Streptococcus pneumoniae Carriage in the Gaza Strip

Background: Pneumococcal infections cause major morbidity and mortality in developing countries. We report the epidemiology of S. pneumoniae carriage in a developing region, the Gaza strip, and evaluate the theoretical coverage of carriage strains by pneumococcal conjugate vaccines (PCVs). Methodology: In 2009 we conducted a cross-sectional survey of S. pneumoniae carriage in healthy children and their parents, living throughout the Gaza strip. Data were collected and nasopharyngeal swabs were obtained. Antibiotic susceptibilities were determined by Vitek-2 and serotypes by the Quellung reaction. Principal Findings: S. pneumoniae carriage was detected in 189/379 (50%) of children and 30/376 (8%) of parents. Carriage prevalence was highest in children <6 months of age (63%). Significant predictors for child carriage were number of household members and DCC attendance. The proportion of pediatric and adults isolates with serotypes included in PCV7 were 32% and 20% respectively, and 46% and 33% in PCV13 respectively. The most prominent non-vaccine serotypes (NVT) were 35B, 15B/C and 23B. Penicillin-nonsusceptible strains were carried by 70% of carriers, penicillin-resistant strains (PRSP) by 13% and Multi-drug-resistant (MDR) by 30%. Of all PRSP isolates 54% belonged to serotypes included in PCV7 and 71% in the PCV13. Similarly, 59% and 73% of MDR-SP isolates, would theoretically be covered by PCV7 and PCV13, respectively. Conclusions: This study demonstrates that, PCV13-included strains were carried by 46% and 33% of pediatric and adult subjects respectively. In the absence of definitive data regarding the virulence of the NVT strains, it is difficult to predict the effect of PCVs on IPD in this region

Positive Deamidated Gliadin Peptide Antibodies and Negative Tissue Transglutaminase IgA Antibodies in a Pediatric Population: To Biopsy or Not To Biopsy▿

Reports from our clinical laboratory database show that 75% of children <2 years old tested for celiac serology who were found positive for deamidated gliadin peptide (DGP) antibodies had negative results for tissue transglutaminase IgA. DGP levels were shown to decline and disappear without a gluten-free diet. This observation questions DGP's specificity for diagnosis of celiac disease

Performance of Serology Assays for Diagnosing Celiac Disease in a Clinical Setting▿

Diagnosis of celiac disease frequently depends upon serology assays. We set out to prospectively assess the diagnostic value of five serology tests: an enzyme-linked immunosorbent assay (ELISA) for tissue transglutaminase (tTG)-immunoglobulin A (IgA) and tTG-IgG, a chemiluminescence assay for tTG-IgA, an ELISA for deamidated gliadin peptide (DGP) IgG and IgA screening, and detection of endomysial antibodies (Abs) by indirect immunofluorescence. One hundred sixteen children at high risk for developing celiac disease were evaluated clinically and underwent small bowel biopsies and blood serology tests. We examined differences between younger and older children in terms of clinical presentation, test performance, and the ability of high Ab levels to correctly predict diagnosis of celiac disease. Celiac disease was diagnosed for 85 (73%) children. No significant clinical differences were observed between the biopsy-positive and biopsy-negative groups. Children ≤3 years of age revealed higher concentrations of tTG-IgA and DGP Abs than children >3 years old (P = 0.017 and 0.007, respectively). High Ab concentrations were predictive of villous atrophies, with sensitivities ranging from 92.8% to 97.9%, depending on the assay and the cutoff points applied. Sensitivities, specificities, positive predictive values, and negative predictive values varied among assays and improved after correction for best cutoff points. Assay specificities obtained in the clinical setting were lower than expected. The new tTG-IgA chemiluminescence assay demonstrated high throughput but low specificity (74.2%). The tTG-IgA ELISA exhibited the highest test efficiency, and the tTG-IgA chemiluminescence assay was suitable for large-scale screening, with reduced specificity. High concentrations of celiac disease-specific Abs bring into question the need for performance of biopsies on children at high risk

Streptococcus pneumoniae carriage in the Gaza strip.

BACKGROUND: Pneumococcal infections cause major morbidity and mortality in developing countries. We report the epidemiology of S. pneumoniae carriage in a developing region, the Gaza strip, and evaluate the theoretical coverage of carriage strains by pneumococcal conjugate vaccines (PCVs). METHODOLOGY: In 2009 we conducted a cross-sectional survey of S. pneumoniae carriage in healthy children and their parents, living throughout the Gaza strip. Data were collected and nasopharyngeal swabs were obtained. Antibiotic susceptibilities were determined by Vitek-2 and serotypes by the Quellung reaction. PRINCIPAL FINDINGS: S. pneumoniae carriage was detected in 189/379 (50%) of children and 30/376 (8%) of parents. Carriage prevalence was highest in children <6 months of age (63%). Significant predictors for child carriage were number of household members and DCC attendance. The proportion of pediatric and adults isolates with serotypes included in PCV7 were 32% and 20% respectively, and 46% and 33% in PCV13 respectively. The most prominent non-vaccine serotypes (NVT) were 35B, 15B/C and 23B. Penicillin-nonsusceptible strains were carried by 70% of carriers, penicillin-resistant strains (PRSP) by 13% and Multi-drug-resistant (MDR) by 30%. Of all PRSP isolates 54% belonged to serotypes included in PCV7 and 71% in the PCV13. Similarly, 59% and 73% of MDR-SP isolates, would theoretically be covered by PCV7 and PCV13, respectively. CONCLUSIONS: This study demonstrates that, PCV13-included strains were carried by 46% and 33% of pediatric and adult subjects respectively. In the absence of definitive data regarding the virulence of the NVT strains, it is difficult to predict the effect of PCVs on IPD in this region

Predictors of <i>S. pneumoniae</i> carriage in children in the Gaza strip.

*<p>N = total number of children with the specified predictor.</p>**<p>% <i>S. pneumoniae</i> carriage among children with the specific predictor.</p

<i>S. pneumoniae</i> carriage by age and by PCV7 vaccine type (VT7) serotypes, serotypes added to PCV7 in PCV10 (a-VT10), serotypes added to PCV10 in PCV13 (a-VT13).

<p>Light grey-VT7 serotype carriage. Dark grey-a-VT10 (1, 5, 7F), Black – a-VT13 (3, 6A, 19A), White - Non-VT13 carriage.</p

Potential coverage of antibiotic resistant strains in children by PCV7 (Light Grey), PCV10 (Light+Dark Grey) and PCV13 (Light+Dark Grey+Black).

<p>PSSP: penicillin susceptible <i>S. pneumoniae</i>, PNSSP: penicillin non-susceptible <i>S. pneumoniae</i> (MIC>0.06 mg/L), PRSP: penicillin resistant <i>S. pneumoniae</i> (MIC≥2.0 mg/L), MDR-SP: multi-drug resistant <i>S. pneumoniae</i>, defined as non-susceptible to at least penicillin and erythromycin.</p

Prevalence of antibiotic resistance among isolates.

<p>Black - children. Grey - Parents. PNSSP: penicillin non-susceptible <i>S. pneumoniae</i> (MIC>0.06 mg/L), PRSP: penicillin resistant <i>S. pneumoniae</i> (MIC≥2.0 mg/L), ERSP: erythromycin resistant <i>S. pneumoniae</i> (MIC>0.5 mg/L), TMP/SXTR-SP: trimethoprim-sulfamethoxazolenon-susceptible <i>S. pneumoniae</i> (MIC>0.5 mg/L),MDR-SP: multi-drug resistant <i>S. pneumoniae</i>, defined as non-susceptible to at least penicillin and erythromycin.</p