The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms.
Current efforts to control human soil-transmitted helminth (STH) infections involve the periodic mass treatment of people, particularly children, in all endemic areas, using benzimidazole and imidothiazole drugs. Given the fact that high levels of resistance have developed to these same drugs in rou...
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ftdoajarticles:oai:doaj.org/article:1abf7e6fb22446f296ba226f7d8784ca 2023-05-15T15:17:29+02:00 The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. Andrew C Kotze Steven R Kopp 2008-01-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0000297 https://doaj.org/article/1abf7e6fb22446f296ba226f7d8784ca EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC2553282?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 doi:10.1371/journal.pntd.0000297 1935-2727 1935-2735 https://doaj.org/article/1abf7e6fb22446f296ba226f7d8784ca PLoS Neglected Tropical Diseases, Vol 2, Iss 10, p e297 (2008) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2008 ftdoajarticles https://doi.org/10.1371/journal.pntd.0000297 2022-12-31T06:28:15Z Current efforts to control human soil-transmitted helminth (STH) infections involve the periodic mass treatment of people, particularly children, in all endemic areas, using benzimidazole and imidothiazole drugs. Given the fact that high levels of resistance have developed to these same drugs in roundworms of livestock, there is a need to monitor drug efficacy in human STHs. The faecal egg count reduction test (FECRT), in which faecal egg output is measured pre- and post-drug treatment, is presently under examination by WHO as a means of detecting the emergence of resistance. We have examined the potential impact of density dependent fecundity on FECRT data. Recent evidence with the canine hookworm indicates that the density dependent egg production phenomenon shows dynamic properties in response to drug treatment. This will impact on measurements of drug efficacy, and hence drug resistance. It is likely that the female worms that survive a FECRT drug treatment in some human cases will respond to the relaxation of density dependent constraints on egg production by increasing their egg output significantly compared to their pre-treatment levels. These cases will therefore underestimate drug efficacy in the FECRT. The degree of underestimation will depend on the ability of the worms within particular hosts to increase their egg output, which will in turn depend on the extent to which their egg output is constrained prior to the drug treatment. As worms within different human cases will likely be present at quite different densities prior to a proposed FECRT, there is potential for the effects of this phenomenon on drug efficacy measurements to vary considerably within any group of potential FECRT candidates. Measurement of relative drug efficacy may be improved by attempting to ensure a consistent degree of underestimation in groups of people involved in separate FECRTs. This may be partly achieved by omission of cases with the heaviest infections from a FECRT, as these cases may have the greatest potential to ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLoS Neglected Tropical Diseases 2 10 e297 |
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Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Andrew C Kotze Steven R Kopp The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
Current efforts to control human soil-transmitted helminth (STH) infections involve the periodic mass treatment of people, particularly children, in all endemic areas, using benzimidazole and imidothiazole drugs. Given the fact that high levels of resistance have developed to these same drugs in roundworms of livestock, there is a need to monitor drug efficacy in human STHs. The faecal egg count reduction test (FECRT), in which faecal egg output is measured pre- and post-drug treatment, is presently under examination by WHO as a means of detecting the emergence of resistance. We have examined the potential impact of density dependent fecundity on FECRT data. Recent evidence with the canine hookworm indicates that the density dependent egg production phenomenon shows dynamic properties in response to drug treatment. This will impact on measurements of drug efficacy, and hence drug resistance. It is likely that the female worms that survive a FECRT drug treatment in some human cases will respond to the relaxation of density dependent constraints on egg production by increasing their egg output significantly compared to their pre-treatment levels. These cases will therefore underestimate drug efficacy in the FECRT. The degree of underestimation will depend on the ability of the worms within particular hosts to increase their egg output, which will in turn depend on the extent to which their egg output is constrained prior to the drug treatment. As worms within different human cases will likely be present at quite different densities prior to a proposed FECRT, there is potential for the effects of this phenomenon on drug efficacy measurements to vary considerably within any group of potential FECRT candidates. Measurement of relative drug efficacy may be improved by attempting to ensure a consistent degree of underestimation in groups of people involved in separate FECRTs. This may be partly achieved by omission of cases with the heaviest infections from a FECRT, as these cases may have the greatest potential to ... |
format |
Article in Journal/Newspaper |
author |
Andrew C Kotze Steven R Kopp |
author_facet |
Andrew C Kotze Steven R Kopp |
author_sort |
Andrew C Kotze |
title |
The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
title_short |
The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
title_full |
The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
title_fullStr |
The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
title_full_unstemmed |
The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
title_sort |
potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2008 |
url |
https://doi.org/10.1371/journal.pntd.0000297 https://doaj.org/article/1abf7e6fb22446f296ba226f7d8784ca |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 2, Iss 10, p e297 (2008) |
op_relation |
http://europepmc.org/articles/PMC2553282?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 doi:10.1371/journal.pntd.0000297 1935-2727 1935-2735 https://doaj.org/article/1abf7e6fb22446f296ba226f7d8784ca |
op_doi |
https://doi.org/10.1371/journal.pntd.0000297 |
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PLoS Neglected Tropical Diseases |
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2 |
container_issue |
10 |
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e297 |
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