The burden of poisoning in children hospitalised at a tertiary-level hospital in South Africa.

Introduction: Globally, childhood poisoning, accounts for a significant proportion of emergency department admissions. There is a paucity of data from low- and middle-income countries on poisoning in children. Objective: To describe the incidence, case fatality rate, and types of poisoning in children admitted to a tertiary-level hospital in Johannesburg, South Africa. Methods: This was a retrospective descriptive study of children hospitalised with poisoning from January 2016 to December 2021 at Chris Hani Baragwanath Academic Hospital. Children were identified from a discharge summary database using ICD-10 codes that describe poisoning. Trends in incidence of poison exposure were reported. Results: Of the 60,901 admissions during the study period, 2,652 (4.4%) children were diagnosed with poisoning. Most (71.3%) children were less than 5 years of age and 55% were male. The incidence of poisoning per 100,000 was highest at 108.4 (95% CI: 104.3-112.6) in 2019 and decreased to 77.3 (95% CI: 73.9-80.7) in 2020 and 59.6 (95% CI: 56.3-62.5) in 2021. Main causes of poisoning were organic solvents (37.6%), medications (32.9%), and pesticides (17.5%). The overall case fatality rate was 2.1%. In a multivariate analysis, poisoning secondary to pesticides (aOR: 13.9; 95% CI: 4.52-60.8; p < 0.001), and unspecified agents (aOR: 12.7; 95% CI: 3.27-62.8; p < 0.001) were associated with an increased odds of death. Conclusion: We report a high prevalence of poisoning in children hospitalised in this tertiary-level hospital in South Africa. Public health measures to reduce the burden of organic solvents, medications and pesticide poisoning are urgently warranted.

Infant serotype specific anti-capsular immunoglobulin G antibody and risk of invasive group B Streptococcal disease.

Past studies have mainly investigated the association of serotype-specific capsular IgG in the mother and risk reduction of invasive Group B Streptococcus (GBS) in their young infants. The efficiency of transplacental transfer of IgG could be affected by multiple maternal factors. Hence, investigation of infant serum GBS anti-capsular IgG and risk reduction for invasive GBS disease may be more robust and generalizable. In a matched case-control study, infant serum serotype-specific capsular polysaccharide Ia and III IgG concentrations were analyzed in infants with invasive GBS cases and healthy controls born to women with recto-vaginal colonization by the homotypic serotype. Using Bayesian modeling, an antibody concentration of 2.5 µg/mL and 1 µg/mL predicted a 90% reduced risk of invasive disease for serotype Ia and III, respectively. These data contribute to the possible licensure of a GBS polysaccharide-protein conjugate vaccine, targeted at pregnant women, based on serological correlates of protection against invasive GBS disease.

The Association Between Breast Milk Group B Streptococcal Capsular Antibody Levels and Late-onset Disease in Young Infants.

BACKGROUND: Animal-model studies have demonstrated less group B streptococcal (GBS) invasive disease and gastrointestinal colonization after enteral administration of serotype-specific capsular antibodies. There is, however, a paucity of information on the association of breast milk GBS serotype-specific capsular antibodies and risks for invasive disease in infants. The aim of this study was to explore the association between natural secretory immunoglobulin A (sIgA) capsular antibodies in breast milk and the occurrence of late-onset disease (LOD) in young infants. METHODS: A matched case-control study was undertaken in infants <3 months of age in Johannesburg, South Africa. Breast milk samples were collected on cases and controls matched for gestational age, maternal age, and human immunodeficiency virus status at time of enrollment. Capsular serotype Ia, Ib, III, and V sIgA antibody concentrations were measured using the fluorescence-based micro-bead immunosorbent assay. RESULTS: Breast milk samples were available for 31 LOD cases (8 serotype Ia and 23 serotype III), 21 recto-vaginally colonized matched controls (10 serotype Ia and 11 serotype III), and 84 serotype Ia and 105 serotype III noncolonized matched controls. Using a Bayesian model to estimate the probability of disease, there were 90% reductions in the risks of developing serotypes Ia and III LOD with sIgA concentrations ≥0.14 µg/mL and ≥2.52 µg/mL, respectively. CONCLUSIONS: Breast milk sIgA capsular antibodies were associated with lower risks for LOD in young infants. The ability of GBS polysaccharide-protein conjugate vaccines currently under development to induce sIgA responses warrant investigation as potential mediators of protection against LOD.