The phrase "average virulence of the" is correct and usable in written English.
It can be used in scientific or medical contexts when discussing the typical severity or harmfulness of a pathogen or disease.
Example: "The researchers measured the average virulence of the bacteria in different environmental conditions."
Alternatives: "mean virulence of the" or "typical virulence of the".
Hence, accelerating epistasis can maintain parasite virulence when it would otherwise not occur and the average virulence of the parasite population under acceleratingly costly epistasis tends to be higher than that observed under linear or deceleratingly costly epistasis (Fig 5A).
As before, changes in the genetic composition and in average virulence of the virus population at equilibrium could be determined (Fig. 1B).
Another important difference between hosts is that average virulence of the virus population steadily increased with i and β e in melon, while it showed a relative minimum in tomato for low β e values and moderate aphid densities (Fig. 1A).
These simulations yielded data on the density of plants infected by isolates Y, A, N and M (Y, A, N and M plants), on which the relative frequency of Y, A, N and M isolates in the virus population could be determined and hence the average virulence of the population.
Note that variation in within- and between-host β e values had a limited effect on the average virulence of the virus population in Host 1, in spite of its dramatic effects on infection frequency, while the reduction in between-host β e values resulted in a reduction in both infection frequency and average virulence in Host 2, particularly noticeable at i < 5 (Fig. 2).
Interestingly, in both hosts, the average virulence of mixed infections was that of the more virulent genotype (N for Host 1, N and A for Host 2), a condition that according to some analyses should prevent genotype co-existence in mixed infections (Alizon 2008).
These data suggest considerable differences in the average virulence (paralytogenicity) of the 3 poliovirus types.
An interesting outcome of our analyses is that the effects of vector density on average virulence at equilibrium may differ broadly from its effects on infection frequency, again underscoring the complexity of the system.
Note that when direction of inoculums transmission between hosts changed, the average virulence did not vary in Host 1 in parallel with infection frequency, while it dramatically changed in Host 2 (compare virulence in both hosts for i ≤ 7, Fig. 3A,B).
To say that Dappy is all over his scantily clad co-star like a rash the moment the cameras are rolling would be to over-estimate the virulence of the average skin complaint.
On average, virulence was higher in accessions of group 2 when infected at vegetative than reproductive phase (mean values of 0.39±0.04 and 0.33±0.04, respectively).
