Data for: Consequences of microsporidian prior exposure for virus infection outcomes and bumble bee host health

Host-parasite interactions do not occur in a vacuum but in connected
multi-parasite networks. Resulting co-exposures and coinfections during an
individual host’s lifetime can affect host health and infectious disease
ecology, including disease outbreaks. However, many host-parasite studies
examine pairwise interactions, meaning we still lack a general
understanding of the influence of co-exposures and coinfections. Using the
bumble bee Bombus impatiens, we study the effects of larval exposure to a
microsporidian, Nosema bombi, implicated in bumble bee declines, and adult
exposure to Israeli Acute Paralysis Virus (IAPV), an emerging
infectious disease from honey bee parasite spillover. We hypothesize that
infection outcomes will be modified by co-exposure or coinfection
depending on relevant temporal interactions, due to changes in host immune
allocation or condition. Nosema bombi is a potentially
severe, larval-infecting parasite, and we predict that prior exposure will
result in decreased host resistance to adult IAPV infection. We predict a
double exposure will also reduce host tolerance, as measured by host
survival. Although our larval Nosema exposure mostly did
not result in viable infections, it reduced resistance to adult IAPV
infection. Exposure to Nosema also negatively affected survival,
potentially due to a cost of immunity in resisting the exposure. There was
also a significant negative effect of IAPV exposure on survivorship, but
in contrast to resistance, prior Nosema exposure did not
alter this survival outcome. These results again demonstrate that
infection outcomes within multi-parasite host networks can be
non-independent, even when exposure to one parasite does not result in a
substantial infection.