Incidence of febrile seizures and associated factors in children in Soweto, South Africa.

BACKGROUND: Febrile seizures (FSs) are a common cause of paediatric emergencies, but there is limited research on the aetiology and epidemiology of FSs, especially in Africa. OBJECTIVES: To determine the incidence of FS hospitalisations in children aged 6 - 59 months in Soweto, South Africa, and factors associated with FS hospitalisations. METHOD: In a secondary data analysis using a cohort of children enrolled in a 9-valent pneumococcal conjugate vaccine efficacy trial conducted in Soweto during 1998 - 2005, the incidence of FS hospitalisation was calculated and stratified by age group. Regression analysis was used to investigate factors associated with FS at the time of hospitalisation. Influenza A, influenza B, respiratory syncytial virus (RSV), adenovirus and parainfluenza were investigated for among those with respiratory symptoms using immunofluorescent assays. RESULTS: FSs accounted for 780 (11.0%) of 7 126 hospitalisations during the study period. The overall incidence of FSs was 4.4 (95% confidence interval (CI) 4.10 - 4.97) per 1 000 person-years, with the highest incidence in children aged 12 - 23 months (7.25; 95% CI 6.44 - 8.14). Among hospitalised children, FS hospitalisation was associated with HIV-negative status (odds ratio (OR) 6.25; 95% CI 4.34 - 8.99), body temperature ≥39ºC (OR 2.03; 95% CI 1.56 - 2.64) and concurrent diagnosis of acute otitis media (OR 2.16; 95% CI 1.74 - 2.67). Influenza A was identified in 44/515 FS hospitalisations (8.5%) compared with 123/3 794 non-FS hospitalisations (3.2%) (OR 2.22; 95% CI 1.56 - 3.16). In contrast, RSV detection was less commonly identified in children with FSs (21; 4.1%) than without (419; 11.0%) (OR 0.36; 95% CI 0.24 - 0.54). CONCLUSIONS: FSs contributed significantly to the burden of paediatric hospitalisations in Soweto, and were strongly associated with influenza A virus infection.

Measles seroprevalence in pregnant women in Soweto, South Africa: a nested cohort study.

OBJECTIVES: Measles infection causes particularly severe disease in young children who, prior to vaccination, are dependent on maternal antibodies for protection against infection. Measles vaccination was introduced into the South African public immunization programme in 1983 and became widely available in 1992. The aim of this study was to determine measles-specific immunoglobulin G (IgG) levels in pregnant women living with and without HIV born before and after measles vaccine introduction in South Africa. METHODS: Measles IgG antibody level from blood obtained at the time of delivery was compared between women who were born before 1983 (n = 349) and since 1992 (n = 349). Serum samples were tested for measles IgG antibody using an enzyme-linked immunosorbent assay. Geometric mean titres (GMTs) and the proportion with seronegative (<200 mIU/mL) or seropositive titres (≥275 mIU/mL) were compared. RESULTS: Women born since 1992 had lower GMTs [379.7 mIU/mL (95% CI 352.7-448.6)] and fewer were seropositive (55.9%, 195/349) than women born before 1983 [905.8 mIU/mL (95% CI 784.7-1045.5); 76.8%, 268/349], for both comparisons p < 0.001. CONCLUSIONS: We found an association between measles vaccine implementation into the public immunization program in South Africa and peri-partum maternal measles immunity, where women born before vaccine introduction had higher measles IgG antibody titres and were more likely to be seropositive. These findings suggest a need to reconsider the infant measles immunization schedule in settings where women have derived immunity mainly from measles vaccine rather than wild-type virus exposure.

Maternal group B Streptococcus-related stillbirth: a systematic review.

BACKGROUND: Limited epidemiological data on the association between maternal rectovaginal group B Streptococcus (GBS) colonisation and stillbirth makes assessment of antenatal interventions for GBS stillbirth difficult. OBJECTIVES: To systematically review the existing literature and evaluate the incidence of GBS-related stillbirth by region up to March 2015. SEARCH STRATEGY: A systematic review of the published literature was completed using PubMed/MEDLINE, EMBASE, LILACS, and Cochrane Library, with Medical Subject Headings (MeSH) and search terms based upon the Centers for Disease Control and Prevention's (CDC) Active Bacterial Core Surveillance (ABCs) GBS-related stillbirth definition and chorioamnionitis. SELECTION CRITERIA: Studies reporting original data on GBS-related stillbirth occurring ≥20 weeks of gestation, with GBS confirmed by autopsy or by culture from the placenta, amniotic fluid, or other normally sterile site samples from the stillborn. DATA COLLECTION AND ANALYSIS: Descriptive analyses were performed with the absolute GBS-related stillbirth rates and proportion of stillbirths attributed to GBS calculated per study where possible. Differences in stillbirth definitions did not allow for pooled estimates to be calculated. MAIN RESULTS: Seventeen studies reported GBS-related stillbirth rates varying from 0.04 to 0.9 per 1000 births, with the proportion of stillbirths associated with GBS ranging from 0 to 12.1%. Most studies reported data from before the year 2000 and from high-income countries. CONCLUSIONS: The sparsely available epidemiological evidence was not reported consistently, emphasising the importance of standardised stillbirth definitions and diagnostic methods to optimally assess the effectiveness of any future antenatal interventions. Timing of stillbirth, GBS serotype, and global diversity were gaps in the current evidence. TWEETABLE ABSTRACT: Systematic review finds Group B Streptococcus causes up to 12.1% of stillbirths, but more research is needed.

Natural acquired humoral immunity against serotype-specific group B Streptococcus rectovaginal colonization acquisition in pregnant women.

Group B Streptococcus (GBS) rectovaginal colonization in pregnant women is associated with invasive GBS disease in newborns, preterm delivery and stillbirths. We studied the association of GBS serotype-specific capsular polysaccharide (CPS) antibody on new acquisition and clearance of rectovaginal GBS colonization in pregnant women from 20 weeks until 37 to 40 weeks' gestation. Serum serotype-specific CPS IgG antibody concentration was measured by multiplex enzyme-linked immunosorbent assay and opsonophagocytic activity (OPA) titres. Rectovaginal swabs were evaluated for GBS colonization, using standard culture methods and serotyping by latex agglutination, at five to six weekly intervals. Higher serotype III CPS antibody concentration was associated with lower risk of rectovaginal acquisition of serotype III during pregnancy (p 0.009). Furthermore, serotype-specific OPA titres to Ia and III were higher in women who remained free of GBS colonization throughout the study compared to those who acquired the homotypic serotype (p <0.001 for both serotypes). Serum CPS IgG values of ≥1µg/mL for serotype V and ≥3µg/mL for serotypes Ia and III were significantly associated with protection against rectovaginal acquisition of the homotypic serotype. A GBS vaccine that induces sufficient capsular antibody in pregnant women, including high OPA titres, could protect against rectovaginal colonization during the latter half of pregnancy.

Use of a rapid test of pneumococcal colonization density to diagnose pneumococcal pneumonia.

BACKGROUND: There is major need for a more sensitive assay for the diagnosis of pneumococcal community-acquired pneumonia (CAP). We hypothesized that pneumococcal nasopharyngeal (NP) proliferation may lead to microaspiration followed by pneumonia. We therefore tested a quantitative lytA real-time polymerase chain reaction (rtPCR) on NP swab samples from patients with pneumonia and controls. METHODS: In the absence of a sensitive reference standard, a composite diagnostic standard for pneumococcal pneumonia was considered positive in South African human immunodeficiency virus (HIV)-infected adults hospitalized with radiographically confirmed CAP, if blood culture, induced good-quality sputum culture, Gram stain, or urinary Binax demonstrated pneumococci. Results of quantitative lytA rtPCR in NP swab samples were compared with quantitative colony counts in patients with CAP and 300 HIV-infected asymptomatic controls. RESULTS: Pneumococci were the leading pathogen identified in 76 of 280 patients with CAP (27.1%) using the composite diagnostic standard. NP colonization density measured by lytA rtPCR correlated with quantitative cultures (r = 0.67; P < .001). The mean lytA rtPCR copy number in patients with pneumococcal pneumonia was 6.0 log(10) copies/mL, compared with patients with CAP outside the composite standard (2.7 log(10) copies/mL; P < .001) and asymptomatic controls (0.8 log(10) copies/mL; P < .001). A lytA rtPCR density ≥8000 copies/mL had a sensitivity of 82.2% and a specificity of 92.0% for distinguishing pneumococcal CAP from asymptomatic colonization. The proportion of CAP cases attributable to pneumococcus increased from 27.1% to 52.5% using that cutoff. CONCLUSIONS: A rapid molecular assay of NP pneumococcal density performed on an easily available specimen may significantly increase pneumococcal pneumonia diagnoses in adults.