Table 2. Histopathological changes of the kidney section observed in infected fish sampled at the Amont and Aval step concerning infection degree, tissue proliferation, and fibrous tissue.

Site	Monthly sampling	Infection degree	Tissue proliferation	% of fish with tissue proliferation	Fibrous tissue	% of fish with fibrous tissue
Amont	July	1.2 ± 0.36	1.33 ± 0.18	33	None	None
	August	1.89 ± 0.24	1.81 ± 0.21	78	1.87 ± 0.35	32
	September	2.35 ± 0.38	2.00 ± 0.28	78	1.91 ± 0.38	69
	October	3.05 ± 0.32	3.00 ± 0.22	82	2.46 ± 0.33	65
	Overall	2.12 ± 0.32	2.03 ± 0.22	68	2.08 ± 0.35	55
Aval	July	1.83 ± 0.24	1.77 ± 0.23	50	None	None
	August	3.33 ± 0.15*	3.04 ± 0.12***	100	2.1 ± 0.31	60
	September	3.16 ± 0.19***	3.26 ± 0.21**	96	2.26 ± 0.34	62
	October	3.4 ± 0.40	3.12 ± 0.25	77	2.35 ± 0.24	91
	Overall	2.93 ± 0.98***	2.79 ± 0.20*	81	2.23 ± 0.29	71

Notes:

No infected fish at either site had presence of fibrous tissue in July sampling. Asterisks indicate levels of significance (t-Test).

^*P < 0.05.

^**P < 0.01.

^***P < 0.001.