Parasite transmission in social interacting hosts: Monogenean epidemics in guppies
Background
Infection incidence increases with the average number of contacts between susceptible and infected individuals. Contact rates are normally assumed to increase linearly with host density. However, social species seek out each other at low density and saturate their contact rates at high densities. Although predicting epidemic behaviour requires knowing how contact rates scale with host density, few empirical studies have investigated the effect of host density. Also, most theory assumes each host has an equal probability of transmitting parasites, even though individual parasite load and infection duration can vary. To our knowledge, the relative importance of characteristics of the primary infected host vs. the susceptible population has never been tested experimentally.
Methodology/Principal Findings
Here, we examine epidemics using a common ectoparasite, Gyrodactylus turnbulli infecting its guppy host (Poecilia reticulata). Hosts were maintained at different densities (3, 6, 12 and 24 fish in 40 L aquaria), and we monitored gyrodactylids both at a population and individual host level. Although parasite population size increased with host density, the probability of an epidemic did not. Epidemics were more likely when the primary infected fish had a high mean intensity and duration of infection. Epidemics only occurred if the primary infected host experienced more than 23 worm days. Female guppies contracted infections sooner than males, probably because females have a higher propensity for shoaling.
Citation Information
| Publication Year | 2011 |
|---|---|
| Title | Parasite transmission in social interacting hosts: Monogenean epidemics in guppies |
| DOI | 10.1371/journal.pone.0022634 |
| Authors | Mirelle B. Johnson, Kevin D. Lafferty, Cock van Oosterhout, Joanne Cable |
| Publication Type | Article |
| Publication Subtype | Journal Article |
| Series Title | PLoS ONE |
| Index ID | 70006137 |
| Record Source | USGS Publications Warehouse |
| USGS Organization | Western Ecological Research Center |