How long post SHTF before a city is safe to re enter?

[NorthernRaider]

Lets just say for example just ONE rat gets ashore from just ONE of the thousands of ships that arrive here EVERY DAY carrying MILLIONS of containers. and lets just say for example that one rat got bitten by a tick or flea in some place east of the Med or south of the equator.
And that flea / tick has plague!!

That one bite infects the one rat, the one rat them passes the infection to the rest of its on average 200 fleas, the rat then dies and the fleas bugger off in all directions looking for other rodent hosts, Black & Brown rats, Voles, Mice, Hairy arsed tree rats, etc etc.

Theoretically that herd of flees could infect hundreds of other rodents within days, within weeks there thousands of rodents infected with plague feasting off the detritus of our collapsed society. You will then get a biblical plague of rodents with huge numbers of them carrying infected fleas.

Then you go into the city on a scavenging trip, you either walk past a recently deceased rodent, or take a drink from a bottle of water found in a shop not realising an infected rat had pissed on it only seconds before. Or you choose to rest in a travel lodge for a few hours and the bed already has a resident flea looking for a warm body !!!!!, Or the dying squirrel in the tree over your head scratches one of its fleas onto your head. etc etc.

Three years and still full NBC kit will be needed in some areas I reckon.

You MAY need to go back to salvage cetain items of kit say like rel;oading presses or bow presses or weldiong kit or whatever, but if you do you must go as though you were walking into a hot zone.