Scorpion, Snail: Zanzibar
Published by The London School of Hygiene & Tropical Medicine:
https://blogs.lshtm.ac.uk/alumni/2020/02/03/scorpion-snail-zanzibar-by-adam-boggon/
I knew there was a scorpion in my room. The problem was I’d lost it. The room was not large: five square metres, whitewashed walls, hard single bed, small desk, a slowly rotating fan. I saw it scuttling along the edge of my bedspread. I grabbed a metal bowl and plate, caught it between the lip of the bowl and the sheet, flicked the cloth to shake it into my trap. Somehow it shrugged me off, darted down the side of the mattress. By the time I'd fumbled for my head torch it was gone.
Shahin and I turned the room upside down. Shook out the pillowcase and bedsheets, lumped the mattress outside, flipped over the slats. Nothing.
We set up a cordon. Having disassembled the bed, put it back together and tucked the mosquito net tight around the mattress we could be confident that wherever the scorpion was, it wasn't in my bed. So I could sleep easy. Theoretically.
Shahin, a doctor from Zambia, seemed unconcerned. He'd seen patients with scorpion stings in Lusaka and they’re painful but generally cause nothing worse than local inflammation. Also, this wasn’t his room.
I flicked through the Oxford Handbook of Tropical Medicine. A sting from a granulated thick-tailed scorpion causes death by respiratory paralysis. I’m pretty sure my little associate wasn’t one of those but this information hardly cradled me to sleep. I double-checked the mosquito net and fidgeted in the darkness. Cicadas clicked outside. Fan blades whirred.
I was with with the London School of Hygiene & Tropical Medicine on the East African Diploma in Tropical Medicine & Hygiene. Which, in addition to being an enormous mouthful, is pretty much the best thing since Bedaquiline. I was on a field trip in Pemba to learn about water and sanitation infrastructure and schistosomiasis control. Pemba is the poorer northerly half of the Zanzibar archipelago: islanders sustain themselves by fishing and growing cloves, chilli and coconuts.
We’d broken up the journey to the island with a night at the coast. Waves grown in the immense belly of the Indian Ocean crumpled onto the shore. The water deepens slowly there and is warm like a bath. The only wrinkle to my idyllic Saturday morning there was that the small fat dog belonging to the resort manager could not swim. I was told Poppy liked to paddle board so had been unruffled when she commandeered the front of my board as I straggled out through breaking waves. I stood up, wobbled like a baby learning to walk, and tottered backwards into the sea. As I clambered back onto the board Poppy was drowning - small paws waggling ineffectually as she sank beneath the surface. I scooped her out onto the board and she gave a shudder. I returned her to the beach.
We had driven ten hours to get there. The road was smooth tar at first but for the last forty miles we were on dirt track. I tried to read but quickly learned to give the ruts and furrows my undivided attention. The goal: protect your spine from being crumpled like an accordion. The technique: spot the next bump coming, perch a few inches above the level of the seat, have the muscles in your thighs become coiled springs. Let them absorb the shock as the bus careened into another pothole.
My backseat companion for the drive was Tom Doherty, a retired Tropical Medicine consultant from London. Cadaverously thin with rimless spectacles, frizzles of wiry hair, and many flamboyant shirts. He’d spent the early years of his career in Jamaica and it wasn’t difficult to imagine. He told of lonely Gambian research outposts, arguments over vaccine trials, a friend who bought a mountain near Bantry. He remembered a mutiny among one-legged sailors near the Panama Canal. Colleagues who had lost their way. Psychopathology among practitioners of Tropical Medicine - how common that is. He felt all things strongly and was full of warmth and slow-won memories. The hours passed quickly.
The Pemba public health laboratory sits in a square of land on the outskirts of Chechefu. Sheep are kept and bled intermittently to make agar for the lab. An outbreak of commotion meant the gardeners had found two cobras and put them in a bucket.
We spent a lot of time that week guddling around in a pond looking for snails. Our group project was on schistosomiasis, a helminth infection which causes varieties of misery from bladder cancer and oesophageal bleeding to infertility and acute febrile illness. Bulinus snails are an intermediate host for the disease and are one target for schistosomiasis control activities (along with mass drug administration and health education campaigns). We wanted to estimate how many snails lived in Mkomani pond, a freshwater pool near a local school. The plan was to catch some snails from a defined area of the pond, mark them, release them back into the pond and come back the next day to see how many of the marked snails we could find.
We bought some bright yellow nail polish from the market to paint the snails. We padded around under the midday sun in galoshes and gloves with sieves attached to a length of wood. The snails were identified, marked with yellow blotches, and returned to a point in the pond marked by a damaged green bucket. Dr Doherty looked on, dragged on a roll-up cigarette, his eyebrows ruffled into a scowl:
"I think this experiment is totally bonkers.”
24-hours later we returned to the pond and found more snails in the same area. Some were marked, some unmarked. We counted them up and used a statistical index to estimate the snail population of the pond: about 500.
If you can understand parasite life cycles, and intervene to interrupt transmission, then you can control the diseases they cause. But controlling schistosomiasis is difficult. The pond had been treated with molluscicide less that a year ago and the snail population had rebounded already. We visited a school and found that more than half of the children regularly play and wash in freshwater ponds - a sure fire way to contract the disease. Yet for all the difficulties there has been progress: in the 1970s, 70% of the Pemba population had schistosomiasis. Now, after years of control efforts, prevalence is 2.7%.
In the airport departure lounge waiting for our plane to Stone Town we huddled around Dr Doherty for an impromptu tutorial on trichuris dysentery and Cuban medical internationalism. Crouching on the floor I cupped my hands behind my ears but heard little over the hubbub.
Soon a small plane lifted us into the air and the dust roads, green trees, red roofs, white breaking waves and long crenelated shore was below us.
Stone Town, the largest town in Zanzibar is a warren of narrow streets, tasty food, and a rich admixture of Tanzanian and Arabic culture. This is a legacy of the slave trade but is now as much a part of the islands as the reef and sand.
Clad in a white linen shirt, leather sandals, black shorts and a broad canvas hat I wandered around Stone Town looking like a mid-Victorian lepidopterist. I grumbled about the unwelcome profusion of powdered milk in Pemba to Colin, a South African who’d worked in Malawi for two decades. He just smiled:
"One advantage of living in Malawi is that you have low expectations of many things, so it's not difficult to be impressed.”
Colin had been a medical student in Mozambique during the civil war and worked as a house officer in the early years of the AIDS epidemic in South Africa. He told me about ‘ghosts’ in Malawi: manufactured individuals created by organisation employees so extra salaries are paid to them. Once, when a government department was closing in on the practice, he heard of a ghost employee being killed off so the fictitious individual would not appear in department records. Their life insurance was subsequently claimed for.
After a week of the same banana curry, dry fish and rock-hard bits of octopus the night market in Stone Town was a revelation. Flavours clamour in your mouth from spiced soup, shawarma, pancakes with mango and chocolate. Fresh sugarcane and lemons are wound through presses straight into your glass and served with ginger. Labyrinthine streets open into the market by the harbour which at night is cave-dark. Vendors and wanderers in the square are lit up from below by lamps on table tops - so that the scene is like a film set, or a photograph taken long ago.
The President of Zanzibar commandeered our connecting flight to Arusha while we were on our way back to Moshi to rejoin the course but this bought us an extra morning in Stone Town. I took the winding stairs to the rooftop terrace of Zanzibar Coffee House. I could see stained glass shutter windows and pastille walls. Narrow streets alive with horns and engines and conversation. Occasionally a propellor plane stirred up the sky. My coffee had cinnamon and cardamom ground into it. The call to prayer sang out - gravelly, mournfully, with feeling.