Fig. 1

Maps of Vietnam showing political division in provinces. a Location of Vietnam in Southeast Asia, showing areas where human strongyloidiasis has been previously analyzed in the country: Ho Chi Minh city (seroprevalence of 18.2%), Dak Lak in rural central highlands (42.4%), Hue in the central coast area (29.9%) and Hanoi city where the Medical University Hospital receiving the patients studied is located. b Distribution of urban and rural areas of northern Vietnam where the patients live. c Geographical map of northern Vietnam showing seroprevalences (in parentheses) according to the 27 provinces analyzed (for province names see corresponding numbers in Table 2)