Seroprevalence and risk factors associated with infection among calves in Narok County, Kenya.

BACKGROUND AND AIM

East Coast fever (ECF), caused by , is a devastating disease that causes significant economic losses to cattle production in sub-Saharan Africa. Prevention and control of ECF are challenging in pastoral settings due to inadequate epidemiological information. This study aimed to estimate the seroprevalence and risk factors associated with infection among calves in different production systems to help design appropriate control interventions.

MATERIALS AND METHODS

Blood samples were collected from 318 calves and tested using an indirect enzyme-linked immunosorbent assay targeting antibodies against polymorphic immunodominant molecules found on the surface of . Information on calf characteristics and management practices was also collected during sampling. Descriptive statistics and logistic regression were used to analyze potential risk factors, such as age and acaricide application, where p < 0.05 was considered significant.

RESULTS

Of the 318 calves sampled, 41 (12.89%) were positive for , with a higher proportion in pastoral systems (36.58%) than in mixed farming systems (34.10%) and agropastoral systems (29.27%). From univariate analysis, calf age (p = 0.002), body weight (p = 0.001), suckling status (p = 0.026), rectal temperature (p = 0.06), calves on pasture (p = 0.022), other feeds (p = 0.004), feed grown within the farm (p = 0.004), acaricide application (p = 0.001), and acaricide application frequency (p = 0.001) were significantly associated with seropositivity. However, calf age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.91-0.99; p = 0.04), other feeds (OR, 8.82; 95% CI, 1.74-44.63; p = 0.009), and suckling status (OR, 0.38; 95% CI, 0.15-0.99; p = 0.05) were significantly associated with infection in the multivariable mixed logistic model.

CONCLUSION

is circulating in young calves in the study area (and possibly in cattle populations due to maternal transfer of antibodies to the calves). There is a need for molecular surveillance to determine the presence and burden of infection.