Nasopharyngeal carriage rate of Streptococcus pneumoniae in Ugandan children with sickle cell disease

Abstract

Background: Nasopharyngeal carriage of Streptococcus pneumoniae is a determinant for invasive pneumococcal disease, which often complicates homozygous sickle cell disease. Here, we determined the nasopharyngeal carriage rate of S. pneumoniae in Ugandan children with homozygous sickle cell disease, who attended the outpatient Sickle Cell Clinic at Mulago National Referral hospital in Kampala, Uganda. Results: S. pneumoniae occurred in 27 of the 81 children with homozygous sickle cell disease (giving a carriage rate of 33%, 27/81). Twenty three children were previously hospitalized of whom S. pneumoniae occurred in only two (9%, 2/23), while among the 58 who were not previously hospitalized it occurred in 25 (43%, 25/58, c2 = 8.8, p = 0.003), meaning there is an association between high carriage rate and no hospitalization. Two children previously immunized with the pneumococcal conjugate vaccine did not carry the organism. Prior antimicrobial usage was reported in 53 children (65%, 53/81). There was high resistance of pneumococci to penicillin (100%, 27/27) and trimethoprime-sulfamethoxazole (97%, 26/27), but low resistance to other antimicrobials. Of the 70 children without sickle cell disease, S. pneumoniae occurred in 38 (54%, 38/70) of whom 43 were males and 27 females (53% males, 23/43, and 56% females, 15/27). Conclusion: Nasopharyngeal carriage of penicillin resistant pneumococci in Ugandan children with homozygous sickle cell disease is high. While nasopharyngeal carriage of S. pneumoniae is a determinant for invasive pneumococcal disease, pneumococcal bacteremia is reportedly low in Ugandan children with sickle cell disease. Studies on the contribution of high carriage rates to invasive pneumococcal disease in these children will be helpful. This is the first report on pneumococcal carriage rate in Ugandan children with sickle cell disease.