Anemia, iron deficiency, and thalassemia among the Thai population inhabiting at the Thailand-Lao PDR-Cambodia triangle.

Anemia is a major public health problem in many areas of Southeast Asia. Ascertaining anemia and defining its underlying causes is essential for providing appropriate care, management, and establishment of a control program. Limited studies on these have been carried out on people living at the borders of Thailand, Lao PDR, and Cambodia. This cross-sectional study was done in four areas along the borders of Thailand, Lao PDR, and Cambodia. Blood specimens were collected from subjects aged 15-18 years in four districts including Kantharalak, Si Sa Ket province (n = 36), Nam Khun (n = 109), Nam Yuen (n = 98), and Na Chaluai (n = 128), Ubon Ratchathani province, Thailand. RBC parameters were recorded, and serum ferritin (SF) level was measured. Diagnosis of thalassemia and hemoglobinopathies was based on hemoglobin (Hb) and DNA analyses. Measurement of C-reactive protein was performed to exclude false-negative result of iron deficiency. The prevalence of anemia was found to be 25.1%. ID accounted for only 10.5%. Various types of thalassemia were identified in 67.7% of the subjects. The overall prevalence of thalassemia included 3.5% α0-thalassemia, 0.8% ß-thalassemia, 47.7% Hb E, and 53.6% α+-thalassemia. The proportions of ID, thalassemia and combined ID and thalassemia among anemic subjects were 6.5%, 66.6%, and 20.4%, respectively. The results indicate that thalassemia and hemoglobinopathies rather than ID are major causes of anemia in Thailand-Lao PDR-Cambodia triangle. This information should prove useful for implementing an anemia control program in the regions.

Micromapping of Thalassemia and Hemoglobinopathies Among Laos, Khmer, Suay and Yer Ethnic Groups Residing in Lower Northeastern Thailand.

Northeastern (NE) Thailand is one of the areas with a prevalence of thalassemias and hemoglobinopathies. Data on the prevalence of the diseases in minorities in the region has been limited. This study aimed to survey the thalassemias and hemoglobinopathies that take into account ethnicity. Four ethnic groups, including Laos (n = 162), Khmer (n = 145), Suay (n = 134), and Yer (n = 101) inhabiting the lower region of NE Thailand, were selected to represent the study populations. The results demonstrated that an extremely high prevalence of Hb E (HBB: c.79G>A) (>50.0%) was observed in the Khmer, Suay and Yer ethnic groups. The highest prevalence of α+-thalassemia (α+-thal) [-α3.7 (rightward)] deletion was found in the Khmer ethnic group (48.28%). The -α4.2 (leftward) deletion (α+-thal) was restricted to the Yer ethnic group. Yer and Suay had a high incidence of Hb Constant Spring (Hb CS; HBA2: c.427T>C) as well as Hb Paksé (HBA2: c.429A>T). As the prevalence of α0-thalassemia (α0-thal) is relatively high in Suay (7.46%), couples who are members of Suay ethnic population should be urged to undergo hematological screening before planning a pregnancy to control the Hb Bart's hydrops fetalis. Micromapping of thalassemias and hemoglobinopathies herein described will be helpful in genetic counseling and public education campaigns, which should be carried out in appropriate languages, with exhibitions at the village levels. This information will be of benefit for the long-term effort to reduce the burden of severe thalassemia disease in the region.