Abstract
Language | English |
---|---|
Pages | 315-325 |
Number of pages | 11 |
Journal | Veterinary Parasitology |
Volume | 47 |
Issue number | 3-4 |
Publication status | Published - May 1993 |
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Keywords
- anthelmintic resistance
- Brazil
- computer simulation
- gene frequency
- sheep
- sheep diseases
- Haemonchiasis
- Haemonchus contortus
- drug resistance
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Model predictions for anthelmintic resistance amongst Haemonchus contortus populations in southern Brazil. / Echevarria, F.A.M.; Gettinby, G.; Hazelwood, S.
In: Veterinary Parasitology, Vol. 47, No. 3-4, 05.1993, p. 315-325.Research output: Contribution to journal › Article
TY - JOUR
T1 - Model predictions for anthelmintic resistance amongst Haemonchus contortus populations in southern Brazil
AU - Echevarria, F.A.M.
AU - Gettinby, G.
AU - Hazelwood, S.
N1 - I have added a scanned copy of the document
PY - 1993/5
Y1 - 1993/5
N2 - A computer model developed to study Ostertagia circumcincta resistance to anthelmintics in UK sheep flocks has been adapted for use with Haemonchus contortus under southern Brazilian conditions. The model simulates the effect of different anthelmintic control regimens on the year-to-year pattern of resistance in breeding ewes. The nematode control regimen most used by Brazilian sheep farmers was found to increase the frequency of genes which confer resistance from approximately 3% to 14% in an H. contortus population over a 20 year period. The effect of early versus late season anthelmintic treatment was investigated. This indicated that early season treatment would select for resistance rapidly, whereas late season treatments would not, owing to large numbers of untreated parasites accumulating at the beginning of the season. A model which can predict the development of anthelmintic resistance in parasites of ewes is a valuable tool in the understanding of the effect of different strategies on nematode control programmes and merits further consideration.
AB - A computer model developed to study Ostertagia circumcincta resistance to anthelmintics in UK sheep flocks has been adapted for use with Haemonchus contortus under southern Brazilian conditions. The model simulates the effect of different anthelmintic control regimens on the year-to-year pattern of resistance in breeding ewes. The nematode control regimen most used by Brazilian sheep farmers was found to increase the frequency of genes which confer resistance from approximately 3% to 14% in an H. contortus population over a 20 year period. The effect of early versus late season anthelmintic treatment was investigated. This indicated that early season treatment would select for resistance rapidly, whereas late season treatments would not, owing to large numbers of untreated parasites accumulating at the beginning of the season. A model which can predict the development of anthelmintic resistance in parasites of ewes is a valuable tool in the understanding of the effect of different strategies on nematode control programmes and merits further consideration.
KW - anthelmintic resistance
KW - Brazil
KW - computer simulation
KW - gene frequency
KW - sheep
KW - sheep diseases
KW - Haemonchiasis
KW - Haemonchus contortus
KW - drug resistance
UR - http://www.ncbi.nlm.nih.gov/pubmed/8333136
M3 - Article
VL - 47
SP - 315
EP - 325
JO - Veterinary Parasitology
T2 - Veterinary Parasitology
JF - Veterinary Parasitology
SN - 0304-4017
IS - 3-4
ER -