"It bites you, and you fall asleep"

I have been in a dusty state capital called Bor, in Jonglei State, for the past few days. We are rolling out a new 12-month work plan and presenting it to our Jonglei team in the field, all of whom are currently grounded in Bor due to deadly cattle raiding between enemy tribes in other parts of the state. The fighting has caused massive displacement and claimed nearly 1,000 South Sudanese lives since December. Our Jonglei staff, a team of about 11 young educated South Sudanese men working in governance, financial management, planning and budgeting and in the education sector, are working and living out of a hotel built on the banks of the Bahr el Jebel, a fast-moving tributary of the Nile. The hotel has spotty electric generators and internet service, and there is no air conditioning, so we have the windows open in the office we are renting here. About 50 yards outside our window there is a borehole with a hand pump where area residents fill yellow jerry cans with fresh water, seemingly round the clock. The empty cans are piled high around the hole as people wait patiently, sometimes for hours, for their turn to pump and fill. The work of obtaining fresh drinking water here is hard and never-ending, and children as small as two and three are enlisted to carry little buckets and containers from the wells.

During a Powerpoint presentation on the work plan yesterday, the team leader raised his hand and pointed at a large brown fly that had entered through the window. All 15 of us in the room silently watched the fly zip around for a minute or so. If it buzzed anyone, the person would duck and swat with wide-eyed alarm. I seemed to be the only person in the room who did not know why this particular fly was cause for such concern.

When it went back out, we closed the windows to prevent if from flying in again, even though it was sweltering in the room (temps are now higher than 100 degrees during the afternoons.) Everyone seemed greatly relieved, and we got back to our business. Later I asked a colleague what would have happened if that dread-inspiring fly had bitten me.

You would be sleeping, she said.

The fly makes you sleep?

Yes. It bites you, and you fall asleep.

Turns out I had just had my first known encounter with a tsetse fly, whose bite carries a disease called Human African trypanosomiasis, also known as sleeping sickness. The disease is endemic in 37 sub-Saharan countries and killed 48,000 people in 2008, according to Wikipedia. This insect, which only lives a few weeks, injects a parasite into its victims that invades the central nervous system, causing confusion, reduced coordination, fatigue, mania, insomnia and progressive mental deterioration leading to coma and death. I now understand why the bug was so deserving of our attention. It is an airborne serial killer.

I kept my eyes peeled for large brown flies when a colleague and I walked down to the river's edge after work. About 100 yards away, on the other side of the water, a cluster of a few hundred Dinka cattle herding families were encamped, with their animals. They were just shadows in a haze of dung fires lit to keep down the mosquitos, but we could hear laughter and the clinks of pots, and make out lines of tents and stick-built huts built on the very edge of the river. We could also occasionally see sets of huge, magnificently arcing cattle horns poking through the smoke, and hear the lowing of the cows, which sounded startlingly close, rolling across the river top. We watched a wiry man hard-paddling a canoe hand-carved from a neem tree and patched with sheets of tin, from our side of the river to the camp, and back.

I want to go across and see them, one of my colleagues said a little wistfully.

I will do it soon.