Journal of Zoonotic Diseases (Jul 2023)
Effect of Deltamethrin Aerial Spraying in Controlling African Animal Trypanosomosis in Cattle in the Sesheke and Shang'ombo Districts of Western, Zambia
Abstract
Trypanosomosis is a vector-borne zoonotic disease transmitted by the tsetse fly (Glossina species). The condition is caused by protozoa known as Trypanosomes. In 2009, large-scale aerial spraying with deltamethrin at 0.26-0.3 g/ha, was undertaken in 5000 km2 covering parts of the Sesheke and Shang’ombo districts to control tsetse flies animal trypanosomosis in cattle in the area. Cattle were sampled for prevalence and incidence of trypanosomosis before, during, and, after aerial spraying as a circuitous way of detecting the presence of the primary vector (tsetse flies). Buffy coats, thick and thin dry smears were applied in the parasitological tests. In the baseline survey, 1,866 cattle were presented, and 25.7% (n = 481) were sampled and examined. Trypanosoma spp. was detected in 1.9% (n = 9) of animals. Six sentinel herds (four treatments and two controls) with 20 animals per herd were monitored for the incidence of AAT during and after aerial spraying, and prevalence was compared among the three phases. The results showed that no new case of trypanosomosis was detected in the treatment herd during the aerial spraying and three months into the postaerial spraying period except 0.83% (n = 1) in the control herd [Mid-P exact; p-value = 0.167 (1-tailed)]. This suggests an association between deltamethrin aerial spraying and trypanosomosis. In conclusion, there was a significant reduction in trypanosomosis prevalence following the aerial spraying operation. This indicates that aerial spraying significantly reduced the tsetse population and subsequently reduced disease transmission to cattle in the area. Furthermore, it indicates that aerial spraying was an effective method of controlling trypanosomosis in cattle. There is a need to extend this operation to other tsetse-infested areas in the country.
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