Frequency of Anaplasma phagocytophilum, Borrelia spp., and coinfections in Ixodes ricinus ticks collected from dogs and cats in Germany

Table 2 Results of the GLMM testing the influence of several predictor variables on the prevalence of A. phagocytophilum (model A and B) and Borrelia spp. (model C and D) infections in female I. ricinus collected from dogs and cats. The models were significantly different from a null model containing only the animal identification number as a random factor (A: chi-square = 26.36, df = 5, P < 0.001; B: chi-square = 15.14, df = 5, P = 0.01; C: chi-square = 145.64, df = 5, P < 0.001; D: chi-square = 30.63; df = 5, P < 0.001). Significant P-values are shown in bold

A. phagocytophilum	Model A: dogs				Model B: cats
A. phagocytophilum	Estimate	SE	z	P	Estimate	SE	z	P
Intercept	−2.00	0.42	−4.725	< 0.001	−1.35	0.20	−6.682	< 0.001
Stage of engorgement^a
Non-engorged versus partially engorged stage 1	−0.23	0.24	−0.977	0.760	−0.03	0.18	−0.144	0.999
Non-engorged versus partially engorged stage 2	−1.01	0.29	−3.429	0.003	−0.24	0.18	−1.303	0.561
Non-engorged versus fully engorged	−0.84	0.30	−2.851	0.022	0.13	0.18	0.74	0.881
Partially engorged stage 1 versus partially engorged stage 2	−0.78	0.28	−2.748	0.030	−0.21	0.18	−1.162	0.651
Fully engorged versus partially engorged stage 1	−0.61	0.28	−2.173	0.129	0.16	0.18	0.882	0.814
Fully engorged versus partially engorged stage 2	0.16	0.28	0.576	0.939	0.37	0.18	2.032	0.176
Infestation type (ref: single)
Multiple	0.20	0.21	0.936	0.349	0.53	0.16	3.260	0.001
Co-infection with Borrelia spp.	0.38	0.20	1.860	0.063	0.07	0.13	0.515	0.606

Borrelia spp.	Model C: dogs				Model D: cats
Borrelia spp.	Estimate	SE	z	P	Estimate	SE	z	P
Intercept	−0.23	0.15	−1.536	0.125	0.45	0.15	2.923	0.003
Stage of engorgement^a
Non-engorged versus partially engorged stage 1	−0.65	0.16	−4.185	< 0.001	−0.43	0.16	−2.647	0.040
Non-engorged versus partially engorged stage 2	−1.30	0.17	−7.461	< 0.001	−0.55	0.16	−3.425	0.003
Non-engorged versus fully engorged	−1.90	0.21	−9.256	< 0.001	−0.78	0.16	−4.781	< 0.001
Partially engorged stage 1 versus partially engorged stage 2	−0.64	0.17	−3.678	0.001	−0.12	0.16	−0.788	0.860
Fully engorged versus partially engorged stage 1	−1.25	0.20	−6.184	< 0.001	−0.35	0.16	−2.195	0.125
Fully engorged versus partially engorged stage 2	−0.61	0.21	-2.843	0.023	−0.23	0.16	−1.441	0.474
Infestation type (ref: single)
Multiple	0.12	0.14	0.910	0.363	0.27	0.13	2.018	0.044
Co-infection with A. phagocytophilum	0.31	0.15	2.038	0.042	0.06	0.12	0.475	0.635

SE standard error, GLMM generalized linear mixed model
^aMultiple comparisons were conducted using the function “glht” from the R package “multcomp” [42] with Tukey contrasts

ISSN: 1756-3305