I vaguely remember watching this when it aired on British TV, sometime in the mid/late '90s. It was a feature-length one-off drama, possibly a pilot for a series that never happened. Can't remember the channel but we never had Sky so it must have been BBC/ITV/C4.
It was about police in London (or at least a big city in the UK, so almost certainly London), in a gritty near-future where things were high-tech (for the '90s), society was more violent, acid rain & pollution, that sort of thing. Basically a fairly standard cyberpunk-influenced near-future setting.
The plot involved a hostage situation, it comes out that the perpetrator had taken his family on holiday to the US and they caught some disease they should have been immunised against - he'd tried to save money with falsified immunisation certificates. Pretty sure the disease was something 'old-fashioned' like TB that had come back in a new strain.
Does this ring a bell with anyone? I've occasionally thought of it in the intervening years but never been able to track down what it was. Every time I've searched I just come up with things like Bugs, Space Precinct, etc. and I know it wasn't any of those.