TY - JOUR
T1 - Spatial distribution of acaricide profiles (Boophilus microplus strains susceptible or resistant to acaricides) in southeastern Mexico
AU - Rodríguez-Vivas, R. I.
AU - Rivas, A. L.
AU - Chowell, G.
AU - Fragoso, S. H.
AU - Rosario, C. R.
AU - García, Z.
AU - Smith, S. D.
AU - Williams, J. J.
AU - Schwager, S. J.
N1 - Funding Information:
This project was financially supported by CONACYT-SAGARPA Mexico (SAGARPA-2002-C01-1754). Thanks are also due to the farmers in the three states who generously gave their time and hospitality.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2007/5/15
Y1 - 2007/5/15
N2 - The ability of Boophilus microplus strains to be susceptible (-) or resistant (+) to amidines (Am), synthetic pyrethroids (SP), and/or organo-phosphates (OP) (or acaricide profiles) was investigated in 217 southeastern Mexican cattle ranches (located in the states of Yucatán, Quintana Roo, and Tabasco). Three questions were asked: (1) whether acaricide profiles varied at random and, if not, which one(s) explained more (or less) cases than expected, (2) whether the spatial distribution of acaricide profiles was randomly or non-randomly distributed, and (3) whether acaricide profiles were associated with farm-related covariates (frequency of annual treatments, herd size, and farm size). Three acaricide profiles explained 73.6% of the data, representing at least twice as many cases as expected (P < 0.001): (1) Am-SP-, (2) Am+SP+, and (3) (among ranches that dispensed acaricides ≥6 times/year) Am-OP+SP+. Because ticks collected in Yucatán ranches tended to be susceptible to Am, those of Quintana Roo ranches displayed, predominantly, resistance to OP/SP, and Tabasco ticks tended to be resistant to Am (all with P ≤ 0.05), acaricide profiles appeared to be non-randomly disseminated over space. Across states, two farm-related covariates were associated with resistance (P ≤ 0.02): (1) high annual frequency of acaricide treatments, and (2) large farm size. Findings supported the hypothesis that spatial acaricide profiles followed neither random nor homogeneous data distributions, being partially explained by agent- and/or farm-specific factors. Some profiles could not be explained by these factors. Further spatially explicit studies (addressing host-related factors) are recommended.
AB - The ability of Boophilus microplus strains to be susceptible (-) or resistant (+) to amidines (Am), synthetic pyrethroids (SP), and/or organo-phosphates (OP) (or acaricide profiles) was investigated in 217 southeastern Mexican cattle ranches (located in the states of Yucatán, Quintana Roo, and Tabasco). Three questions were asked: (1) whether acaricide profiles varied at random and, if not, which one(s) explained more (or less) cases than expected, (2) whether the spatial distribution of acaricide profiles was randomly or non-randomly distributed, and (3) whether acaricide profiles were associated with farm-related covariates (frequency of annual treatments, herd size, and farm size). Three acaricide profiles explained 73.6% of the data, representing at least twice as many cases as expected (P < 0.001): (1) Am-SP-, (2) Am+SP+, and (3) (among ranches that dispensed acaricides ≥6 times/year) Am-OP+SP+. Because ticks collected in Yucatán ranches tended to be susceptible to Am, those of Quintana Roo ranches displayed, predominantly, resistance to OP/SP, and Tabasco ticks tended to be resistant to Am (all with P ≤ 0.05), acaricide profiles appeared to be non-randomly disseminated over space. Across states, two farm-related covariates were associated with resistance (P ≤ 0.02): (1) high annual frequency of acaricide treatments, and (2) large farm size. Findings supported the hypothesis that spatial acaricide profiles followed neither random nor homogeneous data distributions, being partially explained by agent- and/or farm-specific factors. Some profiles could not be explained by these factors. Further spatially explicit studies (addressing host-related factors) are recommended.
KW - Acaricide resistance
KW - Boophilus microplus
KW - Mexico
KW - Spatial analysis
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U2 - 10.1016/j.vetpar.2007.01.016
DO - 10.1016/j.vetpar.2007.01.016
M3 - Article
C2 - 17349747
AN - SCOPUS:34147158715
VL - 146
SP - 158
EP - 169
JO - Veterinary Parasitology
JF - Veterinary Parasitology
SN - 0304-4017
IS - 1-2
ER -