever, painful swollen lymph nodes (buboes) in the groin, axillae, or cervical region; pneumonic form adds cough with bloody sputum and can lead to shock.
Rat‑bite fever (Streptobacillus moniliformis): fever, rash, polyarthralgia, and migratory polyarthritis; joint swelling may be pronounced.
Lymphocytic choriomeningitis virus: prodrome of fever, malaise, and myalgia followed by meningitis or encephalitis; neck stiffness and photophobia are frequent.
Salmonella spp. from rodent carriers: gastro‑intestinal cramps, diarrhea, and fever; invasive disease may cause bacteremia, especially in immunocompromised hosts.

Incubation periods vary: hantavirus (1–2 weeks), leptospirosis (5–14 days), plague (2–6 days), rat‑bite fever (2–10 days), LCMV (1–2 weeks), salmonellosis (6–72 hours). Recognizing the temporal relationship between exposure and symptom onset refines differential diagnosis.

Laboratory evaluation often reveals leukocytosis with left shift, elevated inflammatory markers, and organ‑specific abnormalities (elevated transaminases in leptospirosis, renal dysfunction in severe cases). Serologic testing, PCR, and culture remain definitive for pathogen identification.

Early clinical recognition, coupled with targeted antimicrobial or antiviral therapy, reduces morbidity and mortality associated with these zoonotic conditions.

Therapeutic Approaches

Therapeutic management of rodent‑borne infections focuses on pathogen‑specific pharmacotherapy, supportive interventions, and, when available, immunologic measures.

Antimicrobial regimens for the most common agents include:

Leptospira spp. – intravenous doxycycline 100 mg every 12 h for 7 days or oral amoxicillin 500 mg three times daily for 10 days; alternative ceftriaxone 1 g daily for 7 days.
Yersinia pestis – initial intravenous streptomycin 1 g every 12 h or gentamicin 5 mg/kg daily for 7 days; followed by oral doxycycline 100 mg twice daily for 7 days to prevent relapse.
Hantavirus – ribavirin 33 mg/kg loading dose, then 16 mg/kg daily divided every 6 h for 4 days; supportive care remains the mainstay.
Streptobacillus moniliformis (rat‑bite fever) – penicillin G 2–4 million units IV every 4 h for 7 days; ceftriaxone 2 g daily as alternative.
Salmonella spp. – ceftriaxone 2 g daily or azithromycin 500 mg daily for 7 days in severe cases; oral fluoroquinolones for uncomplicated disease.

Supportive care addresses hemodynamic instability, respiratory failure, and organ dysfunction. Rapid fluid replacement, vasopressor support, and mechanical ventilation are employed according to standard critical‑care protocols. Renal replacement therapy is indicated for acute kidney injury secondary to leptospirosis or severe sepsis.

Immunologic strategies comprise:

Passive immunization – administration of plague‑specific monoclonal antibodies (e.g., rF1‑IgG) for high‑risk exposure.
Vaccination – licensed inactivated plague vaccine for laboratory personnel; recombinant leptospiral vaccines for endemic regions; experimental hantavirus vaccines under clinical evaluation.

Emerging approaches target resistant organisms and viral replication. Bacteriophage preparations against multidrug‑resistant Y. pestis show efficacy in animal models. Novel antivirals inhibiting hantavirus RNA polymerase are progressing through phase II trials. Host‑directed therapies, such as modulation of inflammatory pathways with corticosteroids, are being investigated for severe hantavirus pulmonary syndrome.

Effective treatment requires early pathogen identification, appropriate antimicrobial selection, and integration of supportive and immunologic modalities. Continuous surveillance of resistance patterns and clinical trial data informs optimal therapeutic protocols.

Lymphocytic Choriomeningitis (LCM)

Viral Agent and Transmission Routes

Rodent‑associated viral infections constitute a significant public‑health concern. The primary viral agents transmitted from rats and mice to people include hantaviruses (e.g., Seoul virus, Hantaan virus), lymphocytic choriomeningitis virus (LCMV), and rat hepatitis E virus. These pathogens share a reliance on specific ecological interactions between rodents and humans.

Transmission occurs through several well‑documented pathways:

Inhalation of aerosolized particles from dried urine, feces, or saliva; the most common route for hantaviruses and LCMV.
Direct contact with contaminated secretions, followed by mucosal exposure or skin abrasion; relevant for LCMV and hepatitis E virus.
Bite wounds inflicted by infected rodents; a documented but less frequent mechanism for LCMV.
Consumption of food or water contaminated with rodent excreta; implicated in hepatitis E virus outbreaks.

Effective prevention requires controlling rodent populations, sealing entry points, and practicing strict hygiene when handling materials that may be contaminated. Early recognition of exposure patterns facilitates timely diagnosis and reduces the risk of severe disease.

Symptoms and Severity

Rodent‑associated infections present a spectrum of clinical manifestations, ranging from mild, self‑limiting illness to rapidly fatal syndromes.

Hantavirus pulmonary syndrome begins with abrupt fever, myalgia, and gastrointestinal upset. Within 24–48 hours, patients develop non‑cardiogenic pulmonary edema, hypoxemia, and severe respiratory distress. Mortality approaches 35 % despite intensive care.

Leptospirosis typically follows exposure to contaminated urine. Early phase features high fever, chills, headache, and conjunctival suffusion. A second phase may involve jaundice, renal impairment, hemorrhagic diathesis, and meningitis. Severe cases progress to Weil’s disease, with mortality up to 10 % without prompt antimicrobial therapy.

Lymphocytic choriomeningitis virus infection starts with flu‑like symptoms—fever, malaise, myalgia—then may advance to meningitis or encephalitis. Neurological involvement causes stiff neck, photophobia, and altered mental status. Case‑fatality rates are low (<5 %), but permanent neurologic deficits occur in a minority of survivors.

Rat‑bite fever presents after a bite or scratch. Initial signs include abrupt fever, chills, and erythematous maculopapular rash. Polyarthritis develops within a week, accompanied by myalgia and headache. Untreated infection can lead to endocarditis, pneumonia, or septicemia, with mortality up to 7 %.

Plague, caused by Yersinia pestis, manifests in three clinical forms. Bubonic plague produces painful, swollen lymph nodes (buboes), fever, and chills; mortality is 10 % with antibiotics, higher without treatment. Septicemic plague yields fulminant shock, disseminated intravascular coagulation, and death in most cases. Pneumonic plague causes cough, hemoptysis, and rapid respiratory failure, with mortality exceeding 50 % if untreated.

Tularemia, transmitted via rodent vectors, often starts with ulcerative skin lesions or ulceroglandular disease—painful lymphadenopathy, fever, and malaise. More severe forms include typhoidal and pneumonic presentations, leading to high fever, organ dysfunction, and mortality up to 30 % without appropriate therapy.

Overall, the severity of rodent‑borne diseases depends on pathogen virulence, host immune status, and timeliness of medical intervention. Prompt recognition of characteristic symptom clusters and early antimicrobial or supportive treatment are essential to reduce morbidity and mortality.

Public Health Implications

Rodent‑borne illnesses such as leptospirosis, hantavirus pulmonary syndrome, salmonellosis, and plague generate measurable morbidity and mortality worldwide. Each pathogen exploits specific ecological niches, yet all rely on close contact between commensal rodents and human environments.

Recent surveillance data reveal thousands of confirmed cases annually, with case‑fatality rates ranging from 1 % for salmonellosis to over 30 % for plague. Direct medical costs, lost productivity, and outbreak response expenditures collectively exceed hundreds of millions of dollars in high‑risk regions.

Transmission occurs primarily through ingestion of contaminated food or water, inhalation of aerosolized urine or feces, and, less frequently, rodent bites. Urban slums, agricultural settings, and waste‑management facilities provide optimal conditions for pathogen spillover.

Public‑health systems confront three persistent obstacles: under‑reporting due to nonspecific symptoms, limited laboratory capacity for rapid pathogen identification, and delayed implementation of containment measures during cluster emergence.

Effective mitigation requires coordinated actions:

Integrated pest‑management programs that reduce rodent populations without compromising ecological balance.
Infrastructure improvements guaranteeing safe water, secure food storage, and waste disposal.
Targeted health‑education campaigns that teach at‑risk communities proper hygiene and early‑symptom recognition.
Development and deployment of vaccines where feasible, notably for hantavirus and leptospira.

These measures lower disease incidence, relieve pressure on clinical services, and protect vulnerable groups such as children, the elderly, and immunocompromised individuals. Sustained investment in surveillance, rodent control, and community outreach remains essential for reducing the public‑health impact of rodent‑transmitted pathogens.

Modes of Transmission

Direct Contact

Bites and Scratches

Rodent bites and scratches constitute a direct pathway for the transfer of infectious agents from commensal and wild species to people. The mechanical injury introduces saliva, skin flora, and, when present, pathogens into subcutaneous tissues, providing an entry point for bacteria, viruses, and parasites that normally inhabit rodent hosts.

Common zoonotic agents transmitted through these wounds include:

Streptobacillus moniliformis – cause of rat‑bite fever, presenting with fever, rash, and polyarthritis.
Spirillum minus – responsible for the less common form of rat‑bite fever, characterized by recurrent febrile episodes and ulcerating lesions.
Leptospira spp. – can be introduced via contaminated teeth or claws, leading to leptospirosis with renal and hepatic involvement.
Bartonella spp. – associated with cat‑scratch disease but also reported after rodent scratches, producing regional lymphadenopathy.
Hantavirus – rare transmission through bite wounds; infection may progress to hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome.

Clinical assessment should focus on wound evaluation, exposure history, and symptom onset. Laboratory confirmation relies on culture (for S. moniliformis and S. minus), serology (for leptospirosis and hantavirus), and polymerase chain reaction when available. Empiric antimicrobial therapy typically includes a third‑generation cephalosporin or doxycycline pending definitive diagnosis; antiviral agents are reserved for confirmed hantavirus infection.

Preventive measures emphasize avoidance of direct contact with rodents, use of protective gloves during pest control, and immediate cleansing of any bite or scratch with antiseptic solution. Prompt medical consultation after injury reduces the risk of severe systemic illness and facilitates early therapeutic intervention.

Contact with Urine or Feces

Contact with rodent urine or feces is a primary route for several zoonotic infections. Pathogens survive in dried excreta for weeks, become aerosolized during cleaning or disturbance, and can be inhaled or ingested. The most significant diseases include:

Leptospirosis – caused by Leptospira spp.; symptoms range from fever and myalgia to severe kidney or liver failure.
Hantavirus pulmonary syndrome – caused by hantaviruses; early signs are fever and muscle aches, progressing to respiratory distress and high mortality.
Salmonellosis – Salmonella spp.; presents with diarrhea, abdominal cramps, and fever, potentially leading to bacteremia.
Lymphocytic choriomeningitis – LCMV; often asymptomatic, but can cause meningitis, encephalitis, or congenital defects when transmitted to pregnant women.
Rat‑bite fever (Streptobacillus moniliformis infection) – may arise from contaminated excreta; produces fever, rash, and arthralgia.

Transmission occurs when individuals handle contaminated bedding, food containers, or surfaces without protective equipment. Inhalation of aerosolized particles is especially hazardous in enclosed spaces such as basements, warehouses, or laboratories. Direct ingestion may result from hand‑to‑mouth contact after cleaning or from food contaminated by excreta.

Preventive measures focus on eliminating rodent infestations, sealing entry points, and maintaining strict sanitation. Personal protective equipment—gloves, masks, eye protection—should be worn during cleaning. Disinfectants containing bleach or phenolic compounds effectively inactivate most excreta‑borne agents. Post‑exposure monitoring includes serologic testing for leptospirosis and hantavirus, with prompt antimicrobial therapy for bacterial infections.

Indirect Contact

Contaminated Food and Water

Rodents commonly contaminate food and water supplies, creating a direct pathway for rodent‑borne illnesses to reach people. Urine, feces, and saliva deposited on stored grains, fruits, or in water sources introduce pathogens that survive long enough to cause infection after consumption.

Typical contamination mechanisms include:

Droppings falling onto uncovered food containers.
Chewed packaging allowing entry of saliva‑laden material.
Water sources polluted by runoff from burrows or sewer connections.

Diseases linked to ingesting contaminated consumables are well documented:

Leptospirosis, caused by Leptospira spp., acquired from water tainted with rodent urine.
Hantavirus pulmonary syndrome, transmitted by aerosolized particles from dried rodent excreta on food surfaces.
Salmonellosis, resulting from Salmonella bacteria introduced via fecal matter on raw produce.
Rat‑bite fever (Streptobacillus moniliformis), occasionally spread through contaminated water.

Effective control measures focus on eliminating contact between rodents and consumables:

Store all food in sealed, rodent‑proof containers.
Implement regular cleaning of storage areas to remove droppings and urine stains.
Install screens and covers on water tanks, and treat water with chlorination or UV filtration.
Conduct routine inspections for gnaw marks and seal entry points in buildings.

By maintaining strict sanitation and securing food and water supplies, the risk of infection from rodent‑originated pathogens can be substantially reduced.

Airborne Particles

Rodent‑derived dust, urine, feces, and saliva can become suspended in air as microscopic particles. When these aerosols are inhaled, they transport infectious agents directly to the respiratory tract of humans.

Aerosol formation occurs during activities that disturb contaminated surfaces—cleaning, sweeping, or moving stored goods. Particle size determines deposition depth: particles larger than 10 µm tend to settle in the upper airway, while those 1–5 µm reach the bronchioles and alveoli, providing a pathway for pathogens that survive outside a host.

Key rodent‑associated infections transmitted by inhalable particles include:

Hantavirus pulmonary syndrome – virus shed in urine and feces remains viable in dried droplets; inhalation triggers severe lung injury.
Seoul virus infection – a hantavirus variant transmitted similarly, causing febrile illness with respiratory involvement.
Lymphocytic choriomeningitis virus (LCMV) – present in rodent excreta; aerosol exposure leads to meningitis or encephalitis.
Salmonella enterica serovar Typhimurium – can be aerosolized from contaminated bedding; inhalation may result in gastrointestinal disease after systemic spread.
Streptobacillus moniliformis – the agent of rat‑bite fever; inhalation of dust containing the bacterium can produce fever, arthritis, and rash.

Preventive measures focus on controlling dust generation, employing wet cleaning methods, and using respiratory protection in environments with known rodent infestations. Regular rodent control and proper waste management reduce the source of airborne contaminants.

Vector-Borne Transmission

Fleas and Ticks as Vectors

Fleas and ticks serve as primary external carriers of pathogens that originate from rodent populations and can infect humans. Their blood‑feeding behavior enables the transfer of microorganisms from infected rats and mice to people who encounter these ectoparasites.

Flea‑mediated infections
- Yersinia pestis – causative agent of plague; transmitted when infected fleas bite a human host.
- Rickettsia typhi – agent of murine typhus; spread through flea feces that contaminate skin abrasions or mucous membranes.
- Bartonella spp. – responsible for cat‑scratch disease and other febrile illnesses; fleas acquire bacteria from rodent blood and inoculate humans during feeding.
Tick‑mediated infections
- Borrelia spp. – agents of relapsing fever; rodent‑infected ticks transmit spirochetes during prolonged attachment.
- Spotted fever group Rickettsia – includes Rickettsia rickettsii and related species; ticks acquire bacteria from infected rodents and deliver them via salivary secretions.
- Anaplasma phagocytophilum – causes human granulocytic anaplasmosis; ticks pick up the pathogen from rodent reservoirs and pass it to humans.

Control measures focus on reducing ectoparasite populations, limiting human exposure to infested environments, and applying repellents or acaricides where appropriate. Prompt identification of flea‑ or tick‑borne diseases facilitates targeted antimicrobial therapy and mitigates outbreak potential.

Role of Mites

Mites that parasitize rats and mice frequently serve as vectors for zoonotic pathogens. When mites feed on infected rodents, they acquire bacteria, viruses, or parasites that persist in their salivary glands or gut. Subsequent contact with humans—through bites, contaminated bedding, or aerosolized mite debris—facilitates pathogen transfer.

Key mite‑borne agents include:

Rickettsia typhi (murine typhus) transmitted by Ornithonyssus bacoti.
Bartonella henselae associated with rodent‑infesting mites.
Leptospira spp. occasionally detected in mite populations feeding on carrier rodents.
Hantavirus RNA identified in mite pools from rodent nests, indicating potential mechanical transmission.

Transmission occurs when mites detach from rodent hosts and seek alternative blood meals, often on humans inhabiting the same environment. Bite lesions may serve as entry points for pathogens, while mite excreta can contaminate food surfaces and inhalation zones. The limited mobility of mites prolongs their presence in indoor settings, increasing exposure risk.

Control strategies focus on reducing mite populations and interrupting their contact with both rodents and people. Effective measures comprise:

Integrated pest management targeting rodent hosts to diminish mite reservoirs.
Regular cleaning of infested areas, removal of nesting material, and vacuuming to eliminate mite stages.
Application of acaricides approved for indoor use, following label directions to prevent resistance.
Monitoring programs employing sticky traps and microscopic examination to assess infestation intensity.

By addressing mite vectors alongside rodent control, public‑health programs can lower the incidence of rodent‑associated infections transmitted to humans.

Prevention and Control Measures

Rodent Control in Homes and Businesses

Exclusion Techniques

Effective exclusion of rodents is essential for controlling zoonotic infections associated with rats and mice. Measures focus on preventing entry, eliminating attractants, and maintaining structural integrity.

Seal all openings larger than ¼ inch with steel wool, metal flashing, or cement.
Install door sweeps and weatherstripping on exterior doors and service entries.
Repair cracks in foundations, walls, and around utility penetrations.
Use rodent‑proof screens on vents, chimneys, and exhaust ducts.
Maintain a clearance of at least 3 inches between stored materials and walls or shelving.

Habitat reduction complements physical barriers. Remove food sources by storing grain, waste, and pet feed in sealed containers. Keep garbage in tightly closed bins and dispose of it regularly. Eliminate standing water and ensure proper drainage to deny rodents hydration sites.

Environmental monitoring supports early detection. Conduct monthly visual inspections for gnaw marks, droppings, and burrows. Deploy motion‑sensitive cameras in high‑risk zones. Record findings in a log to identify patterns and prioritize remediation.

When structural exclusion is insufficient, integrate chemical deterrents judiciously. Apply non‑repellent rodenticide baits in tamper‑proof stations placed outside the building envelope. Rotate active ingredients to prevent resistance, and follow label instructions to minimize non‑target exposure.

Training personnel reinforces compliance. Provide clear written protocols for sealing repairs, waste management, and inspection routines. Conduct quarterly briefings to review performance metrics and adjust strategies based on observed outcomes.

Collectively, these techniques create a multilayered defense that reduces human exposure to rodent‑borne pathogens and supports long‑term public health protection.

Trapping and Baiting

Effective control of rodent‑borne illnesses relies on systematic trapping and baiting. Proper implementation reduces the likelihood of pathogen transmission from rats and mice to people by lowering population density and limiting contact with contaminated environments.

Selection of devices must match target species and setting. Snap traps, live‑capture cages, and electronic models provide rapid kill or humane removal. Glue boards are discouraged because they can cause prolonged suffering and may release disease agents when animals die in inaccessible locations. Placement should focus on walls, near food sources, and along established runways; devices must be positioned perpendicular to travel paths to maximize encounter rates.

Bait formulation influences trap success. Protein‑rich foods such as peanut butter, dried fish, or commercial rodent attractants outperform grain alone. Bait should be applied in small quantities to prevent spillage that could attract non‑target wildlife. Rotating bait types every few days helps prevent habituation.

Routine monitoring and maintenance complete the program. Check traps daily, record captures, and replace devices promptly. Dispose of carcasses in sealed containers to prevent secondary contamination. Integrate trapping with sanitation measures—eliminate food residues, seal entry points, and manage waste—to sustain low rodent activity and protect public health.

Personal Protective Measures

Hygiene Practices

Effective hygiene measures reduce the risk of rodent‑borne illnesses that affect humans. Regular removal of food residues eliminates attractants, preventing rodents from entering kitchens and storage areas. Sealed containers for dry goods and prompt disposal of waste in tightly closed bins limit access to potential sources of infection.

Cleaning protocols should include:

Daily sweeping and mopping of floors to remove droppings and urine traces.
Disinfection of surfaces with agents proven to inactivate hantavirus, leptospira, and other pathogens.
Routine laundering of cloth items that may have contacted rodent excreta.

Structural controls complement personal habits. Repairing cracks in walls, sealing openings around pipes, and installing door sweeps block entry points. Maintaining vegetation at a distance from building foundations reduces shelter for rodents.

Personal practices further protect health. Hand washing with soap after handling waste, cleaning after contact with rodents, or performing any pest‑control activity prevents accidental ingestion or mucosal exposure. Protective gloves and masks should be worn during removal of nests or droppings, followed by thorough decontamination of equipment.

Integrated pest‑management programs combine sanitation, exclusion, and monitored trapping. Regular inspection for signs of infestation, combined with immediate corrective actions, sustains a low‑risk environment for disease transmission.

Avoiding Contaminated Areas

Rodent-borne illnesses can be acquired through contact with environments where rats or mice have left urine, feces, or saliva. Preventing exposure requires strict avoidance of areas known to be contaminated.

Typical high‑risk locations include:

sewer systems and drainage tunnels
grain silos, warehouses, and food processing facilities
abandoned buildings, basements, and crawl spaces
outdoor refuse piles and compost heaps
agricultural fields after recent rodent activity

Effective avoidance strategies:

Restrict entry to identified hotspots; use locked gates or signage where necessary.
Wear disposable gloves and protective clothing when passage through a suspect zone cannot be avoided.
Disinfect footwear and equipment with an EPA‑approved rodent‑pathogen sanitizer before leaving the area.
Implement physical barriers such as metal mesh or sealed doors to separate clean zones from contaminated spaces.
Conduct regular inspections for signs of rodent droppings, gnaw marks, or nesting material; remove any evidence promptly.

Maintain a documented surveillance program that records inspections, identified risks, and corrective actions. Immediate reporting of suspected contamination enables rapid containment and reduces the likelihood of human infection.

Public Health Interventions

Surveillance Programs

Surveillance systems targeting infections spread by rodents focus on early identification of human cases and detection of pathogens within rodent populations. Field teams collect live traps, environmental samples, and clinical specimens, then forward material to accredited laboratories for molecular or serological testing. Data on species distribution, infection prevalence, and seasonal trends feed into risk‑assessment models that guide public‑health interventions.

Key components include:

Routine trapping and testing of rats and mice in urban, peri‑urban, and rural settings.
Mandatory reporting of laboratory‑confirmed human cases to local health authorities.
Integration of wildlife, veterinary, and human health databases for cross‑sectoral analysis.
Geographic information system (GIS) mapping of hotspots and movement patterns.
Automated alert thresholds that trigger targeted rodent control and community education.

Information flows from field collectors to regional public‑health offices, then to national disease‑monitoring agencies. Standardized case definitions and laboratory protocols ensure comparability across jurisdictions. Real‑time dashboards display incidence curves, enabling rapid allocation of resources to emerging clusters.

Effective programs have reduced morbidity from hantavirus pulmonary syndrome in the western United States and limited leptospirosis outbreaks in Southeast Asian cities by coupling surveillance with targeted baiting and habitat modification. These successes rely on sustained funding, trained personnel, and inter‑agency coordination.

Persistent obstacles encompass incomplete case capture, especially in underserved areas, and limited laboratory capacity for exotic rodent pathogens. Urban expansion introduces new habitats that complicate trapping logistics. Addressing these gaps demands investment in sentinel sites, portable diagnostic platforms, and community‑based reporting mechanisms.

Educational Campaigns

Educational initiatives aimed at reducing rodent‑borne illnesses must convey clear, actionable information to at‑risk populations. Campaigns should identify high‑exposure groups—such as food‑service workers, waste‑management personnel, residents of low‑income housing, and children in urban schools—and tailor messages to their specific behaviors and environments.

Key components of an effective program include:

Accurate risk description – brief overview of pathogens transmitted by rats and mice (e.g., hantavirus, leptospirosis, salmonellosis, plague) and typical routes of infection.
Preventive practices – steps for proper food storage, waste disposal, rodent proofing of structures, personal hygiene after handling animals or contaminated materials.
Recognition of symptoms – concise list of early signs for each disease to prompt timely medical consultation.
Response actions – guidance on reporting infestations, seeking veterinary or public‑health assistance, and accessing treatment.

Delivery channels must reach the intended audience efficiently. Proven methods comprise:

Printed flyers and posters displayed in community centers, schools, and workplaces.
Short video clips shared via social media platforms and local television.
Interactive workshops conducted by health‑department staff or trained community volunteers.
Mobile alerts and text messages during outbreak alerts.

Evaluation relies on measurable indicators:

Pre‑ and post‑campaign surveys assessing knowledge gain.
Reduction in reported rodent sightings and infestation complaints.
Decrease in confirmed cases of rodent‑related diseases within the target area.
Participation rates in training sessions and distribution metrics for educational materials.

Sustained impact requires collaboration among public‑health agencies, municipal sanitation services, educational institutions, and non‑governmental organizations. Shared resources—such as graphic templates, translation services, and data‑collection tools—enhance consistency and allow rapid adaptation to emerging threats.

Risk Factors and Vulnerable Populations

Occupational Exposure

Agricultural Workers

Agricultural workers encounter rodents in storage facilities, grain bins, livestock pens, and field margins, creating frequent opportunities for exposure to rodent‑borne illnesses. Direct handling of captured animals, cleaning contaminated equipment, and inhalation of dust laden with droppings or urine constitute primary contact points.

Hantavirus – pulmonary syndrome after inhalation of aerosolized rodent excreta.
Leptospira – leptospirosis through skin abrasions exposed to urine‑contaminated water.
Salmonella – gastrointestinal infection from ingestion of food or water contaminated by rodent feces.
Yersinia pestis – plague transmitted by flea bites after rodents serve as reservoirs.

Transmission on farms occurs when rodents infiltrate feed stores, contaminate irrigation water, or nest in equipment. Activities that disturb settled droppings—such as sweeping grain or loading feed—release infectious particles. Open wounds provide portals for bacterial entry, while consumption of unwashed produce introduces pathogens orally.

Clinical outcomes range from mild febrile illness to severe respiratory distress, renal failure, or hemorrhagic manifestations. Early identification is hampered by nonspecific symptoms; occupational health surveillance must include targeted questioning about rodent exposure.

Control strategies require a coordinated approach:

Implement integrated pest‑management programs to reduce rodent populations.
Seal entry points in barns, silos, and storage sheds.
Maintain regular cleaning schedules using wet methods to minimize dust.
Provide personal protective equipment—gloves, masks, eye protection—during high‑risk tasks.
Ensure prompt reporting and medical evaluation of any illness consistent with rodent‑associated infection.

Adherence to these measures limits disease transmission and safeguards the health of the farming workforce.

Pest Control Professionals

Pest control professionals serve as the primary barrier against rodent-borne illnesses that affect human populations. Their interventions reduce exposure to pathogens carried by rats and mice, limiting outbreaks in residential, commercial, and institutional settings.

Common diseases transmitted by these rodents include:

Leptospirosis
Hantavirus pulmonary syndrome
Salmonellosis
Lymphocytic choriomeningitis
Plague

Effective control strategies require a systematic approach:

Inspection of structures to identify entry points, nesting sites, and signs of activity.
Assessment of sanitation practices that attract rodents, such as improper waste storage.
Implementation of exclusion measures, including sealing gaps, installing door sweeps, and repairing damaged screens.
Deployment of traps and, where legally permissible, rodenticides following integrated pest management (IPM) principles.
Documentation of actions taken, monitoring results, and adjusting tactics based on observed rodent behavior.

Regulatory compliance mandates that professionals maintain certification, adhere to pesticide safety standards, and provide clients with clear instructions for post‑treatment sanitation. Continuous education on emerging pathogens and resistance patterns ensures that control measures remain effective and protect public health.

Environmental Factors

Poor Sanitation

Poor sanitation creates environments where rats and mice thrive, increasing the likelihood of human exposure to rodent‑borne pathogens. Accumulated garbage, standing water, and unsealed food storage provide both nourishment and shelter for these pests, facilitating their proximity to residential and occupational spaces.

Key illnesses associated with rodent contact in unsanitary settings include:

Leptospirosis, transmitted through urine‑contaminated water.
Hantavirus pulmonary syndrome, spread by inhalation of aerosolized rodent droppings.
Salmonellosis, resulting from ingestion of food tainted by rodent feces.
Plague, maintained in flea‑infested rodent populations and transferred to humans via bites.

Mechanisms linking inadequate hygiene to disease transmission are:

Food waste attracts rodents, leading to direct contamination of kitchen surfaces and stored provisions.
Leaking sewage or standing water serves as a medium for pathogens such as Leptospira spp., which rodents excrete.
Overcrowded, poorly maintained waste bins allow rodents to nest within or near human dwellings, increasing droplet and dust exposure.

Effective control measures focus on eliminating the sanitary conditions that support rodent populations:

Secure, sealed waste containers and regular collection schedules.
Repair of leaky pipes and removal of stagnant water sources.
Routine cleaning of food preparation areas and prompt disposal of food scraps.
Structural repairs to prevent rodent entry, including sealing cracks and installing door sweeps.

By addressing these sanitation deficiencies, the risk of rodent‑related infections to humans can be substantially reduced.

Urbanization

Urban growth expands habitats that attract commensal rodents, increasing contact between humans and disease‑carrying rats and mice. Dense housing clusters create concealed pathways—such as utility conduits and building cracks—through which rodents move freely, facilitating the spread of pathogens like hantavirus, leptospira, and plague‑related bacteria.

Key urban factors that amplify rodent‑borne health threats include:

Inadequate waste disposal generates abundant food sources, sustaining larger rodent populations.
Overcrowded neighborhoods reduce living space per person, heightening the probability of accidental bites or exposure to contaminated droppings.
Aging infrastructure, especially aging sewer systems, provides subterranean routes that link residential blocks and commercial areas.
Limited green space forces rodents into built environments, where they encounter more humans.
Insufficient pest‑control programs allow rapid population rebounds after short‑term reductions.

Mitigation requires coordinated municipal actions: systematic garbage collection, regular inspection and repair of building envelopes, targeted rodent surveillance, and public education on safe waste handling. When these measures are integrated into city planning, the incidence of infections transmitted by rats and mice declines noticeably.

Immunocompromised Individuals

Children and Elderly

Rodents such as rats and mice carry pathogens that disproportionately affect children and older adults. Immature immune systems and age‑related physiological decline increase susceptibility to severe outcomes after exposure.

Leptospira spp. – causes leptospirosis; children often present with fever, headache, and jaundice, while the elderly may develop acute kidney injury and pulmonary hemorrhage.
Hantavirus – leads to hantavirus pulmonary syndrome; pediatric cases can progress rapidly to respiratory failure, and seniors experience higher mortality due to pre‑existing cardiovascular disease.
Salmonella enterica – transmitted through contaminated food or rodent droppings; infants and toddlers risk dehydration from diarrhoea, whereas elderly patients risk bacteremia and septic shock.
Bartonella henselae – agent of cat‑scratch disease, also spread by rodents; children commonly develop lymphadenopathy, while older adults may suffer prolonged fever and hepatic involvement.
Yersinia pestis – responsible for plague; children exhibit atypical symptoms that delay diagnosis, and the aged population shows increased risk of septicemic and pneumonic forms.

Prevention measures must address the specific vulnerabilities of these groups. Household sanitation, sealing entry points, and prompt removal of rodent nests reduce exposure. Caregivers should ensure that food is stored in rodent‑proof containers and that children’s play areas are kept free of droppings. Vaccination, where available (e.g., hantavirus experimental candidates), should be prioritized for high‑risk seniors.

Healthcare providers should maintain a high index of suspicion for rodent‑borne infections in children presenting with unexplained fever or gastrointestinal symptoms, and in elderly patients with atypical respiratory or renal signs. Early laboratory testing, appropriate antimicrobial therapy, and supportive care improve prognosis across both age groups.

Individuals with Underlying Health Conditions

Individuals with chronic medical conditions face heightened susceptibility to infections spread by rodents. Impaired immune function, reduced respiratory capacity, or compromised skin integrity diminish the body’s ability to contain pathogens introduced through bites, scratches, contaminated food, or aerosolized excreta.

Common underlying conditions that amplify risk include:

Diabetes mellitus
Chronic obstructive pulmonary disease (COPD) and other respiratory diseases
Cardiovascular disease
Chronic kidney disease
HIV/AIDS and other immunodeficiency disorders
Cancer undergoing chemotherapy or radiotherapy
Autoimmune diseases treated with immunosuppressive agents

Rodent-associated illnesses such as leptospirosis, hantavirus pulmonary syndrome, rat‑bite fever, and lymphocytic choriomeningitis often progress more rapidly in these patients. Diabetes can exacerbate leptospiral kidney injury; respiratory disorders increase mortality from hantavirus infection; immunosuppression predisposes to severe rat‑bite fever and persistent viral replication.

Preventive actions tailored for vulnerable individuals encompass:

Avoiding direct contact with wild rodents and their habitats
Ensuring food storage in sealed containers and maintaining clean kitchen surfaces
Using protective gloves when handling materials that may be contaminated
Seeking prompt medical evaluation after any rodent bite, scratch, or exposure to urine or droppings
Receiving recommended vaccinations where available (e.g., tetanus) and maintaining up‑to‑date immunizations for other preventable diseases

Targeted education and strict hygiene practices reduce the likelihood of severe outcomes for those already burdened by chronic health issues.