Data from: Infection sequence alters disease severity—Effects of the sequential exposure of two larval trematodes to Polypedates cruciger tadpoles

Multiple pathogens co-exist in nature and the sequence in which the host encounters the parasites influences interactions between parasites and host pathology. Here the effects of infection by two larval trematodes, pleurolophocercous cercariae of Acanthostomum burminis and a furcocercous cercariae, on common hourglass tree frog (Polypedates cruciger) was examined. Ten days post-hatch tadpoles (Gosner stage 27/28) were used for infection exposures. First, infection of individuals was carried out by introducing each cercariae type to the tadpoles separately. Second, co-infection of the two cercariae was carried out by alternating the sequences of exposure. For all the experiments, appropriate controls were instituted. Tadpoles exposed to parasites had lower survival compared to controls. The highest survival was observed in the co-infection when furcocercous was introduced first (82.5%). The lowest survival was observed in the co-infection when the A. burminis cercariae was introduced first (65.0%). In co-infections, when A. burminis was introduced prior to furcocercous, survival of the tadpoles was reduced by 17.0% compared to the exposures of furcocercous prior to A. burminis. Prior infection with A. burminis induced negative effect on the host with an increased infection severity while prior infection with furcocercous had reduced infection severity than lone exposures. These results suggest that furcocercous infections can be beneficial for hosts challenged with A. burminis provided that A. burminis exposure occurs second. None of the treatments had an effect on the growth of the tadpoles but lengthening of developmental period was observed in some exposures. All exposed tadpoles developed malformations which were exclusively axial – kyphosis and scoliosis. However, there was no difference in the number of malformed individuals in the single infection (19.0-25.0%) compared to co-infection (20.0-22.5%) or between coinfections. The results suggest that the sequence of parasite exposure affects host parasite interactions and hence the disease outcomes.cysts numbers in 4 treatmentsMean number of cysts disappearance in 4 treatmentscysts numbers.csvgrowth of the survived tadpolesThe file consists the growth measurements of the survived tadpoles as length, weight and time to metamorph (TE50)growth.cs