A Sentinel Survey in Remote Western Thailand Indicates that School-Aged Children and Reproductive-Aged Women of the Indigenous Pwo Karen Community are Iodine Sufficient

Indigenous peoples are often not routinely included in iodine programs because of language barriers and remote access, and may thus be at higher risk of iodine deficiency disorders, which could adversely impact their quality of life. We conducted this cross-sectional study in the remote Pwo Karen community of Thailand to determine the urinary iodine concentration (UIC) of school-aged children (SAC) and women of reproductive age (WRA) and investigate the iodine content in household salt. We measured UIC in spot urine samples from healthy SAC and WRA, administered a questionnaire, estimated daily iodine intake and collected household salt samples to determine salt iodine concentration. The median UIC (range) of SAC (n=170) was 192 (136 - 263) µg/L, which was significantly higher than WRA (n=306) [147 (89 - 233) µg/L] (P < 0.001). The estimated daily iodine intake in the SAC and WRA were 135 and 195 μg/day, respectively. The median (range) iodine concentration in rock and granulated salts consumed in the households were 2.32 (0.52 - 3.19) and 26.64 (20.86 - 31.01) ppm, respectively. Surprisingly, use of iodized salt and frequency of seafood consumption were not significant predictors of UIC in these two groups. Our data suggest that school children and women of the Pwo Karen community have sufficient iodine intake, indicating the Thai salt iodization program is effectively reaching even this isolated indigenous community. Sentinel surveys of remote vulnerable populations can be a useful tool in national iodine programs to ensure that program coverage is truly universal.