{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T09:38:01Z","timestamp":1792748281301,"version":"4.5.0"},"reference-count":58,"publisher":"American Society of Tropical Medicine and Hygiene","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,2,5]]},"abstract":"<jats:title>ABSTRACT.<\/jats:title>\n<jats:p>Deworming for pregnant women using a single dose of albendazole or mebendazole is recommended by the WHO in areas where the baseline prevalence of hookworm and\/or trichuriasis is &gt;20%. However, other helminths and protozoa infecting pregnant women are not affected by these drugs and dosages. To assess the prevalence and diversity of intestinal helminth and protozoan infections, we analyzed stool samples from pregnant women recently enrolled into a birth cohort, along a rural-urban gradient in northern coastal Ecuador from 2019 to 2022. Participants provided a stool sample in their third trimester (<jats:italic>n<\/jats:italic> = 444). Samples were concentrated by the Ritchie method and observed microscopically for the detection of cysts, eggs, and larvae. The overall prevalence of infection with one or more parasites was 69% (95% CI: 67\u201374%), ranging from 52% in urban participants to 76% in rural participants (percentile rank = 1.39, 95% CI: 1.07\u20131.87). This differential between urban and rural communities persisted when data were disaggregated into helminth and protozoan infections (prevalence = 19% and 46%, respectively, in urban participants compared with 42% and 58% among rural participants). The most prevalent helminth was <jats:italic>Ascaris lumbricoides<\/jats:italic> (27%), followed by <jats:italic>Trichuris trichiura<\/jats:italic> (13%) and hookworm (7.4%). <jats:italic>Hymenolepis nana<\/jats:italic>, <jats:italic>Strongyloides stercoralis<\/jats:italic>, and <jats:italic>Enterobius vermicularis<\/jats:italic> were also observed. Six protozoan pathogens were detected, including <jats:italic>Entamoeba histolytica\/dispar<\/jats:italic> (23%), <jats:italic>Giardia intestinalis<\/jats:italic> (5%), and <jats:italic>Balantidium coli<\/jats:italic>, along with nine protozoa that are nonpathogenic or of debated pathogenicity. The high infection burden and diversity of intestinal parasites found in this study highlight a need to revise strategies for preventing and treating intestinal parasitic infections in pregnant women.<\/jats:p>","DOI":"10.4269\/ajtmh.24-0164","type":"journal-article","created":{"date-parts":[[2024,11,26]],"date-time":"2024-11-26T14:27:51Z","timestamp":1732631271000},"page":"307-313","source":"Crossref","is-referenced-by-count":3,"title":["Diversity and Prevalence of Helminths and Protozoa Among Pregnant Women in Tropical Ecuador: Implications for Chemotherapy"],"prefix":"10.4269","volume":"112","author":[{"given":"Manuel","family":"Calvopina","sequence":"first","affiliation":[{"name":"One Health Research Group, Facultad de Medicina, Universidad de las Am\u00e9ricas (UDLA), Quito, Ecuador;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jesse","family":"Contreras","sequence":"additional","affiliation":[{"name":"Department of Epidemiology, University of Michigan, Ann Arbor, Michigan;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William","family":"Cevallos","sequence":"additional","affiliation":[{"name":"Instituto de Biomedicina, Facultad de Ciencias M\u00e9dicas, Universidad Central del Ecuador, Quito, Ecuador;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gwenyth","family":"Lee","sequence":"additional","affiliation":[{"name":"Rutgers Global Health Institute and Department of Biostatistics and Epidemiology, Rutgers University, New Brunswick, New Jersey;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karen","family":"Levy","sequence":"additional","affiliation":[{"name":"Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joseph N. S.","family":"Eisenberg","sequence":"additional","affiliation":[{"name":"Department of Epidemiology, University of Michigan, Ann Arbor, Michigan;"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2795","reference":[{"key":"b1","series-title":"Trends Parasitol","first-page":"547","article-title":"Soil-transmitted helminth infections: Updating the global picture","volume":"19","author":"de Silva","year":"2003"},{"key":"b2","series-title":"Guideline: Preventive Chemotherapy to Control Soil-Transmitted Helminth Infections in At-Risk Population Groups","year":"2017"},{"key":"b3","series-title":"Trans R Soc Trop Med Hyg","first-page":"457","article-title":"Global prevalence of intestinal parasitic infections and associated risk factors in pregnant women: A systematic review and meta-analysis","volume":"115","author":"Taghipour","year":"2021"},{"key":"b4","series-title":"BMC Public Health","first-page":"1071","article-title":"Prevalence and risk factors for intestinal parasitic infections in pregnant women residing in three districts of Bogot\u00e1, Colombia","volume":"18","author":"Espinosa Aranzales","year":"2018"},{"key":"b5","series-title":"Trans R Soc Trop Med Hyg","first-page":"521","article-title":"Hookworm infection in pregnancy","volume":"89","author":"Bundy","year":"1995"},{"key":"b6","series-title":"Lancet","first-page":"981","article-title":"Antenatal anthelmintic treatment, birthweight, and infant survival in rural Nepal","volume":"364","author":"Christian","year":"2004"},{"key":"b7","series-title":"Res Rep Trop Med","first-page":"219","article-title":"A review on strongyloidiasis in pregnant women","volume":"12","author":"Wikman-Jorgensen","year":"2021"},{"key":"b8","series-title":"PLoS Negl Trop Dis","first-page":"e2718","article-title":"Risk factors for soil-transmitted helminth infections during the first 3 years of life in the tropics; Findings from a birth cohort","volume":"8","author":"Menzies","year":"2014"},{"key":"b9","series-title":"Front Immunol","first-page":"53","article-title":"Are pregnant women with chronic helminth infections more susceptible to congenital infections?","volume":"5","author":"Abdoli","year":"2014"},{"key":"b10","series-title":"PLoS Negl Trop Dis","first-page":"e2419","article-title":"Update on the mapping of prevalence and intensity of infection for soil-transmitted helminth infections in Latin America and the Caribbean: A call for action","volume":"7","author":"Saboy\u00e1","year":"2013"},{"key":"b11","series-title":"Cochrane Database Syst Rev","first-page":"CD005547","article-title":"Effect of mass deworming with antihelminthics for soil-transmitted helminths during pregnancy","volume":"2021","author":"Salam","year":"2021"},{"key":"b12","series-title":"Goldman-Cecil Medicine 26th Edition","author":"Goldman","year":"2020"},{"key":"b13","year":"2024"},{"key":"b14","series-title":"Infect Dis (Auckl)","first-page":"117863361773229","article-title":"Climate change contribution to the emergence or re-emergence of parasitic diseases","volume":"10","author":"Short","year":"2017"},{"key":"b15","series-title":"Parasite Epidemiol Control","first-page":"e00217","article-title":"Geographic differences in the distribution of parasitic infections in children of Bolivia","volume":"14","author":"Camacho-Alvarez","year":"2021"},{"key":"b16","series-title":"J Trop Pediatr","first-page":"60","article-title":"High prevalence of soil-transmitted helminths in western Kenya: Failure to implement deworming guidelines in rural Nyanza Province","volume":"56","author":"Riesel","year":"2009"},{"key":"b17","series-title":"Am J Trop Med Hyg","first-page":"907","article-title":"Urban versus rural prevalence of intestinal parasites using multi-parallel qPCR in Colombia","volume":"104","author":"Bryan","year":"2021"},{"key":"b18","series-title":"J Family Med Prim Care","first-page":"1607","article-title":"Prevalence of intestinal parasites among rural and urban population in Puducherry, South India\u2014A community-based study","volume":"8","author":"Langbang","year":"2019"},{"key":"b19","series-title":"BMC Public Health","first-page":"117","article-title":"Epidemiology of intestinal parasitic infections in preschool and school-aged Ethiopian children: A systematic review and meta-analysis","volume":"20","author":"Chelkeba","year":"2020"},{"key":"b20","series-title":"Ann Trop Med Parasitol","first-page":"381","article-title":"Urban\/rural differences in prevalence and risk factors for intestinal helminth infection in southern Malawi","volume":"94","author":"Phiri","year":"2000"},{"key":"b21","series-title":"Popul Dev Rev","first-page":"59","article-title":"Slum definitions in urban India: Implications for the measurement of health inequalities","volume":"41","author":"Nolan","year":"2015"},{"key":"b22","series-title":"Guidelines for the Evaluation of Soil-Transmitted Helminthiasis and Schistosomiasis at Community Level","author":"Montresor","year":"1998"},{"key":"b23","series-title":"Ann Parasitol","first-page":"489","article-title":"Prevalence of intestinal parasitic infections among pregnant women in Bobo-Dioulasso (Burkina Faso)","volume":"67","author":"Sangar\u00e9","year":"2021"},{"key":"b24","series-title":"Am J Trop Med Hyg","first-page":"760","article-title":"Extensive multiparasitism in a village of Yunnan province, People\u2019s Republic of China, revealed by a suite of diagnostic methods","volume":"78","author":"Steinmann","year":"2008"},{"key":"b25","year":"2020"},{"key":"b26","author":"Dur\u00e1n Pincay","year":"2023"},{"key":"b27","series-title":"PLoS Negl Trop Dis","first-page":"e0011339","article-title":"Prevalence and associated risk factors of intestinal parasites among schoolchildren in Ecuador, with emphasis on the molecular diversity of Giardia duodenalis, Blastocystis sp. and Enterocytozoon bieneusi.","volume":"17","author":"Tapia-Veloz","year":"2023"},{"key":"b28","series-title":"MASKANA","first-page":"111","article-title":"Prevalencia de Cryptosporidium spp. y Giardia spp. en terneros, y su presencia en agua y en ni\u00f1os con problemas digestivos en el cant\u00f3n San Fernando, Ecuador","volume":"8","author":"Palacios","year":"2017"},{"key":"b29","series-title":"Appl Environ Microbiol","first-page":"4218","article-title":"Detection of zoonotic enteropathogens in children and domestic animals in a semirural community in Ecuador","volume":"82","author":"Vasco","year":"2016"},{"key":"b30","series-title":"Am J Trop Med Hyg","first-page":"1394","article-title":"Comparison of cytokine responses in Ecuadorian children infected with Giardia, Ascaris, or both parasites","volume":"96","author":"Weatherhead","year":"2017"},{"key":"b31","series-title":"Int J Acad Med","first-page":"171","article-title":"Identification of intestinal parasite infections and associated risk factors in indigenous Ts\u00e1chilas communities of Ecuador","volume":"5","author":"Calvopina","year":"2019"},{"key":"b32","series-title":"Int J Environ Res Public Health","first-page":"6901","article-title":"Influence of environmental pollution and living conditions on parasite transmission among indigenous Ecuadorians","volume":"19","author":"Gonz\u00e1lez-Ram\u00edrez","year":"2022"},{"key":"b33","series-title":"Am J Trop Med Hyg","first-page":"45","article-title":"High rates of exposures to waterborne pathogens in indigenous communities in the Amazon region of Ecuador","volume":"101","author":"Romero-Sandoval","year":"2019"},{"key":"b34","series-title":"Am J Phys Anthropol","first-page":"65","article-title":"Soil-transmitted helminth infection and intestinal inflammation among the Shuar of Amazonian Ecuador","volume":"170","author":"Cepon-Robins","year":"2019"},{"key":"b35","series-title":"Int J Epidemiol","first-page":"1517","article-title":"Cohort profile: The Ecuador Life (ECUAVIDA) study in Esmeraldas Province, Ecuador","volume":"44","author":"Cooper","year":"2015"},{"key":"b36","series-title":"PLoS Negl Trop Dis","first-page":"e0009972","article-title":"The epidemiology of soil-transmitted helminth infections in children up to 8 years of age: Findings from an Ecuadorian birth cohort","volume":"15","author":"Ster","year":"2021"},{"key":"b37","series-title":"BMJ Open","first-page":"e046241","article-title":"Gut microbiome, enteric infections and child growth across a rural-urban gradient: Protocol for the ECoMiD prospective cohort study","volume":"11","author":"Lee","year":"2021"},{"key":"b38","series-title":"Hydrobiologia","first-page":"4191","article-title":"History of limnology in Ecuador: A foundation for a growing field in the country","volume":"847","author":"Steinitz-Kannan","year":"2020"},{"key":"b39","series-title":"Cuadro Nacional de Medicamentos B\u00e1sicos, 9na. Edici\u00f3n","year":"2014"},{"key":"b40","year":"2016"},{"key":"b41","series-title":"S Afr Med J","first-page":"972","article-title":"Efficacy of albendazole against the whipworm Trichuris trichiura\u2014A randomised, controlled trial","volume":"94","author":"Adams","year":"2004"},{"key":"b42","year":"2013"},{"key":"b43","series-title":"PLoS Negl Trop Dis","first-page":"e682","article-title":"A meta-analysis of the effectiveness of albendazole compared with metronidazole as treatments for infections with Giardia duodenalis","volume":"4","author":"Solaymani-Mohammadi","year":"2010"},{"key":"b44","series-title":"World J Gastroenterol","first-page":"1215","article-title":"Albendazole versus metronidazole treatment of adult giardiasis: An open randomized clinical study","volume":"10","author":"Karabay","year":"2004"},{"key":"b45","series-title":"East Mediterr Health J","first-page":"787","article-title":"Efficacy of albendazole in giardiasis","volume":"7","author":"Baqai","year":"2001"},{"key":"b46","series-title":"Trans R Soc Trop Med Hyg","first-page":"84","article-title":"Albendazole as a treatment for infections with Giardia duodenalis in children in Bangladesh","volume":"87","author":"Hall","year":"1993"},{"key":"b47","series-title":"Lancet Infect Dis","first-page":"123","article-title":"Efficacy and safety of co-administered ivermectin and albendazole in school-aged children and adults infected with Trichuris trichiura in C\u00f4te d\u2019Ivoire, Laos, and Pemba Island, Tanzania: A double-blind, parallel-group, phase 3, randomised controlled trial","volume":"22","author":"H\u00fcrlimann","year":"2022"},{"key":"b48","series-title":"Antimicrob Agents Chemother","first-page":"227","article-title":"Single-dose tinidazole for the treatment of giardiasis","volume":"27","author":"Speelman","year":"1985"},{"key":"b49","series-title":"Int J Womens Health","first-page":"59","article-title":"Tinidazole in the treatment of bacterial vaginosis","volume":"1","author":"Armstrong","year":"2009"},{"key":"b50","series-title":"Antimicrob Agents Chemother","first-page":"4800","article-title":"Investigation of metronidazole use during pregnancy and adverse birth outcomes","volume":"56","author":"Koss","year":"2012"},{"key":"b51","series-title":"MMWR Recomm Rep","first-page":"1","article-title":"Sexually transmitted diseases treatment guidelines, 2010","volume":"59","author":"Workowski","year":"2010"},{"key":"b52","series-title":"Ectoparasites: Scabies","author":"Thomas","year":"2020"},{"key":"b53","series-title":"Lancet Glob Health","first-page":"e92","article-title":"Safety of oral ivermectin during pregnancy: A systematic review and meta-analysis","volume":"8","author":"Nicolas","year":"2020"},{"key":"b54","series-title":"Cuadro Nacional de Medicamentos B\u00e1sicos, 11a Revisi\u00f3n","year":"2022"},{"key":"b55","year":"2020"},{"key":"b56","series-title":"Preventive Chemotherapy in Human Helminthiasis. Coordinated Use of Anthelminthic Drugs in Control Interventions\u2014Guidelines for Health Professionals and Programme Managers","year":"2006"},{"key":"b57","series-title":"WHO Recommendations on Antenatal Care for a Positive Pregnancy Experience","year":"2016"},{"key":"b58","series-title":"Basic Laboratory Methods in Medical Parasitology","year":"1991"}],"container-title":["The American Journal of Tropical Medicine and Hygiene"],"original-title":[],"link":[{"URL":"https:\/\/www.ajtmh.org\/view\/journals\/tpmd\/112\/2\/article-p307.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.ajtmh.org\/downloadpdf\/journals\/tpmd\/112\/2\/article-p307.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/www.ajtmh.org\/downloadpdf\/journals\/tpmd\/112\/2\/article-p307.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,2,5]],"date-time":"2025-02-05T18:43:34Z","timestamp":1738781014000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ajtmh.org\/view\/journals\/tpmd\/112\/2\/article-p307.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,5]]},"references-count":58,"journal-issue":{"issue":"2"},"URL":"https:\/\/doi.org\/10.4269\/ajtmh.24-0164","relation":{},"ISSN":["0002-9637","1476-1645"],"issn-type":[{"value":"0002-9637","type":"print"},{"value":"1476-1645","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,2,5]]}}}