{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T16:13:19Z","timestamp":1780330399251,"version":"3.54.1"},"reference-count":35,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,1,13]],"date-time":"2021-01-13T00:00:00Z","timestamp":1610496000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2021,1,13]],"date-time":"2021-01-13T00:00:00Z","timestamp":1610496000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Malar J"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      Characterizing the genetic diversity of malaria parasite populations in different endemic settings (from low to high) could be helpful in determining the effectiveness of malaria interventions. This study compared\n                      <jats:italic>Plasmodium falciparum<\/jats:italic>\n                      parasite population diversity from two sites with low (pre-elimination) and high transmission in Senegal and Nigeria, respectively.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Parasite genomic DNA was extracted from 187 dried blood spot collected from confirmed uncomplicated\n                      <jats:italic>P. falciparum<\/jats:italic>\n                      malaria infected patients in Senegal (94) and Nigeria (93). Allelic polymorphism at\n                      <jats:italic>merozoite surface protein<\/jats:italic>\n                      1 (\n                      <jats:italic>msp1<\/jats:italic>\n                      ) and\n                      <jats:italic>merozoite surface protein<\/jats:italic>\n                      - 2 (\n                      <jats:italic>msp2<\/jats:italic>\n                      ) genes were assessed by nested PCR.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The most frequent\n                      <jats:italic>msp1<\/jats:italic>\n                      and\n                      <jats:italic>msp2<\/jats:italic>\n                      allelic families are the K1 and IC3D7 allelotypes in both Senegal and Nigeria. Multiplicity of infection (MOI) of greater that 1 and thus complex infections was common in both study sites in Senegal (Thies:1.51\/2.53; Kedougou:2.2\/2.0 for\n                      <jats:italic>msp<\/jats:italic>\n                      1\/2) than in Nigeria (Gbagada: 1.39\/1.96; Oredo: 1.35\/1.75]). The heterozygosity of\n                      <jats:italic>msp1<\/jats:italic>\n                      gene was higher in\n                      <jats:italic>P. falciparum<\/jats:italic>\n                      isolates from Senegal (Thies: 0.62; Kedougou: 0.53) than isolates from Nigeria (Gbagada: 0.55; Oredo: 0.50). In Senegal, K1 alleles was associated with heavy than with moderate parasite density. Meanwhile, equal proportions of K1 were observed in both heavy and moderate infection types in Nigeria. The IC3D7 subtype allele of the\n                      <jats:italic>msp2<\/jats:italic>\n                      family was the most frequent in heavily parasitaemic individuals from both countries than in the moderately infected participants.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>The unexpectedly low genetic diversity of infections high endemic Nigerian setting compared to the low endemic settings in Senegal is suggestive of possible epidemic outbreak in Nigeria.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s12936-020-03563-4","type":"journal-article","created":{"date-parts":[[2021,1,12]],"date-time":"2021-01-12T20:02:42Z","timestamp":1610481762000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Allelic diversity of MSP1 and MSP2 repeat loci correlate with levels of malaria endemicity in Senegal and Nigerian populations"],"prefix":"10.1186","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5720-8425","authenticated-orcid":false,"given":"Mary A.","family":"Oboh","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tolla","family":"Ndiaye","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Khadim","family":"Diongue","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yaye D.","family":"Ndiaye","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mouhamad","family":"Sy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Awa B.","family":"Deme","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mamadou A.","family":"Diallo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mamadou S.","family":"Yade","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah K.","family":"Volkman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aida S.","family":"Badiane","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alfred","family":"Amambua-Ngwa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daouda","family":"Ndiaye","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2021,1,13]]},"reference":[{"key":"3563_CR1","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1159\/000197327","volume":"36","author":"J Bl\u00fcmel","year":"2009","unstructured":"Bl\u00fcmel J, Burger R, Drosten C, Gr\u00f6ner A, G\u00fcrtler L, Heiden M, et al. Malaria. Transfus Med Hemother. 2009;36:48\u201360.","journal-title":"Transfus Med Hemother"},{"key":"3563_CR2","unstructured":"WHO. World malaria report 2019. Geneva, World Health Organization. https:\/\/www.who.int\/publications\/i\/item\/world-malaria-report-2019."},{"key":"3563_CR3","unstructured":"Programme national de lutte contre le paludisme (PNLP). Bulletin \u00e9pid\u00e9miologique annuel du paludisme au Senegal. Dakar. 2015. http:\/\/www.pnlp.sn\/telechargements\/Rapports\/Bulletin-Epidemiologique-Annuel-2015-du-Paludisme-au-Senegal.pdf."},{"key":"3563_CR4","unstructured":"Programme national de lutte contre le paludisme (PNLP). Bulletin \u00e9pid\u00e9miologique annuel du paludisme au Senegal. Dakar. 2017. https:\/\/fr.africacheck.org\/wp-content\/uploads\/2018\/04\/Senegal-paludisme-bulletin-annuel-2017-PNLP.pdf."},{"key":"3563_CR5","unstructured":"Federal Ministry of Health. Nigeria Malaria Indicator Survey (MIS) 2015. Abuja, 2015."},{"key":"3563_CR6","doi-asserted-by":"publisher","first-page":"104","DOI":"10.4314\/njpar.v38i1.19","volume":"38","author":"MA Oboh","year":"2017","unstructured":"Oboh MA, Idowu ET, Oyebola MK, Olukosi YA, Otubanjo O, Mafe M. Genetic diversity of Plasmodium falciparum among pregnant women in south-west Nigeria. Niger J Parasitol. 2017;38:104\u201310.","journal-title":"Niger J Parasitol."},{"key":"3563_CR7","doi-asserted-by":"publisher","first-page":"704","DOI":"10.4314\/ahs.v16i3.10","volume":"16","author":"OM Kolawole","year":"2016","unstructured":"Kolawole OM, Mokuolu OA, Olukosi YA, Oloyede TO. Population genomics diversity of Plasmodium falciparum in malaria patients attending Okelele Health Centre, Okelele, Ilorin, Kwara State, Nigeria. Afr Health Sci. 2016;16:704\u201311.","journal-title":"Afr Health Sci."},{"key":"3563_CR8","doi-asserted-by":"publisher","first-page":"26","DOI":"10.1186\/1475-2875-13-26","volume":"13","author":"MSO Ahmedou-Salem","year":"2014","unstructured":"Ahmedou-Salem MSO, Ndiaye M, Ouldabdallahi M, Lekweiry KM, Bogreau H, Konat\u00e9 L, et al. Polymorphism of the merozoite surface protein-1 block 2 region in Plasmodium falciparum isolates from Mauritania. Malar J. 2014;13:26.","journal-title":"Malar J."},{"key":"3563_CR9","doi-asserted-by":"publisher","first-page":"12","DOI":"10.1186\/1475-2875-2-12","volume":"2","author":"A Aubouy","year":"2003","unstructured":"Aubouy A, Migot-nabias F, Deloron P. Polymorphism in two merozoite surface proteins of Plasmodium falciparum isolates from Gabon. Malar J. 2003;2:12.","journal-title":"Malar J."},{"key":"3563_CR10","doi-asserted-by":"publisher","first-page":"458","DOI":"10.1186\/s12936-018-2611-z","volume":"17","author":"JT Chen","year":"2018","unstructured":"Chen JT, Li J, Zha GC, Huang G, Huang ZX, Xie D, et al. Genetic diversity and allele frequencies of Plasmodium falciparum msp1 and msp2 in parasite isolates from Bioko Island, Equatorial. Malar J. 2018;17:458.","journal-title":"Malar J."},{"key":"3563_CR11","doi-asserted-by":"publisher","first-page":"309","DOI":"10.1186\/s12879-015-1066-x","volume":"15","author":"TO Apinjoh","year":"2015","unstructured":"Apinjoh TO, Tata RB, Anchang-Kimbi JK, Chi HF, Fon EM, Mugri RN, et al. Plasmodium falciparum merozoite surface protein 1 block 2 gene polymorphism in field isolates along the slope of mount Cameroon: a cross\u2014sectional study. BMC Infect Dis. 2015;15:309.","journal-title":"BMC Infect Dis"},{"key":"3563_CR12","doi-asserted-by":"publisher","first-page":"589","DOI":"10.1016\/S1995-7645(13)60102-9","volume":"6","author":"SI Oyedeji","year":"2013","unstructured":"Oyedeji SI, Awobode HO, Anumudu C, Kun J. Genetic diversity of Plasmodium falciparum isolates from naturally infected children in north-central Nigeria using the merozoite surface protein-2 as molecular marker. Asian Pac J Trop Med. 2013;6:589\u201394.","journal-title":"Asian Pac J Trop Med."},{"key":"3563_CR13","doi-asserted-by":"publisher","first-page":"73","DOI":"10.1186\/s12936-015-0604-8","volume":"14","author":"H Mohammed","year":"2015","unstructured":"Mohammed H, Mindaye T, Belayneh M, Kassa M, Assefa A, Tadesse M, et al. Genetic diversity of Plasmodium falciparum isolates based on MSP-1 and MSP-2 genes from Kolla-Shele area, Arbaminch Zuria District, southwest Ethiopia. Malar J. 2015;14:73.","journal-title":"Malar J."},{"key":"3563_CR14","doi-asserted-by":"publisher","first-page":"343","DOI":"10.1093\/femsre\/fuw001","volume":"40","author":"JG Beeson","year":"2016","unstructured":"Beeson JG, Drew DR, Boyle MJ, Feng G, Fowkes FJI, Richards JS. Merozoite surface proteins in red blood cell invasion, immunity and vaccines against malaria. FEMS Microbiol Rev. 2016;40:343\u201372.","journal-title":"FEMS Microbiol Rev"},{"key":"3563_CR15","doi-asserted-by":"publisher","first-page":"757","DOI":"10.4161\/hv.6.9.12468","volume":"6","author":"VS Chauhan","year":"2010","unstructured":"Chauhan VS, Yazdani SS, Gaur D. Malaria vaccine development based on merozoite surface proteins of Plasmodium falciparum. Hum Vaccin. 2010;6:757\u201362.","journal-title":"Hum Vaccin."},{"key":"3563_CR16","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1186\/1475-2875-12-22","volume":"12","author":"A Agyeman-budu","year":"2013","unstructured":"Agyeman-budu A, Brown C, Adjei G, Adams M, Dosoo D, Dery D, et al. Trends in multiplicity of Plasmodium falciparum infections among asymptomatic residents in the middle belt of Ghana. Malar J. 2013;12:22.","journal-title":"Malar J."},{"key":"3563_CR17","doi-asserted-by":"publisher","first-page":"105","DOI":"10.3347\/kjp.2014.52.1.105","volume":"52","author":"J Kuesap","year":"2014","unstructured":"Kuesap J, Chaijaroenkul W, Ketprathum K, Tattiyapong P. Evolution of genetic polymorphisms of Plasmodium falciparum merozoite surface protein (PfMSP) in Thailand. Korean J Parasitol. 2014;52:105\u20139.","journal-title":"Korean J Parasitol"},{"key":"3563_CR18","doi-asserted-by":"publisher","first-page":"439","DOI":"10.1186\/s12936-018-2588-7","volume":"17","author":"MA Oboh","year":"2018","unstructured":"Oboh MA, Badiane AS, Ntadom G, Ndiaye YD, Diongue K, Diallo MA, et al. Molecular identification of Plasmodium species responsible for malaria reveals Plasmodium vivax isolates in Duffy negative individuals from southwestern Nigeria. Malar J. 2018;17:439.","journal-title":"Malar J."},{"key":"3563_CR19","doi-asserted-by":"publisher","first-page":"458","DOI":"10.1186\/s12936-016-1507-z","volume":"15","author":"BA Odugbemi","year":"2016","unstructured":"Odugbemi BA, Wright KO, Onajole AT, Kuyinu YA, Goodman OO, Odugbemi TO, et al. A malariometric survey of under\u2014fives residing in indoor residual spraying\u2014implementing and non-implementing communities of Lagos, Nigeria. Malar J. 2016;15:458.","journal-title":"Malar J."},{"key":"3563_CR20","first-page":"1","volume":"7","author":"O Babamale","year":"2016","unstructured":"Babamale O, Ugbomoiko U. Status of malaria infection in peri-urban community of north central region of Nigeria. J Bacteriol Parasitol. 2016;7:1\u20136.","journal-title":"J Bacteriol Parasitol."},{"key":"3563_CR21","unstructured":"Programme national de lutte contre le paludisme (PNLP). Cadre strat\u00e9gique national de lutte contre le paludisme au S\u00e9n\u00e9gal 2014\u20132018. http:\/\/www.pnlp.sn\/wp-content\/uploads\/2016\/08\/PNLP_CADRE_STRATEGIQUE.pdf."},{"key":"3563_CR22","doi-asserted-by":"publisher","first-page":"369","DOI":"10.1016\/S0035-9203(99)90120-7","volume":"93","author":"G Snounou","year":"1999","unstructured":"Snounou G, Zhu X, Spiripoon N, Jarra W, Thaithong S, Brown KN, et al. Biased distribution of msp1 and msp2 allelic variant in Plasmodium falciparum populations in Thailand. Trans R Soc Trop Med Hyg. 1999;93:369\u201374.","journal-title":"Trans R Soc Trop Med Hyg"},{"key":"3563_CR23","doi-asserted-by":"publisher","first-page":"373","DOI":"10.1186\/s12936-015-0861-6","volume":"14","author":"N Papa Mze","year":"2015","unstructured":"Papa Mze N, Ndiaye YD, Diedhiou CK, Rahamatou S, Dieye B, Daniels RF, et al. RDTs as a source of DNA to study Plasmodium falciparum drug resistance in isolates from Senegal and the Comoros Islands. Malar J. 2015;14:373.","journal-title":"Malar J."},{"key":"3563_CR24","doi-asserted-by":"publisher","first-page":"e0177559","DOI":"10.1371\/journal.pone.0177559","volume":"12","author":"H Mohammed","year":"2017","unstructured":"Mohammed H, Kassa M, Assefa A, Tadesse M, Kebede A. Genetic polymorphism of Merozoite Surface Protein-2 (MSP-2) in Plasmodium falciparum isolates from Pawe District, North West Ethiopia. PLoS One. 2017;12:e0177559.","journal-title":"PLoS One."},{"key":"3563_CR25","doi-asserted-by":"publisher","first-page":"219","DOI":"10.1016\/j.actatropica.2005.06.001","volume":"95","author":"PI Mayengue","year":"2007","unstructured":"Mayengue PI, Ndounga M, Davy MM, Tandou N, Ntoumi F. In vivo chloroquine resistance and prevalence of the pfcrt codon 76 mutation in Plasmodium falciparum isolates from the republic of Congo. Acta Trop. 2007;95:219\u201325.","journal-title":"Acta Trop"},{"key":"3563_CR26","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1093\/genetics\/89.3.583","volume":"89","author":"M Nei","year":"1978","unstructured":"Nei M. Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics. 1978;89:583\u201390.","journal-title":"Genetics"},{"key":"3563_CR27","doi-asserted-by":"publisher","first-page":"237","DOI":"10.1186\/s12936-016-1287-5","volume":"15","author":"F Kateera","year":"2016","unstructured":"Kateera F, Nsobya SL, Tukwasibwe S, Mens PF, Hakizimana E, Grobusch MP, et al. Malaria case clinical profiles and Plasmodium falciparum parasite genetic diversity: a cross sectional survey at two sites of different malaria transmission intensities in Rwanda. Malar J. 2016;15:237.","journal-title":"Malar J."},{"key":"3563_CR28","doi-asserted-by":"publisher","first-page":"3074803","DOI":"10.1155\/2016\/3074803","volume":"2016","author":"W Yavo","year":"2016","unstructured":"Yavo W, Konat\u00e9 A, Mawili-Mboumba DP, Kassi FK, Tshibola Mbuyi ML, Angora EK. Genetic polymorphism of msp1 and msp2 in Plasmodium falciparum isolates from C\u00f4te d\u2019Ivoire versus Gabon. J Parasitol Res. 2016;2016:3074803.","journal-title":"J Parasitol Res."},{"key":"3563_CR29","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1186\/s13071-017-1976-0","volume":"10","author":"M Niang","year":"2017","unstructured":"Niang M, Thiam LG, Loucoubar C, Sow A, Sadio BD, Diallo M, et al. Spatio-temporal analysis of the genetic diversity and complexity of Plasmodium falciparum infections in K\u00e9dougou, Southeastern Senegal. Parasit Vectors. 2017;10:33.","journal-title":"Parasit Vectors."},{"key":"3563_CR30","doi-asserted-by":"publisher","first-page":"1346","DOI":"10.1093\/infdis\/jiz305","volume":"220","author":"ME Roh","year":"2019","unstructured":"Roh ME, Tessema SK, Murphy M, Nhlabathi N, Mkhonta N, Vilakati S, et al. High genetic diversity of Plasmodium falciparum in the low-transmission setting of the Kingdom of Eswatini. J Infect Dis. 2019;220:1346\u201354.","journal-title":"J Infect Dis"},{"key":"3563_CR31","doi-asserted-by":"publisher","first-page":"213","DOI":"10.1016\/j.jmii.2014.01.004","volume":"48","author":"NK Ghanchi","year":"2015","unstructured":"Ghanchi NK, Hasan Z, Islam M, Beg MA. MAD 20 alleles of merozoite surface protein-1 (msp-1) are associated with severe Plasmodium falciparum malaria in Pakistan. J Microbiol Immunol Infect. 2015;48:213\u20138.","journal-title":"J Microbiol Immunol Infect"},{"key":"3563_CR32","doi-asserted-by":"publisher","first-page":"146","DOI":"10.4269\/ajtmh.2006.75.146","volume":"75","author":"M Henry","year":"2006","unstructured":"Henry M, Diallo I, Bordes J, Ka S, Pradines B, Diatta B, et al. Urban malaria in Dakar, Senegal: chemosusceptibility and genetic diversity of Plasmodium falciparum isolates. Am J Trop Med Hyg. 2006;75:146\u201351.","journal-title":"Am J Trop Med Hyg"},{"key":"3563_CR33","doi-asserted-by":"publisher","first-page":"607","DOI":"10.1046\/j.1365-3156.2001.00761.x","volume":"6","author":"G Peyerl-Hoffmann","year":"2001","unstructured":"Peyerl-Hoffmann G, Jelinek T, Kilian A, Kabagambe G, Metzger WG, von Sonnenburg F. Genetic diversity of Plasmodium falciparum and its relationship to parasite density in an area with different malaria endemicities in West Ouganda. Trop Med Int Health. 2001;6:607\u201313.","journal-title":"Trop Med Int Health."},{"key":"3563_CR34","doi-asserted-by":"crossref","unstructured":"Heidari A, Keshavarz H, B Rokni M, Jelinek T. Genetic diversity in merozoite surface protein msp1 and msp2 genes of Plasmodium falciparum in a major endemic region of Iran. Korean J Parasitol 2007;45:59\u201363.","DOI":"10.3347\/kjp.2007.45.1.59"},{"key":"3563_CR35","doi-asserted-by":"publisher","first-page":"95","DOI":"10.4103\/1947-2714.107524","volume":"5","author":"MM Hamid","year":"2013","unstructured":"Hamid MM, Mohammed SB, El Hassan IM. Genetic diversity of Plasmodium falciparum field isolates in Central Sudan inferred by PCR genotyping of merozoite surface protein 1 and 2. N Am J Med Sci. 2013;5:95\u2013101.","journal-title":"N Am J Med Sci."}],"container-title":["Malaria Journal"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1186\/s12936-020-03563-4.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/article\/10.1186\/s12936-020-03563-4\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1186\/s12936-020-03563-4.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,11]],"date-time":"2022-12-11T05:24:35Z","timestamp":1670736275000},"score":1,"resource":{"primary":{"URL":"https:\/\/malariajournal.biomedcentral.com\/articles\/10.1186\/s12936-020-03563-4"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,13]]},"references-count":35,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2021,12]]}},"alternative-id":["3563"],"URL":"https:\/\/doi.org\/10.1186\/s12936-020-03563-4","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2020.08.27.20183178","asserted-by":"object"}]},"ISSN":["1475-2875"],"issn-type":[{"value":"1475-2875","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,13]]},"assertion":[{"value":"23 September 2020","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"20 December 2020","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"13 January 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The study was ethically approved by the Institutional Review Board of the Nigerian Institute of Medical Research, Lagos and the Senegalese National Ethics committee. Written informed consent and\/or assent was obtained from the parents and guardian of children prior to recruitment.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare that they have no competing interests.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"38"}}