269 Shifting Seropositivity for Hepatitis A in Children in Istanbul, Turkey from 1996 to 2011

Abstract

Abstractsserotypes with the exception of serotype 19A which is covered only by PCV13. Serotype 19A has steadily increased in prevalence and become increasingly resistant to common antibiotic classes. Rational antibiotic use and vaccination of infants with pneumococcal conjugate vaccines should be considered as essential strategies for prevention of pediatric invasive infections in Turkey. Background Hepatitis A virus (HAV) is transmitted by the fecaloral route, and the epidemiology of HAV is associated with hygiene and socioeconomic status. However, due to improvements in living conditions, there is an epidemiological shift in HAV infection. Methods In this study, we investigated the seropositivity for HAV in children aged between 2 and 18 years. In addition, we compared the results with previously reported seropositivity data from the same center in Uskudar, Istanbul, Turkey, from 1996. Results The mean age of the 400 children was 7.9±3.7 years (range: 2-18). Of the 400 serum samples collected, all were tested for anti-HAV IgG, and 50 (12.5%) were positive. The rates of anti-HAV seropositivity within the age groups of 2-< 6, 6-< 10 and 10-18 years were determined. The seropositivity increased with increasing age: 11.5% in the 2-to < 6-year-old group and 13.2% in the 10-to 18-yearold group. Conclusions There was a significant decline in the overall seropositivity for anti-HAV between 1996 and 2011 (p<0.001), and the pediatric age group has a high risk of HAV infection. SHIFTING SEROPOSITIVITY FOR HEPATITISAbstract 269 Figure 1 Shifting seropositivity for Hepatitis A In 1996, the overall seropositivity was 41.3%. In the 1996 study, the seropositivity was 35.2% in 2-to < 6-year-old age group, 35.3% in the 6-to < 10-year-old age group and 54.3% in children older than 10 years. Given the serological shift over time, greater susceptibility and a persistent risk of exposure to HAV suggest that outbreaks are possible. Background and Aims Transmission of immune competence from mothers to newborns is crucial for optimal development of neonate immune system. Maternal perinatal probiotics supplementation having been observed to be able to modulate this process, the goal of the present study was to investigate the importance of the time window of probiotics intervention (pregnancy/lactation) on early-life immune maturation and response to immunization. Methods Pregnant C57/BL6 mice were supplemented with Bifidobacterium lactis CNCM I-3446, 2.5x10 8 CFU/day, during either end of gestation and lactation, end of gestation only or lactation only. Maltodextrin was given during both periods (placebo) or in replacement of probiotics when not administered. Immune maturation was assessed by measuring natural mucosal IgA production (ELISPOTs) at weaning and 6 weeks later. Pups were mucosally immunized at weaning, and again four weeks later, with live attenuated Salmonella typhimurium ΔaroA. Two weeks after the second immunization, specific antibody responses in serum were analyzed. Results All probiotic regimens significantly enhance...