Calculating the basic reproductive rate Ro when there are 2 or more pathogens.
Some reasons why observed prevalences of the 3 major trypanosomes in cattle and livestock animals might not be independent are discussed. Apart from genuine interactions between the infections, averaging over heterogeneous populations produces an apparent correlation between pathogens. More subtly, chemotherapy and mortality both induce a positive correlation between pathogens. The calculation of the basic reproductive rate Ro for one pathogen in the endemic presence of another is explained, and illustrated by a simple calculation. Although multi-pathogen calculations are difficult, the calculation of Ro is both useful and feasible.
Baker
R D
RD
D000349:Africa / Q000453:epidemiology; D000818:Animals; D002417:Cattle; D008954:Models, Biological; D012098:Reproduction; D014345:Trypanosoma / Q000502:physiology*; D014346:Trypanosoma brucei brucei / Q000502:physiology*; D014348:Trypanosoma congolense / Q000502:physiology*; D014354:Trypanosomiasis, Bovine / Q000453:epidemiology / Q000401:mortality