Endemic Townships Research Articles

Choice of health providers and health-seeking behaviour among forest goer population in Myanmar: findings from a cross-sectional household survey

BackgroundIn Myanmar, malaria still poses a significant burden for vulnerable populations particularly forest goers even though impressive progress has been made over the past decade. Limited evidence existed related to forest goers’ health-seeking behaviour and factors that drive decision making for providers’ choice to support national malaria programmes towards elimination. In response to that, this research is conducted to identify who they preferred and what are the factors associated with providers’ choice in malaria febrile illness and Rapid Diagnostic Testing (RDT).MethodsA cross-sectional study applying quantitative household survey was completed with 479 forest goer households in 20 malaria endemic townships across Myanmar. The household data was collected with the types of providers that they consulted for recent and previous febrile episodes. To identify the factors associated with providers’ choices, univariate and multivariate multinomial logistic regressions were done using Stata version 14.1. Statistical significance was set as p = 0.05.ResultsA total of 307 individuals experienced fever within one month and 72.3% sought care from providers. Also, a total of 509 forest goers reported that they had a previous febrile episode and 62.6% received care from a provider. Furthermore, 56.2% said that they had RDT testing during these previous febrile illnesses. They consulted public facilities and public health staff, private facilities, private and semi-private providers, community health volunteers or workers in their residing village and those located outside their villages but majority preferred those within their villages. On multivariate analyses, second richest quintile (public, RRR = 12.9) (semi-private, RRR = 17.9), (outside, RRR = 8.4) and access to 4 and above nearby providers (public, RRR = 30.3) (semi-private, RRR = 1.5) (outside, RRR = 0.5) were found to be significantly associated with provider choice for recent fever episode. Similar findings were also found for previous febrile illness and RDT testing among forest goers.ConclusionsIt was highlighted in this study that in forest goer households, they preferred nearby providers and the decision to choose providers seemed to be influenced by their access to number of nearby providers and socio-economic status when they sought care from a provider regardless of fever occurrence location. It was important that the national programmes considere involving these nearby providers in elimination efforts.

Key factors associated with malaria infection among patients seeking care through the public sector in endemic townships of Ayeyarwady Region, Myanmar

BackgroundAyeyarwady Region in Myanmar has made significant progress towards malaria elimination, with cases decreasing from 12,312 in 2015 to 122 in 2019. As transmission declines, malaria becomes increasingly focalized both in geographic hotspots and among population groups sharing certain risk factors. Developing a thorough profile of high-risk activities associated with malaria infections is critical to ensure intervention approaches are evidence-based.MethodsA test-negative study was conducted from September 2017 to May 2018 in Ngaputaw, Pathein and Thabaung townships in Ayeyarwady Region. Patients that presented to selected public facilities or community health volunteers with fever answered survey questions on demographic and behavioural risk factors, including exposure to malaria interventions, and were assigned to case and control groups based on the result of a malaria rapid diagnostic test. A random-effects logistic regression model adjusted for clustering at the facility level, as well as any variables along the causal pathway described by a directed acyclic graph, was used to determine odds ratios and association with malaria infections.ResultsA total of 119 cases and 1744 controls were recruited from 41 public facilities, with a mean age of 31.3 and 63.7% male. Higher risk groups were identified as males (aOR 1.8, 95% CI 1.2–2.9) and those with a worksite located within the forest (aOR 2.8, 95% CI 1.4–5.3), specifically working in the logging (aOR 2.7, 95% CI 1.5–4.6) and rubber plantation (aOR 3.0, 95% CI 1.4–6.8) industries. Additionally, links between forest travel and malaria were observed, with risk factors identified to be sleeping in the forest within the past month (aOR 2.6, 95% CI 1.1–6.3), and extended forest travel with durations from 3 to 14 days (aOR 8.6, 95% CI 3.5–21.4) or longer periods (aOR 8.4, 95% CI 3.2–21.6).ConclusionMalaria transmission is highly focalized in Ayeyarwady, and results illustrate the need to target interventions to the most at-risk populations of working males and forest goers. It will become increasingly necessary to ensure full intervention coverage of at-risk populations active in forested areas as Myanmar moves closer to malaria elimination goals.

Community-Based Screening for Hepatitis B and C Infectivity Using Two Quantitative Antigens to Identify Endemic Townships.

Screening and linkage to care are essential to achieve viral hepatitis elimination before 2030. The accurate identification of endemic areas is important for controlling diseases with geographic aggregation. Viral activity drives prognosis of chronic hepatitis B and hepatitis C virus infection. This screening was conducted in Chiayi County from 2018–2019. All residents aged 30 years or older were invited to participate in quantitative HBsAg (qHBsAg) and HCV Ag screening. Among the 4010 participants (male:female = 1630:2380), the prevalence of qHBsAg and HCV Ag was 9.9% (396/4010) and 4.1% (163/4010), respectively. High-prevalence townships were identified, three for qHBsAg > 15% and two for HCV Ag > 10%. The age-specific prevalence of qHBsAg was distributed in an inverse U-shape with a peak (16.0%, 68/424) for subjects in their 40 s; for HCV, prevalence increased with age. Concentrations of qHBsAg < 200 IU/mL were found in 54% (214/396) of carriers. The rate of oral antiviral treatment for HCV was 75.5% (114/151), with subjects younger than 75 years tending to undergo treatment (85.6% vs. 57.4%, p < 0.001). QHBsAg and HCV Ag core antigens can reflect the concentration of the viral load, which serves as a feasible screening tool. Using quantitative antigen screening for hepatitis B and C in community-based screening, two hyperendemic townships were identified from an endemic county.

Analysis of factors affecting health-related behaviors for schistosomiasis prevention and control among primary and secondary school students in Sichuan Province

To analyze the influencing factors of health-related behaviors for schistosomiasis prevention and control among primary and secondary school students in Sichuan Province using a multilevel and multivariate logistic model, so as to provide the theoretical evidence for developing the schistosomiasis prevention and control strategy among primary and secondary school students in Sichuan Province. A multi-stage sampling was conducted among 63 schistosomiasis-endemic counties (districts) in Sichuan Province. Five endemic townships were sampled from each county (district), and 100 Grade 4 to 6 students in each primary school and 100 Grade 1 to 3 students in each secondary school were sampled from each township as the study subjects. The health-related behaviors for schistosomiasis prevention and control were investigated using a questionnaire survey, and factors affecting infested water contact behaviors were identified using univariate and multilevel logistic analyses. Among the 62 200 questionnaires distributed, there were 59 134 recovered, and 56 510 were qualified. The qualified 56 510 respondents included 22 955 secondary school students and 33 555 primary school students, and 28 297 male students and 28 213 females. A higher proportion of infested water contacts was seen in male students than in females (P < 0.001), and the students living in heavily endemic areas had a higher proportion of infested water contacts than those in mildly endemic areas (P < 0.001). In addition, there was no significant difference in the proportion of infested water contacts between primary and secondary school students (P >0.05). Multilevel and multivariate logistic analyses revealed a lower proportion of infested water contacts with the increase of knowledge, belief and self-efficacy levels (P < 0.001), and there was a cluster of infested water contacts among students at a county scale (P < 0.001). There is a cluster of infested-water contact behaviors among primary and secondary school students at a county scale in Sichuan Province. Individual and environmental factors should be considered during the formulation of health education strategy and interventions for schistosomiasis among primary and secondary school students.

Socioeconomic and behavioural determinants of malaria among the migrants in gold mining, rubber and oil palm plantation areas in Myanmar

BackgroundMalaria is a major public health problem in Myanmar. Migrant populations are at high risk of contracting malaria and its control is more difficult than for settled population. Studies on malaria and migration are rare in Myanmar. This study was undertaken with the main objective of identifying socioeconomic and behavioural determinants of malaria among the migrant workers involved in gold mining, rubber and oil palm plantations.MethodsA cross-sectional analytic study was conducted using pretested interview-administered questionnaires among internal migrants (n = 406) in the malaria endemic townships of Shwegyin, Bago Region, Thanbyuzayat, Mon State and Kawthaung, Taninthayi Region from August to November, 2015. Data were collected by well-trained Basic Health Staff members in study areas, and then analysed by SPSS version 16.0 using Chi-square tests with significant level at 0.05.ResultsMajority of participants were male, Bahmar nationals, married and with primary basic education level and below. The mean duration of migratory work was 4.51 years. 43.1% of them gave definite previous history of malaria within last two years during migration. 92.9% (377/406) of them always used bed nets. Malaria determinants found were male gender (OR = 1.84, 95% CI: 1.22–2.77; P = 0.0040), habit of going out at dawn (OR = 2.36, 95% CI: 1.58–3.52; P < 0.001), usual sleeping indoors (OR = 2.14, 95% CI: 1.04–4.42; P = 0.036), torn bed net or net with large hole(s) (OR = 2.0, 95% CI: 1.21–3.3; P = 0.006), habit of not always sleeping under a bed net at night (OR = 2.02, 95% CI: 1.15–3.52; P = 0.014), alcohol drinking (OR = 2.71, 95% CI: 1.73–4.26; P < 0.001) and failure to attend malaria health talk (OR = 1.78, 95% CI: 1.2–2.65; P = 0.004).ConclusionsThe present study highlighted that it is warranted to launch an effective health education programme for malaria, and to encourage the proper use of insecticide-treated bed nets, blankets and/or mufflers and mosquito repellents to reduce the occurrence of malaria among the migrants.

Dose Response Relationship Between Arsenic Exposure From Drinking Water And End-Stage Renal Disease In Highly-Exposed Area In Taiwan

Background: There is a scarcity of epidemiological studies evaluating the association of arsenic exposure on kidney diseases. The aim of this study was to examine the association of chronic arsenic exposure from drinking water and end-stage renal disease (ESRD) in highly-exposed areas in Taiwan by long-term perspective study. Methods: The southwestern (SW) cohort was recruited from blackfoot disease endemic townships with high arsenic levels of 350–1140μg/L (median: 780μg/L) in their well water. The arsenic concentration in the wells was measured using the mercuric bromide stain method. The status of ESRD for study subjects was ascertained through linkage with the computerized Taiwan National Health Insurance (NHI) database from 1998 to 2009. Cox regression analysis was used to determine the hazard ratios (HRs) for developing ESRD. Results: A total of 98 ESRD patients were observed, corresponding to 465.6 per 100,000 person-years. Significant dose-response relationship between arsenic exposure indices and ESRD was observed after adjustment with potential confounding factors. The HRs were 1.00 (referent), 1.20 (0.54-2.69), 1.41 (0.69-2.89) and 2.25(1.14-4.45) in relation to lifetime cumulative arsenic exposure of

Dose response relationship between arsenic exposure from drinking water and Diabetes mellitus in high and low-to-moderate exposed area in Taiwan

Background: Epidemiological studies have shown that high level arsenic exposure is associated with type 2 diabetes (T2D). The association between low-to-moderate arsenic exposure and T2D remains inconclusive. The aim of this study was to examine the association of chronic arsenic exposure from drinking water and T2D across low to high levels in two exposed areas in Taiwan by long-term perspective study. Methods:The southwestern (SW) cohort was recruited from blackfoot disease endemic townships with high arsenic levels in their well water, while the northeastern (NE) cohort was recruited from four townships in the Lanyang Basin with low-to-moderate arsenic level. The status of diabetes for study subjects was ascertained through linkage with the computerized Taiwan National Health Insurance (NHI) database from 1998 to 2009.Cox regression analysis was used to determine the hazard ratios (HRs) and 95% confidence intervals (CIs) for developing newly-diagnosed T2D. Results: A total of 489 and 1,310 newly diagnosed diabetes patients, corresponding to 33.7 and 21.7 per 1000 person-years, were observed in SW and NE cohort, respectively. Significant dose-response relationship between arsenic and T2D was observed in SW cohort. The adjusted hazard ratio were 1.00 (referent), 1.16 (0.85-1.59), 1.31 (0.98-1.76) and 1.88 (1.39-2.53) in relation to cumulative arsenic exposure of 0, 0.1-9.9, 10.0-19.9 and?20.0 mg/L*years, respectively. No significant association was observed in NE cohort. However, among NE cohort with BMI &lt;20, people having consumed water with arsenic &gt;10?g/L had 74%~145% increased T2D risk when compared to those consuming water with arsenic ?10?g/L. Conclusions: Dose-response relationship between arsenic exposure from drinking water and T2D was consistently observed among highly-exposed study cohort. For people with low-to-moderate arsenic exposure, the association was more confined to those with lower BMI.

The association of diabetes mellitus with subsequent internal cancers in the arsenic-exposed area of Taiwan

BackgroundEpidemiological studies have shown that diabetes mellitus (DM) is associated with an increased risk of cancer. The aim of this study was to examine the association of diabetes with subsequent internal cancers in an arsenic-exposed area where the prevalence of diabetes is remarkably higher than in the general Taiwan population. MethodsThe southwestern cohort was recruited from blackfoot disease (BFD) endemic townships with high arsenic levels in their well water, while the northeastern cohort was recruited from four townships in the Lanyang Basin with low-to-moderate arsenic level in their well water. These two cohorts were combined and a total of 9525 subjects were recruited for the analysis. The disease status of the subjects, including diabetes, hypertension or dyslipidemia, was ascertained through linkage with the computerized Taiwan National Health Insurance (NHI) database, while the cancer status of the subjects was ascertained through linkage with National Cancer Registry and via the NHI database for major illness/injury certificates/catastrophic illness cards. The subjects were followed from study entry through December 31, 2009. Cox regression analysis with time-dependent DM status was used to determine the hazard ratios (HRs) and 95% confidence intervals (CIs) for developing internal malignancies. ResultsDiabetic patients had a 58% higher risk of any site internal cancer compared to non-DM individuals (HR, 1.58; 95% CI: 1.39–1.79) after adjusting for age, sex, education level, cigarette smoking, alcohol drinking, geographical location, cumulative arsenic exposure and history of hypertension or dyslipidemia. A significant association of DM with cancers of the stomach (HR, 1.75; 95% CI: 1.12–2.76), colon (HR, 1.76; 95% CI: 1.20–2.59), liver (HR, 2.46; 95% CI: 1.81–3.34), pancreas (HR, 2.80; 95% CI: 1.30–6.20) and lungs (HR, 1.35; 95% CI: 1.04–1.76) was observed. The association with lung, bladder and kidney cancer was largely confined to diabetic patients with arsenic level in consumed water ≧500μg/L, while the association with other cancer sites did not show such an effect. With the adjustment of arsenic exposure, marked attenuation for the association was observed, suggesting high level arsenic exposure plays an important role in the development of diabetes mellitus and concomitantly lung, bladder and kidney cancer.

Association between gallbladder stones and chronic hepatitis C: Ultrasonographic survey in a hepatitis C and B hyperendemic township in Taiwan

Gallbladder (GB) stones have been associated with several metabolic factors and liver diseases. This community-based study aimed at investigating the prevalence rate of GB stones and its associated factors in a hepatitis B virus (HBV)/hepatitis C virus (HCV)-endemic township in southern Taiwan. A total of 1701 residents (689 males and 1012 females; mean age: 51.2 ± 16.0 years) were enrolled in this prospectively designed screening project. Serum biochemistry tests, including testing for levels of serum aspartate aminotransferase, alanine aminotransferase (ALT), hepatitis B surface antigen (HBsAg), and antibody to HCV (anti-HCV) were conducted. In addition, a hepatobiliary ultrasonographic (US) examination was also conducted. Of the 1701 residents, 243 (14.3%) and 475 (27.9%) were found to be positive for HBsAg and anti-HCV, respectively. Results of the US examination revealed the prevalence rate of GB stone and fatty liver to be 6.8% and 55.6%, respectively. Using univariate analyses we found that significantly higher proportions of the participants with GB stone were male, over 50 years of age, positive for anti-HCV (p = 0.001, p < 0.001, and p = 0.001, respectively), with significantly higher mean age and ALT level (p ≤ 0.001 and p = 0.048, respectively) than did those without GB stone. By applying multivariate analyses, male gender, positive anti-HCV, and older age (>50 year) were identified as independent factors associated with the formation of GB stones. Anti-HCV was associated with GB stones in males but not in females in both univariate and multivariate analyses. GB stones were found to have a prevalence rate of 6.8% in this HCV/HBV hyperendemic township and are associated with higher mean age. A correlation between chronic hepatitis C and GB stones is observed only among males.

Application of a method of improving the quality of sampling in review to determine the light areas of endemic fluorosis in quality control

Objective To study an application of a method of improving the quality of sampling in review to determine the light areas of endemic fluorosis(referred to as endemic fluorosis) in quality control. Methods Of 15 light endemic fluorosis township(town), six were randomly sampled, and the prevalence of dental fluorosis in 22 village primary school children aged 8 to 12 were reviewed to determine the improved quality of sampling in Xuyong county Sichuan province. Results Six townships(towns) were selected by simple random sampling from 15 endemic fluorosis townships(towns) for review inspection in Xuyong country. A total of 22 villages were verified, accounting for 22.7％ of the total 97 villages verified. Of the 416 children for review inspection of dental fluorosis, 383 children were positive. The consistent rate of children' s dental fluorosis was 92.07％, and the verification to be slight villages was up to 21 endemic villages, accounting for 95.45％. Conclusions The application of a method of improving the quality of sampling can improve the efficiency of quality control, and improve the accuracy. It is a novel quality control method. Key words: Sampling studies; Fluoride poisoning; Quality control

Evolution of Hepatitis B and C serum markers: a still challenging issue

Evolution of Hepatitis B and C serum markers: a still challenging issue

Acquirement and disappearance of HBsAg and anti-HCV in an aged population: a follow-up study in an endemic township

HBsAg and anti-hepatitis C virus (anti-HCV) are stable markers and widely used. The seroconversion and seroclearance of HBsAg and anti-HCV are important for disease control and prognosis of diseases. To investigate acquirement and disappearance of HBsAg and anti-HCV in an endemic area. Seven years after a community screening, 1002 of 2909 residents of Tzukuan Township were recruited. HBsAg, anti-HCV and alanine transaminase (ALT) were checked in all who participated and hepatitis B virus (HBV) DNA, anti-HBs, anti-HBc, HCV RNA, anti-HDV and upper abdominal ultrasonography were studied in different groups. There were 461 male and 541 female residents with a mean age of 66.7 ± 8.6 years. No new HBsAg carrier was noted and the HBsAg clearance rate was 1.58% per year. One of the 17 cases with HBsAg clearance had positive HBV DNA, three had ALT elevation, two had cirrhosis and seven had anti-HBs seroconversion. Quantitative of HBsAg and HBV DNA were concordant and 78.1% subjects had low levels of titration. Anti-HBc alone contributed to 32.1% and was prominent in old age and the anti-HCV-positive group. The anti-HCV seroconversion rate was only 0.74% per year and household transmission was the only risk factor. Only 37.5% of cases with anti-HCV seroconversion had HCV viraemia and the anti-HCV seroreversion rate was 0.63% per year. The anti-HDV seroconversion rate was 0.72% per year and no subject showed anti-HDV clearance. Much higher rates of HBsAg seroclearance, anti-HCV seroreversion and anti-HBc alone were noted in this endemic area and no subject showed anti-HDV clearance.

Geographic variations of predominantly hepatitis C virus associated male hepatocellular carcinoma townships in Taiwan: identification of potential high HCV endemic areas

The proportion of B-HCC cases in Taiwan has progressively decreased over the last 20 years. It was not really due to an overall decrease in B-HCC but due to an increase in HCV-related HCC. The identification of potential HCV endemic areas in Taiwan has consequently become important. Data were collected retrospectively from eight Taiwan medical centers from 1981 to 2001, the geographical variations of male C-HCC townships in Taiwan were illustrated on maps. Goodness of fit was used to compare the anti-HCV prevalence in townships and cities, with the mean anti-HCV prevalence for Taiwan as a whole. Township-, city-, and county-specific prevalence of anti-HCV was presented as the median, ranges, and SMRs. Geographic variation can be analyzed in only 263 townships and cities. The maps were designed on the basis of different SMRs. The mean anti-HCV prevalence for male HCC patients in Taiwan was 31.9% (95% confidence interval: 30.7-33.0). Twenty-five townships distributed throughout central-western and south-western Taiwan have significantly higher prevalence (P < 0.05) (12 townships SMR >/= 2; 13 townships 1.5 </= SMR < 2). Twenty-two townships have significantly lower prevalence (P < 0.05) (6 townships 0.5 </= SMR<1; 16 townships SMR < 0.5). Four different patterns of geographic variation in different counties were also noted and demonstrated. We successfully highlighted some potential high HCV endemic townships in Taiwan.

Arseniasis prevalence and mortality in a multiethnic, endemic township in Guizhou, China

Farmers in Southwest Guizhou Autonomous Prefecture, China, represent a unique case of arseniasis, which is related to indoor combustion of high arsenic-containing coal instead of to arsenic-contaminated drinking water. A significant difference in the prevalence of arseniasis was observed in two neighboring ethnic clans in one village. The question arose whether the ethnicity-dependent difference observed in this village was more widely spread throughout the whole township. An epidemiologic investigation was designed to explore arseniasis distribution and mortality among all four ethnic groups in a multiethnic township. The cohort of arseniasis patients, diagnosed and registered in the overall field survey of 1991 as well as all the asymptomatic residents of the township, were enrolled in the present investigation. Indirect standardization was used for calculating the age-adjusted standardized incidence ratio (SIR) of arseniasis, the standardized mortality ratio (SMR) of various death causes (including some cancers), and their corresponding intervals of 95% confidence in both genders and in each local ethnic group. The descending rank of arseniasis SIRs among local ethnic groups was found as: Hui>Han>Bouyei>Hmong. The descending rank of SMRs of malignancies was displayed as: Han>Hui>Bouyei>Hmong in males and both genders together as well. Concerning deaths of non-malignant causes the rank was observed as: Hui>Han>Bouyei>Hmong in males. The arseniasis SIR for ethnic Hmong residents (both genders combined) was found to be significantly less profound than the overall level in the township. No death cases in diagnosed ethnic Hmong patients and no cases of death from malignant causes in asymptomatic Hmong residents were recorded. The significant increase of arseniasis prevalence was observed in all males, compared with the overall prevalence of all residents. However, a significantly lower prevalence was seen in all females. Significant ethnicity-dependent difference in arseniasis prevalence and mortality from all causes was found in a multiethnic rural township where farmers have been exposed to the indoor combustion of high arsenic coal for decades. The ethnic Hmong residents seemed to be the least susceptible to arseniasis among the four local ethnic groups.

Aflatoxin Exposure and Hepatitis C Virus in Advanced Liver Disease in a Hepatitis C Virus–Endemic Area in Taiwan

This community-based study evaluated the role of aflatoxin exposure in advanced liver disease in hepatitis C virus (HCV)-endemic townships. Preventive health examination was performed on 314 adults > or = 40 years of age recruited from HCV-endemic townships in Tainan, Taiwan. Aflatoxin-albumin in serum was quantified by a new enzyme-linked immunosorbent assay method. After adjusting serum albumin levels and platelet counts, aflatoxin-Bi albumin adducts was still an independent risk factor for advanced liver disease among all 314 residents (> 8 versus < or = 8 (AFBi)-albumin/albumin; OR = 2.29, 95% CI = 1.23-4.27, P = 0.009) and particularly in anti-HCV-positive subjects (OR = 2.09, 95% CI = 1.09-4.0, P = 0.026). Levels of AFB1-albumin/albumin were significantly related to ultrasonographic parenchyma scores (P < 0.001, one-way ANOVA) in all and anti-HCV-positive subjects. The findings indicated aflatoxin exposure may be associated with advanced liver disease in chronic hepatitis C patients in HCV-endemic regions in Taiwan.

A follow-up study of mortality among the arseniasis patients exposed to indoor combustion of high arsenic coal in Southwest Guizhou Autonomous Prefecture, China

This study was directed to ascertain the mortality of a group of arseniasis patients in an endemic rural township in Southwest China, where the residents were exposed for decades to indoor combustion of high arsenic coal. All the diagnosed arseniasis cases registered in 1991 were defined as the target population, which were assigned to three symptom subgroups by the severity of dermal lesions. The death cases were surveyed and checked. The follow-up period was 12.5 years. The standardized mortality ratio (SMR) of all death causes combined, all cancers combined, and the cancers at every site were analyzed. The age standardized mortality rates (ASMRs) were calculated in three subgroups using the procedure of standardization. One hundred and six death cases were recorded. Liver cirrhosis, non-melanotic skin cancer, lung and liver cancer were the four most prevalent death causes and referred to 70.8% (75/106) of the total death cases. The mortality of all death causes combined was not higher than that of the whole of China in 2001 (SMR = 0.76, 95% CI 0.63-0.93). The crude mortality rate of non-melanotic skin cancer in males reached up to 128.66/10(5). SMRs of lung cancer and larynx cancer in males (SMRs 2.84 and 27.27, 95% CIs 1.51-4.86 and 5.61-79.62, respectively) significantly exceeded the levels for all male Chinese. ASMRs of all death causes combined, all cancers combined and non-melanotic skin cancer in males of the severe dermal symptoms subgroup were significantly higher than those in medium and/or mild dermal symptom subgroups. A significantly increased mortality due to lung cancer and non-melanotic skin cancer was confirmed, alike the situation in other arseniasis endemic areas in the world. No significant elevation of mortality due to liver cancer and bladder cancer was observed. Male arseniasis patients diagnosed with severe skin lesions face higher risks of malignancies and of non-melanotic skin cancer in particular in the following years.

Hepatitis C virus infection among teenagers in an endemic township in Taiwan: epidemiological and clinical follow-up studies

The aim of the study was to elucidate the epidemiological features of Hepatitis C virus (HCV) infection among teenagers in an endemic area by conducting a mass screening study. We also investigated the clinical outcome of the anti-HCV-positive subjects by conducting subsequent short-term and long-term follow-up studies. All 2837 students of two junior middle schools in Tzukuan, aged 13-16 years, were invited to be screened for anti-HCV, HBsAg, AST and ALT in October 1995. A total of 2726 (96%) students responded. Anti-HCV, HCV RNA and aminotransferase levels were evaluated among anti-HCV-positive students 1 month and 30 months later, respectively. A total of 38 (1.4%; M/F = 22/16) participants were anti-HCV-positive. The anti-HCV-positive students had higher rates of exposures to transfusion, anti-HCV-positive families and surgery. The prevalence (2.8%) of the 7 maritime villages was markedly higher than that (0.7%) of the other 8 villages (P < 0.001). Subsequent follow-up studies demonstrated that there might be 5 cases of acute or recent HCV infection, and 6 cases who had recovered from chronic HCV infection.

Hepatitis C virus infection among teenagers in an endemic township in Taiwan: epidemiological and clinical follow-up studies

The aim of the study was to elucidate the epidemiological features of Hepatitis C virus (HCV) infection among teenagers in an endemic area by conducting a mass screening study. We also investigated the clinical outcome of the anti-HCV-positive subjects by conducting subsequent short-term and long-term follow-up studies. All 2837 students of two junior middle schools in Tzukuan, aged 13-16 years, were invited to be screened for anti-HCV, HBsAg, AST and ALT in October 1995. A total of 2726 (96%) students responded. Anti-HCV, HCV RNA and aminotransferase levels were evaluated among anti-HCV-positive students 1 month and 30 months later, respectively. A total of 38 (1.4%; M/F = 22/16) participants were anti-HCV-positive. The anti-HCV-positive students had higher rates of exposures to transfusion, anti-HCV-positive families and surgery. The prevalence (2.8%) of the 7 maritime villages was markedly higher than that (0.7%) of the other 8 villages (P < 0.001). Subsequent follow-up studies demonstrated that there might be 5 cases of acute or recent HCV infection, and 6 cases who had recovered from chronic HCV infection.

Excess mortality from hepatocellular carcinoma in an HCV-endemic township of an HBV-endemic country (Taiwan)

Taiwan is an endemic area of hepatitis B virus (HBV). All previous studies have concluded that HBV is the major cause of hepatocellular carcinoma (HCC) in Taiwan. An HBV- and hepatitis C virus (HCV)-endemic township, Tzukuan, in southern Taiwan has been identified with the prevalence of 24% for HB surface antigen (HBsAg) and 37% for anti-HCV antibodies. To elucidate the aetiology of HCC and impact of HCV in this township, we conducted a case-control study and compared HBV-related liver cancer mortality in Tzukuan and Taiwan as a whole. Based on cancer registration datasets of 2 medical centres from 1991 to 1995, we recruited 18 male and 9 female HCC cases from the study township. Their mean age (±standard deviation) was 60·3 (± 7.3) years. Randomly sampled from a community-based survey, 4 age- (± 2 years) and sex-matched residents were selected as community controls for each HCC case. The HBsAg carrier rate was 40·7% in cases and 25·0% in controls ( P = 0·1). Anti-HCV positive rate was 88·9% in cases and 53·7% in controls ( P = 0·008). Age-adjusted liver cancer mortality in Tzukuan (36·5 per 10 5) was significantly higher than that of Taiwan as a whole (20 per 10 5). Based on the HBsAg-positive rate among HCC patients (40·7% in Tzukuan and 77·4–86·6% in Taiwan), the estimated HBV-related liver cancer mortality was similar in Tzukuan (14·9 per 10 5) and Taiwan (15·8–17·3 per 10 5). We concluded that HCV was the major risk factor for excess liver cancer mortality in this HCV-endemic township of the HBV-endemic country.

Incidence of hepatitis C infection in a hepatitis C endemic township in southern Taiwan.

To realize the incidence of hepatitis C virus (HCV) infection in an HCV endemic township, Tzukuan, in Taiwan, we conducted a follow-up community-based survey. A total of 173 adults, 82 males and 91 females, with mean age of 55.5 +/- 9.9 years received initial and follow-up anti-HCV tests with one-year interval. One (1.2%, 95% CI: 0%-5.5%) of 84 anti-HCV-positive subjects was negative-seroconversion, and 4 (4.5%, 95% CI: 0.2%-8.8%) of 89 anti-HCV-negative subjects were positive-seroconversion. The results indicated that hepatitis C might be still spreading in the HCV-endemic area now.