I don't think it's a wind up.
Because it's outside your realm of experience or comfort zone doesn't make it fantasy.
Au contraire, I’ve worked in a fair few far flung places myself in my younger days and have many stories to tell, some of them relating to hygiene (or lack of) and having the squits overseas where the loos are holes in the floor (and I’ve never been able to squat :/)
I also studied Comparative Pathology as part of my degree in Biology, so am aware through that of some of the more exotic pests and parasites that might affect an international traveller.
With the litigious society we have today, most employers sending staff overseas are scrupulous about medical care, providing medicals, regular health checks, medical insurance and the like. So it rings very untrue that such a person would feel the need to trust in a UK-based pharmacist’s knowledge of his or her likely parasitic load and the treatment for it.
And as to the allusion to Basildon Bond or other writing papers, anyone who had actually done any even very mundane classified work would not mention or allude to that.
So, I maintain, it’s a wind up, and I’d lock the thread.