Lizard bites, guinea worm infections, malaria: the ailments and stream of patients is endless.

In the grounds of a ramshackle clinic they wait patiently in the baking heat that comes with the end of the dry season in South Sudan.

Most are women and very small children born into the world's youngest nation and one of the harshest places on the planet.

This is a region so hot that eggs have been known to become partially cooked, a place where termites will devour clothes left on the ground and scorpions will lurk in your shoes.

It's not uncommon to see vultures waddle on the dusty earth, unafraid of people, as if hoping for a repeat of a previous bonanza when famine left hundreds of thousands to die. There has never been any shortage of hunger, disease and war.

At varying times, droughts, floods and locusts destroy crops and rinderpest kills cattle. In the dry season meningitis flourishes. It is endemic. When the rains come the meningitis stops, but swarms of mosquitoes carry the annual plague of malaria.

In all, the people here have to resist an environment seemingly hell-bent on their destruction, as well as the disruption, trauma and bloodletting of past wars, current insurrections and inter-tribal clashes.

I was last here in the town of Marial Bai 12 years ago. War ravaged the land then and South Sudan was a big, bad, ugly place as it struggled for the independence from the Republic of Sudan's northern rulers in Khartoum it finally achieved on July 9, 2011.

"This is as close to the frontline as you can get,'' I recall Andy Wren, a logistics officer for the humanitarian agency Concern Worldwide, saying, as we disembarked from our small plane into a blizzard of flies on the sodden rainy-season landing strip.

How right he was. In the days that followed it wasn't uncommon to hear the distant drone of a Sudanese military Antonov transport plane in the sky above. Out the rear door of these would be rolled makeshift oil-drum bombs filled with explosives that plunged into terrified civilian communities below.

Today, the old airstrip at Marial Bai is still there, and alongside it sits the tumbledown clinic supported by Concern at which I came across 10-year-old Abulo Garang. In her bright orange dress the little girl lay sprawled on the floor of the clinic, too weak to stand and burning up with fever.

"Her temperature is racing. She's a very sick girl," announced Andrew Wieu Kuach, the head clinical officer, out of earshot of Abulo, her mother and little brother who looked on anxiously. Every day the clinic's handful of staff struggle to cope with more than 100 patients like Abulo.

"In the next few months the number doubles," says Kuach, pointing out that Abulo is just one of many new malaria victims as the first rains bring an escalation of the disease that continues to plague so many parts of Africa and beyond.

"Malaria is bad enough but when it's inflicted on those who are already badly malnourished and their metabolism rundown, it is lethal," says Kauch as we walk across to a drab ward where children on drips lie on old wrought-iron beds.

"Along with malaria it's all here, pneumonia, intestinal infections, diarrhoea, dehydration," he points out with a sweep of his arm. I ask about one newborn baby who has been brought in and at first glance looks well enough, only to be told he has a nasty infection caused by the cutting of his umbilical cord with a non-sterile knife or razor blade following his birth in a remote village.

Even here at the clinic the challenges of trying to maintain hygienic conditions in such a harsh environment are obvious.

Around the ward plaster is peeling from the walls and fungus grows, while a grisly mat of dead insects is jammed into the holes of a mesh grill on the window, put there in a vain attempt to keep the mosquitoes and other night bugs from bringing more sickness. On one of the walls a faded, torn poster warns of the dangers of guinea worm infection.

At one point South Sudan had 80% of the world's cases of infestation by guinea worm, whose larva enters the human body via unclean drinking water and grows in the bloodstream into a three-foot-long white worm before chewing its way through the skin, usually at the foot, and emerging in its entirety in an agonising and horribly disgusting process that takes a minimum of weeks, and usually months.

On my previous visit here a Sudanese Concern worker told me of one horrifying case of a man who was brought to a clinic with 15 worms emerging simultaneously across his entire body.

Fortunately, today, guinea worm cases, while still common, are on the wane. This to some extent is a result of community health education campaigns but more significantly because of the hand-pumped clean water wells that Concern and other aid agencies have built in this region of South Sudan.

For those who doubt the benefit of humanitarian aid, this is a superb example of how it can transform the quality of people's lives. This is not the type of aid where bags of maize or biscuits are lobbed out of the back of a plane, but the kind that enables communities to do things for themselves.

South Sudan may be rich with oil but for the vast majority of ordinary Sudanese, water is thicker than oil. Oil may run a few trucks, but here the possibility of dying due to the lack of water is built into the soul.

At Marial Bai clinic I came across two-year-old Makach Mdu and his grandmother, the toddler now recovering from an intestinal infection most likely caused by tainted drinking water that almost killed him.

www.concern.net/sudan