Figure 7: Chain migration model of MMWs. Cross-border microfilaremic MMWs who may or may not be treated with MDA 2 drugs in Myanmar become short-term migrant carriers initially after migration to Thailand. If external migration to Myanmar exists, there will be short-term migrant carriers due to discontinuing treatment (nonexposed) with the interventions available in permitted provinces. If internal migration in Thailand exists, there will be long-term migrants that appear to continue treatment (exposed). This long-term migration into Thailand will reflect reduction of microfilaremic infection among the cross-border MMWs.