Influence of age and body condition on astrovirus infection of bats in Singapore: An evolutionary and epidemiological analysis

Mendenhall, Ian H.; Skiles, Maggie M.; Neves, Erica Sena; Borthwick, Sophie A.; Low, Dolyce H.W.; Liang, Benjamin; Lee, Benjamin P.Y.-H.; Su, Yvonne C.F.; Smith, Gavin J.D.

The epidemiological models indicate that bat age is the most predictive characteristic beyond that of species, displaying an overall viral burden bias towards juveniles. The overall effect was largely driven by the larger E. spelaea sample size, especially the larger juvenile cohort, however, the proportion of juveniles positive for astrovirus in both species tested were not significantly different. Astroviruses predominantly infect juveniles [53] [54] [55] [56] [57] and the later an animal in life is infected, the shorter the period of detection, possibly reflecting a reduced period of viral shedding [58] . Our results did not yield a significant effect of bat gender on astrovirus infection, and while bat body condition and roost location were significant in the crude analyses, these two variables were not included in our main model due to extreme collinearity with other predictors. This was mirrored in a study on insectivorous bats in Borneo, where poor body condition was slightly significant for astrovirus detection while gender was not [35] .