Modeling the non-monetary societal burden of Tick-borne diseases for cattle: A case study of East Coast Fever in the traditional cattle-keeping households of Namwala District of Zambia

Abstract

The study aimed to estimate the disease burden of East Coast fever (ECF) among rural cattle-keeping households of Namwala District of Zambia using Productivity Adjusted Life Years(PALYs). We modified Disability Adjusted Life Year (DALY) equations for humans to PALYs to estimate the societal burden of tick-borne animal diseases. We used a structured questionnaire to collect data on parameters that feed into PALY equations. We coded and entered data from questionnaires directly into Statistical Package of Social Sciences (IBM SPSS Version 20) and entered the estimated values of PALY parameters into Mathematical Calculus Software called integral calculator (https://www.integral-calculator.com/). We then used the integral calculator to calculate PALY equations, which we used to estimate the societal disease burden of ECF in cattle. PALYs calculations were done in three categories; PALYs without discounting and age weighting, PALYs with only discounting, and PALYs with discounting and age weighting. Results revealed that the years of productivity lost by a cow, bull, and ox that suffered from ECF were estimated at 15, 10, and 15 years, respectively. In the second category, the years of productivity lost by a cow, bull, and ox were seven, six, and seven years, respectively. In the final category, the years of productivity lost by a cow, bull, and ox were five years. ECF caused a total of 517,165 PALYs in Namwala District. The quality of life reduced in years due to disability (YLD) caused by ECF per cow, bull, and ox was 0.07, 0.07, and 0.02 percent of their life expectancy, respectively. The estimated values for the years of a lifetime lost due to mortality (YLL) caused by ECF were 35%, 49%, and 35% of the life expectancy per cow, bull, and ox. These results are essential for measuring outcomes of animal health problems in terms of PALYs. The findings are helpful in future projections for the future burden of any disease and can be used as a basis in policy-making and decision-making, particularly priorities in animal health research. We recommend that a classification of animal diseases of national economic importance should consider both the societal burden (non-monetary) and economic impact instead of the common practice of only considering the economic (monetary) impact.