Childhood Hygiene Research Articles

Clinical Study and Microbiological Analysis of Periodontopathogenic Microflora Analyzed among Children and Adolescents with Cardiovascular Diseases Compared to Group with Good General Status.

Periodontal diseases, as an important part of oral pathology, present different characteristics when affecting children and adolescents or young adults. Studies have shown that adolescence and childhood are closely related to a high risk of periodontal disease, but the follow-up for periodontal health or damage at this age has been insufficiently appreciated until now. The aim of this study was to identify subgingival microorganisms using a real-time polymerase chain reaction (PCR) in a group of children and adolescents aged 7-17 years with and without cardiovascular disease. The group of 62 subjects with gingival inflammation and poor hygiene was divided into two groups according to general condition: 31 subjects with carduivascular disease (group A) and 31 subjects without cardiovascular disease (group C). Subjects were examined in the initial consultation, the state of hygiene and periodontal inflammation was assessed using the plaque index (PI) and gingival index (GI), and samples were taken from the gingival sulcus using sterile paper cones to determine nine subgingival microorganisms. Nine subgingival microorganisms were identified: Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythias (Tf), Prevotella intermedia (Pi), Peptostreptococcus (Micromonas) micros (Pm), Fusobacterium nucleatum (Fn), Eubacterium nodatum (En), and Capnocytophaga gingivalis (Cg). The patients were included in a specialist treatment program which aimed to relieve the inflammatory condition, remove local irritative factors, and train the patients to perform proper oral hygiene at home by using primary and secondary oral hygiene products. Subjects were reevaluated 3 months after treatment, when measurements for the PI and GI and microbiological determinations were repeated. The results showed a predominance of subjects aged 16-17 years (12.4%). Among the subjects with marked gingival inflammation, the male gender was predominant (58.06%). The PI values changed considerably after treatment, with lower values in patients presenting a general condition without cardiovascular disease (PI = 8.10%) compared with the patients with cardiovascular disease (PI = 13.77%). After treatment, the GI showed considerable changes in both groups. Red, orange, and purple complex microorganisms were found before treatment and decreased considerably after treatment in both groups. The highest values were found for Treponema denticola (140,000 (1.4 × 105)) in patients with cardiovascular disease and generalized gingival inflammation. Of the pathogenic microorganisms, the most common was Tannerella forsythia in 52 patients before treatment, and red microorganisms considerably appeared in only 10 patients after treatment. Capnocytophaga gingivalis remained constant both in the diseased state and after treatment and was consistent with periodontal health. Children with cardiovascular diseases had a higher prevalence of gingival manifestations. The composition of the subgingival microbial plaque was directly influenced by the degree of oral hygiene, but the response to specialized treatment was also influenced by the general health status. The results of this study support the conclusion that periodontal pathogens appear and multiply in the absence of proper hygiene in childhood after the eruption of permanent teeth, and their action leads to the initiation of periodontal diseases.

Helicobacter pylori infection may influence prevalence and disease course in myelin oligodendrocyte glycoprotein antibody associated disorder (MOGAD) similar to MS but not AQP4-IgG associated NMOSD.

Helicobacter pylori (Hp) persists after colonizing the gut in childhood, and potentially regulates host immune system through this process. Earlier studies have shown that Hp infection in childhood, may protect against MS in later life. Such an association was not seen with AQP4-IgG positive NMOSD, while the association with MOGAD is unclear. To evaluate frequency of Hp IgG among patients with MOGAD, MS, NMOSD and matched controls and its effect on disease course. To ascertain whether childhood socio economic factors were linked to prevalence of Hp infection. In all, 99 patients diagnosed to have MOGAD, 99 AQP4 IgG+ NMOSD, 254MS and 243 matched controls were included. Patient demographics, diagnosis, age at disease onset, duration and the last recorded expanded disability status scale (EDSS) were obtained from our records. Socioeconomic and educational status was queried using a previously validated questionnaire. Serum HpIgG was detected using ELISA kits (Vircell, Spain). Frequency of Hp IgG was significantly lower among MOGAD (28.3% vs 44%, p-0.007) and MS (21.2% vs 44%, p-0.0001) but not AQP4-IgG+ NMOSD patients (42.4% vs 44%, p-0.78) when compared to controls. Frequency of Hp IgG in MOGAD & MS patients combined (MOGAD-MS) was significantly lower than those with NMOSD (23.2% vs 42.4%, p- 0.0001). Seropositive patients with MOGAD- MS were older (p-0.001. OR -1.04, 95% CI- 1.01- 1.06) and had longer disease duration (p- 0.04, OR- 1.04, 95% CI- 1.002- 1.08) at time of testing. Educational status was lower among parents/caregivers of this study cohort (p- 0.001, OR -2.34, 95% CI- 1.48-3.69) who were Hp IgG+. In developing countries Hp infection may be a significant environmental factor related to autoimmune demyelinating CNS disease. Our preliminary data suggests that Hp may exert a differential influence -a largely protective role for MS-MOGAD but not NMOSD and may influence disease onset and course. This differential response maybe related to immuno-pathological similarities between MOGAD and MS in contrast to NMOSD. Our study further underscores the role of Hp as a surrogate marker for poor gut hygiene in childhood and its association with later onset of autoimmune diseases.

The Effect of Primary School Education on Preventive Behaviours during COVID-19 in Japan

Education plays a critical role in promoting preventive behaviours against the spread of pandemics. In Japan, handwashing education in primary schools was positively correlated with preventive behaviours against COVID-19 transmission for adults in 2020, during the early stages of COVID-19. The following year, the Tokyo Olympics were held in Japan, and a state of emergency was declared several times. Public perceptions of and risks associated with the pandemic changed drastically with the emergence of COVID-19 vaccines. We re-examined whether the effect of handwashing education on preventive behaviours persisted by covering a longer period of the COVID-19 pandemic than previous studies. A total of 26 surveys were conducted nearly once a month for 30 months from March 2020 (the early stage of COVID-19) to September 2022 in Japan. By corresponding with the same individuals across surveys, we comprehensively gathered data on preventive behaviours during this period. In addition, we asked about the handwashing education they had received in their primary school. We used the data to investigate how and to what degree school education is associated with pandemic-mitigating preventive behaviours. We found that handwashing education in primary school is positively associated with behaviours such as handwashing and mask wearing as a COVID-19 preventive measure but not related to staying at home. We observed a statistically significant difference in handwashing between adults who received childhood handwashing education and those who did not. This difference persisted throughout the study period. In comparison, the difference in mask wearing between the two groups was smaller but still statistically significant. Furthermore, there was no difference in staying at home between them. Childhood hygiene education has resulted in individuals engaging in handwashing and mask wearing to cope with COVID-19. Individuals can form sustainable development-related habits through childhood education.

Анализ кататравм по Республике Башкортостан среди взрослого и детского населения за 2019–2021 гг. — медико-социальные аспекты

The widespread growth of the traumatic epidemic associated with the urbanization of states, revealed the problem of severe injuries due to catatrauma. The components of the problem go beyond the purely medical sphere and refer to psychophysiology, hygiene of childhood and adolescence (carelessness, drunkenness, drug addiction, substance abuse, zombification, reactive states (deviant behavior)), conflict in society and family, mental disorders, suicidal tendencies, underestimation of danger (train hoppers, traceurs), crime. Digitalization of crash events and assistance algorithms allows normalizing this complex type of humanitarian technologies. It enables to simplify the logging, monitoring and examination of the entire eclectic spectrum of lesions received.

Environmental factors, medical and family history, and comorbidities associated with primary biliary cholangitis in Japan: a multicenter case-control study.

Primary biliary cholangitis (PBC) is considered to be caused by the interaction between genetic background and environmental triggers. Previous case-control studies have indicated the associations of environmental factors (tobacco smoking, a history of urinary tract infection, and hair dye) use with PBC. Therefore, we conducted a multicenter case-control study to identify the environmental factors associated with the development of PBC in Japan. From 21 participating centers in Japan, we prospectively enrolled 548 patients with PBC (male/female = 78/470, median age 66), and 548 age- and sex-matched controls. These participants completed a questionnaire comprising 121 items with respect to demographic, anthropometric, socioeconomic features, lifestyle, medical/familial history, and reproductive history in female individuals. The association was determined using conditional multivariate logistic regression analysis. The identified factors were vault toilet at home in childhood [odds ratio (OR), 1.63; 95% confidence interval (CI), 1.01-2.62], unpaved roads around the house in childhood (OR, 1.43; 95% CI, 1.07-1.92), ever smoking (OR, 1.70; 95% CI, 1.28-2.25), and hair dye use (OR, 1.57; 95% CI, 1.15-2.14) in the model for lifestyle factors, and a history of any type of autoimmune disease (OR, 8.74; 95% CI, 3.99-19.13), a history of Cesarean section (OR, 0.20; 95% CI, 0.077-0.53), and presence of PBC in first-degree relatives (OR, 21.1; 95% CI, 6.52-68.0) in the model for medical and familial factors. These results suggest that poor environmental hygiene in childhood (vault toilets and unpaved roads) and chronic exposure to chemicals (smoking and hair dye use) are likely to be risk factors for the development of PBC in Japan.

Prospective clinical investigations of children with periodontal Ehlers–Danlos syndrome identify generalized lack of attached gingiva as a pathognomonic feature

PurposeWe report prospective clinical investigations of children affected with periodontal Ehlers–Danlos syndrome (pEDS). The main clinical features of pEDS in adults are early severe periodontitis, generalized lack of attached gingiva, and pretibial hemosiderin plaques due to dominant pathogenic variants in the C1R or C1S genes. MethodsNineteen children with a parent diagnosed with molecularly confirmed pEDS underwent physical examination including oral and radiological investigations followed by genetic testing. ResultsThe only consistent manifestation of pEDS in childhood was a characteristic gingival phenotype: generalized lack of attached gingiva. All children with this gingival phenotype had inherited the familial pathogenic variant (n = 12) whereas the gingival phenotype was absent in children without the familial pathogenic variant (n = 7). Easy bruising was reported in eight affected and zero unaffected children. Other manifestations of pEDS were rarely present in children. Only 2/12 affected children aged 8 and 13 years fulfilled the clinical criteria for pEDS. ConclusionGeneralized lack of attached gingiva is a pathognomonic feature of pEDS and the only clinical finding that is consistently present in affected adults and children. This is important because an early diagnosis may facilitate better dental hygiene in childhood, which may be essential to prevent early dental loss.

Usos da pedagogia racionalista na escola moderna nº 1 de São Paulo (1913-1919)

El presente artículo analiza los usos de la pedagogía racionalista, elaborada por el educador anarquista Francisco Ferrer y Guardia y sus colaboradores en la Escuela Moderna de Barcelona a principios del siglo XX, por la Escuela Moderna Nº 1, ubicada en la ciudad de São Paulo (Brasil). Además de su fuerte contenido anarquista y anticlerical, la pedagogía racionalista se caracterizó por el positivismo científico, defendiendo banderas como la educación integral, el aprendizaje a través de los sentidos, la coeducación de las clases sociales y de género y la higiene de la infancia. La ejecución de Ferrer y Guardia, en 1909, desencadenó en Brasil, así como en otras partes del mundo, un gran interés por su pensamiento pedagógico. De ese movimiento surgió la Escuela Moderna Nº 1, dirigida, en la mayor parte del tiempo, por el anarquista João Penteado. Se busca en el presente trabajo comprender el proceso de apropiación de la pedagogía racionalista en tal institución, utilizando, para tal fin, diarios escolares y documentos escritos producidos en la institución dirigida por Penteado. Se concluyó que, a pesar de la idea de que la Escuela Moderna Nº 1 era una escuela totalmente aparte del pensamiento pedagógico hegemónico del período, los involucrados en la institución accedieron a los recursos culturales que tenían a disposición. De esta forma, se construyó en la escuela una propuesta pedagógica híbrida, que se apropió tanto de la pedagogía racionalista como del modelo pedagógico existente en las escuelas graduadas, que en Brasil se llamó grupo escolar.

Cost-Benefit Analysis of Early Childhood Hygiene Interventions in Uzbekistan

This paper applies cost-benefit analysis (CBA) technique to estimate the effectiveness of hand hygiene and oral health interventions in Uzbekistan for children of kindergarten age (3-6 years old). Our primary objective in this study is to apply CBA framework to investigate economic viability of hand hygiene and oral health interventions on respiratory diseases (influenza, bronchitis, pneumonia), intestinal diseases (diarrhea, hepatitis A, and helminthiasis), and dental caries and stomatitis. Though it is often difficult to attribute a specific hygiene intervention to a reduction in specific illness, our study shows that prevention of disease through hygiene promotion is cost-effective. To be the most effective, however, hygiene interventions should be accompanied by education and awareness-raising of teachers, parents and children.

Herpesviruses and the microbiome

The focus of this article will be to examine the role of common herpesviruses as a component of the microbiome of atopic patients and to review clinical observations suggesting that atopic patients might be predisposed to more severe and atypical herpes-related illness because their immune response is biased toward a TH2 cytokine profile. Human populations are infected with 8 herpesviruses, including herpes simplex virus HSV1 and HSV2 (also termed HHV1 and HHV2), varicella zoster virus (VZV or HHV3), EBV (HHV4), cytomegalovirus (HHV5), HHV6, HHV7, and Kaposi sarcoma-associated herpesvirus (termed KSV or HHV8). Herpesviruses are highly adapted to lifelong infection of their human hosts and thus can be considered a component of the human "microbiome" in addition to their role in illness triggered by primary infection. HSV1 and HSV2 infection and reactivation can present with more severe cutaneous symptoms termed eczema herpeticum in the atopic population, similar to the more severe eczema vaccinatum, and drug reaction with eosinophilia and systemic symptoms syndrome (DRESS) is associated with reactivation of HSV6 and possibly other herpesviruses in both atopic and nonatopic patients. In this review evidence is reviewed that primary infection with herpesviruses may have an atypical presentation in the atopic patient and conversely that childhood infection might alter the atopic phenotype. Reactivation of latent herpesviruses can directly alter host cytokine profiles through viral expression of cytokine-like proteins, such as IL-10 (EBV) or IL-6 (cytomegalovirus and HHV8), viral encoded and secreted siRNA and microRNAs, and modulation of expression of host transcription pathways, such as nuclear factor κB. Physicians caring for allergic and atopic populations should be aware of common and uncommon presentations of herpes-related disease in atopic patients to provide accurate diagnosis and avoid unnecessary laboratory testing or incorrect diagnosis of other conditions, such as drug allergy or autoimmune disease. Antiviral therapy and vaccines should be administered promptly when indicated clinically.

Risk factors for inflammatory bowel diseases according to the “hygiene hypothesis”: A case–control, multi-centre, prospective study in Southern Italy

BackgroundUlcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD) of unknown aetiology. The ‘hygiene hypothesis’ (HH) suggests that several hygiene-related factors may have contributed to the increased incidence of IBD. The aim of the study was to evaluate risk factors for IBD related to HH in a cohort of IBD patients from the south of Italy. MethodsWe prospectively performed a one-year, questionnaire-based, case–control, multi-centre study focusing on the principal risk factors for IBD according to HH. We investigated the main surrogate markers of HH (helmintic infections and antibiotics in childhood; breastfeeding; family size/sibship;urban upbringing; personal and domestic hygiene in childhood) in UC and CD patients, in comparison with a control group of healthy subjects. In addition, the traditional risk factors for IBD were also recorded. ResultsThe study population included 527 cases of UC, 468 CD and 562 controls. None of the surrogate risk factors of HH was significantly associated with IBD. On the contrary, the traditional risk factors confirmed their statistical significance in this IBD population. Familial aggregation: OR 4.07 for UC; OR 4.83 for CD; smoking: OR 0.38 for UC; OR 1.40 for CD; appendectomy: OR 0.28 for UC; OR 1.61 for CD. ConclusionEven though risk factors associated to the HH have been proposed as a possible explanation for the increasing calendar trend of IBD incidence, their role does not appear to be statistically significant. Familial aggregation, smoking habits and appendectomy still remain the main risk factors associated with IBD.

Higiene e infância no Paraná: a missão de formar hábitos saudáveis (1931-1949)

Com base na investigação dos discursos médicos referentes à higienização da infância, este estudo teve por objetivo problematizar a difusão da higiene na sociedade paranaense no período compreendido entre 1931 e 1949. Trata-se de uma pesquisa de caráter histórico, inspirada nas ideias de processo civilizador de Norbert Elias. Os discursos que evidenciavam a missão de criar na infância local uma consciência sanitária com vistas ao progresso e a inserção do Paraná no cenário político nacional foram resgatados na Revista Médica do Paraná. Emergiram percepções de uma medicina com uma nova função social: educar e civilizar a infância, utilizando para tanto a estratégia da higienização.

Innocence of Experience: Rousseau on Puberty in the State of Civilization

This article contributes to current discussions of the origins of modern sexuality by exploring an episode from Book II of Jean-Jacques Rousseau’s Confessions (1782), in the context of eighteenth-century childhood hygiene theory. In this episode, the sixteen-year-old Rousseau is the object of an aggressive sexual advance on the part of another young man, and witnesses this young man’s orgasm. By stressing his unusual immunity to understanding the sexual nature of this encounter, Rousseau places himself outside the cultural argument that moral degradation was bringing on premature puberty (ejaculation, in males) and thus degradation of the human species in eighteenth-century Europe.

Environmentally-acquired bacteria influence microbial diversity and natural innate immune responses at gut surfaces

BackgroundEarly microbial colonization of the gut reduces the incidence of infectious, inflammatory and autoimmune diseases. Recent population studies reveal that childhood hygiene is a significant risk factor for development of inflammatory bowel disease, thereby reinforcing the hygiene hypothesis and the potential importance of microbial colonization during early life. The extent to which early-life environment impacts on microbial diversity of the adult gut and subsequent immune processes has not been comprehensively investigated thus far. We addressed this important question using the pig as a model to evaluate the impact of early-life environment on microbe/host gut interactions during development.ResultsGenetically-related piglets were housed in either indoor or outdoor environments or in experimental isolators. Analysis of over 3,000 16S rRNA sequences revealed major differences in mucosa-adherent microbial diversity in the ileum of adult pigs attributable to differences in early-life environment. Pigs housed in a natural outdoor environment showed a dominance of Firmicutes, in particular Lactobacillus, whereas animals housed in a hygienic indoor environment had reduced Lactobacillus and higher numbers of potentially pathogenic phylotypes. Our analysis revealed a strong negative correlation between the abundance of Firmicutes and pathogenic bacterial populations in the gut. These differences were exaggerated in animals housed in experimental isolators. Affymetrix microarray technology and Real-time Polymerase Chain Reaction revealed significant gut-specific gene responses also related to early-life environment. Significantly, indoor-housed pigs displayed increased expression of Type 1 interferon genes, Major Histocompatibility Complex class I and several chemokines. Gene Ontology and pathway analysis further confirmed these results.ConclusionEarly-life environment significantly affects both microbial composition of the adult gut and mucosal innate immune function. We observed that a microbiota dominated by lactobacilli may function to maintain mucosal immune homeostasis and limit pathogen colonization.

Association of diarrhoea, poor hygiene and poor social conditions in childhood with blood pressure in adulthood

BackgroundPrevious research has suggested that dehydration in infancy may lead to high blood pressure in later life because of sodium retention. The purpose of this study was to examine the...

M1119 Childhood Hygiene Shifts Serological Profiles in Adult CD

M1119 Childhood Hygiene Shifts Serological Profiles in Adult CD

Developmental aspects of sleep hygiene: Findings from the 2004 National Sleep Foundation Sleep in America Poll

Objective To examine the associations between sleep hygiene and sleep patterns in children ages newborn to 10 years. The relationships between key features of good sleep hygiene in childhood and recognizable outcomes have not been studied in large, nationally representative samples. Participants and methods A national poll of 1473 parents/caregivers of children ages newborn to 10 years was conducted in 2004. The poll included questions on sleep hygiene (poor sleep hygiene operationally defined as not having a consistent bedtime routine, bedtime after 9:00 PM, having a parent present when falling asleep at bedtime, having a television in the bedroom, and consuming caffeinated beverages daily) and sleep patterns (sleep onset latency, frequency of night wakings, and total sleep time). Results Across all ages, a late bedtime and having a parent present when the child falls asleep had the strongest negative association with reported sleep patterns. A late bedtime was associated with longer sleep onset latency and shorter total sleep time, whereas parental presence was associated with more night wakings. Those children (ages 3+) without a consistent bedtime routine also were reported to obtain less sleep. Furthermore, a television in the bedroom (ages 3+) and regular caffeine consumption (ages 5+) were associated with shorter total sleep time. Conclusions Overall, this study found that good sleep hygiene practices are associated with better sleep across several age ranges. These findings support the importance of common US based recommendations that children of all ages should fall asleep independently, go to bed before 9:00 PM, have an established bedtime routine, include reading as part of their bedtime routine, refrain from caffeine, and sleep in bedrooms without televisions.

Childhood hygiene is associated with risk of IBD

Childhood hygiene is associated with risk of IBD

Childhood Hygiene Is Associated With the Risk for Inflammatory Bowel Disease: A Population-Based Study

The "hygiene hypothesis" postulates that individuals raised in a sanitary environment are more likely to develop inflammatory bowel disease (IBD). Several studies previously demonstrated contradictory results in this regard. We performed for the first time a population-based study on the association of surrogate markers of childhood hygiene with the risk for IBD. A cross-sectional population-based study was undertaken. Information on number of siblings, birth order, and living in an urban versus rural environment was obtained for 399,251 Jewish adolescents at the age of 17 yr from 1998 to 2004. The study population included only subjects born in Israel. In order to control for genetic confounding, subjects were also divided according to their ethnic group as being Ashkenazi, Sephardic, or Israeli in origin. In total, 768 cases of inflammatory bowel disease (IBD) were diagnosed (0.19%), with 53.8% of the cases being of Ashkenazi origin. On multivariate analysis, variables significantly associated with IBD were male gender (odds ratio [OR] 1.44, 95% confidence interval [CI] 1.24-1.67), Ashkenazi origin (OR 1.91, 95% CI 1.63-2.22), living in an urban environment (OR 1.38, 95% CI 1.02-1.78), small number of siblings in the family (for 1 sibling vs 5 or more, OR 2.63, 95% CI 1.49-4.62), and higher birth order (for birth order of 5 or higher vs 1, OR 2.35, 95% CI 1.47-3.77), showing for both variables an almost strictly highly significant monotonic association (P value for trend <0.001). Surrogate markers of childhood hygiene are associated with the risk for IBD, thus reinforcing the "hygiene hypothesis."

Risk factors for ulcerative colitis: A population-based, case–control study in Spain

Background Environmental factors seem to be very important in the aetiology of Ulcerative Colitis (UC), with smoking, contraceptive use, and hygiene being the factors most commonly linked to disease. Aim To analyse the association between different risk factors and development of UC in our community. Patients and methods This is a case–control, population-based study. The UC population consists of an inception-case population of all cases diagnosed, using Lennard–Jones criteria, in our community from 1st February 1992 to 31st January 1995 that were prospectively included. Controls were selected from healthy population and matched with patients for age, sex and rural/urban habitat. We used the SPSS/PC+ software, EpiInfo and Statistix for statistical analysis, giving the rates as point estimates and 95% confidence intervals (95%CI) or as mean ± standard deviation in quantitative variables. For multivariate analysis we used conditional logistic regression. Results 205 patients were diagnosed of UC. 38 patients (18.5%) with UC were smokers, compared with 84 (40.8%) controls ( p < 0.001). Smoking behaved as a protector factor for UC (OR = 0.55 (CI 95% 0.33–0.92) and ex-smoker acted as a risk factor (OR = 1.94 (CI 95% 1.14–3.34). After the multivariate analysis, both associations were maintained. We did not detect statistical differences in the analysis of previous appendectomy, childhood hygiene or oral contraceptive use. Five of the 12 cases with family aggregation had first-degree relatives and 7 of them second-degree relatives. None of the controls had previous IBD history ( p = 0.0002). Conclusion Ex-smoking and previous family history of inflammatory bowel disease appeared as risk factors for developing ulcerative colitis while current smoking behaved as a protective factor in this population.

Risk factors for Helicobacter pylori infection among a rural population in Japan: relation to living environment and medical history.

Helicobacter pylori infection is related to several gastroduodenal diseases, though the route of transmission remains unclear. A cross-sectional study that included 695 healthy people (males 308, females 387; median age 60 years) participating in a health checkup program in Yamagata Prefecture was conducted. H. pylori status was determined in all subjects by evaluation of serum anti-H. pylori immunoglobulin G antibody. Antibody against hepatitis A virus was used as a marker of fecal-oral exposure to assess the agreement between H. pylori infection and hepatitis A virus infection. Data on other factors known or suspected to be related to infection status were also collected using a questionnaire. Seroprevalence of H. pylori and hepatitis A virus was 60% and 70%, respectively. Kappa values for subjects aged 20-49 and aged 50 or older were 0.07 and 0.02, respectively, and agreement between the presences of both infections was assessed as slight. In the multivariate logistic regression analysis, H. pylori infection was significantly associated with availability of a sewage system in childhood (presence [reference], absence [odds ratio (OR) = 4.06, 95% confidence interval (CI): 1.36-13.94]) and the number of gastrointestinal endoscopies undergone (none [reference], once [OR = 1.64, 95% CI: 0.83-3.27], 2-3 times [OR = 3.11, 95% CI: 1.65-5.99], or 4 or more times [OR = 3.18, 95% CI: 1.71-6.03]), (p < 0.01 for trend). Our results suggest that poor hygiene in childhood is related to H. pylori infection. The fecal-oral route does not seem to be an important mode of transmission, but the possibility of transmission by gastrointestinal endoscopic examination exists.