[Rubella immunity in Japanese women of childbearing age, 2008-2013: commercial diagnostic laboratory data analysis].

BACKGROUND: For effective non-routine vaccination in women of childbearing age as a countermeasure against congenital rubella syndrome (CRS), it is important to know the specific age group in which fewer members have rubella immunity. METHODS: We analyzed rubella hemagglutination-inhibition (HI) antibody data (about 890,000) accumulated from 2008 through 2013 at a commercial diagnostic laboratory, which originated from the serum specimens sent mainly from obstetrics & gynecology clinics and hospital departments in Japan. Changes during the above period in the pattern of the annual curve for the prevalence of rubella antibodies (HI antibody titer > or = 8) by age, were observed. RESULTS: The antibody prevalence among women in their twenties decreased gradually from 2008 to 2013. However, the prevalence at < or = 22 years of age in the 2013 specimens was found to have risen, which we believe is the effect of the five-year interim vaccination program for high-school students that began in 2008. The lowest antibody prevalence at 23 years of age in 2013 corresponded to the highest numbers of female patients at the same age in the 2013 rubella epidemic among the adult population. CONCLUSIONS: The analysis of extensive data accumulated for rubella antibodies assayed at the commercial diagnostic laboratory was useful for monitoring the susceptibility of the women to rubella infection in Japan, and that the Oct. 1987 to Mar. 1990 birth cohort (age 23 - 25 in 2013) is a high-risk group for CRS.

[Rubella immunity in Japanese women 20- 39-years-old, 1999-2007: commercial diagnostic laboratory data analysis].

We analyzed rubella antibody data from hemagglutination-inhibition tests on 600,000 serum specimens from Japanese women 20- 39-years-old. Specimens had been sent by gynecology clinics nationwide to a commercial diagnostic laboratory from 1999 through 2007. Antibody-positive percentages in women in their 20s to mid 30s in 1999 to 2001 were 95%, while those in women in their early 20s from 2002 to 2007 were lower at 88% among 20-year-olds in 2002 born in 1982 and 86% among those in 2007 born in 1987. These lower percentages resulted from a change in rubella vaccination policy under which junior high school girls between 1977 and 1994-those born between 1962 and 1981-underwent mandatory rubella vaccination, while mandatory vaccination was administered to younger children, instead, from 1995. Due to this policy change, girls born between 1982 and 1987 were not subjected to mandatory vaccination. We believe that women in this group have a relatively higher risk of bearing children with congenital rubella syndrome (CRS). Additional campaigns for voluntary rubella vaccination should thus be addressed to this female cohort.

Analysis of herpes simplex virus type 1 restriction fragment length polymorphism variants associated with herpes gladiatorum and Kaposi's varicelliform eruption in sumo wrestlers.

The geographical distribution of herpes simplex virus type 1 (HSV-1) restriction fragment length polymorphism (RFLP) variants BgK(L) and BgO(L) and the high relative frequency (RF) of BgK(L) in orolabial lesions has led to a dispersion-replacement hypothesis for these variants. The pathogenic properties of HSV-1 variants in mice and professional sumo wrestlers were examined here. The wrestlers herpes gladiatorum (HG) was caused by primary and non-primary HSV-1 infections and recurred in many wrestlers. HSV-1 neutralizing antibody titres in sera from wrestlers who did not develop HG were relatively high. HG was caused by distinct HSV-1 variants and strains from wrestlers living in the same sumo stable. The BgK(L) RF was significantly higher in HG cases, particularly in those with Kaposi's varicelliform eruption. These data indicated that reactivation and transmission of latent HSV-1 infections, especially BgK(L), occurred frequently among wrestlers and was caused by severe skin damage. These results support the BgK(L) dispersion hypothesis.

[2007 measles outbreaks among Tokyo youths: analysis of data on serum IgM antibody detection at a commercial diagnostic laboratory].

We analyzed data on measles-specific serum IgM detection at a commercial diagnostic laboratory in outbreaks among youths in the greater Tokyo area in 2007. Trends in monthly numbers of IgM antibody-positive specimens from persons aged > or =15 or <15 years from January 2000 to June 2007 corresponded well to weekly numbers of adult or pediatric patients per sentinel hospital or clinic as reported by the National Epidemiological Surveillance of Infectious Diseases (NESID). In 2007, the number of IgM-positive specimens greatly increased, mainly peaking at ages 0-1 and 18-30 years. The largest number occurred at 18 years, and the number of IgM-positive specimens in the > or =15 years group was 41% larger among males than females. The proportion of IgM-positive specimens among hospitalized patients was 22% in the >15 years or = group and 11% in the < 15 years group.

[Detection of IgM antibody to Epstein-Barr virus, 1999-2006: analysis of data collected at a commercial diagnostic laboratory in Japan].

The status of infectious mononucleosis in Japanese youth has been little studied. To gain more information, we analyzed data from tests for Epstein-Barr virus-specific IgM in about 180,000 serum specimens sent to a commercial diagnostic laboratory from clinics nationwide between 1999 and 2006. The IgM antibody to the viral capsid antigen (VCA) was assayed by indirect immunofluorescence with P3HR-1 cells. In an age-distribution graph of IgM positive specimens, two peaks were found both in young children and youth. Boys outnumbered girls in the group of children aged 0 to 3, and vice versa in the group of youth aged 15 to 25. IgM-positive specimens increased from spring to autumn only in the youth group, suggesting that infectious mononucleosis in this group occurs more during this time. Infectious mononucleosis symptoms are more severe in youth, and further epidemiological studies are needed to clarify the disease status in young Japanese adults.

[IgM antibody detection in acute viral diseases, 1995-2004: analysis of data collected at a commercial diagnostic laboratory in Japan].

We analyzed data from tests for virus-specific IgM in 376,000 serum specimens sent to a commercial diagnostic laboratory from clinics nationwide between 1995 and 2004. IgM antibodies to measles, rubella, mumps, parvo B19, and varicella-zoster viruses were tested using IgM-capture ELISA kits. Among specimens, 254,000 (68%) had documentation of age, of which 56% were sera from persons<20 and 44%> or = 20 years of age. Monthly or yearly trends in IgM antibody-positive tests in<20 year-old persons were similar to those in pediatric patients per sentinel clinic reported by the National Epidemiological Surveillance of Infectious Diseases (NESID), which collects weekly numbers of patients with designated infectious diseases from 3000 pediatrics clinics nationwide. Patterns of changes in monthly IgM positive tests in both < 20 and > or = 20 y specimens were similar, indicating that infections occur simultaneously in both children and adults. Adult IgM-positive specimens came from internal medicine clinics and from dermatology clinics for measles; from dermatology and obstetrics clinics for rubella and parvo B19; from otolaryngology clinics for mumps; and from dermatology and otolaryngology clinics for varicella-zoster virus. Analysis of large numbers of IgM test results at regular intervals may contribute to understanding of the epidemiology of these viral diseases in Japan.

The herpes simplex virus type 1 BgKL variant, unlike the BgOL variant, shows a higher association with orolabial infection than with infections at other sites, supporting the variant-dispersion-replacement hypothesis.

The identification and geographic distribution of the herpes simplex virus type 1 (HSV-1) BglII restriction fragment length polymorphism (RFLP) variants named BgK(L) and BgO(L) in clinical isolates from orolabial and cutaneous sites were described in our previous reports, in which the dispersion and replacement of HSV-1 variants were proposed. The base substitution sites deduced from the BgK(L) multiple RFLP variations were mapped to the U(L)12 (DNase), R(L)2 (alpha0 transactivator), and latency-associated transcript genes in the present study. The results show that the relative frequencies (RFs) of BgK(L) are significantly higher in orolabial and cutaneous HSV-1 infections than in ocular infections. For the BgO(L) variant, the opposite was found; i.e., the RF of BgO(L) was significantly lower in orolabial and cutaneous infections than in ocular infections. No significant differences in the RFs of non-BgK(L):non-BgO(L) isolates were observed. The ratio of the BgK(L) RF to the BgO(L) RF was much higher for the orolabial and cutaneous infection groups than for the ocular infection group, whereas the BgK(L) RF-to-non-BgK(L):non-BgO(L) RF ratios for the former groups were slightly higher than those for the latter group. The higher efficiency of orolabial and cutaneous infections caused by BgK(L) compared to the efficiency of infections caused by BgO(L) allows BgK(L) to spread more efficiently in human populations and to displace BgO(L), because the mouth and lips are the most common HSV-1 infection sites in children. The present study supports our HSV-1 dispersion-and-replacement hypothesis and suggests that HSV-1, the latency-reactivation of which allows variants to accumulate in human populations, has evolved under competitive conditions, providing a new perspective on the polymorphism or variation of HSV-1.

Maintenance of serum immunoglobulin G antibodies to Epstein-Barr virus (EBV) nuclear antigen 2 in healthy individuals from different age groups in a Japanese population with a high childhood incidence of asymptomatic primary EBV infection.

Immunoglobulin G (IgG) antibodies to Epstein-Barr virus (EBV) nuclear antigens 2 and 1 (EBNA-2 and EBNA-1, respectively) were studied using sera from healthy individuals of a population with a high incidence of asymptomatic primary EBV infections during infancy or childhood in Japan. Two CHO-K1 cell lines expressing EBNA-2 and EBNA-1 were used for anticomplement and indirect immunofluorescence assays. The positivity rate for EBNA-2 IgG rose in the 1- to 2-year age group, increased and remained at a plateau ( approximately 45%) between 3 and 29 years of age (3- to 4-, 5- to 9-, 10- to 14-, and 15- to 29-year age groups), and then reached 98% by age 40 (>/== 40-year age group). Both seropositivity for EBNA-1 and seropositivity for EBNAs in Raji cells (EBNA/Raji) were detected in the 1- to 2-year age group, remained high, and finally reached 100% by age 40. The geometric mean titer (GMT) of EBNA-2 IgG reached a plateau in the 5- to 9- and 10- to 14-year-old groups and remained elevated in the older age groups (15 to 29 and >/== 40 years). The GMT of EBNA-1 IgGs increased to a plateau in the 1- to 2-year-old group and remained unchanged in the older age groups. The GMT of EBNA/Raji IgGs also reached a plateau in the 1- to 2-year-old group, remained level throughout the 3- to 14-year age groups, and decreased in the 15- to 29-year-olds. EBNA-2 IgGs emerged earlier than EBNA-1 IgGs in 8 of 10 patients with infectious mononucleosis, who were between 1 and 27 years old, and declined with time in three of eight cases. These results suggest that EBNA-2 IgG antibodies evoked in young children by asymptomatic primary EBV infections remain elevated throughout life, probably because of reactivation of latent and/or exogenous EBV superinfection.