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Hugh Pennington


4 June 2020

Overdispersion

Covid-19 has made A&E departments very quiet. I worked in the one at St Thomas’s Hospital when it was called Casualty. Undressing a homeless patient once caused the centrifugal escape from his clothes of a shimmering sheen of lice, hundreds of them. Sister Cas was called. She rolled up her sleeves and said: ‘This reminds me of Dunkirk!’ Most lousy people have only a handful. The best quantitative study of lousiness was done by Alexander Peacock, an RAMC entomologist, in the trenches on the Western Front in the First World War. He found that 95 per cent of the soldiers were infested, more than 60 per cent with 20 lice or fewer, but 2.8 per cent – he called them ‘horrible examples’ – had more than 350 on their trousers and shirts. This pattern of distribution, in which most of a human population’s parasites are concentrated in only a few individuals, is very common. Statisticians call it ‘overdispersion’.

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21 April 2020

Memories of the 1957 Flu

More than sixty years ago, puffing on an untipped Senior Service (we were allowed to smoke in those days) to cover up the reek in a dissecting room at St Thomas’s Hospital, I was struck down by a pandemic virus that had recently evolved in China. By the time I fell ill (its onset was very sudden) the virus had already killed more than 20,000 people in the UK, with 1150 dying every week at its peak, and 80,000 in the US. In the first UK wave, more than half the deaths occurred in the under-55s. It went for the elderly later, in its second wave. It killed quickly: nearly 20 per cent of its younger victims died before getting to hospital and two-thirds were dead within 48 hours of admission. But it has been airbrushed out of history, despite being by far the most lethal pandemic to affect Britain at any time in the hundred years after the ‘Spanish’ flu pandemic at the end of the First World War.

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24 January 2020

Host to Host to Host

The emergence of a new coronavirus in Wuhan at the end of 2019 has not been a virological surprise. New coronaviruses causing respiratory infections have been detected from time to time since SARS (which was a surprise) in 2002-3; MERS came in 2012. How ‘new’ these viruses are is debatable.

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13 May 2019

The Measles Scandal

In 2004 I described the basis of attacks on the MMR vaccine as ‘unsubstantiated speculation masquerading as science’, and finished the piece: ‘I despair.’ Measles is now busier in Europe than it was fifteen years ago.

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6 March 2019

What’s wrong with chlorinated chicken?

‘Chlorinated chicken’ is pejorative. Chlorine gas doesn’t come into it. The meat isn’t bleached. Poultry carcasses are washed with dissolved antimicrobials such as sodium chlorite, chlorine dioxide and trisodium phosphate. The EU banned it in 1997, not because the washes leave the meat dangerous to eat but because it might incentivise poultry producers and processors to give hygiene a lower priority. This argument was used in the 1930s by opponents of milk pasteurisation.

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15 February 2019

Not Enough Insects?

A recent review by scientists in Australia of 73 historical studies of insect decline concluded that insect biodiversity is threatened worldwide, and 40 per cent of insect species are threatened with extinction over the next few decades. But there is a puzzle. The classes that are declining fastest are butterflies, bees and dung beetles. No one is going out of their way to eliminate them. Other insects that we attack deliberately and for which extinction would be a cause for celebration are doing well.

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27 November 2018

E. coli strikes America (again)

Romaine lettuce in the US is currently under the cosh of a Food Safety Alert: don’t eat it, whether head or heart or baby; don’t sell it; and don’t eat ready-mixed Caesar salad, which contains it. Contamination with E. coli O157:H7 is the reason. An outbreak started in October, with 50 cases across 11 states, as well as in Ontario and Quebec, with 13 in the US admitted to hospital. The lettuce may have been grown in California, unlike the produce that caused the first romaine outbreak this year, which was grown in Yuma, Arizona. That outbreak lasted from March to June, and was the biggest E. coli O157:H7 outbreak in the US for many years, with 201 cases (96 hospitalised) and five deaths.

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13 April 2018

Novichok and Other Toxins

The UK has the highest incidence in the world of poisonings caused by the toxins produced by E.coli O157:H7. It killed 17 people in the outbreak centred on Wishaw in central Scotland in 1996, still a world record for lethality. My involvement in attempts to stop a repeat led to an invitation to visit the Defence Science and Technology Laboratory at Porton Down. Security was impressive. The heavily armed welcome at the gate left an abiding memory. It is reasonable to guess that the Russian chemical warfare facility at Shikhany is as well guarded. The notion that nasty substances of high purity could leave it without some kind of authorisation seems highly unlikely.

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20 February 2018

Oxfam, Haiti and Miles’s Law

Oxfam is in serious difficulties. It is reasonable to speculate that the hard time it is being given by the international development secretary, Penny Mordaunt, is due to the workings of Miles’s law - 'Where you stand depends on where you sit' – in that it reflects forces in the British government and the Tory party hostile to the foreign aid programme. I sit as a microbiologist, and see the harmful events in Haiti following the arrival of foreigners after the 2010 Port-au-Prince earthquake very differently, both from a quantitative and from a political point of view.

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9 October 2017

Trench Fever

Some reviewers of the film Goodbye Christopher Robin are saying that A.A. Milne had post-traumatic stress disorder. Yes, he was at the front during the Battle of the Somme; in August 1916 he was a signals officer there, and worked in no man’s land. But PTSD didn’t send him home. He was brought down by trench fever (bartonellosis). A bacterial infection spread by body lice (not those of the head or pubes), it causes a high fever, which repeats itself a few times every five days. It doesn’t kill, but sometimes leaves its victims feeling weak for many months. This happened to Milne. After being invalided home, he lost weight and developed fatigue, said to be caused by ‘overwork’, but much more likely due to the persistent effects of Bartonella quintana. In the early autumn of 1917 he spent three weeks at Osborne House on the Isle of Wight, then a convalescent hospital for officers.

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