Dust to dust

FOUR

John Motram took his time on the walk through the streets of Oxford, savouring the undoubted charm of the place and letting its history seep into his bones. He smiled as he realised that his affection for its dreaming spires was not entirely born of academic regard; being an avid fan of Inspector Morse was certainly playing its part. He found himself keeping an eye out for a Mark Two Jaguar.

Nothing disappointed him about the interior of Balliol College either. Everything just got better.

‘The Master will see you now,’ said a suitably deferential woman who looked as if she might have been a pillar of her church guild, sensibly dressed from her high collar with the cameo brooch to her polished brogues.

Motram was shown into a large office that couldn’t fail to impress. Minimalist it was not; metal and plastic pointedly failed to make an appearance. Wood — old polished wood — reigned supreme, comfortable in the light that came in through a series of tall, leaded windows that also admitted the sound of chimes and bells, confirming Motram’s arrival at the appointed hour of eleven a.m.

A tall, patrician man rose from behind his desk and smiled. ‘Dr Motram, good of you to come. I’m Andrew Harvey, Master of Balliol. Please come and sit down. You must be wondering what all this is about.’

It wasn’t a question, but Motram, who’d been thinking about little else for the past week, said, ‘I think I’d be lying if I said I wasn’t intrigued.’

‘Quite so,’ said Harvey. ‘I’m afraid microbiology isn’t exactly my field, but I understand that you are an expert on both the viruses of today and the epidemics of the past, shall we say?’

‘That’s a fair enough description.’

‘What is it that intrigues you about past plagues, doctor?’

‘Their cause. What many people don’t realise is that microbiology is a very young science. Bacteria weren’t discovered until the late 1800s and viruses even later, so the identification of the causes of the great epidemics of the past has been based largely on guesswork… or presumption.’

Harvey smiled at the acid emphasis Motram had put on the last word. ‘I understand there is… something of a disagreement between you and your academic colleagues over the origin of the Black Death. Am I right?’

‘You are.’

‘Tell me about it.’

Motram frowned slightly. He didn’t quite see where all this was leading, but he continued, ‘There’s a general assumption among the public and indeed some of my colleagues that the fourteenth-century pandemic generally called the Black Death, which wiped out a third of the population of Europe, was caused by an outbreak of bubonic plague.’

‘I’m afraid I have to admit to being one of the public who subscribe to that view,’ said Harvey. ‘Wasn’t it?’

‘I don’t think so.’

‘Then what?’

‘I’m convinced it was caused by a virus.’

Harvey looked slightly bemused and Motram smiled, recognising the problem. ‘There is a very big difference between bacteria and viruses,’ he said. ‘They are completely different entities but, for some reason that escapes me, people appear reluctant to take this on board.’

‘Ah, educating the public,’ sighed Harvey, relaxing into his chair with a slightly amused expression on his face. ‘Never an easy business. But in what way are they different, doctor?’ He managed to endow the question with the unspoken rider, And does it matter?

‘Bacteria can exist independently,’ Motram explained. ‘They are living entities in their own right. They have all they need to grow and divide provided they can find suitable nutriment. Viruses can only exist inside living cells. In fact, there is a longstanding argument over whether they should actually be regarded as living things at all.’

Harvey nodded. ‘I see.’

‘Another major and more practical difference is that you can treat bacterial infections with antibiotics: antibiotics are useless against viruses.’

‘So what makes you think Black Death was caused by a virus and not plague — which presumably, in the light of what you’ve just said, is a bacterium?’

Motram nodded. ‘A rod-shaped bacterium called Yersinia pestis, named after a Russian microbiologist called Yersin who worked with Louis Pasteur. It was originally called Pasteurella pestis after his boss, but in the end justice prevailed.’

Harvey gave a slightly pained smile that suggested too much information and Motram cut short the lecture. ‘I suppose I began to wonder about ten years ago when I was studying the rate of spread of Black Death in Europe. It was all wrong for a bacterial infection like plague and it didn’t show the seasonal differences you would expect.’

‘Was the spread faster or slower than you expected?’

‘Much faster. Plague is primarily a disease of rats. Human beings get it from fleas, but Black Death spread like wildfire, as if it were an airborne infection like flu.’

‘Are you alone in your suspicions?’

‘Not any more,’ said Motram. ‘Scientists have been working on a genetic mutation in human beings which confers resistance to certain virus infections. It’s called Delta 32: basically it leads to the absence of a receptor on the surface of certain cells in the body, which denies viruses access to the cells they would normally infect.’

Harvey nodded, then said, ‘I’m sorry, I must seem terribly dense but… where does the connection with Black Death come in?’

‘Before Black Death swept over Europe, we estimate that the Delta 32 mutation was present in the general population at a frequency of about one in forty thousand.

‘And after?’ asked Harvey.

‘About one in seven.’

Harvey let out his breath in a low, silent whistle. ‘Now I see,’ he said. ‘So people without the mutation were much more susceptible to Black Death than those few at the time who had it.’

‘Precisely. It was clearly an enormous advantage to have the Delta 32 mutation,’ said Motram. ‘What, of course, is absolutely crucial from my point of view is that the mutation stops viruses from entering cells, not bacteria. Bacteria don’t need to enter cells. It makes absolutely no difference to them whether you have the Delta 32 mutation or not.’

‘So there we have it,’ said Harvey. ‘Game, set and match to you, it would appear. Black Death was caused by a virus, not a bacterium.’

‘I believe so.’

Harvey picked up on Motram’s guarded response. ‘So shouldn’t that be an end to the argument?’ he asked.

‘I’m afraid not. The old guard still insist Black Death was caused by plague and see the new findings as academic stuff and nonsense — Disraeli’s third kind of lie, if you like.’

‘Statistics.’ Harvey smiled.

‘Even those who’ve moved to the virus camp are now falling out over which virus it might have been. Smallpox is one of the favourites and it’s been shown that that could have exerted the selective pressure necessary for such a dramatic genetic shift in the population while plague certainly couldn’t. There are others who propose it could have been due to a combination of infections, and there is of course one other intriguing possibility, that it could have been caused by a completely different virus altogether — something that existed then but is unknown to us today.’

‘A killer from the past,’ said Harvey, raising his eyebrows. ‘Do pardon my ignorance, but isn’t it possible to find out what caused it simply by… digging up the past, so to speak?’

‘It’s been tried on a number of occasions,’ said Motram. ‘But we’re talking about seven hundred years ago. Mortal remains tend not to last that long.’

Harvey rested his elbows on his desk and formed a steeple with his fingertips as he appeared to gaze off into the middle distance. ‘You know, I seem to remember reading something about a group of workers claiming to have recovered plague from Black Death victims… somewhere in Europe, I think.’

Motram nodded. ‘France. They found plague bacilli in the dental pulp of an exhumed corpse. Trouble is, no one else has been able to reproduce their findings. Everyone else has drawn a blank.’

‘So the French findings are… doubtful?’

‘I wouldn’t go that far,’ said Motram. ‘There seems little doubt that the body they examined was a plague victim, but without wholesale corroboration you can’t really say that plague caused Black Death, only that plague caused the death of the body they were examining.’

Harvey nodded thoughtfully. ‘So, it would help enormously if you were to come across a number of victims of Black Death preserved in good condition?’

‘Indeed it would,’ said Motram, ‘but after seven hundred years the chances of that are-’

‘That’s really why I asked you here, Dr Motram.’