Background: Several refugee settlements in Bangladesh have provided housing and medical care for the forciblydisplaced Myanmar nationals (FDMN, also known as Rohingya) population. The identification of malaria infection status in the refugee settlements is useful in treating infected persons and in developing malaria prevention recommendations. Assays for Plasmodium antigens and human IgG against Plasmodium parasites can be used as indicators to determine malaria infection status and exposure. Methods: Dried blood spot (DBS) samples (N = 1239) from a household survey performed April-May 2018 in three settlements in Cox's Bazar district, Bangladesh were utilized for a sample population of children from ages 1-14 years of age. The samples were tested using a bead-based multiplex antigen assay for presence of the pan-Plasmodium antigen aldolase as well as Plasmodium falciparum histidine rich protein 2 (HRP2). A bead-based multiplex assay was also used to measure human IgG antibody response to P. falciparum, Plasmodium malariae, and Plasmodium vivax merozoite surface protein 1 antigen (MSP1) isoforms, and P. falciparum antigens LSA1, CSP, and GLURP-R0. Results: There were no detectable Plasmodium antigens in any samples, suggesting no active malaria parasite infections in the tested children. IgG seroprevalence was highest to P. vivax (3.1%), but this was not significantly different from the percentages of children antibody responses to P. falciparum (2.1%) and P. malariae (1.8%). The likelihood of an anti-Plasmodium IgG response increased with age for all three malaria species. Evidence of exposure to any malaria species was highest for children residing 8-10 months in the settlements, and was lower for children arriving before and after this period of time. Conclusions: Absence of Plasmodium antigen in this population provides evidence that children in these three Bangladeshi refugee settlements did not have malaria at time of sampling. Higher rates of anti-malarial IgG carriage from children who were leaving Myanmar during the malaria high-transmission season indicate these migrant populations were likely at increased risk of malaria exposure during their transit.

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. Some recent studies suggest ongoing transmission of parasitic diseases in the American South; however, surveys in Mississippi children are lacking. We enrolled 166 children (median age 8 years, range 4–13 years) from the Mississippi Delta region and carried out multi-parallel real-time polymerase chain reaction (PCR) for Necator americanus , Ascaris lumbricoides , and Strongyloides stercoralis on their stool samples. Dried blood spots were obtained for multiplex serology antibody detection. Of 166 children, all reported having flushable toilets, 11% had soil exposure, and 34% had a pet dog or cat. None had prior diagnosis or treatment of parasitic disease. Multi-parallel real-time PCRs were negative on the 89 stool DNA extracts available for testing. Dried blood spot testing of all 166 children determined the seroprevalence of IgG antibodies to Toxocara spp . (3.6%), Cryptosporidium (2.4%), S. stercoralis , Fasciola hepatica , and Giardia duodenalis (all 0%). In conclusion, parasitic infections and exposure were scarce in this population. Larger studies of at-risk populations are needed.