Oh dear,
You can legionnaires from staying in a hotel or flying in aircraft, you can get Weil's disease from angling, canoeing or paddling in the local brook, should everyone who does anything that might bring them into contact with these diseases be 'risk' assessed ? That would be interesting.
As one of the BDMA early qualified Senior Technicians in 2000 obtained at Southampton University,also the usual IICRC flood school training, plus continued and ongoing training and attendance of courses at amongst such places as Cranfield University, plus vast experience in the field, I would say that I am 'qualified' to advise those that ask a pretty simple and basic question .
I'm sure chappie wasn't intending to offend anyone including me even though his comments were aimed in my direction.