Evaluation of a new vaccination program for infants born to HBsAg-positive mothers in Stockholm County.

To overcome previous shortcomings in the routines for prophylaxis to newborns of hepatitis B infected pregnant women, we established a new program in 2005. This program combined monovalent hepatitis B vaccine at birth and at one month with three doses of hexavalent vaccine, including a hepatitis B vaccine component, at 3, 5 and 12 months, respectively. The hexavalent vaccine and follow-up serologies were administered at the well baby clinics. Three hundred and eighty babies born to 356 HBsAg positive mothers (9% HBeAg positive), were evaluated. Twenty-two children were lost to follow-up, 329 of the remaining 358 children (92%) completed follow-up serology at ages 13-18 months, with protective anti-HBs levels in 99%. For comparison, in a previous cohort from 2000 to 2001, only 63% completed follow-up serology. We conclude that the adherence to the new program was good and that it resulted in a very high rate of protective antibody levels.

Multilocus genotyping of human Giardia isolates suggests limited zoonotic transmission and association between assemblage B and flatulence in children.

BACKGROUND: Giardia intestinalis is one of the most common diarrhea-related parasites in humans, where infection ranges from asymptomatic to acute or chronic disease. G. intestinalis consists of eight genetically distinct genotypes or assemblages, designated A-H, and assemblages A and B can infect humans. Giardiasis has been classified as a possible zoonotic disease but the role of animals in human disease transmission still needs to be proven. We tried to link different assemblages and sub-assemblages of G. intestinalis isolates from Swedish human patients to clinical symptoms and zoonotic transmission. METHODOLOGY/PRINCIPAL FINDINGS: Multilocus sequence-based genotyping of 207 human Giardia isolates using three gene loci: ß-giardin, glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) was combined with assemblage-specific tpi PCRs. This analysis identified 73 patients infected with assemblage A, 128 with assemblage B, and six with mixed assemblages A+B. Multilocus genotypes (MLGs) were easily determined for the assemblage A isolates, and most patients with this genotype had apparently been infected through anthroponotic transmission. However, we also found evidence of limited zoonotic transmission of Giardia in Sweden, since a few domestic human infections involved the same assemblage A MLGs previously reported in Swedish cats and ruminants. Assemblage B was detected more frequently than assemblage A and it was also more common in patients with suspected treatment failure. However, a large genetic variability made determination of assemblage B MLGs problematic. Correlation between symptoms and assemblages was found only for flatulence, which was significantly more common in children less than six years of age infected with assemblage B. CONCLUSIONS/SIGNIFICANCE: This study shows that certain assemblage A subtypes are potentially zoonotic and that flatulence is connected to assemblage B infections in young children. Determination of MLGs from assemblages A and B can be a valuable tool in outbreak situations and to help identify possible zoonotic transmission.