Indiscriminate use of agro-veterinary pesticides in plague endemic foci in Tanzania: potential risk for development of insecticide resistance in flea vectors
Background: Agro-veterinary pesticides are increasingly associated with the development of resistance in arthropod disease vectors. However, no has been conducted so far to assess such risk in flea vectors despite the indiscriminate use of pesticides in plague endemic foci in Tanzania.
Methods: We identified risk factors associated with the use of agro-veterinary pesticides, which could enhance development of resistance in flea vectors in two plague endemic districts, using structured questionnaire and direct observations.
Results: Excessive and injudicious use of agricultural and veterinary pesticides was common in both Lushoto and Mbulu district. Most farmers (80%, n=73) were applying agricultural pesticides over three times per cropping season, did not adhere to manufacturers recommended doses, and had limited or no knowledge on safety procedures and adverse effects associated with pesticides. Up to 49% were applying pesticides more than twice the recommended doses. About 91% of respondents in Lushoto and 93% respondents in Mbulu reported using agricultural pesticides. The three (3) out of fourteen (14) most commonly used agricultural pesticides in Lushoto were master kinga72WP (mancozeb 640g/kg+cymoxanil 80g/kg) (44%), suracron720EC (profenos 500g/l EC) (25.3%) and Sumo 5EC (lambda-cyhalothrin) (18.7%). The three (3) out of seventeen (17) most commonly used agricultural pesticides in Mbulu were Dursban50W (Chlorpyrifos) (29%), Duduban 450EC (Cypermethrin 10g/lt+chloropyrifos 35g/lt) (18%) and Dursban+farmerzeb (Chlorpyrifos 48%, Mancozeb 80%WP). Cybadip (Cypermethrin) (≥45%) and paranex (alphacypermethrin) (≥13%) were the most commonly used livestock pesticides.
Conclusion: This study identified injudicious uses and/or other malpractices, which enhance contamination of environments/surfaces with pesticides and consequently the exposure of flea vectors. Therefore, the flea vector populations in Lushoto and Mbulu districts are putatively under high risk of resistance development. Further studies are underway to confirm the insecticide resistance status, unravel distribution of the resistance, and involved resistance mechanisms.
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Posted 22 Jun, 2020
Indiscriminate use of agro-veterinary pesticides in plague endemic foci in Tanzania: potential risk for development of insecticide resistance in flea vectors
Posted 22 Jun, 2020
Background: Agro-veterinary pesticides are increasingly associated with the development of resistance in arthropod disease vectors. However, no has been conducted so far to assess such risk in flea vectors despite the indiscriminate use of pesticides in plague endemic foci in Tanzania.
Methods: We identified risk factors associated with the use of agro-veterinary pesticides, which could enhance development of resistance in flea vectors in two plague endemic districts, using structured questionnaire and direct observations.
Results: Excessive and injudicious use of agricultural and veterinary pesticides was common in both Lushoto and Mbulu district. Most farmers (80%, n=73) were applying agricultural pesticides over three times per cropping season, did not adhere to manufacturers recommended doses, and had limited or no knowledge on safety procedures and adverse effects associated with pesticides. Up to 49% were applying pesticides more than twice the recommended doses. About 91% of respondents in Lushoto and 93% respondents in Mbulu reported using agricultural pesticides. The three (3) out of fourteen (14) most commonly used agricultural pesticides in Lushoto were master kinga72WP (mancozeb 640g/kg+cymoxanil 80g/kg) (44%), suracron720EC (profenos 500g/l EC) (25.3%) and Sumo 5EC (lambda-cyhalothrin) (18.7%). The three (3) out of seventeen (17) most commonly used agricultural pesticides in Mbulu were Dursban50W (Chlorpyrifos) (29%), Duduban 450EC (Cypermethrin 10g/lt+chloropyrifos 35g/lt) (18%) and Dursban+farmerzeb (Chlorpyrifos 48%, Mancozeb 80%WP). Cybadip (Cypermethrin) (≥45%) and paranex (alphacypermethrin) (≥13%) were the most commonly used livestock pesticides.
Conclusion: This study identified injudicious uses and/or other malpractices, which enhance contamination of environments/surfaces with pesticides and consequently the exposure of flea vectors. Therefore, the flea vector populations in Lushoto and Mbulu districts are putatively under high risk of resistance development. Further studies are underway to confirm the insecticide resistance status, unravel distribution of the resistance, and involved resistance mechanisms.
Figure 1
Figure 2
Figure 3
Figure 4