Subsite-specific trends in mid- and long-term survival for head and neck cancer patients in Japan: A population-based study.

Advances in diagnostic techniques and treatment modalities have impacted head and neck cancer (HNC) prognosis, but their effects on subsite-specific prognosis remain unclear. This study aimed to assess subsite-specific trends in mid- and long-term survival for HNC patients diagnosed from 1993 to 2011 using data from population-based cancer registries in Japan. We estimated the net survival (NS) for HNC by subsite using data from 13 prefectural population-based cancer registries in Japan. Changes in survival over time were assessed by multivariate excess hazard model of mortality. In total, 68,312 HNC patients were included in this analysis. We observed an overall improvement in 5-year NS for HNC patients in Japan. However, survival varied among subsites of HNC, with some, such as naso-, oro- and hypopharyngeal cancers, showing significant improvement in both 5- and 10-year NS, whereas others such as laryngeal cancer showed only a slight improvement in 5-year NS and no significant change in 10-year NS after adjustment for age, sex and stage. In conclusion, the study provides insights into changing HNC survival by site at the population level in Japan. Although advances in diagnostic techniques and treatment modalities have improved survival, these improvements are not shared equally among subsites.

[Report on COVID-19 infection prevention and control training sessions for care homes provided by Kawaguchi city and comparison with those provided by the local governments in Japan].

Objectives　We compared COVID-19 prevention and control information provided to care homes (CHs) by the Kawaguchi City public health center (PHC), which utilizes our precedent advice on nfection, with the information from several local governments (LGs) in Japan. This study aimed to highlight the role of LG-associated doctors in providing information to CHs, utilizing their precedent advice on infection control in CHs and medical facilities. This study analyzed the sector and type of information the LGs should provide to CHs to prevent and control COVID-19.Methods　We compared training sessions on COVID-19 prevention and control information provided to CHs by the Kawaguchi City PHC with training sessions offered by several other LGs in Japan that are available on their websites.Results　The Kawaguchi City PHC has been providing COVID-19 information to CHs when needed, including prevention and control information, through their doctors, utilizing our precedent advice on infection control, management of health conditions of staff and residents, and early detection of COVID-19. In contrast, 68 LGs announced that they have provided training sessions to CHs for the prevention and control of COVID-19 through their official homepages from March to September 2022. These training sessions involved information dissemination by infection control specialist nurses (42.6%), clinic or hospital doctors (32.4%), infection control specialist doctors (11.8%), and staff from LG headquarters, PHC, or LG-associated doctors (51.5%). Among the 68 LGs, 41 provided information that included hand hygiene (95.1%), personal protective equipment (92.7%), proper ventilation (51.2%), and management of staff (90.2%) and resident (58.5%) health conditions. Furthermore, Kawaguchi City PHC and several LGs provided information for the early detection of COVID-19.Conclusion　We suggest that LGs provide COVID-19 training sessions conducted by LG doctors that include management of staff and resident health conditions, provision of early detection information, and utilization of precedent advice on infection in CHs and medical facilities.

[Impact of COVID-19 on cancer treatment: Results from 18 hospital-based cancer registries in Tochigi prefecture].

Objectives　To show the impact of COVID-19 on cancer treatment in Tochigi prefecture.Methods　The number of cancer cases registered in Tochigi prefecture before (2019) and after (2020) COVID-19 was compared using cancer registry data from 18 member hospitals of the Tochigi Prefecture Cancer Care Collaboration Council. Data were compared by sex, age, patient's address at the time of diagnosis, month of diagnosis, cancer site, cancer stage, and treatment. Data on screenings for stomach, colorectum, lung, female breast, cervix, and prostate cancers were investigated in detail.Results　The total number of registered cancer cases was 19,748 in 2019 and 18,912 in 2020 (a decrease of 836 cases [-4.2%]). Among the total cases, there were 11,223 and 10,511 males in 2019 and 2020, respectively (a decrease of 712 cases [-6.3%]) and 8,525 and 8,401 females in 2019 and 2020, respectively (a decrease of 124 cases [-1.5%]). The decrease was greater among males than among females. There was no decrease in the number of registered patients aged <40 years between 2019 and 2020. Based on the patients' address at the time of diagnosis, there was no decrease in the number of cases from outside of the Tochigi prefecture. Regarding the month of diagnosis, there was a notable decrease in the number of registered patients in May and August of 2020. Among the decrease of 836 cases detected by screening, 689(82.4%) were cases of stomach, lung, colorectum, female breast, cervix, and prostate cancer. The number of registered cases of malignant lymphoma, leukemia, and cancer of the oral cavity and pharynx, pancreas, bone and soft tissue, corpus uteri, and bladder did not decrease between 2019 and 2020. In terms of stage of cancer, the number of registered cases of carcinoma in situ, localized cancer, and regional lymph node metastases was lower in 2020 than in 2019, but there was no decrease in the number of registered cases of distant metastases or regional extension.Conclusion　The number of cancer cases registered in 2020 was lower than in 2019, and the degree of change varied by age, hospital, site, whether the case was detected by screening, and stage of cancer. In particular, a marked decrease was observed in the number of cases detected by screening. Furthermore, the decrease in the number of cancer cases registered in May and August of 2020 were believed to be due to the peak in the spread of COVID-19 and the associated declaration of a state of emergency.

Recent Increasing Incidence of Early-Stage Cervical Cancers of the Squamous Cell Carcinoma Subtype among Young Women.

Few studies have reported on the increase in cervical cancer incidence in Japan. We aimed to determine the relevant trends in the metropolitan regions of Japan and to identify the population with the highest risk, based on histological subtype, cancer stage, and diagnostic processes. Using population-based data (2009-2013), we identified 2110 women, aged ≥20 years, with cervical cancer. We estimated the age-standardized and age-specific incidence rates of cervical cancer for the study period based on the 1985 national model population. The average annual percent change (AAPC) and 95% confidence interval (CI) were calculated using the joinpoint regression analysis. We stratified the analyses based on histological subtypes, stage, and diagnostic process via cancer screening. The increase in the overall age-standardized incidence was not significant. However, the increase was significant for women aged 30-39 years (AAPC 20.0%/year, 95% CI: 9.9-31.1), which was attributable to the increase in the incidence of the squamous cell carcinoma (SCC) subtype (AAPC 23.1%/year, 95% CI: 10.7-36.8). Among younger women, aged <50 years, further stratification showed an increase in the undiagnosed early-stage SCC subtype via cancer screening. In Japan, the incidence of HPV-related cervical cancer has been increasing in undiagnosed younger women.

Impact of D3 lymph node dissection on survival for patients with T3 and T4 colon cancer.

PURPOSE: The clinical significance of D3 lymph node dissection for patients with colon cancer remains controversial. This study aims to clarify the impact of D3 lymph node dissection on survival in patients with colon cancer. METHODS: This is a retrospective cohort study from a prospectively registered multi-institutional database of colorectal cancer in Japan. Propensity score matching method was applied to balance potential confounders of the treatment. A cohort of 10,098 patients who underwent radical colectomy for pT3 and pT4 colon cancer between 1985 and 1994 were identified. A total of 3,425 propensity score matched pairs were extracted from the entire cohort. The primary outcome measure was overall survival (OS). RESULTS: In the entire cohort, there was a statistically significant difference in overall survival (OS) between the patients who had D3 and D2 lymph node dissection (p = 0.00003). The estimated hazard ratio (HR) for OS of patients who had D3 versus D2 lymph node dissection was 0.827 (95 % confidence interval, 0.757 to 0.904). In the matched cohort, there was also a significant difference in OS between the two groups (p = 0.0001), and the estimated HR for OS was 0.814 (95 % confidence interval, 0.734 to 0.904). CONCLUSIONS: We found D3 lymph node dissection for pT3 and pT4 colon cancer to be associated with a significant survival advantage in a large-scale database, even after adjusting potential confounders of lymph node dissection. This finding may provide a rationale for D3 lymph node dissection in radical surgery for pT3 and pT4 colon cancer.

Comparison of three measurements on computed tomography for the prediction of less invasiveness in patients with clinical stage I non-small cell lung cancer.

BACKGROUND: A greater proportion of ground-glass opacity (GGO) is well known to be strongly associated with less invasive lung adenocarcinoma. Recently, the solid area diameter has also been reported to be a simple and better marker for the same purpose compared with the whole nodule diameter. METHODS: From 1997 to 2009, 383 patients with clinical T1-2N0M0 non-small cell lung cancer (NSCLC) with a solid area of 3 cm or less underwent surgical resection, and their preoperative high-resolution computed tomographic images were preserved in Digital Imaging and Communications in Medicine format. Less invasive lung cancer was defined as having no vascular, lymphatic, or pleural invasion or lymph node metastasis. We compared the solid area and whole nodule diameters and proportion of GGO, with the objective of predicting less invasive lung cancer. RESULTS: Among the 383 patients, 187 were men, 335 had adenocarcinoma histologic type, 242 had less invasive lung cancer, and 43 experienced recurrence. Receiver operating characteristic (ROC) analysis to predict less invasive lung cancer showed that the area under the curve of proportion of GGO was the highest (0.848; 95% confidence interval [CI], 0.810-0.886), followed by the solid area diameter (0.785; 95% CI, 0.740-0.829), and then whole nodule diameter (0.621; 95% CI, 0.565-0.677). Multiple logistic regression analyses revealed that proportion of GGO was the only significant predictor of less invasive lung cancer. The proportion of GGO was also found to be a significant prognostic factor of disease-free survival (DFS) along with solid area diameter by multivariate analysis. Regardless of the solid area diameter, no patient with a greater proportion of GGO (> 50%) experienced recurrence. CONCLUSIONS: Proportion of GGO remains important for predicting less invasive lung cancer.

Proposal of new nodal classifications for non-small-cell lung cancer based on the number and ratio of metastatic lymph nodes.

OBJECTIVE: The study aimed to evaluate the effectiveness of two new nodal classifications based on the number of metastatic lymph nodes (LNs) or ratio of metastatic to examined LNs (LNR) in making a prognosis, compared with the current nodal classification based on the location of metastatic LNs. METHODS: We analyzed 651 non-small-cell lung cancer patients who had undergone complete resection with the removal of more than five LNs between 1986 and 2003, excluding preoperative treatment cases, and a Tis, T4, N3, and M1 status, along with limited resection and operative death cases. The cutoff numbers for each category in the two new nodal classifications (number of metastatic LNs (nN0-2): 0, 1-2, and >3, and LNR (rN0-2): 0, 1-12, and >12%) were defined so that the numbers corresponded with paired categories within the current nodal classification. RESULTS: The 5-year survival rate was 75.4% for patients with the N0 categories in all three classifications. The 5-year survival rates for patients with N1 and N2 categories were 52.2% and 42.6% according to the current nodal classification, 54.3% and 39.8% according to the number of metastatic LNs, and 58.8% and 35.0% according to the LNR, respectively. Although all three nodal classifications were independent prognostic factors along with the age and pathological T status, when the three nodal classifications were entered into multivariate analysis individually, the hazard ratio of rN2 was the highest, at 3.15, followed by that of nN2 at 2.96. CONCLUSIONS: The LNR followed by the number of metastatic LNs may be more effective prognostic indicators than the current nodal classification based on the location of metastatic LNs. For the future revision, the number of metastatic LNs and LNR should be evaluated as indicators for the nodal classification of lung cancer.

Six principal symptoms and coronary artery sequelae in Kawasaki disease.

BACKGROUND: The relationship between coronary artery sequelae due to Kawasaki disease and the six principal symptoms associated with the latter are still unknown. METHODS: Among the 16,952 patients reported in the 17th nationwide survey on Kawasaki disease, 14,068 were found to have definite and typical cases with five or six principal symptoms. The proportions of coronary artery aneurysms including dilatation of the artery were compared between the patient group with six symptoms and that with five. RESULTS: Percentages for those with all six symptoms (7223) were 4.7% for coronary dilatations (i.e. small aneurysms), 1.7% for coronary aneurysms (i.e. middle-sized aneurysms), and 0.42% for giant coronary aneurysms (i.e. large aneurysms) 1 month after onset, whereas for those with five symptoms (6,845), the corresponding percentages were 4.1%, 1.4%, and 0.22%, respectively. For overall observation, the odds ratios were 1.44, 1.28, and 1.70 for the three types of aneurysm, respectively. For male patients, all the odds ratios were >1.0, and some were significant. In contrast, odds ratios <1.0 were observed among those with six symptoms in some subgroups among female patients despite the lack of significance. CONCLUSIONS: Because odds ratios were elevated - especially for male patients with Kawasaki disease - with all six principal symptoms, patients with the six symptoms are more problematic for coronary sequelae among the definite cases, although there was not a specific symptom for the sequelae.

Monthly observation of the number of patients with Kawasaki disease and its incidence rates in Japan: chronological and geographical observation from nationwide surveys.

BACKGROUND: Although the epidemiologic features of Kawasaki disease for Japan have been observed, recently, chronological and geographical observations of the number of patients and incidence rate of the disease have not been conducted using observation units smaller than the whole country. METHODS: We used the recent 5 nationwide surveys (the 15th to 19th) of Kawasaki disease in Japan, which covered patients for 10 years, i.e., between 1997 and 2006. The monthly number of patients by prefecture was calculated, and the number was corrected by the response rate of the target institutes of the prefecture. Chronological changes in the number of patients were observed by district. Geographical changes in the incidence rates were observed bimonthly by prefecture for the recent 6 years, from 2001 through 2006. RESULTS: On the whole, the monthly number of patients increased gradually. For each year, the number was the highest in January and the lowest in October; it was relatively high during summer as well. Some differences existed among the districts with regard to the monthly observations. Bimonthly observations of the incidence rate by prefecture revealed the differences in the characteristics of the epidemics in different geographic areas. CONCLUSION: The chronological and geographical changes in the occurrence of Kawasaki disease in Japan for the recent 10 years suggested the involvement of one or more infectious agents in the occurrence of the disease.

Epidemiologic features of Kawasaki disease in Japan: results from the nationwide survey in 2005-2006.

BACKGROUND: The most recent epidemiologic features of Kawasaki disease are unknown. METHODS: The 19th nationwide survey of the disease was conducted in 2007, targeting patients who were affected by this disease in 2005 and 2006. All pediatric departments in hospitals with 100 or more beds and pediatric hospitals were asked to report all Kawasaki disease patients during the 2 survey years. RESULTS: From 1543 departments and hospitals, a total of 20475 patients (10041 in 2005 and 10434 in 2006) were reported. There were 11892 male patients and 8583 female patients. The average annual incidence rate was 184.6 per 100000 children aged 0-4 years. The number of patients and the incidence rate have increased significantly during the past 12 years. The age-specific incidence rate was distributed monomodally with a peak at 6-8 months of age. The prevalence of cardiac lesions in the acute phase of the disease and of cardiac sequelae were higher among infants and old patients. CONCLUSION: The number of patients with Kawasaki disease and its incidence rate in Japan are continuously increasing.

Increasing incidence of Kawasaki disease in Japan: nationwide survey.

BACKGROUND: The last nationwide survey of Kawasaki disease in Japan was conducted in 2003; the epidemiologic features of the disease in Japan since then are unknown. METHODS: All the hospitals with a pediatric department and a bed capacity of > or =100, or hospitals having a bed capacity of <100 but specializing in pediatrics in Japan were asked to report (by mail) all patients with Kawasaki disease who visited the hospital due to the disease in 2003 and 2004. RESULTS: Of the 2335 hospitals asked to participate, 1058 reported 19,138 patients with Kawasaki disease during the 2 year period 2003-2004. The annual incidence in 2004 reached 174.0 per 100,000 children under 5 years of age. The yearly number of patients and annual incidence increased significantly after the last nationwide epidemic of the disease in 1986. The number of patients was largest in January and lowest in October. The age-specific incidence was highest for those aged 9-11 months, and 88.9% of the patients were under 5 years of age. Of the reported patients, 2595 (13.6%) had cardiac lesions in the acute phase of the disease and 844 (4.4%) had cardiac sequelae 1 month after the onset of the disease. CONCLUSION: The number of patients and the incidence of Kawasaki disease in Japan has increased year by year in the last two decades.

Relationship between BMI and all-cause mortality in Japan: NIPPON DATA80.

As body composition in Asian populations is largely different from Western populations, a healthy BMI could also differ between the two populations. Thus, further study is needed to determine whether a healthy BMI in Asians should be lower than Western populations, as recommended by the World Health Organization (WHO). We investigated the relationship between BMI and mortality in a sample of 8,924 Japanese men and women without stroke or heart disease. During 19 years of follow-up, 1,718 deaths were observed. We found a U-shaped relationship between BMI and fatal events. Risk of total mortality was highest in participants with BMI <18.5 kg/m(2) and lowest in participants with BMI 23.0-24.9 kg/m(2). These findings persisted even after excluding the first 5 years of follow-up with a focus on healthy participants who never smoked, were aged <70 years, and had total cholesterol (TC) levels >or=4.1 mmol/l (N=3712). For both the full sample and healthy participants, all-cause mortality risk did not differ between BMI ranges 21.0-22.9 and 23.0-24.9 kg/m(2). Our findings do not support the recent WHO implications that BMIs <23.0 kg/m(2) is healthy for Asians. Therefore, further studies are needed to identify an optimal BMI range for Asia.

Analysis of potential risk factors associated with nonresponse to initial intravenous immunoglobulin treatment among Kawasaki disease patients in Japan.

BACKGROUND: Some Kawasaki disease (KD) patients do not respond to initial treatment with intravenous immunoglobulin (IVIG). The purpose of this study was to determine potential risk factors associated with IVIG nonresponse among KD patients in Japan. METHODS: Data were obtained from questionnaires used for the 18th nationwide KD survey of patients who visited hospitals in Japan from 2003 through 2004. Data for patients who met the case definition for KD and received 2 g/kg single infusion IVIG as the initial treatment within 10 days of illness were analyzed. IVIG nonresponders were defined as patients who needed secondary treatment after initial IVIG administration. RESULTS: Among 15,940 KD patients in Japan during 2003-2004, 6330 patients received 2 g/kg single infusion IVIG within 10 days of illness onset. IVIG nonresponders accounted for 20.3% of them (n = 1286). Male sex [odds ratio (OR), 1.21, 95% confidence interval (CI), 1.06-1.37], receipt of the initial IVIG before the fifth day of illness (OR: 1.89, 95% CI: 1.66-2.15), and having recurrent KD (OR: 1.38, 95% CI: 1.00-1.90) were significantly associated with IVIG nonresponse. In addition, IVIG nonresponders had significantly higher risks for coronary artery aneurysms (OR: 10.38, 95% CI: 6.98-15.45) or giant coronary artery aneurysms (OR: 54.06, 95% CI: 12.84-227.65). CONCLUSIONS: Physicians should consider potential IVIG nonresponse among recurrent KD patients or KD patients diagnosed and treated before the fifth day of illness, particularly if they are boys and have laboratory values associated with nonresponse such as low platelet count, and elevated alanine aminotransferase and C-reactive protein. Some of these patients may benefit from administration of the alternative secondary treatment early during the illness along with the initial IVIG treatment.

Mortality among persons with a history of kawasaki disease in Japan: mortality among males with cardiac sequelae is significantly higher than that of the general population.

BACKGROUND: The long-term prognosis of those having a history of Kawasaki disease (KD) is still unknown. METHODS AND RESULTS: Between July 1982 and December 1992, 52 collaborating hospitals collected data on all patients having a new definite diagnosis of KD. Patients were followed-up until December 31, 2004 or their death. Standardized mortality ratios (SMRs) were calculated based on the Japanese vital statistics data. Of 6,576 patients enrolled, 36 (27 males, 9 females) died and the SMR was 1.14. Despite the high SMRs during the acute phase, the mortality rate was not high after the acute phase for the entire group of patients. Although the SMR after the acute phase was 0.71 for those without cardiac sequelae, 10 males (but none of the females) with cardiac sequelae died during the observation period; and the SMR for the male group with cardiac sequelae was 2.55 (95% confidence interval: 1.23-4.70). CONCLUSIONS: The mortality rate among males with cardiac sequelae because of KD was significantly higher in this cohort than in the general population. On the other hand, those for females with the sequelae and for both males and females without sequelae were not elevated.

Re-treatment regimens for acute stage of Kawasaki disease patients who failed to respond to initial intravenous immunoglobulin therapy: analysis from the 17th nationwide survey.

BACKGROUND: Current regimens for re-treatment of patients with Kawasaki disease who failed to respond to the initial intravenous immunoglobulin (IVIG) therapy are still uncertain. The purpose of this study is to reveal what regimens were used as the initial therapy and re-treatment for acute stage of Kawasaki disease in the current Japanese medical setting. METHODS: The 17th nationwide survey on Kawasaki disease covered patients whose onset was in 2001 and 2002. In questionnaires sent to all hospitals with a bed capacity of 100 or more and a pediatric department, several questions related to therapeutic regimens for Kawasaki disease were posed. The authors observed the proportions of hospitals that had regimens for patients who failed to respond to the initial therapy. RESULTS: Among those hospitals that responded to the survey, 1052 (64.1%) reported that at least one patient with Kawasaki disease visited the hospital. Among these 1052 hospitals, 73.3% had a regimen to administer 30-39 mg/kg per day of oral aspirin with initial IVIG. The proportion of hospitals that used 1 g/kg per day of IVIG for 2 days was the largest among the options for the initial treatment. For those patients who fail to respond to the initial therapy, 464 hospitals (44.1%) reported that their pediatricians would use additional IVIG only. The number of hospitals that planned to administer high-dose IVIG and ulinastatin was 185 (17.6%). The number of hospitals having regimens of additional IVIG and steroids was 54 (5.1%). CONCLUSIONS: The current status of the treatment for patients with Kawasaki disease not responding to the initial IVIG therapy in Japan was revealed. A randomized trial of a large sample is needed to ascertain the effectiveness of several options for re-treating Kawasaki disease.

Impact of the universal hepatitis B immunization program in Mongolia: achievements and challenges.

BACKGROUND: The impact of the universal infant hepatitis B (HB) immunization program initiated in 1991 in Mongolia is still unclear. METHODS: A nationwide school-based cross-sectional serosurvey was conducted in 2004, with stratified, multistage, random cluster sampling from all public elementary schools (n=593) in Mongolia. All children were tested for serological markers of hepatitis B virus (HBV). RESULTS: Serology results were available for 1,145 children (592 boys and 553 girls) aged 7-12 years (survey response rate: 93%). Immunization card was available for 702 (61.3%) children. The coverage of complete HB vaccination was 60.1% and it was increased by birth cohort from 44% to 76%. Significantly higher proportion of children in Metropolitan cities (75.2%) was completely vaccinated with HB compared to those in Province centers (55.7%) and rural areas (59.1%). HBV infection occurred in 5.9%, 13.2%, and 20.8% of complete vaccinees living in Metropolitan, Province centers, and rural areas, respectively; of whom 1.2%, 2.9%, and 8.6% were HB surface antigen (HBsAg) carriers, respectively. Only 17.0% of the children had protective anti-HBs which decreased from 31.1% to 16.3% among 7 to 12-year-olds indicating its decay with time. CONCLUSIONS: Prevalence of HBV infection and carriage among young generation meaningfully declined compared with those of previous studies in Mongolia. The coverage of birth dose and complete HB vaccination was significantly low in Province centers and rural areas which should be taken into consideration.

Administration of hepatitis B vaccine in winter as a significant predictor of the poor effectiveness of vaccination in rural Mongolia: evidence from a nationwide survey.

BACKGROUND: Universal hepatitis B (HB) immunisation is the most effective means for prevention of hepatitis B virus (HBV) infection worldwide. Maintaining the vaccine cold chain is an essential part of a successful immunisation programme. Our recent nationwide survey in Mongolia has observed significant urban-rural differences in the prevalence of HBV infection among vaccinated cohorts. OBJECTIVE: To examine whether the administration of HB vaccine in winter contributes to these residential discrepancies on the effectiveness of vaccination. DESIGN AND SETTING: In 2004, a nationwide serosurvey was carried out covering both urban and rural areas of Mongolia. Sampling was multistage, with random probability from all public schools in the country. PARTICIPANTS: A random sample of 1145 children (51.7% boys; aged 7-12 years), representative of Mongolian elementary school children. RESULTS: Multivariate logistic regression analysis identified that total (past and current) HBV infection (OR 2.31, 95% CI 1.20 to 4.42; p = 0.012) was independently associated with the administration of all HB vaccines in winter. An increased OR for current HBV infection was also observed (OR 2.58, 95% CI 0.87 to 7.68; p = 0.089), but without significance. Interestingly, after stratifying by residence, the association between winter vaccination and total HBV infection was evident for rural (p = 0.008) but not for urban areas (p = 0.294). The frequency of vaccine-induced immunity was significantly (p = 0.007) lower for those who received HB vaccine at birth during winter in rural areas. CONCLUSION: Administration of HB vaccine during winter is an important predictor of the low effectiveness of vaccination in rural Mongolia. To improve the effectiveness of HB vaccination in remote areas, cold chain control should be addressed with particular attention to the winter season.

Seroepidemiology of hepatitis B virus infection among children in Mongolia: results of a nationwide survey.

BACKGROUND: Because Mongolia is one of the highly endemic countries for hepatitis B virus (HBV) infection in the world, hepatitis B (HB) vaccine was introduced into the National Expanded Program on Immunization in 1991. However, relatively few data are available concerning HBV infection among children born after the start of the program, so far. The aim of the present paper was to describe the seroepidemiology of HBV infection among primary school children using representative national data. METHODS: In 2004, a nationwide school-based cross-sectional serosurvey was carried out throughout Mongolia, covering both urban and rural areas. Serum samples were tested for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc) and hepatitis B e antigen (HBeAg) as well as for liver enzymes. RESULTS: A total of 1145 children aged 7-12 years were studied, which represents nearly 2% of the second grade population of elementary schools in Mongolia. The overall prevalence of HBsAg and anti-HBc was 5.2% (95% confidence interval [CI]: 3.9-6.5%) and 15.6% (95%CI: 13.5-17.7%), respectively. Among HBsAg-positive children 67.8% (95%CI: 55.9-79.7%) were also positive for HBeAg. The prevalence of chronic HBV infection increased by age and was significantly higher among children from rural areas compared to those from urban areas (7.7% vs 3.0%; P < 0.001). In the multivariate logistic regression analysis, rural residence (odds ratio [OR]: 2.57; 95%CI: 1.45-4.58), male sex (OR: 1.9; 95%CI: 1.08-3.26) and age (OR: 1.5; 95%CI: 1.10-2.05) were independent demographic predictors for chronic HBV infection. CONCLUSIONS: The prevalence of chronic HBV infection has been decreasing in the Mongolian young generation, most likely due to infant HB vaccination. However, significant rural-urban differences in the prevalence of HBV infection were found that demand further investigation to estimate the potential causes.

Hepatitis delta virus infection in mongolia: analyses of geographic distribution, risk factors, and disease severity.

The prevalence and risk factors for hepatitis delta virus (HDV) infection among Mongolian school children were assessed by detecting the antibody against HDV and HDV RNA, and through structured interviews. The study subjects consisted of 181 children with the past or ongoing hepatitis B virus infection who were investigated during the nationwide serosurvey conducted in 2004. The prevalence of antibody to HDV was 6.1%, with the proportion of 13.6% among hepatitis B surface antigen (HBsAg)-positive subjects, all of whom had HDV RNA. Multivariate logistic regression analyses showed that injections (> 11 times) (odds ratio [OR] = 8.31, 95% confidence interval [CI] = 1.28-54.07) and blood sampling (> 3 times) (OR = 5.34, 95% CI = 1.12-25.53) in health care settings, hospitalization (> 3 times) (OR = 6.20, 95% CI = 1.18-32.71), and cohabitating with patients with chronic hepatitis (OR = 4.57, 95% CI = 1.26-16.55) predicted the seropositivity for antibody to HDV. These results suggest that parenteral exposures in health care settings and household transmission are the main routes of HDV transmission among Mongolian children.

Body mass index and risk of stroke mortality among a random sample of Japanese adults: 19-year follow-up of NIPPON DATA80.

BACKGROUND: The relationship between body mass index (BMI) and stroke mortality remains unclear. The aim of the present study was to elucidate the relationship between BMI and stroke death in a representative cohort of Japanese men and women. METHODS: We analyzed a database of 9,526 men and women aged 30 years and older who were randomly selected throughout Japan in 1980. These individuals had no history of stroke and were followed for 19 years. Hazard ratios (HR) and their 95% confidence intervals (CI) of deaths due to total stroke, cerebral infarction, and intracerebral hemorrhage were examined using Cox's proportional hazards regression models of BMI levels. RESULTS: A U-shaped association between BMI and cerebral infarction mortality was observed. Participants with the highest BMI category (BMI > or = 30.0) showed a significantly highest HR for cerebral infarction (HR 2.46, 95% CI 1.01-5.99). The excess risk at the lower extreme of the BMI was confined to men. These associations did not change after excluding deaths occurring in the first 2 years of follow-up. CONCLUSIONS: In the Japanese general population, a U-shaped association between BMI and cerebral infarction mortality was found and the excess risk at the lower extreme of the BMI was confined to men.