Preventing and treating infections in children with asplenia or hyposplenia

Question 1

Which organisms are asplenic patients at risk from? Why?

Answer 1

Encapsulated bacteria:
Streptococcus pneumonia (50% of cases)
Haemophilus influenzae type B
Neisseria meningiditis
Salmonella spp
(SHiNS)

Others include:
Escherichia coli
Pseudomonas spp
Klebsiella

Question 2

What age group is most at risk from overwhelming sepsis?

Answer 2

At risk throughout life, but greater in first 3 years post splenectomy, or first 3 years of life. But infection risk continues throughout life

Question 3

Asplenic patients have what mortality risk from sepsis with encapsulated organisms?

Answer 3

50-70%

Question 4

Does conjugated or pholysaccharide vaccines provide superior response?

Answer 4

Conjugated. Immune tolerance or hypo-responsiveness can develop with polysaccharide vaccine.

Question 5

What type of Pneumococcus vaccine should asplenic patients receive? When?

Answer 5

Both conjugated 13 valent and 23 valent polysaccharide vaccine.

PCV13 (Prevnar) x 4 doses at 2, 4, 6, and 12-15mo (if haven’t received Prevnar and between 12-24 months, give 2 doses 8 weeks apart. If > 24 months needs only one dose

PPV23 (Pneumovax) given after 24 months for additional protection. Though to prime system with PCV13, then give dose at least 8 weeks after the final PCV13 dose

Question 6

What meningococcus vaccines should asplenic patients receive? When?

Answer 6

MCV4 - quadrivalent conjugated vaccine (Menveo, Menactra, or Nimenrix)

Menveo should be given at 2, 4, 6, and 12-15 months. If identified asplenia from 12-24 months, Child should get two doses of Menveo (8 weeks apart). If identified after 24 months, give two doses of any quadrivalent vaccine (8 weeks apart)

Vaccinate q 5 years.
No role for polysaccharide vaccine

New 4 component Meningococcal vaccine designed against serotype B (4CMenB) should be given to all asplenic patients, including infants.

Question 7

What HiB vaccine should asplenic patients receive? When?

Answer 7

Give primary series at 2, 4, 6, months. Booster at 18 months.

If > 5 years, or if missed any dose, patient should receive one dose.

If presenting with HiB sepsis –> should still receive vaccine as infection does not confer lifelong immunity.

Question 8

When should the influenza vaccine be given in asplenic patients?

Answer 8

Yearly, starting at 6 months of age.

Question 9

Should asplenic patients receive Salmonella typhi vaccine?

Answer 9

Only if traveling to developing countries

Question 10

When should vaccines be given before a splenectomy?

Answer 10

At least 2 weeks. Evidence that best response occurs when giving > 2 weeks, but must weigh pro’s or cons of waiting 2 weeks.

Question 11

Which asplenic patients should be prophylaxed? With what drug? Covering which organism?

Answer 11

CPS: All patients should be prophylaxed until age 5, or at least 2 year from surgery (minimum), but ideally lifelong. (Controversy exists for prophylaxis past 5 years)
AAP Red Book: May D/C at 5 years or > 1 year post surgery
British Task Force: Lifelong prophylaxis

Birth to 3 months:
Amoxicillin/Clavulanate with Penicillin VK to cover E. coli, Klebsiella and S. pneumoniae

3 months to 5 years
Penicillin VK to cover S. pneumoniae

> 5 years
Penicillin V to cover S. pneumoniae

Question 12

What tropical disease are asplenic patients at risk of getting?

Answer 12

Malaria. Should receive malaria prophylaxis if traveling to endemic area and take preventive measures.

Question 13

What is the initial treatment of suspected sepsis in asplenic patients?

Answer 13

Can die within hours if truely septic. Obtain blood culture and start Ceftriaxone. If high prevalence of penicillin resistant pneumococci start Ceftriaxone and vancomycin.