Failure of Mebendazole in Treatment of Human Hookworm Infections in the Southern Region of Mali

Abstract

Preliminary studies indicated that single-dose (500 mg) mebendazole gave disappointing results in the treat ment of hookworm infections (Necator americanus) in Mali. A placebo-controlled, randomized trial conducted with the participation of 103 infected subjects (background hookworm prevalence > 50%) confirmed that mebendazole (Vermox®) did not reduce parasite burdens significanfly, as assessed through fecal egg counts. In contrast, a group of subjects treated with pyrantel (Combantrin®) experienced a significant reduction in fecal worm egg counts (overall, both sexes combined showed a 75% reduction). Male subjects carried significantly more intense infections compared with females, but there was no gender difference in response to treatment. A standard egg hatch assay showed that N. americanus from our subjects in Mali was more resistant to benzimidazoles compared with a laboratory-maintained strain that had not been exposed to anthelmintics in more than 100 generations (50% effective dose = 0.12 and 0.07 p.g/ml of thiabendazole, DE CLERCQ AND OTHERSruniversitaire Raad (Flemish Inter University Council), Brussels, Belgium.

Prevalence and associated factors of soil transmitted helminthes infestation among preschool children of Vadamaradchi Educational Zone

“…At the same time, there are reports for anti helminthic resistance in Belgium (Geerts and Gryseels, 2001) and in Mali (De Clercq et al, 1997). Hence, the question arises, "is the anti helminthic prophylaxis used in a rational manner?"…”

In vitro and in vivo anthelmintic efficacy of plant cysteine proteinases against the rodent gastrointestinal nematode, Trichuris muris

“…Since each class of drugs has a specific mechanism of action (Martin, Robertson and Bjorn, 1997), resistance to one drug within each class automatically leads to resistance to all other drugs with the same mechanism of action (Michel, 1985). Anthelmintic resistance is not yet common amongst GI nematodes of humans, but already there are some indications that previously effective anthelmintics are losing efficacy (De Clercq et al 1997 ;Reynoldson et al 1997 ;Albonico et al 2003). Resistance is now a major threat to sheep and goat farming in the Southern hemisphere, with multiple drug-resistant parasites present (Varady et al 1993 ;Mwamachi et al 1995 ;van Wyk, Malan and Randles, 1997 ;Waruiru, Ngotho and Mukiri, 1998).…”

Assessment of the anthelmintic effect of natural plant cysteine proteinases against the gastrointestinal nematode,Heligmosomoides polygyrus,in vitro

“…This latter problem is by far the most important because frequent mass chemotherapy with the currently available anthelmintics has generated an environment favouring selection for resistant parasites. Resistance is now virtually global among GI nematodes of livestock (Waller, 1986 ;Gill & Lacey, 1998 ;Jackson & Coop, 2000), and there are some indications of resistance among GI nematodes of humans (Coles, 1995 ;de Clercq et al 1997 ;Reynoldson et al 1997). Resistance has already developed to the three drug classes in current use (the benzimidazoles, the imidazothiazoles/ tetrahydropyrimidines and the macrocyclic lactones), despite each class having a different mode of action (Coles, 1998 ;Martin & Robertson, 2000).…”