Unraveling the epidemiology of tick-borne infections in cattle and the potential impact of a novel biopesticide in coastal Kenya

Samenvatting (Engelstalig)

Ticks pose a significant threat to livestock health and productivity in Africa, Asia, and Latin America, causing substantial economic losses, especially to resource-poor smallholder farmers. This thesis investigated the epidemiology of tick-borne pathogens (TBPs) and evaluated the effectiveness of entomopathogenic fungi (EPF) as a potential biological alternative to synthetic chemicals for tick control. We found a high diversity of TBPs in ticks and cattle, albeit with low infection rates. Risk variables assessed for TBP infection in cattle were not statistically significant. Laboratory and field experiments showed that the tick-killing effect of Tickoff biopesticide (a formulation of EPF) is delayed, which would hamper the direct protection of treated cattle, but could result in indirect protection by preventing onward transmission to other animals (both treated and untreated). Using a mathematical model, we show that sufficiently high levels of population coverage and treatment frequency are needed for EPF to reduce the tick population size and considerably reduce TBP transmission in cattle populations. Further, increasing the persistence time of EPF on cattle skin could substantially enhance its impact.