Overwhelming postsplenectomy infection with vaccine-type Streptococcus pneumoniae in a 12-year-old girl despite vaccination and antibiotic prophylaxis

[Hereditary spherocytosis: guidelines for the diagnosis and management in children]

Hereditary spherocytosis (HS) is the commonest inherited disorder of the erythrocyte membrane in Northern Europe and North America. It is marked by a regenerative anemia which varies widely from asymptomatic patients to severe hemolysis. In 75% of HS patients, inheritance is autosomal dominant. The diagnosis of HS is easily made when there are a family history, hemolytic anemia, reticulocytosis, spherocytes and increased hyperdense cells. Specialized testing to clarify the nature of membrane disorder is required when the film appearance is atypical without a positive family history, in the absence of a family history, in the newborn and before the splenectomy, to rule out the stomatocytosis which is contraindicated. The indication for splenectomy is dependent on the degree of anemia and its clinical manifestation.

The prevention and treatment of bacterial infections in children with asplenia or hyposplenia: practice considerations at the Hospital for Sick Children, Toronto

Children born without a spleen or who have impaired splenic function, due to disease or splenectomy, are at significantly increased risk of life-threatening bacterial sepsis. The mainstays of prevention are education, immunization, and prophylactic antibiotics. The availability of conjugate 7-valent pneumococcal vaccines for use in children to age 9 years at least, as well as conjugate meningococcal C vaccine in some countries, for use beginning in infancy, appear to represent beneficial additions, but not substitutions, to previous recommendations for the use of polysaccharide 23-valent pneumococcal and quadrivalent A, C, Y, W-135 vaccines. Routine immunization against H. influenzae type b should continue with non-immunized children older than age 5 years receiving two doses 2 months apart, similar to children who have not previously received conjugate pneumococcal vaccine in infancy. Annual influenza immunization, which reduces the risk of secondary bacterial infection, is also recommended for asplenic children and their household contacts. Many experts continue prophylaxis indefinitely although prophylaxis of the penicillin allergic child remains suboptimal.

[Perioperative management of asplenic patients]

OBJECTIVE

In 2003, asplenia had involved 250000 patients in France. These patients are at risk of severe infection, mostly with capsulated bacteria as pneumococci, meningococci and Haemophilus. The higher mortality and morbidity due to infection in asplenic patient led in June 2003 a French expert committee to propose preventive management based on vaccination and antibioprophylaxis.

STUDY DESIGN

Update article.

DATA SYNTHESIS

For vaccination, two vaccines against pneumococci are available. The first one, the antipolysaccharide (Pneumo 23) is recommended for adults. It is effective for the majority of the serotypes even if its efficacy can be variable. The second one a conjugated pneumococcal vaccine (Prenevar) is used for children under two years because it has higher activity on antibiotic resistant strains therefore increasing antibiotic prophylaxis efficiency. When splenectomy is required, vaccination against pneumococci, Haemophilus (b type) and C meningococci must be performed at least 15 days before surgery, in order to get better immune stimulation. In case of emergency, vaccines have to be administrated within 30 days after surgery. Antibioprophylaxis is based on cefazolin injection before splenectomy and by postoperative intravenous amoxicillin administration. As soon as oral intake is allowed, antibioprophylaxis is continued for at least two years in adults and five years in children. Both antibiotic and vaccination have been reported to reduce pneumococcus infections.

Prevention of life-threatening infections due to encapsulated bacteria in children with hyposplenia or asplenia: a brief review of current recommendations for practical purposes

The aim of the present work was to summarise in a single paper all the options for prevention of life-threatening infections due to encapsulated bacteria in patients with hyposplenism or asplenia. Prevention of these infections should be obtained in all patients with 1) patient and family education, 2) prophylaxis by means of vaccination against Haemophilus influenzae and Streptococcus pneumoniae, 3) antibiotic prophylaxis, based primarily on penicillin, 4) delay of elective splenectomy or use methods of tissue salvage in splenic trauma. Vaccination is not effective against all serotypes of S. pneumoniae and Neisseria meningitidis causing life-threatening infections in hypo/asplenic patients. Moreover, antibacterial prophylaxis could select antibacterial-resistant pathogens and is highly conditioned by patient's compliance. Therefore, empirical antibacterial therapy of fever and/or suspected infection should be recommended to all splenectomised patients independently from time elapsing from splenectomy, vaccinal status and assumption of antibacterial prophylaxis.

Invasive pneumococcal infections in children with asplenia

BACKGROUND

Asplenia is associated with an increased risk of infections caused by Streptococcus pneumoniae. Overwhelming infection can be fulminate and lead to a fatal outcome.

OBJECTIVE

To review the epidemiology and clinical course of invasive S. pneumoniae infections in children with asplenia before the release of the conjugate pneumococcal vaccine.

METHODS

Children with S. pneumoniae infections from eight children's hospitals in the US were identified prospectively from September, 1993, to August, 1999. Further demographic, medical and microbiologic information was gathered retrospectively from the charts of patients with asplenia.

RESULTS

Twenty-two asplenic patients with 26 episodes of invasive S. pneumoniae were identified. This represents 1% of the 2,581 episodes of invasive S. pneumoniae infections identified in our study. Twelve had congenital asplenia (CA), and 10 had undergone surgical splenectomy. Nine of the patients with CA had associated complex congenital heart disease. The median age at first infection was 12.5 months for CA patients as compared with 69 months in children with surgical splenectomy (P < 0.001). Seventy-five percent of those eligible had received the polysaccharide pneumococcal vaccine. The most common serotypes isolated were 6B (8), 23F (7), 18C (2) and 19A (2). Antimicrobial prophylaxis had been prescribed for 82% of the study cohort. Clinical presentations of the 26 episodes included fever (22), shock (7), petechiae or purpura (7), disseminated intravascular coagulation (5) and respiratory distress (5). Clinical illness included bacteremia alone (12), meningitis alone (8), bacteremia with otitis media-sinusitis (3), bacteremia with pneumonia (2) and meningitis with osteomyelitis (1). Five of the 6 patients who died had meningitis. Three of the survivors (19%) had significant morbidity, and all of them had meningitis. Two patients had 2 episodes each, and 1 patient had 3 episodes. All but 1 of the multiple episodes was with a different serotype. Forty-six percent of isolates were nonsusceptible to penicillin, and 19% were nonsusceptible to ceftriaxone. There was no association between antimicrobial resistance and mortality.

CONCLUSIONS

Invasive pneumococcal disease in patients with asplenia has a high mortality, especially in those with meningitis. Even though the new conjugate vaccine might increase protection, 19% of patients had disease caused by serotypes not included in the current heptavalent vaccine. Clinicians should continue to be aggressive in evaluating asplenic patients with unexplained fevers.

Overwhelming infection in asplenic patients: current best practice preventive measures are not being followed

AIMS

Patients without spleens are at increased risk of overwhelming infection. Recently, greater efforts, including the publication of national guidelines, have been made to improve the management of asplenic individuals. In theory, risks of serious sepsis can be reduced by good advice, immunisation, and antibiotic prophylaxis. In practice, such preventive measures might not be followed or may fail. A study of recent cases of overwhelming postsplenectomy infection (OPSI) was undertaken to examine specific associated factors and to determine whether currently recommended preventive measures are being followed.

METHODS

Cases of OPSI were identified and reported mainly by microbiologists across the country using a specifically designed proforma. Data including the nature of the infection and vaccination/ antibiotic prophylaxis history since splenectomy were obtained.

RESULTS

Seventy seven cases were reported. The age range varied from 3 months (congenital asplenia) to 87 years. In those who had undergone surgical splenectomy, the time interval between surgery and OPSI varied from 24 days to 65 years. Overall mortality reached 50%, with underlying haematological malignancy associated with the highest death rate. Streptococcus pneumoniae caused approximately 90% episodes. Only 31% individuals had received pneumococcal vaccination before OPSI. Seven of 17 pneumococcal infections in immunised cases could be considered vaccine failures. Few patients had been adequately advised on antibiotic prophylaxis or other measures.

CONCLUSIONS

Currently accepted best practice for managing asplenic patients is not being followed. Some OPSI cases may still be preventable but many asplenic individuals remain unrecognised. The compilation of asplenic patient registers might help to implement agreed policies with audit necessary to evaluate compliance. More is needed to ensure optimal management for this cohort of the population.