Japanese Infants Research Articles

Evaluating the seasonality of growth in infants using a mobile phone application

It has been observed that growth velocity of toddlers and school children shows seasonal variation, while such seasonality is unknown in infants. The aim of this study was to examine whether growth velocity (length and weight) of infants differs by seasons. We assessed longitudinal measurement data obtained for 9,409 Japanese infants whose parents used the mobile phone application, “Papatto Ikuji”, during the period from January 2014 to October 2017. On average, each infant had 4.8 entries for length and 5.4 entries for weight. The mean daily change in sex- and age-adjusted z-scores between two time points was estimated as the growth velocity during that period: ΔLAZ/day and ΔWAZ/day for length and weight, respectively. We analyzed 20,007 ΔLAZ/day (mean, −0.0022) and 33,236 ΔWAZ/day (mean, 0.0005) measurements, and found that ΔLAZ/day showed seasonal differences with increases during summer. We conducted a multilevel linear regression analysis, in which effects of age, sex, nutrition and season of birth were adjusted, showing significant difference in ΔLAZ/day between winter and summer with a mean ΔLAZ/day difference of 0.0026 (95%CI 0.0015 to 0.0036; P < 0.001). This seasonal difference corresponded to 13% of the average linear growth velocity in 6-month-old infants. A modest effect of nutrition on linear growth was observed with a mean ΔLAZ/day difference of 0.0015 (95%CI 0.0006 to 0.0025; P < 0.001) between predominantly formula-fed infants and breastfed infants. In conclusion, we observed that linear growth, but not weight gain, of Japanese infants showed significant seasonality effects represented by increases in summer and decreases in winter.

The development of temperament and maternal perception of child: A cross-cultural examination in the United States and Japan

Previous research shows cross-cultural differences in adult personality and child temperament, yet the developmental origin of these cultural differences remains unclear. To understand a potential role of socialization grounded in cultural values, this study investigated culturally specific maternal perceptions of child and children's development of temperament in the U.S. and Japan. Maternal perception of child was assessed via maternal interview in the U.S. (n = 42) and Japan (n = 40). Six months after the interview, child's temperament was assessed. Cross-cultural differences in maternal perception of child and child's temperament, and the relation between the two were analyzed. US-American infants scored higher on the surgency/extraversion trait than Japanese infants, whereas Japanese infants scored higher on the negative affectivity/neuroticism trait than US-American infants. US-American mothers used more positive evaluation and private/autonomy descriptions of their infants, whereas Japanese mothers used more negative evaluation and context-specific descriptions of their infants by making references to other people, time, or location. Child's negative affectivity trait was closely related to maternal perception of child's social/context characteristics and negative evaluations. The findings provide support for the socio-cultural framework of temperament development and suggest an important consideration of cultural factors when designing educational and parenting programs.

Staphylococcus Agr virulence is critical for epidermal colonization and associates with atopic dermatitis development.

Atopic dermatitis (AD) is commonly associated with colonization by Staphylococcus aureus in the affected skin. To understand the role of S. aureus in the development of AD, we performed whole-genome sequencing of S. aureus strains isolated from the cheek skin of 268 Japanese infants 1 and 6 months after birth. About 45% of infants were colonized with S. aureus at 1 month regardless of AD outcome. In contrast, skin colonization by S. aureus at 6 months of age increased the risk of developing AD. Acquisition of dysfunctional mutations in the S. aureus Agr quorum-sensing (QS) system was primarily observed in strains from 6-month-old infants who did not develop AD. Expression of a functional Agr system in S. aureus was required for epidermal colonization and the induction of AD-like inflammation in mice. Thus, retention of functional S. aureus agr virulence during infancy is associated with pathogen skin colonization and the development of AD.

Serum 25-Hydroxy Vitamin D Levels in Japanese Infants with Respiratory Syncytial Virus Infection Younger than 3 Months of Age.

Low blood levels of vitamin D have been reported in children who have frequent respiratory tract infections. We measured serum concentrations of 25-hydroxy (OH) vitamin D in Japanese infants under 3 months of age who had respiratory syncytial virus (RSV) infection. Serum levels of 25-OH vitamin D in the 10 infants, excluding those with underlying diseases, were between < 4 and 29.8 ng/mL. In 8 out of 10 subjects (80.0%), serum 25-OH vitamin D levels were lower than 20 ng/mL. There was no statistically significant association between the levels of 25-OH vitamin D and age, duration of admission, respiratory severity score, white blood cell count, blood gas levels, and N-terminal pro-natriuretic peptide levels. Levels of serum 25-OH vitamin D in children who required hospitalization owing to RSV infection were low, indicating deficiency. These results suggest that vitamin D deficiency affects the susceptibility to RSV infection, but not the severity of the infection.

Season of birth is associated with increased risk of atopic dermatitis in Japanese infants: a retrospective cohort study

BackgroundSeveral epidemiological studies have examined the possibility of a relationship between season of birth and atopic dermatitis (AD) and food allergy (FA), yet their results are contradictory. We investigated the association between season of birth and risk of AD and FA in Japanese infants.MethodsStudy subjects were 612 newborn infants born at a single obstetric/pediatric clinic without perinatal diseases. Season of birth was classified as spring (March–May), summer (June–August), autumn (September–November) or winter (December–February). AD was diagnosed according to the United Kingdom Working Party’s criteria. FA was defined as present if there was a history of immediate allergic symptoms within 2 h after ingestion of a food. Specific IgE to the corresponding food was also assessed to support the diagnosis. We assessed the association between season of birth and risk of AD and FA using Cox proportional hazard models.ResultsWe identified a total of 365 cases of AD occurring during 3659 person-months of follow-up. Compared with summer birth, autumn, winter, and spring birth were significantly positively associated with the risk of AD: adjusted HRs (95% CIs) were 2.67 (1.96–3.63), 1.42 (1.03–1.95), and 1.43 (1.04–1.98), respectively. We identified a total of 23 cases of physician-diagnosed FA occurring during 6815 person-months of follow-up.ConclusionsBeing born in the summer is associated with a lower risk of AD compared to other seasons of birth. The low incidence of FA in our cohort group made it difficult to establish a valid association between FA and season of birth as the statistical power was low.

Maternal prenatal stress and infantile wheeze and asthma: The Osaka Maternal and Child Health Study

ObjectiveSome recent studies suggest that maternal prenatal stress (MPS) increases allergic diseases in the children. However, knowledge on this issue in Asian children are lacking. We investigated the association between MPS and the risks of wheeze and asthma in Japanese infants aged 16–24 months. MethodsThe present subjects were 763 Japanese mother–child pairs. The first, second, and third surveys based on self-administered questionnaires were performed during pregnancy, between 2 and 9 months postpartum, and from 16 to 24 months postpartum, respectively. Data on MPS was obtained in the first survey, using the Stress Inventory (SI), which constructs 12 specific behavioral patterns as response styles to stressors. Data on wheeze and asthma was obtained in the third survey, where wheeze was based on the International Study of Asthma and Allergies in Childhood criteria and asthma was based on doctors' diagnosis. ResultsThere were 169 infants with wheeze (22.1%) and 33 infants with asthma (4.3%), at the time of the third survey. Multiple logistic regression analyses found that a maternal behavioral pattern characterized by chronic irritation and anger was associated with the risk of childhood asthma (adjusted odds ratio [OR] = 1.56, 95% confidence interval [CI]: 1.11 to 2.22), but not wheeze (adjusted OR = 1.02, 95%CI: 0.88 to 1.19), while there was no appreciable association between the other SI scales and the risk of childhood wheeze or asthma. ConclusionsThe results partly supported the hypothesis that MPS might increase the risk of asthma in their infants in Japanese.

Immunogenicity and safety of a DTaP-IPV/Hib pentavalent vaccine given as primary and booster vaccinations in healthy infants and toddlers in Japan

BackgroundGlobally, the use of single DTaP-IPV/Hib vaccines that combine DTaP-IPV and Hib is widespread, but in Japan vaccination is usually concomitant at separate sites. The immunogenicity and safety of a primary vaccination series and booster of a combined pentavalent DTaP-IPV/Hib vaccine were evaluated and compared to separate administration of DTaP-IPV and Hib in Japanese infants. MethodsHealthy Japanese infants were administered DTaP-IPV/Hib (Group A: N = 207) or DTaP-IPV + Hib (Group B: N = 207) by the subcutaneous (SC) or DTaP-IPV/Hib by the intramuscular (IM) route (Group C: N = 10). All subjects received a 3-dose primary vaccination series and a booster. Non-inferiority (Group A versus Group B) was tested post-primary series and subsequent post hoc analyses were performed for anti-Hib. Safety was assessed by parental reports. ResultsNon-inferiority for SC administration of Group A versus Group B for the primary series was demonstrated for antibody responses to all antigens except Hib using the threshold of 1.0 μg/mL. Post hoc analyses for anti-Hib demonstrated non-inferiority for the primary series response using 0.15 μg/mL, and for pre-booster antibody persistence and the booster response using 0.15 μg/mL and 1.0 μg/mL. The immune response was similar for each antigen following SC or IM administration. There were no safety concerns in any group, and a lower incidence of injection sites for the IM route was observed as expected. ConclusionsThese data show the good immunogenicity and safety profile of the DTaP-IPV/Hib vaccine as a 3-dose infant primary series followed by a booster in the second year of life in Japan.

Immune thrombocytopenic purpura risk by live, inactivated and simultaneous vaccinations among Japanese adults, children and infants: a matched case-control study.

This case–control study investigated immune thrombocytopenic purpura (ITP) risk following live, inactivated, and simultaneous vaccination, with a focus on infants aged < 2 years. We matched case patients with ITP to one or two control patients with other diseases by institution, hospital visit timing, sex, and age. We calculated McNemar’s pairwise odds ratios (ORs [95% confidence interval]) with 114 case–control pairs. The case group had 27 (44%) males and 22 (35%) infants, and the control group included 49 (43%) males and 42 (37%) infants. For all age groups, the McNemar’s OR for ITP occurrence was 1.80 (0.54–6.84, p = 0.64) for all vaccines. Among infants, these were 1.50 (0.17–18.0, p = 0.50) for all vaccines, 2.00 (0.29–22.1, p = 0.67) for live vaccines, and 1.00 (0.01–78.5, p = 0.50) for inactivated vaccines. Sex-adjusted common ORs for simultaneous vaccination were 1.52 (0.45–5.21, p = 0.71) for all vaccines, 1.83 (0.44–7.59, p = 0.40) for inactivated vaccines only, and 1.36 (0.29–6.30, p = 0.69) for mixed live and inactivated vaccines. In infants, these were 1.95 (0.44–8.72, p = 0.38), 1.41 (0.29–6.94, p = 0.67) and 2.85 (0.43–18.9, p = 0.28), respectively. These limited data suggest no significant ITP risk following vaccinations or simultaneous vaccination in any age group, including infants.Electronic supplementary materialThe online version of this article (10.1007/s12185-020-02866-1) contains supplementary material, which is available to authorized users.

Neurodevelopmental outcomes following intravitreal bevacizumab injection in Japanese preterm infants with type 1 retinopathy of prematurity.

PurposeThe purpose of this study was to evaluate neurodevelopmental outcomes in 18-month old (corrected age) preterm infants who received an intravitreal bevacizumab (IVB) injection for the treatment of type 1 retinopathy of prematurity (ROP).MethodsIn this ten-year retrospective study, we reviewed the medical records of patients who underwent ROP screening at Kyushu University Hospital. Among the patients who received IVB or laser photocoagulation (LPC) for the treatment of type 1 ROP, we included infants whose neurodevelopmental examination (the Kyoto Scale of Psychological Development [KSPD]) results at 18 months corrected age were available. Then, the effect of IVB on the developmental quotient (DQ) in each KSPD domain (Postural-Movement, Cognitive-Adaptive, or Language-Social domain) or the overall DQ was investigated by performing linear regression analysis.ResultsOut of the 513 patients reviewed, 53 were included in the study. IVB and LPC were performed for 14 and 39 patients, respectively. Administration of IVB was significantly associated with neurodevelopmental delay in the Language-Social domain (p = 0.01). The observed association remained even after adjusting for gestational age and birth weight (p = 0.03).ConclusionsAdministration of IVB may introduce a risk of developmental impairment of interpersonal relationships, socializations, and/or verbal abilities of preterm children. We recommended that preterm infants who received IVB undergo a neurodevelopmental reassessment during their school years or in adulthood.

Intravenous fat induces changes in PUFA and their bioactive metabolites: Comparison between Japanese and Australian preterm infants

ObjectiveOxylipins are biologically active signaling molecules that initiate and resolve inflammation; they are synthesized by oxidation of polyunsaturated fatty acids (PUFAs) and reflect PUFA intake and status. The PUFA intake in preterm infants differs between countries because of the type of lipid emulsions used and the PUFA content of breast milk. We compared total blood PUFA, free PUFA and their oxylipin levels in dried whole blood samples from preterm infants born in Australia and Japan. MethodsWe enrolled 30 and 14 preterm infants born less than 31 weeks’ gestation, from Adelaide and Japan respectively. Blood samples were obtained from cord blood, and on postnatal days 4, 7, 14 and 28. Total PUFAs were measured using gas chromatography, while free fatty acids and oxylipins were screened using ultra high-performance liquid chromatography mass spectroscopy. ResultsDifferences in the levels of blood PUFA between the centres were found which were in line with the timing and type of lipid emulsion administration. Significant differences in longitudinal levels were seen more often in free PUFA and their oxylipins than in total blood PUFA. This was particularly true for AA and DHA. In contrast, differences in the levels could be seen in total blood EPA, as well as in free EPA and its oxylipins. Further, levels of many free PUFA and their oxylipins were higher in Japanese infants than in Australian infants. ConclusionDifferences in total and free fatty acids and unesterified oxylipins, were observed during the first weeks of life and between preterm infants born in Australia and Japan, which were likely a reflection of the type of lipid emulsion and timing of administration. The clinical significance of these changes remains to be explored.

Associations of erythrocyte fatty acid compositions with FADS1 gene polymorphism in Japanese mothers and infants

Long-chain polyunsaturated fatty acids (LC-PUFAs) are involved in the fetal growth in utero, and are essential for the development of visual and cognitive functions during infancy. The purpose of this study was to examine the associations of erythrocyte fatty acid compositions with FADS1 gene polymorphism in Japanese mothers and infants. The subjects were 383 mothers who participated in an adjunct birth cohort study of the Japan Environment and Children's Study (JECS). In maternal FADS1 SNP genotypes, the precursor fatty acids composition of the Δ5 desaturase in the maternal blood showed significant differences in levels among the groups, and showed increasing values in the order of TT < TC < CC genotype groups. On the other hand, many product fatty acids levels were significantly reduced in the order of TT > TC > CC genotype groups, and DHA levels were significantly lower in the CC genotype group relative to the other groups. Likewise, the relationship between fetal genotype group and fatty acid composition in cord blood was very similar to the maternal relationship. These results indicate the maternal and fetal blood fatty acid compositions are strongly influenced by the FADS1 genotypes. With respect to the cord blood DHA composition, the levels in the fetal CC genotype group showed a trend toward lower values in the maternal CC genotype group pair (p = 0.066) compared to the maternal TC genotype group pair. However, in the fetal TT and TC genotype groups (p = 0.131, p = 0.729, respectively), the maternal genotype did not have a significant effect. The DHA composition was more influenced by the maternal genotype in the fetal CC genotype group than in the fetal TT and TC genotype groups. It was shown that DHA transport via the placenta from the mother might be promoted in the fetal CC genotype compared to the other fetal genotype groups. In conclusion, differences in the FADS1 SNP genotypes of pregnant women and their children may greatly affect the supply of LC-PUFAs. Further studies on the involvement of the FADS1 polymorphisms and the fetal LC-PUFA levels in the fetal growth and development are warranted.

Congenital nasolacrimal duct obstruction continues trend for spontaneous resolution beyond first year of life

PurposeTo investigate spontaneous resolution of congenital nasolacrimal duct obstruction (CNLDO) beyond 12 months of age in Japanese infants.MethodsRetrospective, observational case series. We retrospectively reviewed the clinical records of patients diagnosed...

Language-general and language-specific influences on Dutch and Japanese infants’ perception of place of articulation

Perceptual asymmetries provide a window into the role of language-general biases and language-specific experiences in early phonetic development. We assessed infant perception of two asymmetries related to coronal place of articulation and documented across the inventories of languages. To disentangle the role of language-general tendencies and experiential factors, we compared early perception of infants learning Dutch (where the input is consistent with language-general tendencies) and Japanese (where this is not the case). First, we document that both Dutch and Japanese infants start out with asymmetric discrimination of labial-coronal consonant contrasts consistent with language-general predictions at 4–6 months of age, but that, consistent with input-based predictions, this pattern declines in Japanese, but not Dutch toddlers by 18 months of age. Second, we show that infants from both language groups develop phonotactic preferences consistent with their input but with different timelines, with French infants developing a labial-coronal preference by 10 months, and Japanese infants a delayed coronal-labial preference by 13 months of age. Together, these results demonstrate that language-specific input characteristics start overriding language-general tendencies, but also suggest that these language-general tendencies continue playing a role in perception. We speculate about sources of these biases on the acoustic, perceptual, and articulatory level.

The association between gut microbiota development and maturation of intestinal bile acid metabolism in the first 3 y of healthy Japanese infants

ABSTRACTThe gut microbial community greatly changes in early life, influencing infant health and subsequent host physiology, notably through its collective metabolism, including host–microbiota interplay of bile acid (BA) metabolism. However, little is known regarding how the development of the intestinal microbial community is associated with maturation of intestinal BA metabolism. To address this, we monitored the succession of gut bacterial community and its association with fecal BA profile in the first 3 y of ten healthy Japanese infants. The BA profiles were classified into four types, defined by high content of conjugated primary BA (Con type), unconjugated primary BA (chenodeoxycholic acid and cholic acid) (Pri type), ursodeoxycholic acid (Urs type), and deoxycholic and lithocholic acid (Sec type). Most subjects begun with Con type or Pri type profiles during lactation and eventually transited to Sec type through Urs type after the start of solid food intake. Con type and Pri type were associated with Enterobacteriaceae-dominant microbiota corresponding to the neonatal type or Bifidobacterium-dominant microbiota corresponding to lactation type, respectively. Urs type subjects were strongly associated with Ruminococcus gnavus colonization, mostly occurring between Pri type and Sec type. Sec type was associated with adult-type complex microbiota dominated by a variety of Firmicutes and Bacteroidetes species. Addressing the link of the common developmental passage of intestinal BA metabolism with infant’s health and subsequent host physiology requires further study.

Genetic and Serological Diversity of Chlamydia trachomatis Strains Detected from Japanese Infants

Background: Classical fifteen serovars and variants of Chlamydia trachomatis were originally classified by the micro-immunofluorescence test which principally distinguished epitopes on the major outer-membrane protein (MOMP). The sequences of MOMP gene including four variable domains (VDs) have been determined for all classic 15 serovars. The PCR assay was used to amplify a large part of the MOMP gene (ompA or omp1) including four VDs and then cataloged restriction fragment length polymorphism (RFLP) was used to identify the serovars from genotypes of C. trachomatis as reported previously. Materials and Methods: Nasopharyngeal specimens were collected from 15 Japanese infants with pneumonia, from 1 month to 1 year old, during the period May 1990 to September 2013. Conjunctival swabs were also collected from 12 Japanese neonates under 1 month old with inclusion conjunctivitis during the same period. The specimens were collected and placed into Abbott LCR proprietary medium and then tested by PCR for typing. The sequencing strategy used was the double-stranded DNA cycle sequencing method. Results: Applied to 15 reference strains, this PCR-RFLP procedure allowed us to determine 13 of the 15 serovars of C. trachomatis. Thirteen of 15 isolates of nasopharyngeal origin and 11 of 12 isolates of conjunctival origin could be un-equivocally assigned to one of the 15 reference serovars with a restriction endonuclease profile identical to that of the prototype. The typing of 15 nasopharyngeal isolates gave the following results: 11 as E, 2 as H, and 2 as unclassified serovars. The typing of 12 conjunctival isolates gave the following results: 5 as D, 4 as E, 1 as F, 1 as H and 1 as unclassified serovar. Among the unclassified serovars, one was B-like and the rest was D-like. Discussion: The sequences of MOMP gene for all classic 15 serovars allowed the construction of restriction endonuclease cleavage-site maps that confirm the fragment-size patterns observed by electrophoresis. Sequencing the entire MOMP gene and cataloging the sequences of VDs of all serovars has confirmed the molecular basis of the serotyping procedure and provided a method for determining serovars by PCR-RFLP. Although geno-variants have also been reported for most serovars the PCR-RFLP method for typing allows quick and objective identification of serovars of C. trachomatis. Antigenic variations of C. trachomatis were also considered among the strains from nasopharyngeal and conjunctival origins.

Incidence and Neonatal Risk factors of Short Stature and Growth Hormone treatment in Japanese Preterm Infants Born Small for Gestational Age

Incidence and neonatal risk factors for short stature in preterm children born small for gestational age (SGA) have not been fully investigated in Japan. In this prospective study, infants born ≤32 weeks’ gestational age (GA) from 2004–2015 were enrolled and followed for 3 years. Incidence of short children born SGA and short stature treated with growth hormone (GH) were investigated. Neonatal risk factors were analysed using univariate and multivariate analyses. GA cut-off value was determined using receiver operating characteristic (ROC) curve analyses. Of 604 infants born ≤32 weeks’ GA, 76 (13%) were SGA at birth. Twenty-seven infants (36%) developed short stature at age 2 and 14 infants (19%) received GH treatment at age 3. GA, birthweight, birth length, birth head circumference, and chronic lung disease at 36 weeks’ corrected GA were determined as risk factors by univariate analyses (p < 0.01). Multivariate analyses only revealed low GA as an independent risk factor. ROC curve analysis determined a cut-off value of 24 weeks’ GA. Nineteen percent of preterm SGA infants ≤32 weeks’ GA developed short stature treated with GH. A low GA at birth could be an early detection marker for short stature that requires GH treatment in preterm infants born SGA.

Diversity of human parechovirus in infants and children with acute gastroenteritis in Japan during 2014–2016

A total of 972 stool samples were collected from infants and children with acute gastroenteritis (AGE) in pediatric clinics encompassing six localities (Hokkaido, Tokyo, Shizuoka, Kyoto, Osaka, and Saga) in Japan during the 2-year period from July 2014 to June 2016. Sixty six of the samples (6.8%) were found to be positive for human parechovirus (HPeV) by multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) and subjected to genotyping based on viral protein 1 (VP1) sequences. Four different HPeV genotypes consisting of HPeV1, -3, -4 and -6 were detected, with HPeV1 clade B being predominant and followed by HPeV3 and -6. The first-time presence of HPeV1 clade A in Japan and rare HPeV4 were noted. This study provides up-to-date information on the genetic diversity of HPeV circulating in Japanese infants and children with AGE.

Clinical Evaluation of 1,000-Hz Tympanometry for the Diagnosis of Exudative Otitis Media in Japanese Infants

Clinical Evaluation of 1,000-Hz Tympanometry for the Diagnosis of Exudative Otitis Media in Japanese Infants

Prevalence of infant and maternal anemia during the lactation period in Japan.

The perinatal period is associated with a high risk of infant anemia. The aim of the present study was to determine the prevalence of infant and maternal anemia during the late lactation period and the risk factors for anemia in Japan. This retrospective cohort study was based on data from health checkups of healthy infants at 6-7 and 9-10 months of age and their mothers who visited Akitsu Children's Clinic between September 2013 and August 2015. Complete blood count data from infant blood samples obtained at 6-7 months and 9-10 months and from maternal blood samples obtained at 6-7 months, information on feeding methods, and other related parameters were analyzed. Data from 388 mother-infant pairs were analyzed. The prevalence of infant anemia was 21.1% at 6-7 months and 29.1% at 9-10 months. The prevalence of anemia in exclusively breast-fed infants was 28.4% at 6-7 months and 40.0% at 9-10 months. The risk factors for infant anemia at 9-10 months were exclusive breast-feeding, lower gestational age at birth, male sex, and high weight gain. The prevalence of maternal anemia was 10.5%. There was no correlation between infant and maternal hemoglobin in exclusively breast-fed infants. Japanese infants who were breast-fed exclusively had a high prevalence of anemia. A nationwide strategy to prevent anemia is required to prevent infant anemia, even in a nutrition-rich country such as Japan.

Immunogenicity and safety of the diphtheria, pertussis, tetanus and inactivated poliovirus vaccine when co-administered with the human rotavirus vaccine (Rotarix) in healthy Japanese infants: a phase IV randomized study

ABSTRACT Rotavirus infections have been reported to account for 40–50% of all hospitalized acute gastroenteritis cases in young children (<5 years) in Japan. Since 2011, Rotarix containing the live attenuated human rotavirus RIX4414 strain (HRV) has been licensed in Japan for infants. Vaccination against rotavirus is optional in Japan whereas administration of diphtheria, pertussis, tetanus, and inactivated poliovirus (DPT-IPV) vaccine is part of the national routine immunization program. In this open-label, randomized, controlled, multicenter study, we evaluated the immunogenicity and safety of the DPT-IPV vaccine (Squarekids) administered concomitantly or staggered with the liquid HRV (Rotarix) vaccine in healthy Japanese infants. A total of 292 infants aged 6–12 weeks were randomly assigned to receive DPT-IPV vaccine and HRV vaccine co-administered (n = 147) or staggered (n = 145). Immune responses to DPT-IPV vaccine were evaluated by measuring the post-vaccination serum antibody titers/concentrations to each antigen at one month following the third dose of DPT-IPV vaccine. Seroprotection/seropositivity against each of the diphtheria, pertussis (pertussis toxin and filamentous hemagglutinin), tetanus, and poliovirus type 1, 2 and 3 antigens was 92.8% or higher in both groups. In terms of immunogenicity, DPT-IPV vaccine co-administered with HRV vaccine was shown to be non-inferior to DPT-IPV vaccine with a staggered administration. The safety profile was comparable in the two vaccine groups with no vaccine-related serious adverse events, no deaths and no cases of intussusception. These results support co-administration of HRV vaccine with DPT-IPV vaccine in Japan. ClinicalTrials.gov NCT02907216