Internal migration in Thailand

Modelling population dynamics and seasonal movement to assess and predict the burden of melioidosis

BACKGROUND

Melioidosis is an infectious disease that is transmitted mainly through contact with contaminated soil or water, and exhibits marked seasonality in most settings, including Southeast Asia. In this study, we used mathematical modelling to examine the impacts of such demographic changes on melioidosis incidence, and to predict the disease burden in a developing country such as Thailand.

METHODOLOGY/PRINCIPAL FINDINGS

A melioidosis infection model was constructed which included demographic data, diabetes mellitus (DM) prevalence, and melioidosis disease processes. The model was fitted to reported melioidosis incidence in Thailand by age, sex, and geographical area, between 2008 and 2015, using a Bayesian Markov Chain Monte Carlo (MCMC) approach. The model was then used to predict the disease burden and future trends of melioidosis incidence in Thailand. Our model predicted two-fold higher incidence rates of melioidosis compared with national surveillance data from 2015. The estimated incidence rates among males were two-fold greater than those in females. Furthermore, the melioidosis incidence rates in the Northeast region population, and among the transient population, were more than double compared to the non-Northeast region population. The highest incidence rates occurred in males aged 45-59 years old for all regions. The average incidence rate of melioidosis between 2005 and 2035 was predicted to be 11.42 to 12.78 per 100,000 population per year, with a slightly increasing trend. Overall, it was estimated that about half of all cases of melioidosis were symptomatic. In addition, the model suggested a greater susceptibility to melioidosis in diabetic compared with non-diabetic individuals.

CONCLUSIONS/SIGNIFICANCE

The increasing trend of melioidosis incidence rates was significantly higher among working-age Northeast and transient populations, males aged ≥45 years old, and diabetic individuals. Targeted intervention strategies, such as health education and awareness raising initiatives, should be implemented on high-risk groups, such as those living in the Northeast region, and the seasonally transient population.

Contraceptive Use among Women Migrants in Nang Rong, Thailand: An Exploratory Study

Understanding the dynamics of contraceptive use among women migrants is considered important, especially to a country like Thailand that is undergoing many changes, and an increasingly female-dominated migration during the last few decades. Using survey data collected in 2000, this study seeks to examine the determinants of modern contraceptive use among women migrants in Nang Rong, Thailand. The study found that several demographic and socioeconomic factors are significant predictors of contraceptive use among women migrants and the magnitude of such effects varies across different migrant types.

The legacies of context: past and present influences on contraceptive choice in Nang Rong, Thailand

This study explores the ways in which women's contraceptive behavior in a rural area of Thailand is shaped by both past and present context, based on the life course framework. Although the importance of contextual influences for contraceptive behavior is well established in the literature, relatively little research has been conducted that explores how behavior is influenced by historical and contemporaneous contextual factors and by individual life experiences. In addition, much of this research has neglected the role of the normative environment within which contraceptive use takes place. The focus of this paper centers on the effect of contraceptive environment at both early and late stages of the life course and on how this effect is shaped by individual experience with migration to urban areas. This study takes advantage of a unique, prospective longitudinal data set with detailed information on community context at multiple points in time, an important improvement upon prior research. The results show that contraceptive behavior is particularly responsive to current community context, with past context primarily exerting an indirect effect on behavior through shaping current contextual influences.

Containing pandemic influenza at the source

Highly pathogenic avian influenza A (subtype H5N1) is threatening to cause a human pandemic of potentially devastating proportions. We used a stochastic influenza simulation model for rural Southeast Asia to investigate the effectiveness of targeted antiviral prophylaxis, quarantine, and pre-vaccination in containing an emerging influenza strain at the source. If the basic reproductive number (R0) was below 1.60, our simulations showed that a prepared response with targeted antivirals would have a high probability of containing the disease. In that case, an antiviral agent stockpile on the order of 100,000 to 1 million courses for treatment and prophylaxis would be sufficient. If pre-vaccination occurred, then targeted antiviral prophylaxis could be effective for containing strains with an R0 as high as 2.1. Combinations of targeted antiviral prophylaxis, pre-vaccination, and quarantine could contain strains with an R(0) as high as 2.4.

Determinants of migration values and expectations in rural Thailand

"Based on the argument that values and expectations underlie behavioral motives, this study explores the determinants of migration-related values and expectations, and whether they are intervening factors in explaining intentions to move among residents of rural northeast Thailand. Data from the 1992 National Migration Survey of Thailand identify four migration-related value-expectancy dimensions: income, affiliation, stimulation, and comfort. Logistic regression analysis shows that landownership and being married are associated with higher expectations, while a diversified village economy, a village economy development program, and a younger and extended household structure are associated with lower expectations of attaining valued goals in the local rural village. The analysis also shows that value-expectancy concepts are only partial intervening explanations for intentions to move or stay."