title: Control of tungiasis through intermittent application of a plant-based repellent: an intervention study in a resource-poor community in Brazil.
abstract: BACKGROUND
  Tungiasis, an ectoparasitosis caused by the female sand flea Tunga penetrans, is an important health problem in many impoverished communities in the tropics. Sand flea disease is associated with a broad spectrum of clinical pathology and severe sequels are frequent. Treatment options are limited.
  
  
  RESULTS
  We assessed the effectiveness of the intermittent application of the plant-based repellent Zanzarin to reduce infestation intensity and tungiasis-associated morbidity in a resource-poor community in Brazil, characterized by a very high attack rate. The study population was randomized into three cohorts. Initially, during a period of four weeks, the repellent was applied twice daily to the feet of all cohort members. This reduced the number of embedded sandfleas to 0 in 98% of the participants. Thereafter members of cohort A applied the repellent every second week twice daily for one week, members of cohort B every fourth week for one week, and members of cohort C served as controls. Infestation intensity and tungiasis-associated morbidity were monitored during five months. The intermittent application of Zanzarin for one week every second week significantly reduced infestation intensity from a median 4 lesions (IQR 1-9) during the whole transmission season. In contrast, in cohort B (application of the repellent every fourth week) the infestation intensity remained twice as high (median 8 lesions, IQR 9-16; p = 0.0035), and in the control cohort C 3.5 times as high (median 14 lesions; IQR 7-26; p = 0.004 during the transmission season). Tungiasis-related acute pathology remained very low in cohort A (median severity score 2; IQR 1-4) as compared to cohort B (median severity score 5; IQR 3-7; p<0.001), and control cohort C (median severity score 6.5; IQR 4-8; p<0.001).
  
  
  CONCLUSIONS
  Our study shows that in a setting with intense transmission, tungiasis-associated morbidity can be minimized through the intermittent application of a plant-based repellent.
authors.affiliation: Department of Microbiology and Hygiene, Campus Benjamin Franklin, Charité University Medicine, Berlin, Germany.
authors.forename: John
authors.initials: J
authors.lastname: Buckendahl
authors.forename: Jörg
authors.initials: J
authors.lastname: Heukelbach
authors.forename: Liana
authors.initials: L
authors.lastname: Ariza
authors.forename: Judith Dorothea
authors.initials: JD
authors.lastname: Kehr
authors.forename: Martin
authors.initials: M
authors.lastname: Seidenschwang
authors.forename: Hermann
authors.initials: H
authors.lastname: Feldmeier
mesh_terms: D000293:Adolescent; D000328:Adult; D000504:Aloe / Q000737:chemistry; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003059:Cocos / Q000737:chemistry; D015331:Cohort Studies; D003140:Communicable Disease Control; D004478:Ectoparasitic Infestations / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007302:Insect Repellents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010938:Plant Oils / Q000008:administration & dosage; D028321:Plant Preparations / Q000008:administration & dosage*; D011203:Poverty; D058253:Tunga / Q000187:drug effects*; D058285:Tungiasis / Q000188:drug therapy / Q000191:economics / Q000469:parasitology / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D007302:Insect Repellents; D010938:Plant Oils; D028321:Plant Preparations