title: Efficacy and reinfection with soil-transmitted helminths 18-weeks post-treatment with albendazole-ivermectin, albendazole-mebendazole, albendazole-oxantel pamoate and mebendazole.
abstract: BACKGROUND
  Preventive chemotherapy with albendazole or mebendazole is the current strategy to control soil-transmitted helminth (STH) infections (i.e. Ascaris lumbricoides, hookworm and Trichuris trichiura). STH reinfections, in particular A. lumbricoides and T. trichiura occur rapidly after treatment with the standard drugs. However, their low efficacy against T. trichiura, made an accurate assessment of reinfection patterns impossible.
  
  
  METHODS
  In 2013 a randomised controlled trial was conducted on Pemba Island, Tanzania. School-aged children diagnosed positive for T. trichiura, were randomly allocated to (i) albendazole-ivermectin; (ii) albendazole-mebendazole; (iii) albendazole-oxantel pamoate; or (iv) mebendazole. Here we report the efficacy [cure rates (CR) and egg-reduction rates (ERR)], reinfection rates and new infections determined 18 weeks post-treatment.
  
  
  RESULTS
  For a total of 405 children complete baseline and follow-up data were available. Similar to the efficacy determined after 3 weeks, 18 weeks after treatment albendazole-oxantel pamoate showed a significantly higher efficacy against T. trichiura (CR: 54.0 %, 95 % CI: 43.7-64.0; ERR: 98.6 %, 95 % CI: 97.8-99.2) compared to the other treatment arms. Children treated with albendazole-oxantel pamoate or albendazole-ivermectin had fewer moderate infections compared to children treated with albendazole. The reinfection rates 18 weeks post-treatment among all treatment arms were 37.2 % for T. trichiura (95 % CI: 28.3-46.8), 34.6 % for A. lumbricoides (95 % CI: 27.3-42.3) and 25.0 % for hookworms (95 % CI: 15.5-36.6).
  
  
  CONCLUSIONS
  The moderate reinfection rates with STHs 18 weeks post-treatment support the concept of regular anthelminthic treatment in highly endemic settings. Combination chemotherapy might achieve decreased morbidity in children since in the albendazole plus oxantel pamoate and albendazole plus ivermectin treatment arms only few moderate T. trichiura infections remained. Further trials should investigate the long term efficacy of albendazole-oxantel pamoate (i.e. 6 and 12 month post-treatment) and after several rounds of treatment in order to develop recommendations for appropriate control approaches for STH infections.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN80245406.
authors.affiliation: Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. beni.speich@gmail.com.|University of Basel, Basel, Switzerland. beni.speich@gmail.com.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Speich
authors.affiliation: Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. wendelin.moser@unibas.ch.|University of Basel, Basel, Switzerland. wendelin.moser@unibas.ch.
authors.forename: Wendelin
authors.initials: W
authors.lastname: Moser
authors.affiliation: Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania. saidmali2003@yahoo.com.
authors.forename: Said M
authors.initials: SM
authors.lastname: Ali
authors.affiliation: Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania. shaaliame@yahoo.com.
authors.forename: Shaali M
authors.initials: SM
authors.lastname: Ame
authors.affiliation: Ivo de Carneri Foundation, Milan, Italy. albonico@tin.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Albonico
authors.affiliation: University of Basel, Basel, Switzerland. jan.hattendorf@unibas.ch.|Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland. jan.hattendorf@unibas.ch.
authors.forename: Jan
authors.initials: J
authors.lastname: Hattendorf
authors.affiliation: Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. jennifer.keiser@unibas.ch.|University of Basel, Basel, Switzerland. jennifer.keiser@unibas.ch.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Keiser
mesh_terms: D000293:Adolescent; D000871:Anthelmintics / Q000008:administration & dosage*; D001196:Ascariasis / Q000188:drug therapy* / Q000517:prevention & control*; D002648:Child; D004338:Drug Combinations; D005260:Female; D006725:Hookworm Infections / Q000188:drug therapy* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D010270:Parasite Egg Count; D012008:Recurrence; D055502:Secondary Prevention; D013636:Tanzania; D016896:Treatment Outcome; D014257:Trichuriasis / Q000188:drug therapy* / Q000517:prevention & control*
chemical_list: D000871:Anthelmintics; D004338:Drug Combinations