Do predictors of incomplete Kawasaki disease exist for infants?

Kawasaki disease (KD), an acute febrile vasculitis, is the most common cause of acquired heart disease in infants and young children. However, the diagnosis of infantile KD can be difficult or delayed due to vague clinical manifestations. This current study aimed to assess the clinical characteristics and cardiac complications of infantile KD. The study retrospectively reviewed the data of 242 patients with KD. The clinical, laboratory, and echocardiographic data between infants and older children were analyzed. The patients were divided into two groups: infants 12 months old or younger and children older than 12 months. The rate of incomplete KD was much more frequent in infants. During all phases, prohormone brain natriuretic peptide (Pro-BNP) levels were higher in infants, as was thrombocytosis. The coronary artery z-score was higher in infants at all phases of KD. On tissue Doppler imaging, the E/E' ratio (ratio of transmitral Doppler early filling velocity to tissue Doppler early diastolic mitral annular velocity) was higher at the septal and lateral annulus in infants. Infant patients with KD are at increased risk for the development of coronary abnormalities and diastolic dysfunction. Higher levels of Pro-BNP and thrombocytosis with diastolic echo parameters of a higher E/E' ratio can help to identify incomplete KD in infants.

Is a booster dose necessary in children after immunization with live attenuated Japanese encephalitis vaccine?

Japanese encephalitis virus is a common cause of encephalitis in Asian children; therefore, maintenance of immunity against Japanese encephalitis virus is essential. Although many countries recommend booster vaccination, some trials have concluded that administration of one or two vaccinations is sufficient. The current study was conducted to evaluate immunogenicity and safety after a booster vaccination with live attenuated vaccine. For 68 study subjects, measurement of antibody titer was performed before and at 4-6 weeks after administration of a booster dose. Adverse reactions occurring at the injection site and systemic adverse reactions were documented. The percentages of subjects with seroprotective neutralizing antibody titers was 100% before and after booster vaccination, and the geometric mean titer increased after booster vaccination. Thus, we predict that immunity will be maintained for a long time by an amnestic response. Low percentages of adverse reactions indicated the safety of the immunizations.

Reappraisal of MMR vaccines currently used in Korea.

BACKGROUND: Although MMR vaccine is widely used in Korea, there are limited studies on the currently used vaccines. We evaluated the immunogenicity and safety of MMR vaccines in Korean children. METHODS: For first and second dose immunization, children aged 12-23 months and 4-6 years were enrolled. All subjects received a single dose of either Priorix™ (Glaxo Smithkline Biologicals, Rixensart, Belgium) or MMRII® (Merck & Co., Inc., West Point, PA, USA). Pre- and postvaccine sera were collected from all participants. Antibody levels were determined by ELISA (Enzygnost®; Dade Behring, Schwalbach, Germany). Safety monitoring included local adverse events for 5 days and systemic adverse events for 42 days following vaccination. RESULTS: One hundred twenty-one subjects were enrolled in the 12-23 months age group and 39 in the 4-6 years age group. The seroconversion rate in the 12-23 months age group was 97.9-100.0% for measles, 85.1-88.9% for mumps and 100.0% for rubella. All children 4-6 years of age previously seronegative showed seroconversion for measles, mumps and rubella. Local adverse events were reported in 8.3-16.1% (12-23 months age) and 27.8-31.6% (4-6 years age), and 40.0-48.2% (12-23 months age) and 42.1-61.1% (4-6 years age) experienced at least more than 1 systemic adverse reaction. No vaccine-related serious adverse events were reported. Among the same age groups, there was no significant difference in adverse events between the two vaccines. CONCLUSION: The MMR vaccines are safe and show good immunogenic responses in children. These data will be invaluable when we introduce diverse vaccines in the following future.

Changes in air saturation and air-water interfacial area during surfactant-enhanced air sparging in saturated sand.

Reduction in the surface tension of groundwater, prior to air sparging for removal of volatile organic contaminant from aquifer, can greatly enhance the air content and the extent of influence when air sparging is implemented. However, detailed information on the functional relationship between water saturation, air-water contact area induced by air sparging and the surface tension of water has not been available. In this study, the influence of adding water-soluble anionic surfactant (sodium dodecyl benzene sulfonate) into groundwater before air sparging on the air-water interfacial area and water saturation was investigated using a laboratory-scale sand packed column. It was found that water saturation decreases with decreasing surface tension of water until it reaches a point where this trend is reversed so that water saturation increases with further decrease in the surface tension. The lowest water saturation of 0.58 was achieved at a surface tension of 45.4 dyn/cm, which is considered as the optimum surface tension for maximum de-saturation for the initially water-saturated sand used in this study. The air-water contact area generated in the sand column due to air sparging was measured using a gaseous interfacial tracer, n-decane, and was found to monotonically increase with decreasing water saturation. The results of this study provide useful design information for surfactant-enhanced air sparging removal of volatile contaminants from aquifers.

Immunogenicity and safety of a novel quadrivalent meningococcal conjugate vaccine (MenACWY-CRM) in healthy Korean adolescents and adults.

OBJECTIVES: This phase III placebo-controlled study evaluated the immunogenicity and safety of MenACWY-CRM vaccination in healthy Korean adolescents and adults. METHODS: Serum bactericidal activity with human complement (hSBA) was measured before and 1 month after vaccination against all four meningococcal serogroups. The IgG concentration specific for serogroup W capsular polysaccharide was measured in a subset of subjects in a post-hoc analysis. Adverse reactions were monitored throughout the study. RESULTS: Four hundred and fifty subjects were randomized 2:1 to receive MenACWY-CRM (N=297) or a saline placebo (N=153). MenACWY-CRM induced a good immune response against all four serogroups, with seroprotection rates (hSBA titers ≥8) of 79%, 99%, 98%, and 94% for serogroups A, C, W, and Y, respectively. Seroresponse rates were high for serogroups A, C, and Y, i.e. 76%, 86%, and 69%, respectively; the rate for serogroup W was 28%. MenACWY-CRM vaccine induced serum bactericidal antibodies against all four serogroups in a majority of subjects regardless of their baseline hSBA titers. MenACWY-CRM was generally well tolerated with most reactions being transient and mild to moderate in severity. CONCLUSIONS: Findings of this first study of a quadrivalent meningococcal polysaccharide conjugate vaccine in Korean adults and adolescents demonstrated that a single dose of MenACWY-CRM was well tolerated and immunogenic, as indicated by the percentages of subjects with hSBA titers ≥8 (79%, 99%, 98%, and 94% of subjects) and geometric mean titers (48, 231, 147, and 107) against serogroups A, C, W, and Y, respectively, at 1 month post-vaccination.

Varicella and varicella vaccination in South Korea.

With continuing occurrence of varicella despite increasing vaccine coverage for the past 20 years, a case-based study, a case-control study, and an immunogenicity and safety study were conducted to address the impact of varicella vaccination in South Korea. Varicella patients under the age of 16 years were enrolled for the case-based study. For the case-control study, varicella patients between 12 months and 15 years of age were enrolled with one control matched for each patient. For the immunogenicity and safety study, otherwise healthy children from 12 to 24 months old were immunized with Suduvax (Green Cross, South Korea). Fluorescent antibody to membrane antigen (FAMA) varicella-zoster virus (VZV) antibody was measured before and 6 weeks after immunization. In the case-based study, the median age of the patients was 4 years. Among 152 patients between 1 and 15 years of age, 139 children received varicella vaccine and all had breakthrough infections. Clinical courses were not ameliorated in vaccinated patients, but more vaccinated patients received outpatient rather than inpatient care. In the case-control study, the adjusted overall effectiveness of varicella vaccination was 54%. In the immunogenicity and safety study, the seroconversion rate and geometric mean titer for FAMA antibody were 76.67% and 5.31. Even with increasing varicella vaccine uptake, we illustrate no upward age shift in the peak incidence, a high proportion of breakthrough disease, almost no amelioration in disease presentation by vaccination, and insufficient immunogenicity of domestic varicella vaccine. There is need to improve the varicella vaccine used in South Korea.

Immunogenicity and safety of 13-valent pneumococcal conjugate vaccine given to korean children receiving routine pediatric vaccines.

BACKGROUND: The immunogenicity and safety of 13-valent and 7-valent pneumococcal conjugate vaccines (PCV13 and PCV7) were compared when administered with routine vaccines in Korea. METHODS: Healthy infants (n = 180) were randomly assigned (1:1) to receive PCV13 or PCV7 at 2, 4, 6 (infant series) and 12 months (toddler dose). Immune responses 1 month after the infant series and toddler dose were measured by enzyme-linked immunosorbent assay and opsonophagocytic activity (OPA) assay. IgG antibody geometric mean concentrations and OPA functional antibody geometric mean titers were calculated. Safety was assessed. RESULTS: After the infant series, for the 7 common serotypes, proportions of responders with IgG concentrations ≥0.35 µg/mL were comparable (≥97.6%) between groups; IgG geometric mean concentrations and OPA geometric mean titers were generally similar, but tended to be lower in the PCV13 group for some serotypes. For the 6 serotypes unique to PCV13, IgG geometric mean concentrations and OPA geometric mean titers were notably higher in the PCV13 group. Importantly, although PCV7 elicited IgG antibodies to PCV13 serotypes 5 and 19A, OPA responses were minimal, whereas serotype 6A elicited both IgG and OPA responses. These observations are consistent with at least some protection by PCV7 against 6A-mediated invasive pneumococcal disease, but no cross-protection for serotypes 5 and 19A. The toddler dose elicited higher IgG and OPA responses than postinfant series responses for most serotypes; however, for serotypes 3 and 14 only OPA responses were increased posttoddler dose. Vaccine safety profiles were similar. CONCLUSIONS: PCV13 is safe and immunogenic in Korean children. PCV13 should provide broader protection than PCV7.

Immunogenicity, reactogenicity and safety of a human rotavirus vaccine (RIX4414) in Korean infants: a randomized, double-blind, placebo-controlled, phase IV study.

Rotavirus (RV) infection is the primary cause for childhood gastroenteritis worldwide. In Korea, RV infection is most common among children less than 5 years of age. This post-licensure study was conducted to further evaluate the RV vaccine (RIX4414) to provide additional local clinical data to the Korean Food and Drug Association. Healthy infants aged 6-12 weeks were enrolled to receive two doses of either RIX4414 or placebo as per 0, 1-2 month schedule. Blood samples were collected before dose-1 and one month post-dose-2 of RIX4414/placebo to assess serum anti-RV IgA antibody concentrations using ELISA. Gastroenteritis stool samples were tested for the presence of RV using ELISA. RV positive samples were subjected to further analysis for G and P typing. Among 684 infants enrolled and vaccinated, 432 infants (RIX4414=318; placebo=114) were included in the according-to-protocol cohort for immunogenicity. The anti-RV IgA antibody seroconversion rates in the RIX4414 group following one month post-dose-2 were 88.1% (95% CI: 84.0-91.4) and the corresponding geometric mean concentration in the RIX4414 group was 208.5 U/ml (95% CI: 174.2-249.5). Occurrence of solicited and unsolicited adverse events were similar in both, RIX4414 and placebo groups. None of the gastroenteritis stool samples tested positive for RV and no fatal SAEs were reported in either groups. The two-dose regimen of RIX4414 was observed to be immunogenic with a similar safety profile as compared to the placebo group, when administered to healthy Korean infants.

Recommendation for use of the newly introduced pneumococcal protein conjugate vaccines in Korea.

Streptococcus pneumoniae remains a leading cause of invasive infections including bacteremia and meningitis, as well as mucosal infections such as otitis media and pneumonia among children and adults. The 7-valent pneumococcal conjugate vaccine (PCV7) was licensed for use among infants and young children in many countries including Korea. The routine use of PCV7 has resulted in a decreased incidence of invasive pneumococcal disease (IPD) by the vaccine serotypes among the vaccinees and substantial declines in IPD among unvaccinated populations such as older children and adults as well. In addition, there are increasing evidences to suggest that routine immunization with PCV7 is changing the epidemiology of pneumococcal diseases such as serotype distribution of IPD, nasopharyngeal colonization, and antibiotic resistance patterns. In contrast, there is an increase in the number of IPDs caused by nonvaccine serotypes, though it is much smaller than overall declines of vaccine serotype diseases. Several vaccines containing additional serotypes have been developed and tested clinically in order to expand the range of serotypes of Streptococcus pneumoniae. Recently two new pneumococcal protein conjugate vaccines, 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13), have been approved for use in several countries including Korea. This report summarizes the recommendations approved by the Committee on Infectious Diseases, the Korean Pediatric Society.

Recommendation for the use of newly introduced Tdap vaccine in Korea.

Pertussis is an acute respiratory infection characterized by paroxysmal cough and inspiratory whoop for over 2 weeks. The incidence of pertussis has decreased markedly after the introduction of DTwP/DTaP vaccine, but the incidence of pertussis has increased steadily among young infant and among adolescents and adults in many countries. Td vaccine was used in this age group but the increase in pertussis has lead to the development of a Tdap vaccine. The Tdap vaccine is a Td vaccine with a pertussis vaccine added and is thought to decrease the incidence and transmission of pertussis in the respective age group. In Korea, two products are approved by the KOREA FOOD & DRUG ADMINISTRATION, which are ADACEL™ (Sanofi-Pasteur, Totonto, Ontario, Canada) and BOOSTRIX® (GlaxoSmithKline Biologicals, Rixensart, Belgium) for those aged between 11-64. This report summarizes the recommendations approved by the Committee on Infectious Diseases, the Korean Pediatric Society.

Reemergence of mumps.

The mumps virus is a single-stranded, non-segmented, negative-sense RNA virus belonging to the Paramyxoviridae family. Mumps is characterized by bilateral or unilateral swelling of the parotid gland. Aseptic meningitis is a common complication, and orchitis is also common in adolescents and adult men. Diagnosis is based on clinical findings, but because of high vaccination coverage, clinical findings alone are not sufficient for diagnosis, and laboratory confirmation is needed. Mumps is preventable by vaccination, but despite high vaccination coverage, epidemics occur in several countries, including Korea. Many hypotheses are suggested for these phenomena. In this review, we investigate the reason for the epidemics, optimal methods of diagnosis, and surveillance of immunization status for the prevention of future epidemics.

[Evaluation of usefulness of the panel test composed of malaria non-specific tests as a surrogate marker].

BACKGROUND: Although malaria-specific antibody or antigen test is useful for the diagnosis of malaria infection, its cost-effectiveness has to be concerned in the area where malaria prevalence is very low. We created a panel test composed of malaria non-specific parameters, namely hematology autoanalyzer-derived results with or without addition of HDL-cholesterol data, and evaluated its usefulness in comparison with malaria-specific antibody test. METHODS: For 395 patients tested for malaria smear, the hematology parameters such as platelet count, NRBC (%) and VCS (volume, conductivity, scattering) parameters of WBC, and HDL-cholesterol data were analyzed. Statistical significance of each parameter and that of panel test with or without addition of HDL-cholesterol were evaluated. RESULTS: Malaria antibody test showed sensitivity of 97.1% and specificity of 99.1%. Each parameter of platelet count, NRBC (%), D parameter and HDL-cholesterol showed sensitivity of 86.8%, 41.2%, 81.8%, and 70.6%, and specificity of 85.9%, 96.3%, 72.3%, and 81.7%, respectively. Panel test without including HDL-cholesterol showed sensitivity of 91.2% and specificity of 81.6%, and that including HDL-cholesterol showed sensitivity of 91.2% and specificity of 86.2%. CONCLUSIONS: The malaria non-specific panel test composed of hematology autoanalyzer-derived parameters showed relatively good, but slightly lower sensitivity than that of malaria-specific antibody test. It might be used as a screening test for the diagnosis of malaria infection, and addition of HDL cholesterol improved little the usefulness of the panel test.

Measurement of gas-accessible NAPL saturation in soil using gaseous tracers.

In this laboratory study, a new experimental method involving the use of a set of four gaseous tracers, was developed for measuring the NAPL saturation directly accessible to the mobile gas as well as the total NAPL saturation in unsaturated sand. One tracer with low water solubility (n-pentane) was used as the tracerthat partitions into NAPL directly accessible to the mobile gas, and another (chloroform)tracer with moderate water solubility and NAPL-partitioning, was selected for detecting total NAPL saturation. Helium and difluoromethane were used as the nonreactive and water-partitioning tracers, respectively. A saturated hydrocarbon, n-decane, was used as NAPL. Column experiments were conducted attwo water saturations (Sw = 0.68 and 0.16). The total NAPL saturation and NAPL saturation not directly accessible to the mobile gas were also successfully measured using the combined results of tracer experiments. At Sw = 0.68, only 28% of the total NAPL was detected by n-pentane, whereas 87% of the total NAPL was accessible to n-pentane at Sw = 0.16, implying more NAPL was accessible to the mobile gas phase at lower water saturation.