Subspecies tularensis (Type A): North America, higher virulence
Subspecies holarctica (Type B): Europe and North America, lower virulence
Infectious dose as low as 10-50 organisms via skin or aerosol route
Intracellular survival mechanism
Survives and replicates inside macrophages and neutrophils
Evades phagolysosomal killing
Neutrophil functional impairment described (Immunological Reviews 2016)
Glandular form pathogenesis
Inoculation via skin
Tick bite, insect bite, or direct animal contact
Bacteria invade via skin, travel via lymphatics to regional nodes
Primary skin ulcer may heal before lymphadenopathy manifests
Lymph node response
Granulomatous inflammation with necrosis
Caseating necrotizing granulomas indistinguishable from TB histologically
Suppuration and abscess formation in severe cases
Systemic spread
Bacteremia can seed lungs, liver, spleen, meninges
Hematogenous pneumonic tularemia can complicate glandular form
Typhoidal form results from widespread hematogenous dissemination
Therapeutic Considerations
Antibiotic mechanism and resistance
Aminoglycosides (bactericidal)
Gentamicin and streptomycin are bactericidal against F. tularensis
Preferred for severe disease due to killing kinetics
No acquired aminoglycoside resistance reported in natural strains
Fluoroquinolones (bactericidal)
Ciprofloxacin and levofloxacin are bactericidal
Lower relapse rate than doxycycline (~5-10%)
2025 CDC MMWR designation as first-line for natural infections
Doxycycline (bacteriostatic)
Effective but higher relapse rate 10-15%
Longer treatment duration required (14-21 days)
Intrinsic beta-lactam resistance
F. tularensis produces beta-lactamase
Penicillins and cephalosporins universally ineffective
Evidence base and guideline evolution
IDSA/ASM 2024 laboratory guidelines on PCR testing
2025 CDC MMWR update on antimicrobial treatment and prophylaxis
Frontiers in Microbiology 2023 (Maurin et al.): comprehensive treatment evidence review
Bioterrorism preparedness context
JAMA 2001 (Dennis et al.): classified as Category A bioterrorism agent
NEJM 2015 (Adalja et al.): clinical management of bioterrorism conditions
Aerosol release would cause pneumonic form with high mortality
Patient Discharge Instructions
copy discharge instructions
Diagnosis and illness explanation
Glandular tularemia (rabbit fever) is a bacterial infection spread by tick bites, insect bites, or contact with infected wild animals
It causes painful swollen lymph nodes and fever
It is not spread from person to person
Most people recover fully with antibiotic treatment
Medications
Take your antibiotic as prescribed for the full course even if you feel better
Do not stop antibiotics early — this increases relapse risk
Ciprofloxacin: take every 12 hours with or without food; avoid antacids within 2 hours
Doxycycline: take every 12 hours with plenty of water; avoid sun exposure
Follow-up instructions
Return to clinic in 48-72 hours to check response to antibiotics
Bring list of current medications
A follow-up blood test at 2-3 weeks may confirm the diagnosis
Return to emergency department immediately for
Worsening or new swollen lymph nodes or drainage from a lymph node
Especially if fever persists beyond 48-72 hours of antibiotics
New cough, difficulty breathing, or chest pain
May indicate spread of infection to the lungs
Confusion, severe headache, or stiff neck
Inability to keep antibiotics down due to vomiting
Worsening fever or new shaking chills despite antibiotics
Prevention counseling
Tick avoidance measures
Use DEET-containing insect repellent on exposed skin
Apply permethrin to clothing and gear
Conduct full-body tick checks after outdoor activities
Remove ticks promptly with fine-tipped tweezers
Animal contact precautions
Wear gloves when handling wild game or animal carcasses
Wear a mask when skinning or butchering wild animals
Ensure thorough cooking of wild game meat
Water safety
Avoid drinking untreated water from natural sources in endemic areas
References
Guidelines and key sources
Primary guidelines
Nelson CA, Meaney-Delman D, Fleck-Derderian S, et al. Tularemia Antimicrobial Treatment and Prophylaxis: CDC Recommendations for Naturally Acquired Infections and Bioterrorism Response — United States, 2025. MMWR Recomm Rep. 2025.
2025 CDC MMWR: designates fluoroquinolones as first-line for natural infections
Dennis DT, Inglesby TV, Henderson DA, et al. Tularemia as a Biological Weapon: Medical and Public Health Management. JAMA. 2001;285(21):2763-2773.
Foundational bioterrorism management framework
Miller JM, Binnicker MJ, Campbell S, et al. Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by IDSA and ASM. Clin Infect Dis. 2024.
PCR and laboratory diagnostic guidance
CDC. Tickborne Diseases of the United States: A Reference Manual for Healthcare Providers, 6th Edition. 2022.
Comprehensive tick-borne disease management
Key clinical studies
Landmark studies and reviews
Maurin M, Gyuranecz M. Tularaemia: Clinical Aspects in Europe. Lancet Infect Dis. 2016.
Epidemiology, clinical presentation, and management in European context
Weber IB, Turabelidze G, Patrick S, et al. Clinical Recognition and Management of Tularemia in Missouri: A Retrospective Records Review of 121 Cases. Clin Infect Dis. 2012.
US clinical series defining glandular form characteristics
Wu HJ, Bostic TD, Horiuchi K, et al. Tularemia Clinical Manifestations, Antimicrobial Treatment, and Outcomes: An Analysis of US Surveillance Data, 2006-2021. Clin Infect Dis. 2024.
National surveillance outcomes data
Maurin M, Pondérand L, Hennebique A, et al. Tularemia Treatment: Experimental and Clinical Data. Front Microbiol. 2023.
Comprehensive antibiotic evidence review including relapse rates
Kossadoum RF, Baron A, Parizot M, et al. Tularemia in Pediatric Patients: A Case Series and Review of the Literature. Pediatr Infect Dis J. 2025.
Pediatric presentation and management guidance
Adalja AA, Toner E, Inglesby TV. Clinical Management of Potential Bioterrorism-Related Conditions. N Engl J Med. 2015.
Bioterrorism preparedness and clinical management
Çakır Kıymaz Y, Bolat S, Katırcı B, et al. Evaluation of Clinical Characteristics, Laboratory Parameters, and Antibiotic Treatment in Patients Diagnosed With Tularemia. J Infect Chemother. 2025.
Recent clinical data on characteristics and treatment outcomes
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.