Enterovirus 71 is a common cause of hand, foot, and mouth disease and encephalitis in Asia and elsewhere. The long-term neurologic and psychiatric effects of this viral infection on the central nervous system (CNS) are not well understood. We conducted long-term follow-up of 142 children after enterovirus 71 infection with CNS involvement — 61 who had aseptic meningitis, 53 who had severe CNS involvement, and 28 who had cardiopulmonary failure after CNS involvement. At a median follow-up of 2.9 years (range, 1.0 to 7.4) after infection, the children received physical and neurologic examinations. We administered the Denver Developmental Screening Test (DDST II) to children 6 years of age or younger and the Wechsler intelligence test to children 4 years of age or older. Nine of the 16 patients with a poliomyelitis-like syndrome (56%) and 1 of the 5 patients with encephalomyelitis (20%) had sequelae involving limb weakness and atrophy. Eighteen of the 28 patients with cardiopulmonary failure after CNS involvement (64%) had limb weakness and atrophy, 17 (61%) required tube feeding, and 16 (57%) required ventilator support. Among patients who underwent DDST II assessment, delayed neurodevelopment was found in only 1 of 20 patients (5%) with severe CNS involvement and in 21 of 28 patients (75%) with cardiopulmonary failure (P<0.001 for the overall comparison). Children with cardiopulmonary failure after CNS involvement scored lower on intelligence tests than did children with CNS involvement alone (P=0.003). Enterovirus 71 infection with CNS involvement and cardiopulmonary failure may be associated with neurologic sequelae, delayed neurodevelopment, and reduced cognitive functioning. Children with CNS involvement without cardiopulmonary failure did well on neurodevelopment tests. (ClinicalTrials.gov number, NCT00172393.)

Background. Whether hepatitis B (HB) vaccine-conferred immunity persists into adulthood is unknown. We aimed to investigate long-term HB immunity in adolescents.

Neonatal immunization with hepatitis B (HB) vaccine is highly effective; however, more needs to be learned about the duration of protection and indications for boosters. We measured antibody to HB core antigen (anti–HBc), HB surface antigen (HBsAg), and pre– and postbooster titers of HBsAg antibody (anti–HBs) 15 years after primary neonatal immunization with plasma–derived HB vaccines in 2 cohorts of 15–year–old children. Group A consisted of 78 children who were born to HB e antigen-positive HBsAg carrier mothers and had developed protective levels of anti–HBs antibodies (≥10 mIU/mL) following HB immunization. Group B consisted of 113 apparently healthy children whose anti–HBs titers after vaccination were unknown. Anti–HBs was undetectable (antibody titer <10 mIU/mL) in 29.9% in group A and 62.4% in group B ( P < .001). Anti–HBc was detected in 33.3 % in group A and 4.4 % in group B ( P < .001). After a single booster dose of HB vaccine, 2.7% in group A and 3.3% in group B remained anti–HBs-negative. A blunted serological response was noted in approximately 20% in both groups. One HBsAg carrier was detected in group A (1.3%) and 4 in group B (3.5%). Fifteen years after neonatal immunization with plasma–derived HB vaccine, a large proportion of children exhibited waning immunity. This poses the risk of breakthrough infection. A single booster augmented the serological response to the vaccine in most but not all subjects. In conclusion , our findings suggest that one or more booster immunizations are needed in seronegative subjects by at least 15 years following neonatal immunization with plasma–derived HB vaccine. (Hepatology 2004;40:1415-1420.)