Even if other alternative methods allow taking covariates into account, we only compared the corrected chi-square to the logistic regression approach. We could have compared it as well to loglinear models, which model the probability of infection with single and multiple parasite species from contingency tables and allow including known risk factors. However, in this approach the independence between parasites is tested using likelihood ratio tests, which are based on an asymptotic approximation of the deviance as in the logistic regression approach. They should therefore have the same limitations than logistic regressions and their robustness should be similarly influenced by the N F /n ratio. In addition, continuous variables are usually discretized in loglinear models, whereas the corrected chi-square allows working with continuous data.