A public health response against Strongyloides stercoralis: time to look at soil-transmitted helminthiasis in full

PLoS Negl Trop Dis. 2013 May 9;7(5):e2165. doi: 10.1371/journal.pntd.0002165. Print 2013.

Abstract

Strongyloides stercoralis infections have a worldwide distribution with a global burden in terms of prevalence and morbidity that is largely ignored. A public health response against soil-transmitted helminth (STH) infections should broaden the strategy to include S. stercoralis and overcome the epidemiological, diagnostic, and therapeutic challenges that this parasite poses in comparison to Ascaris lumbricoides, Trichuris trichiura, and hookworms. The relatively poor sensitivity of single stool evaluations, which is further lowered when quantitative techniques aimed at detecting eggs are used, also complicates morbidity evaluations and adequate drug efficacy measurements, since S. stercoralis is eliminated in stools in a larval stage. Specific stool techniques for the detection of larvae of S. stercoralis, like Baermann's and Koga's agar plate, despite superiority over direct techniques are still suboptimal. New serologies using recombinant antigens and molecular-based techniques offer new hopes in those areas. The use of ivermectin rather than benzimidazoles for its treatment and the need to have curative regimens rather than lowering the parasite burden are also unique for S. stercoralis in comparison to the other STH due to its life cycle, which allows reproduction and amplification of the worm burden within the human host. The potential impact on STH of the benzimidazoles/ivermectin combinations, already used for control/elimination of lymphatic filariasis, should be further evaluated in public health settings. While waiting for more effective single-dose drug regimens and new sensitive diagnostics, the evidence and the tools already available warrant the planning of a common platform for STH and S. stercoralis control.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Anthelmintics / therapeutic use
  • Communicable Disease Control / methods*
  • Drug Therapy, Combination / methods
  • Feces / parasitology
  • Global Health
  • Humans
  • Microscopy / methods
  • Neglected Diseases / diagnosis
  • Neglected Diseases / drug therapy
  • Neglected Diseases / epidemiology*
  • Neglected Diseases / prevention & control*
  • Parasitology / methods
  • Public Health Administration / methods*
  • Serologic Tests / methods
  • Strongyloidiasis / diagnosis
  • Strongyloidiasis / drug therapy
  • Strongyloidiasis / epidemiology*
  • Strongyloidiasis / prevention & control*

Substances

  • Anthelmintics

Grant support

This paper was produced as a result of a Meeting on “Optimizing Therapeutic Options for STH”, sponsored by the Bill & Melinda Gates Foundation, the Ministry of Health of the Province of Salta, Argentina and Fundación Mundo Sano, held in Oran, Salta, Argentina; 16 and 17 August 2011. This paper reflects the personal views of the authors and should not be interpreted to represent official policies or positions of their respective institutions. The Bill & Melinda Gates Foundation supported the participation of most international experts. MA was co-funded by the EC within the 7th Framework Program under grant agreement no. FP7-GA-261495 (COHEMI network). AFG's participation was supported by WHO. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.