I don't have the link to that lecture, but his ted talk gives you some idea of epidemiology and disease.

Actually, cyanide poisoning from cassava is an ongoing problem in Africa, where that root vegetable is used for food. It is actually a pure carbohydrate, so most of the problems we saw with it was protein malnutrition (aka Kwashiorkor). But if you eat the wrong roots or don't cook it properly you can die.

One of the horrible stories of World War II in the Philippines was that the Japanese soldiers were not allowed to surrender, so instead fled into the mountains of northern Luzon etc. If they approached villages, often the villagers would kill them. And there are reports that when they used their guns to demand food, the villagers would give them the wrong root, and they would die because it was poisoned. There is little knowledge of this in the west, but I once saw a Japanese movie about it, and the horrors of starvation and cannibalism among the soldiers is a subplot in at least one short story by Endo.

Back to cyanide....linkto an abstract on chronic cyanide poisoning in Africa and South America.

Africa produces more than 30 million tons of cassava on about 5 million hectares (6 tons per hectare).

Approximately 80% of the root production and 70% of the harvested area are from Western Africa. Recent reports suggest that the ingestion of poorly processed cassava roots is associated with the incidence of an ataxic neuropathy (konzo) in African countries.

When cassava-based diets are not supplemented with good sources of protein and iodine, goiter and rickets are also prevalent. In certain countries of Africa where the rate of ataxic neuropathy is high, the incidence of thyroid disorders is also high.

Persons consuming poorly processed cassava in large quantities are susceptible to neuropathologies caused by cyanide. Cyanide detoxification in the body is impaired by protein deficiency.

When properly processed, the root of cassava is safe and cheap as a major dietary energy source for humans and domestic animals; however, a cassava-based diet will lack sufficient protein and will be particularly deficient for the growth and development of children unless it is supplemented by protein from animal, including fish, or legume sources. Cassava leaves, if they are appropriately cooked, can be a useful source of some nutrients

the nodding disease also has been worse in those living along rivers, where river blindness is found. link

Or maybe it is that the casslava near the rivers is higher in cyanide? or is it a co factor?

But the background of the disease is war and unrest, as the that article points out.

also related; that there are several other disease outbreaks in the area. From Fides, a Catholic international news service:

Kampala (Agenzia Fides) - The recent outbreak of cholera identified, threatens to spread throughout the country. After the death of three people belonging to the same family (see Fides 15/11/2012), in the district of Luwero, 5 other people who had close contact with them are suspected of having contracted the disease. Two are in isolation at Mulago National Referral Hospital in Kampala, other two are in health care facilities in Luwero and Bombo Military hospital, 30 km north of the capital.

According to local sources, another man seems to have died with symptoms of Ebola virus in a health facility in the north-western district of Koboko. According to the Uganda Virus Research Institute (UVRI), the virus in Luwero belongs to the same strain as that of Sudan. Uganda is also fighting an epidemic of Marburg, a viral haemorrhagic fever similar to Ebola, which has killed eight people in the south-west. (AP) (Agenzia Fides 16/11/2012)

however, contrary to all this bad news, the dirty little secret in Africa is that despite the wars and disease, life goes on, and there is now a cellphone revolution there.

In stable countries, the economy is booming, and China is changing the monopoly of the previous western powers on the economy. Of course the Chinese racism and the fact that they bribe people will eventually make them unpopular, and the fact that they are aiming to export raw materials 9similar to the colonial powers) and not build up local industries is not good in the long run, but the Chinese, unlike the NGO's from the west will push modern methods of farming, including GM crops. So it will pan out in the long run.

Quick: Which would you prefer: Having chronic malnutrition and ataxia from mild cyanide poisoning from eating local cassava, or safe, pesticide free GM cassava, aka "Frankencassava"?