Ha ha ha Hazmat suit . I can see it now ha ha ha full kit with rebreathing oxegen bottles and bio hazard sighn on a lawn chair and mutibox with carp rods ha ha ha ha ha ha ha
On a more serious note bilharsia is the least of your worries.
But you can stay safe if you are a real germophobe. Wash hands with clean water and soap after baiting up. Cover hands if you have broken skin on your hands
Dont bite off rigs to put on another,dont put line in your mouth. Use waders if you need to or want to enter the water. Dont eat the fish you catch.
I dont know the river but take care and you should not be to worried.
Regards
Malboer