Immunization coverage and predictive factors for complete and age-appropriate vaccination among preschoolers in Athens, Greece: a cross--sectional study.

BACKGROUND: In Greece, several new childhood vaccines were introduced recently but were reimbursed gradually and at different time points. The aim of this study was to assess immunization coverage and identify factors influencing complete and age-appropriate vaccination among children attending public nurseries in the municipal district of Athens. METHODS: A cross-sectional study, using stratified sampling was performed. Immunization history was obtained from vaccination booklets. Demographic and socioeconomic data were obtained from school registries and telephone interviews. Vaccination rates were estimated by sample weighted proportions while associations between complete and age-appropriate immunization and potential determinants by logistic regression analysis. RESULTS: A total of 731 children (mean age: 46, median: 48, range: 10-65 months) were included. Overall immunization coverage with traditional vaccines (DTP, polio, Hib, HBV, 1st dose MMR) was satisfactory, exceeding 90%, but the administration of booster doses was delayed (range: 33.7- 97.4%, at 60 months of age). Complete vaccination rates were lower for new vaccines (Men C, PCV7, varicella, hepatitis A), ranging between 61-92%. In addition, a significant delay in timely administration of Men C, PCV7, as well as HBV was noted (22.9%, 16.0% and 27.7% at 12 months of age, respectively). Child's age was strongly associated with incomplete vaccination with all vaccines (p< 0.001), while as immigrant status was a predictor of incomplete (p=0.034) and delayed vaccination (p<0.001) with traditional vaccines. Increasing household size and higher maternal education were negatively associated with the receipt of all and newly licensed vaccines, respectively (p=0.035). CONCLUSIONS: Our findings highlight the need to monitor uptake of new vaccines and improve age- appropriate administration of booster doses as well as early vaccination against hepatitis B. Immigrant status, increased household size and high maternal education may warrant targeted intervention.

Age, beta thalassaemia trait, and iron-deficient anaemia significantly affect reticulocyte indices in pre-school children.

BACKGROUND: Reticulocyte indices are easy to obtain, low cost parameters and have gained interest in the field of diagnosing anaemias of childhood. METHODS: We assessed distribution, age and gender variation, relation to indices of iron metabolism and diagnostic performance of reticulocyte haemoglobin content (CHr), percentage of microcytic reticulocytes (micro_r), percentage of hypochromic reticulocytes (hypo_r), and percentage of reticulocytes with low CHr (low_CHr) in 386 pre-school children classified in four groups: healthy, iron deficiency (ID), iron deficiency anaemia (IDA), and beta-thalassaemia carriers (beta-thal). RESULTS: Age had a positive effect in CHr (Spearman's rho = 0.21) and a negative effect in hypo_r (Spearman's rho = -0.2) in healthy children. CHr and low_CHr were related to ferritin in the IDA group (Spearman's rho 0.55 and -0.53, respectively). In the beta-thal group, HbA(2) is strongly related to all reticulocyte indices. micro_r and CHr performed best in discriminating between IDA and beta-thal heterozygosity (ROC analysis, area under the curve (AUC): 0.76 and 0.74, respectively). CHr achieved the best AUC (0.58) in identifying ID among children without anaemia. CONCLUSION: Age, IDA and beta-thal significantly affect reticulocyte indices. CHr and micro_r may have a role as screening tools in discriminating between IDA and beta-thal heterozygosity.

Serum transferrin receptors: Distribution and diagnostic performance in pre-school children.

Soluble transferrin receptors have gained interest in the field of diagnosing anemias. Reference ranges differ according to the method used for the quantification of sTfR. We aim to explore the distributional properties and diagnostic performance of sTfR in pre-school healthy children as well as in children with beta-thalassemia carriers, iron deficiency with normal hematological phenotype (ID) and iron deficiency anemia (IDA). Circulating sTfR as well as biochemical and hematological indices were determined in 521 pre-school children and four groups (normal children, beta-thalassemia traits, ID and IDA) were formed. Diagnostic performance and distribution of sTfR according to age and in relation to several parameters were evaluated in every group. Three hundred eighty one children (261 normal, 60 beta-thalassemia traits, 44 ID and 16 IDA) aged 1-6 years were included. We found that distribution of sTfR differed significantly among the four groups (Kruskal Wallis p<0.001) with children in the normal group exhibiting lower concentrations compared to all other. A negative correlation between sTfR and age occurred in the normal (beta=-0.12, p<0.001) and the ID groups (beta=-0.13, p=0.035). In the beta-thal and IDA groups sTfR is correlated to HbA(2) (beta=0.34, p=0.001) and ferritin (Spearman's rho=-0.6, p=0.014) respectively. An area under the curve equal to 0.63 was achieved by sTfR in distinguishing between normal and ID children. Sensitivity and specificity were 70.5% and 50% respectively at a cut-off of 2.5 mg/l. Levels of sTfR are negatively correlated to age in pre-school children while dyserythropoietic procedures like beta-thal, ID, and IDA significantly affect them. These findings indicated that the accuracy of sTfR in diagnosing ID from normal children is limited. Standardization will allow the use of formulas that combine sTfR and ferritin which are of greater diagnostic value than sTfR alone.