Prevalence of Serious Bacterial Infections in Children with Sickle Cell Disease at King Abdulaziz Hospital, Al Ahsa

Risk of invasive meningococcal disease in people with sickle cell disease: A systematic review

BACKGROUND

Asplenia and splenic dysfunction is associated with an increased risk of severe and fatal infections, especially due to encapsulated bacteria including Streptococcus pneumoniae, Haemophilus influenzae serotype b (Hib) and Neisseria meningitidis. People with sickle cell disease (SCD) develop recurrent splenic infarcts rendering them functionally asplenic. Consequently, additional vaccination against these three pathogens is recommended. There is robust evidence of an increased risk for invasive pneumococcal (IPD) and Hib disease, in people with SCD, but for not invasive meningococcal disease (IMD).

METHODS

We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) recommendations. Studies published in any language before June 2024 and including people with SCD of all ages and from all geographical locations were included. Studies were included if they documented bacterial culture and/or PCR in patients with SCD with suspected infection. The primary outcome was to estimate IMD risk in people with SCD. Secondary outcomes included estimating the risk of IMD and Hib disease in people with SCD.

FINDINGS

We identified 3804 publications and included 86 in the final analyses. Among 74 cohort studies published during 1971-2023, there were three IMD cases among 26,404 persons with SCD compared with 570 IPD and 113 Hib cases. Eight case-control studies published during 1983-2022 reported one IMD case among 932 people with SCD (0.1%) compared to 118 IMD cases among 7143 people without SCD (1.65%). In contrast, there were 126 IPD cases (126/932, 13.5%) in people with SCD compared to 588 (588/7143, 8.2%) in those without SCD. For Hib, the rates were 32/932 (3.4%) and 316/7143 (4.4%), respectively. After including all published studies, we identified five IMD cases in people with SCD across studies published worldwide during 1965-1995 and all five survived their infection.

INTERPRETATION

We found no evidence of any increased risk of IMD in people with SCD. This has important implications for policymakers in countries and organisations that currently recommend meningococcal vaccination for people with SCD.

Prevalence, Risk Factors, and Complications of Sickle Cell Disease in Saudi Arabia: A Systematic Review

This study examined sickle cell disease (SCD) in Saudi Arabia. A systematic search of relevant databases was conducted to identify studies investigating SCD in the Saudi population. Studies were then screened based on predefined criteria and critically appraised for methodological quality. Data was extracted and synthesized to provide an overall picture of the SCD burden in Saudi Arabia. The most commonly reported complications were vaso-occlusive crises (VOC), acute chest syndrome (ACS), acute painful crisis, splenic sequestration, osteomyelitis, aplastic crisis, hemolytic crisis, serious bacterial infections, chronic vascular occlusion (CVO), depression, sickle cell nephropathy (SCN), obstructive sleep apnea (OSA), and renal complications. Reduced blood levels of antioxidant trace elements (Cu, Zn, and Se) may encourage oxidative stress, which in turn may contribute to the pathophysiology of SCD. Infections and ACS were common among young children (<7 years) while pain attacks were common in older children (>7 years). The high rate of hospitalizations among SCD patients highlights the need for better management strategies. Future research should focus on understanding the underlying causes of SCD complications and developing new ways to control them.

Frequency of bacteremia in patients with sickle cell disease: a longitudinal study

Bacterial infections in sickle cell disease (SCD) are associated with major risks of morbidity and mortality. Here, we describe the occurrence of bacteremia in SCD patients from 2000 to 2017. This is an observational study which included children and adults with SCD and fever and had confirmed positive blood cultures. During the study period, there were 1095 SCD patients with 17,053 blood cultures. Of all the patients, 699 (63.8%) were children and 396 (36.2%) adults with 576 (52.6%) males and 519 (47.4%) females. The mean age ± SD was 17.8 (± 14.7), and a median age (IQR) of 13.6 (6.8-23.5) years. The mean (SD) follow up was 7.4 (5.4) years and the total number of patient-years was 8069.1 years. Out of the 1095 patients, 91 (8.3%) had bacteremia with 35 (38.5%) children and 65 (61.5%) adults (p = .079). The rate of bacteremia in all patients, children, and adults were 1.5 (95% CI: 1.3-1.8), 0.6 (95% CI: 0.4-0.8), and 2.4 (95% CI: 1.8-3.1) per 100 patient-years, respectively. The risk of Gram-positive bacteremia was 0.5 (96% CI: 0.36-0.69) in all patients, 0.1 (95% CI: 0.06-0.20) in children, and 1.4 (95% CI: 1.0-2.0) in adults per 100 patient-years. The risk of Gram-negative bacteremia was 1.0 (95% CI: 0.81-1.3) in all patients, 0.6 (95% CI: 0.4-0.8) in children, and 2 (95% CI: 1.5-2.7) in adults per 100 patient-years. The risk of Gram-negative bacteremia was higher than Gram-positive bacteremia in children (p < .001) but not in adults (p = .113) and adults had higher risk in general than children. In this study of SCD cohort, 8.3% had bacteremia with predominant Gram-negative infections. Bacteremia was more frequently encountered in the adult age group. Further studies are needed to verify the findings and explore possible reasons predisposing SCD patients to bacteremia.