Univariable analysis showed that many variables had a trend toward significance ( P < 0.2) for association with the presence of individual, or groups of infectious agent(s) (Table 5 , Table 6 , Additional file 2 : Table S1, Additional file 3 : Table S2), and these were entered into the multivariable logistic regression analysis, together with variables having significant associations ( P ≤ 0.05).
Univariable analysis showed that many variables had a trend toward significance ( P < 0.2) for association with the presence of individual, or groups of infectious agent(s) (Table 5 , Table 6 , Additional file 2 : Table S1, Additional file 3 : Table S2), and these were entered into the multivariable logistic regression analysis, together with variables having significant associations ( P ≤ 0.05). Thirteen sets of multivariable logistic regression, one for each infectious agent or group of infectious agents, were constructed using the independent variables that showed at least a trend towards significance ( P < 0.2) in the univariable analysis.