W03　Establishing demographic surveillance systems for the studies of tropical medicine and international health (in English)

Matlab is a rural area of Bangladesh where ICDDR,B: Centre for Health and Population Research has been maintaining a Demographic Surveillance System (DSS) over 220,000 people since 1966. The Surveillance System collects information on births, deaths, migration (in, out, and internal), marriages, divorce and household splits. The system also maintains cross-sectional socioeconomic data and such data is available for 1974, 1982, 1996 and 2005. The DSS events are collected by the Community Health Research Worker through monthly household visits and supervised by the Field Research Assistant. In October 1977 an experimental maternal and child health and family planning (MCH-FP) programme was introduced in half (treatment area) of the DSS villages while the other half (comparison area) continued to receive limited services provided by the government programme. Since 1977 health (reproductive status, child health-ARI, diarrhoea, immunization etc) as well as contraceptive use data have been added to the system (initially in treatment area) while GIS information was added in the System in 1993. A Medical Assistant started reading VA and assigning cause of death code (ICD-9) since 1987 (since 1966 Health Assistant) and recently structured VA questionnaire has been administered to address the adulthood issue. The DSS provides sampling frame for all the studies conducted in Matlab and currently 20 studies are underway. The DSS site also allows testing intervention and clinical trials. Linking Surveillance data with socio-economic and special studies has widened the scope of research particularly in the area of poverty-health, health-equity, adult heath and so on.

【Background】The purpose of this study is to describe the fetal growth in a population where maternal malnutrition is prevalent, and to determine whether maternal nutritional supplementation introduced during the first trimester of pregnancy had more positive effect on fetal growth compared to the usual later introduction of maternal supplementation.【Methods】This study was conducted in a rural area of Bangladesh (Matlab) where the health and demographic surveillance system is maintained. All pregnant women were randomized to receive 600 kcal food supplementation beginning in early or late pregnancy and multiple micronutrients or iron and folic acid only. Enrolled women were examined by ultrasound first at 8-13 weeks of gestational age and 3 times during pregnancy. 【Results】Fetal growth during the first half of gestation approximated the 50th percentile of reference values except for abdominal circumference, which was significantly lower. At 31-36 week gestation, head and abdominal circumference as well as femur and tibia length were significantly below the 50th percentile of reference values. Neither the timing of food supplementation nor type of micronutrient supplement offered to the women in this study affected any measure of fetal growth at any of the 3 times at which it was assessed by ultrasound - except for femur and tibia length.【Conclusion】Various IUGR patterns were identified at various timing of gestation. This study did not provide support to shift from the current strategy of prenatal supplementation promoted by UNICEF and WHO.

The Lahanam demographic surveillance system was established in Lahanam zone of Songkhone district, Savannakhet province of Lao P.D.R. in 2004. It consists of six villages, and the total population is 4,413 of 713 households as of 1st September 2005. The Phu Thai ethnic group is dominant in five villages near Banghiang river, while Lao is dominant in the remaining village. There are one health centre, five primary schools and one secondary school in the area. The main subsistence is wet-rice cultivation. Between June and August in the rainy season, many villagers stay in their huts in the wet rice field 2-10km away from their village houses in order to cultivate the rice field. Cotton weaving is the popular source of cash income in this area.
The National Institute of Public Health (NIOPH), Ministry of Health of Lao P.D.R. is the main body of the study supported by Japanese institutions. The initial household and demographic census was conducted in 2004 and 2005. After the census, 16 field workers were trained and they are monthly visiting all the households for collecting demographic data The crude death rate between March 2005 and February 2006 was 19.5 per 1,000, and the crude birth rate was 30.8 per 1,000. The total fertility rate was 3.1. The study is focusing on the Thai liver fluke (Opisthorchis viverrini; Ov) infection, because this was the first DSS site established in the endemic area. Prevalence among school children was 62% before the mass-treatment in September 2004.

This program is one of the major activities of the project launched by Nagas aki University Institute of Tropical Medicine (NUTIM) in collaboration with Kenya Medical Research Institute (KEMRI) in September of 2005, aiming at est ablishment of a new framework for research activities on tropical diseases a nd health related problems in the East African countries. The concept of thi s project is to deploy various research programs based on research hypothese s, formulated using information rising from the demographic and health infor mation system. We selected two sites in Kenya; a part of Kwale and Suba dist ricts for the program. We have started a pilot study for demographic data co llection in Suba district covering 22,000 populations since August, 2006. We have deployed field assistants for mapping and interviewing in the communit ies. The mapping team uses the Satellite images and GPS (geographical positi oning system) units to produce digital maps of all dwelling units prior to d ata collection by interviewers. The interviewers use PDA (Personal Digital A ssistants) devices for data entry instead of paper questionnaire sheets. After collection of mapping and demographic data, we are going to move to data collection on pregnancy status, migration, morbidity, and mortality, includi ng verbal autopsy. The information collected by all the above system is supp osed to be linked interactively to each other and used comprehensively. In this presentation, we introduce the activities of the pilot study in Suba district of Kenya.