Thursday, 9 February 2017

Rosling Gonzo

Hans Rosling died on 7th Feb 2017 after a year with diagnosed pancreatic cancer. My Uncle John died thus and it's not pretty: pancreatic adenocarcinoma hits the exocrine digestive enzyme part of the organ, eventually blocks the common bile duct and causes all sorts of toxic symptoms through the body; it is horribly painful in its latter stages. The problem is that you are without symptoms as the cancer develops and by the time symptoms are enough to suggest a visit to the doctor, the disease has progressed too far for likely cure. At that stage you have several deteriorating months of misery to endure: more if you allow medical intervention.

I've cited Rosling on The Blob before, notably for his ability to display Big Data [prev-recent] as easily readable graphics. He is soft-spoken and evidence-rich and has a sense of humour. He has been accordingly a darling of Ted Talks: Population - Development - Childhood mortality - etc.

But let's go back to the beginning of his scientific career when he was part of a team that cracked a peculiarly fatal conundrum in Africa. The tropics can be quite brutal to human children: there are so many ways in which small black babies can die. Malaria, Dengue, Yellow Fever; infectious enteritis, TB, HCV; scorpions, snakes, river blindness; not to mention civil war, genocide, mad traffic. I've given a couple of examples of how dedicated scientists can, through perseverance, data and insight can reveal the causes of some pathogenesis and open the way to a cure. You don't have to be nice to make a positive contribution [Kuru] but being a Christian doesn't get in the way either [Burkitt].

In the early 80s, Rosling served as a District Medical Officer in Northern Mozambique. How he got there is an interesting radical story because Sweden has no obvious connexion with that previously Portuguese colony [for answer see this biographical documentary]. ANNYway, he noted that several of his poor black parishioners showed symptoms of motor neuron disease like paralysis that affected the legs more than the arms and manifested as a peculiar spastic gait. It seemed to come in waves sweeping through a district as if an infectious entity was involved. It eventually transpired that it was dietary and not microbial in origin. Konzo turned out to be caused by the consumption of an unremitting diet of inadequately processed cassava Manihot esculenta. I've talked about this starchy root before because it is loaded with cyanide, which is a potent neurotoxin. But you can survive a diet with some cassava providing calories, so long as it is part of a mixed diet, especially if rich in methionine and cysteine the two sulphur-containing amino acids. Forming a thiocyanate is one way to neutralise some of the toxic effects of cyanide. Soaking chips of cassava in water for at least 5 days can also help leach out HCN and reduce the quantity remaining in the pulp - don't drink the water boys!

In West Africa, the cassava is peeled and grated and pressed in a porous bag which also gets rid of a lot of the cyanide-enriched water. The dried pellets are sold as gari, which is reconstituted with fresh water and made into a glutinous porridge. My in-laws like the stuff because they are old West Africa hands, whereas I eat it without seeing what the fuss is about.  Nobody gets konzo in West Africa and most folks in Mozambique, Tanzania and DR Congo get along with only sub-clinical effects, it is only a serious problem in bone-poor districts where cassava rules and people are too hungry to wait for the 5 day retting process.

Hans Rosling developed his research on the etiology of konzo into a PhD thesis and a dozen publications on top of his original medical qualification. He was thus a serious scientist who did more than most of us to reduce mortality among the dispossessed.  But it is arguably true that he has had more effect on the Third World by engaging the rich techno-hipsters who inhabit TED conferences with his amusing, insightful and counter-intuitive displays of data about what really happens South of the Border.
And now he's dead. Hattar av!

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