Lien T. Luong
Study systems include
Intestinal nematodes (Pterygodermatites peromysci) in wild mice (Peromyscus spp.)
Luong, L. T.*, Vigliotti, B. A., Campbell, S., Comer, J. A., Mills. J. N., and Hudson, P. J. In press. Dynamics of hantavirus infection in Peromyscus leucopus of central Pennsylvania. Vector-Borne Zoonotic Diseases.
Luong, L. T. and Hudson, P. J. 2011. Complex life cycle of Pterygodermatites peromysci, a trophically transmitted parasite of the white-footed mouse (Peromyscus leucopus). Parasitol. Res. DOI 10.1007/s00436-011-2542-x.
Luong, L. T., Vigliotti, B. A., and Hudson, P. J. 2011. Strong density-dependent competition and acquired immunity constrain parasite establishment: implications for parasite aggregation. Intl J. Parasitol. 40: 505-511.
Luong, L.T, Perkins, S.E., Grear, D.A., Hudson, P.J. 2010. The relative importance of host characteristics and co-infection in generating variation in helminth fecundity: implications for infectiousness. Parasitology 137:1003-1012.
Luong, L.T., Grear, D.A., and Hudson, P.J. 2009. Male hosts are responsible for the transmission of a trophically transmitted parasite (Pterygodermatites peromysci) to the intermediate host. Intl. J. Parasitol. 39: 1263-1268.
Luong, L.T. and Polak, M. 2007a. Costs of resistance in the Drosophila-Macrocheles system: a negative genetic correlation between ectoparasite resistance and reproduction. Evolution 61: 1391-1402.
My research interests include the ecology of infectious diseases and the evolutionary ecology of parasite-host interactions.
I am currently working on a gastrointestinal nematode(Pterygodermatites peromysci) that infects the white-footed mouse (Peromyscus leucopus). The parasite has a complex life-cycle, requiring passage through an intermediate host for transmission. I use a combination of field and laboratory experiments to investigate questions such as:
- What key hosts are responsible for transmission?
- How do individual heterogeneities in exposure and susceptibility impact parasite transmission?
- What factors constrain parasite establishment, and what are the consequences for parasite aggregation in host populations?
- What is the link between host foraging ecology and exposure to trophically-transmitted parasites?
- Can parasites with complex life cycles alter host behavior as an adaptive strategy for enhancing transmission?
- What is the relationship between host biodiversity and the transmission of trophically-embedded parasites (i.e., dilution effect)?
Influence of host characteristics on parasite transmission
Host sex can have important consequences for parasite transmission even when there is no obvious sex bias in infection. In a field study, infection by a trophically-transmitted parasite (P. peromysci) was experimentally removed in either male or female definitive hosts, white-footed mice (P. leucopus) on independent trapping grids using an anthelmintic. Results show that the intensity of infection in the intermediate host population was higher on the grids where females were treated compared to the grids where males were treated. Removing parasites from male mice resulted in lower infection rates among female mice in male-treated sites compared to females in control sites. However, de-worming females alone had no effect on transmission rates among male mice. These findings indicate that male hosts contribute disproportionately more infective stages to the environment and may therefore be responsible for the majority of parasite transmission even when there is no discernible sex biased infection.
Linking predator-prey interactions with exposure to a trophically transmitted parasite
The rate at which parasite transmission occurs depends on several factors, including the rate of exposure to infective stages and susceptibility to infection. Measuring natural levels of exposure under field conditions can be especially challenging, partly because contact rates between host and infective stages can be highly heterogeneous. A further challenge is delineating the factors that drive heterogeneity in exposure. For a major class of parasites, transmission is intimately linked to the host’s feeding ecology; these trophically transmitted parasites rely on the ingestion of infective intermediate hosts by the definitive host for transmission. In a recent study, I tested the hypothesis that heterogeneity in exposure to parasites is driven by variations in host feeding behavior. I combined epidemiological data and molecular analysis of host predation to investigate the link between host predation and parasite transmission in the white-footed mouse (P. leucopus) and its trophically transmitted parasite, P. peromysci.