Terrible suffering afflicts many regions of the world, and some are noticed by the wider world more often than others.

Most neglected of all is the humanitarian catastrophe in the Lake Chad basin, where more than eight million people are destitute, including at least half a million children.

Many people in Lake Chad are suffering from malunitrition and even "teetering on the brink of famine", according to a survey of 19 top aid agencies by the Thomson Reuters Foundation.

Next most neglected of the world's crisis hot spots is Yemen, where thousands of children are starving.

Third worst is South Sudan, the world's newest nation.

Aid organisations told Thomson Reuters that the crisis in Chad is "on an epic scale" with "terrifying rates of child malnutrition".

Suzanna Tkalec, humanitarian director at the Catholic aid agency Caritas, said: "Syria broke my heart, but for out and out human suffering and almost zero media coverage, the food crisis sparked by Boko Haram in Nigeria and Niger was the pits."

Northern Nigeria is also a place of severe suffering due to the Islamic group Boko Haram, with seven million people facing famine, according to Action Against Hunger.

Ognjen Radosavljevic of International Medical Corps warned agriculture is collapsing and food has become unaffordable. "It is essential that the global community wakes up to the horrors in this region," he said.