The pathological importance of mixed viral infections in plants might be underestimated
except for a few well-characterized synergistic combinations in certain crops. Considering …

Why is it that some parasites cause high levels of host damage (ie virulence) whereas others
are relatively benign? There are now numerous reviews of virulence evolution in the …

Standard virulence evolution theory assumes that virulence factors are maintained because
they aid parasitic exploitation, increasing growth within and/or transmission between hosts …

Infections that consist of multiple parasite strains or species are common in the wild and are
a major public health concern. Theory suggests that these infections have a key influence on …

Co-infections by multiple pathogen strains are common in the wild. Theory predicts co-
infections to have major consequences for both within-and between-host disease dynamics …

Parasites can dramatically reduce the fitness of their hosts, and natural selection should
favor defense mechanisms that can protect hosts against disease. Much work has focused …

Tolerance, the ability of a host to limit the negative fitness effects of a given parasite load, is
now recognised as an important host defence strategy in animals. Together with resistance …

The COVID‐19 pandemic has led to a resurgence of the debate on whether host–parasite
interactions should evolve towards avirulence. In this review, we first show that SARS‐CoV …

Infectious diseases could be expected to evolve towards complete avirulence to their hosts if
given enough time. However, this is not the case. Often, virulence is maintained because it is …

Double infections of related or unrelated viruses frequently occur in single plants, the viral
agents being inoculated into the host plant simultaneously (co‐infection) or sequentially …