Ayako Morita

Evaluation of colorimetric detection methods for Shigella, Salmonella, and Vibrio cholerae by loop-mediated isothermal amplification

We evaluated loop-mediated isothermal amplification end-point detection methods for Salmonella, Shigella, and Vibrio cholerae. Detection sensitivities were comparable to real-time PCR methods. The colorimetric dyes hydroxynaphthol blue and SYBR Green I showed increased sensitivity when compared to visual and automated turbidity readings. End-point colorimetric dyes promise great utility in developing settings.

Contribution of interaction with family, friends and neighbours, and sense of neighbourhood attachment to survival in senior citizens: 5-year follow-up study.

This study examines how social engagement with family, friends and neighbours and a sense of attachment to neighbourhood are associated with 5-year survival among senior citizens in Japan. A cohort study was conducted with 3283 seniors of Tokyo born in 1903, 1908, 1913, or 1918 who were recruited from stratified random sampling of resident registration records of two cities in the Tokyo metropolitan area. They were administered with a questionnaire in 1992, and the responses were compared with their 5-year survival status in 1997. Multiple logistic regression analyses indicated that activities with family, friends and neighbours are significant predictors of 5-year survival of senior citizens, independent of the baseline demographics, lifestyle and health status. The analysis further indicated that a sense of attachment to neighbourhood (i.e., expression of a desire to continue staying in the current residential area) significantly predicts 5-year survival of female senior citizens and enhances the survival benefits of activities with friends and neighbourhood activities. Our results highlight the importance of strengthening and enhancing the quality of community life to sustain the health and well-being of seniors and overcome challenges associated with an aging population.

Detection of enteric viral and bacterial pathogens associated with paediatric diarrhoea in Goroka, Papua New Guinea

OBJECTIVES The aim of this study was to investigate the viral and bacterial causes of acute watery diarrhoea in hospitalized children in Papua New Guinea. METHODS A retrospective analysis was conducted on stool samples collected from 199 children (age <5 years) admitted to the paediatric ward of Goroka General Hospital from August 2009 through November 2010. A large range of viral and bacterial enteric pathogens were targeted using real-time PCR/RT-PCR assays. RESULTS Young children were much more likely to be admitted with acute gastroenteritis, with 62.8% of patients aged <1 year and 88.4% aged <2 years. An enteric pathogen was detected in 69.8% (n=138) of patients. The most commonly detected pathogens were Shigella spp (26.6%), rotavirus (25.6%), adenovirus types 40/41 (11.6%), enterotoxigenic Escherichia coli (11.1%), enteropathogenic E. coli (8.5%), norovirus G2 (6.0%), and Campylobacter spp (4.0%). Norovirus G1, sapovirus, and Salmonella spp were also detected, but below our statistical limit of detection. Vibrio cholerae and astrovirus were not detected in any patients. Mixed infections were detected in 22.1% of patients, with Shigella and rotavirus most commonly detected in co-infections with other pathogens. CONCLUSIONS This study demonstrates that Shigella and rotavirus are the major pathogens associated with acute paediatric gastroenteritis in this setting.

Development, validation, and use of a semi-quantitative food frequency questionnaire for assessing protein intake in Papua New Guinean Highlanders

The aim of this article was to develop a semi‐quantitative food frequency questionnaire (FFQ) and evaluate its validity to estimate habitual protein intake, and investigate current dietary protein intakes of Papua New Guinea (PNG) Highlanders.

Association of protein intakes and variation of diet-scalp hair nitrogen isotopic discrimination factor in Papua New Guinea highlanders.

OBJECTIVES We present new nitrogen isotopic discrimination factor between diets and scalp hairs (Δ(15) NHair-Diet : δ(15) NHair - δ(15) NDiet ) for indigenous residents in three communities in the Papua New Guinea Highlands who consumed various amounts and qualities of protein. The Δ(15) N is important for precise evaluation of the dietary habits of human populations; in both contemporary and traditional lifestyles. Several hypotheses have been proposed regarding factors that affect Δ(15) N values, based largely on observations from animal feeding experiments. However, variations and factors controlling Δ(15) N in humans are not well understood, mainly due to the difficulty of controlling the diets of participants. MATERIALS AND METHODS These residents were studied because they have maintained relatively traditional dietary habits, which allow quantitative recording of diets. Δ(15) N was estimated by comparing hair δ(15) N values to mean dietary δ(15) N values calculated from the recorded intake of each food item and their δ(15) N values. RESULTS The results showed that: i) there was a significant difference in Δ(15) N among study locations (3.9 ± 0.9‰ for most urbanized, 5.2 ± 1.0‰ for medium and 5.0 ± 0.9‰ for least urbanized communities; range = 1.2-7.3‰ for all participants); and ii) estimated Δ(15) N values were negatively correlated with several indicators of animal protein intake (% nitrogen in diet: range = 0.9-7.6%). DISCUSSION We hypothesize that a combination of several factors, which presumably included urea recycling and amino acid and protein recycling and/or de novo synthesis during metabolic processes, altered the Δ(15) N values of the participants.

Impact of the 2011 Great East Japan Earthquake on community health: ecological time series on transient increase in indirect mortality and recovery of health and long-term-care system

Background The objectives were to clarify the trend in the cause-specific mortality rate and changes in health and long-term-care use after the Great East Japan Earthquake in 2011. Methods We obtained the following data from national sources: the number of deaths by cause, age and month; the amount of healthcare insurance expenditures by type of services, age and month; the amount of long-term-care insurance expenditures by type of services, age, care need and month. We estimated increase in standardised mortality rate postearthquake compared with pre-earthquake, and change in the standardised amount of health and long-term-care insurance expenditures post-earthquake compared with pre-earthquake in three severely affected prefectures, Iwate, Miyagi and Fukushima, by the adjustment for trends in the other prefectures. Results The risk of indirect mortality increased in the month of the earthquake (relative risk (RR) with 95% CI 1.20 (1.13 to 1.28) for those 60–69 years of age, 1.25 (1.17 to 1.32) for 70–79 years, and 1.33 (1.27 to 1.38) for 80 years and older). The amount of health and long-term-care insurance expenditures decreased among elderly persons in the month of the earthquake, and recovered to 95% of usual level within 1–5 months. Among cities and towns hit by tsunami, higher percentage of households flooded was associated with higher risk of indirect mortality (p<0.001), lower expenditures for outpatient medical care (p<0.001), and lower expenditures for home-care services (p<0.001). Conclusions This study showed transient increase in indirect mortality and recovery of health and long-term-care system after the earthquake.

Characterization of the gut microbiota of Papua New Guineans using reverse transcription quantitative PCR.

There has been considerable interest in composition of gut microbiota in recent years, leading to a better understanding of the role the gut microbiota plays in health and disease. Most studies have been limited in their geographical and socioeconomic diversity to high-income settings, and have been conducted using small sample sizes. To date, few analyses have been conducted in low-income settings, where a better understanding of the gut microbiome could lead to the greatest return in terms of health benefits. Here, we have used quantitative real-time polymerase chain reaction targeting dominant and sub-dominant groups of microorganisms associated with human gut microbiome in 115 people living a subsistence lifestyle in rural areas of Papua New Guinea. Quantification of Clostridium coccoides group, C. leptum subgroup, C. perfringens, Bacteroides fragilis group, Bifidobacterium, Atopobium cluster, Prevotella, Enterobacteriaceae, Enterococcus, Staphylococcus, and Lactobacillus spp. was conducted. Principle coordinates analysis (PCoA) revealed two dimensions with Prevotella, clostridia, Atopobium, Enterobacteriaceae, Enterococcus and Staphylococcus grouping in one dimension, while B. fragilis, Bifidobacterium and Lactobacillus grouping in the second dimension. Highland people had higher numbers of most groups of bacteria detected, and this is likely a key factor for the differences revealed by PCoA between highland and lowland study participants. Age and sex were not major determinants in microbial population composition. The study demonstrates a gut microbial composition with some similarities to those observed in other low-income settings where traditional diets are consumed, which have previously been suggested to favor energy extraction from a carbohydrate rich diet.

Great inclination to smoke among younger adults coming from low-socioeconomic class in Thailand

Background WHO estimates that 8.4 million deaths will be counted a year due to tobacco by 2020, and 70% of those deaths will occur in developing countries. Examination of the magnitude of socioeconomic differences in smoking between different age groups reveals specific groups anti-smoking programs should target on. This study aimed to measure socioeconomic gradients related inequality in smoking behavior among young and old Thai male population, where general progress in reduction on smoking prevalence has already shown. Methods Data of Thai males aged 21 years and older from Health and Welfare Survey and Socio-Economic Survey, Thailand, 2006 were used in the analyses. Variables in education, household income, age, marital status, and region of residence were used to examine their associations with smoking status. Results Of the 12,200 respondents, overall prevalence of smoking among males aged 21 years and older was 41.5%. Lower education was strongly associated with smoking (OR 3.15; 95% CI, 2.74-3.62). Youngest age, reside in South region and lowest income were more associated with smoking (OR = 2.66, 1.30, and 1.91, p < 0.05, respectively). Smoking among young adults (age 21-30) (OR = 5.88; 95% CI, 4.3-8.0) showed stronger gradients with educational level than that among older adults (OR = 3.96; 95% CI, 2.8-5.3). Conclusions The inverse associations between smoking prevalence and socioeconomic status among the Thai adult male population were consistently confirmed. The social gradient in smoking was greater among young adult males than that among older adult males.

Nitrogen fixation and nifH diversity in human gut microbiota.

It has been hypothesized that nitrogen fixation occurs in the human gut. However, whether the gut microbiota truly has this potential remains unclear. We investigated the nitrogen-fixing activity and diversity of the nitrogenase reductase (NifH) genes in the faecal microbiota of humans, focusing on Papua New Guinean and Japanese individuals with low to high habitual nitrogen intake. A 15N2 incorporation assay showed significant enrichment of 15N in all faecal samples, irrespective of the host nitrogen intake, which was also supported by an acetylene reduction assay. The fixed nitrogen corresponded to 0.01% of the standard nitrogen requirement for humans, although our data implied that the contribution in the gut in vivo might be higher than this value. The nifH genes recovered in cloning and metagenomic analyses were classified in two clusters: one comprising sequences almost identical to Klebsiella sequences and the other related to sequences of Clostridiales members. These results are consistent with an analysis of databases of faecal metagenomes from other human populations. Collectively, the human gut microbiota has a potential for nitrogen fixation, which may be attributable to Klebsiella and Clostridiales strains, although no evidence was found that the nitrogen-fixing activity substantially contributes to the host nitrogen balance.

Healthcare use for communicable diseases among migrant workers in comparison with Thai workers.

This study examines healthcare use in 2011 for communicable diseases among migrant workers compared with Thai workers in Thailand. The relative risks (RRs) of 14 communicable diseases (803,817 cases between ages 18 and 59) were calculated using the National Epidemiological Surveillance System, a nationwide hospital database. Regarding the migrant workers, 71.0% were Burmese and 17.3% were Cambodians. Significantly high comparative RRs for migrant workers were found for tuberculosis (TB) (male, RR=1.41; female, RR=2.33), sexually transmitted infections (STIs) (male, RR=2.39; female, RR=1.64), and malaria (male, RR=8.31; female, RR=11.45). Significantly low comparative RRs for migrant workers were found for diarrhea (male, RR=0.39; female, RR=0.28), food poisoning (male, RR=0.33; female, RR=0.24), dengue (male, RR=0.82; female, RR=0.68), and others. By occupation, RRs for TB and STIs were high among laborers but low among farmers. RRs for malaria among farmers (male, RR=18.26, female, RR=25.49) was higher than among laborers (male, RR=10.04; female, RR=13.93). The study indicated a higher risk of TB, STIs, and malaria for migrant workers, but a lower risk of diarrhea, food poisoning, dengue, and others. Although general health support program for migrants have promoted maternal and child health, prevention of communicable diseases should be further strengthened to meet the needs of migrants.