Prevalence of pneumococcal polysaccharide vaccine administration and incidence of invasive pneumococcal disease in children in Jamaica aged over 4 years with sickle cell disease diagnosed by newborn screening.

BACKGROUND

Patients with sickle cell disease (SCD) are susceptible to bacterial infections, especially those caused by encapsulated organisms such as Streptococcus pneumoniae which is an important cause of morbidity and mortality in early childhood. Preventive measures such as penicillin prophylaxis and immunisation are therefore required. Although penicillin is the mainstay of prophylaxis, pneumococcal vaccination is also important for defence against invasive pneumococcal disease (IPD).

AIM

To determine the prevalence of pneumococcal polysaccharide vaccination among patients with SCD diagnosed by newborn screening, and the incidence of IPD in this group of patients.

METHODS

In this retrospective study, data were obtained from the pneumococcal polysaccharide vaccine (PPV) log books and the electronic clinic database. Patients' dockets were searched to confirm their vaccine status if they were over 4 years of age and PPV data had not been found by the above methods. Episodes of invasive pneumococcal disease (sepsis or meningitis) were obtained from the clinic database. Data were analysed using STATA version 9.

RESULTS

Ninety-one per cent of participating patients in the study population who were eligible for PPV had been appropriately immunised. Also, 94.8% of patients with a severe form of SCD had appropriately received PPV. The incidence rate of IPD was 480/100,000 person years in the study population and 160/100,000 person years in patients over 4 years of age.

CONCLUSION

The high prevalence of PPV administration in children with SCD diagnosed by newborn screening had a significant impact on the incidence of IPD with improved patient outcomes.