What are the vaccination and antibiotic recommendations for individuals with asplenia (absence of a spleen)?

Vaccination and Antibiotic Recommendations for Individuals with Asplenia

Individuals with asplenia require pneumococcal, meningococcal, Haemophilus influenzae type b, and annual influenza vaccinations, along with lifelong antibiotic prophylaxis with phenoxymethylpenicillin (or erythromycin if penicillin-allergic) to prevent overwhelming post-splenectomy infection. 1

Vaccination Recommendations

Timing

• Administer vaccines at least 2 weeks before elective splenectomy for optimal antibody response 2, 1
• If emergency splenectomy was performed, vaccinate as soon as the patient's condition stabilizes 2

Required Vaccines

1. Pneumococcal Vaccine

   • Polyvalent pneumococcal vaccine (23 serotypes) - >90% effective in healthy adults under 55 2
   • Reimmunization recommended every 5-10 years 2, 1
   • For children <60 months: Consider sequential administration of 2 doses of pneumococcal conjugate vaccine followed by pneumococcal polysaccharide vaccine (8 weeks between doses) 2

2. Meningococcal Vaccine

   • Recommended for all asplenic patients 2
   • Age-specific recommendations:
     • Children 2-10 years and adults >56 years: MPSV
     • Ages 11-55 years: MCV4 preferred (MPSV acceptable alternative) 2
   • Consider a second dose of MPSV at least 5 years after initial dose 2

3. Haemophilus influenzae type b (Hib) Vaccine

   • Recommended for all asplenic patients 2
   • Shows good immunogenicity in patients with splenectomies 2

4. Influenza Vaccine

   • Recommended annually for all asplenic patients over 6 months of age 2, 1
   • Reduces risk of secondary bacterial infections 2
   • Best avoided during pregnancy 2

Antibiotic Prophylaxis

Recommendations

• Lifelong prophylactic antibiotics should be offered in all cases, especially important in the first two years after splenectomy 2
• First-line: Phenoxymethylpenicillin (Penicillin V) 250-500 mg twice daily 1
• For penicillin-allergic patients: Erythromycin 500 mg twice daily 2, 1

Emergency Antibiotics

• Patients should keep a supply of amoxicillin at home for immediate use if symptoms of infection develop 2
• Adult dosage: 3 g starting dose followed by 1 g every 8 hours 1
• Children dosage: 50 mg/kg in three divided daily doses 1

Special Considerations

Animal and Tick Bites

• Asplenic patients are particularly susceptible to infection by Capnocytophaga canimorsus after animal bites 2
• Provide a five-day course of co-amoxiclav (or erythromycin for allergic patients) after animal bites 2
• Warn patients about tick bites that can transmit babesiosis, which presents with fever, fatigue, and hemolytic anemia 2

Travel Recommendations

• Patients should seek immediate medical help for any feverish illness while traveling 2
• Take special precautions in malaria-endemic areas 1
• Consider additional meningococcal vaccinations (A, Y, W135) when traveling to endemic areas 2

Patient Education and Awareness

• Patients should understand the lifelong risk of infection 1
• Carry a medical alert card/bracelet indicating asplenic status 2, 1
• Seek immediate medical attention for fever >38°C (101°F) 1
• Recognize that despite vaccination and antibiotic prophylaxis, overwhelming infection can still occur 3

Implementation Challenges

• Vaccination coverage remains suboptimal globally: pneumococcal (55.1%), Hib (48.3%), meningococcal C/ACYW135 (33.7%), meningococcal B (13.3%), and influenza (53.2%) 4
• Better education of healthcare workers is needed to improve adherence to guidelines 4

Important Caveats

• The risk of overwhelming post-splenectomy infection (OPSI) is lifelong, with mortality rates up to 50% within 48 hours if untreated 5
• Children under 5 years have greater risk of OPSI with increased mortality compared to adults 1
• Vaccination is not effective against all serotypes of encapsulated bacteria that cause life-threatening infections 3
• Antibiotic prophylaxis effectiveness depends heavily on patient compliance 3

Immediate empirical antibiotic therapy for fever and/or suspected infection is crucial regardless of time since splenectomy, vaccination status, or ongoing antibiotic prophylaxis 3.