One evening sitting on the deck overlooking Lango Bai, drink in hand, the conversation turned to the extraordinary perils of my homeland. This was a theme already explored by Leon Varley in Zimbabwe and encountered again on the TV in a Johannesburg hotel. Everyone, it seems, is aware that Australia is home to the world’s most poisonous snakes and deadliest spiders. A swim entails the risk of Great White Sharks, marine stingers, crocodile attack, blue-ringed octopus and killer stingrays. Less well known are the stinging trees that when touched cause pain that recurs for months on contact with water. It takes courage to be an Australian, it’s a miracle any of us grew up.
It’s much safer sitting here on this deck, isn’t it?
Walking through the bai earlier my socks got wet. They have been hanging outside my little thatched hut all afternoon. I slapped a fly or two whilst we were walking, nasty little bite. Is that a mosquito now that the sun has gone? Slap … no appears to have been just a beatle.
Fortunately the last paragraph was a flight of fancy. No one leaves wet socks or any clothing out to dry. That would be an open invitation for the Mango Fly to lay its eggs. The larvae appear in two or three days and can penetrate intact skin. An itchy and later painful swelling follows, the little maggot lives happily in your flesh until maturity then it finds its way out, metamorphoses into a fly and heads off to find some more damp washing.
The day biting flies could be the vector of a number of other nasty problems. The tsetse fly has a most unpleasant bite and they tend to hunt in packs. Bad enough for that reason alone but worse still they may spread sleeping sickness. The agent is a trypanosome, a single celled organism, that when injected in the sub-cutaneous tissue …
moves into the lymphatic system, leading to a characteristic swelling of the lymph glands called Winterbottom’s sign. The infection progresses into the blood stream and eventually crosses into the central nervous system and invades the brain leading to extreme lethargy and eventually to death.
If diagnosed early sleeping sickness can be cured relatively easily these days. But the biting fly may have been carrying filaria instead producing a disease called Loa loa …
Some patients develop lymphatic dysfunction causing lymphedema. Episodic angioedema (Calabar swellings) in the arms and legs, caused by immune reactions are common. Calabar swellings are 3-10 cm in surface non erythematous and not pitting. When chronic, they can form cyst-like enlargements of the connective tissue around the sheaths of muscletendons, becoming very painful when moved. The swellings may last for 1–3 days, and may be accompanied by localized urticaria (skin eruptions) and pruritus (itching). They reappear at referent locations at irregular time intervals. Subconjunctival migration of an adult worm to the eyes can also occur frequently, and this is the reason Loa loa is also called the “African eye worm.” The passage over the eyeball can be sensed, but it usually takes less than 15 minutes.
Eosinophilia is often prominent in filarial infections. Dead worms may cause chronic abscesses …
In the human host, Loa loa larvae migrate to the subcutaneous tissue where they mature to adult worms in approximately one year, but sometimes up to four years. Adult worms migrate in the subcutaneous tissues at a speed less than 1cm/min, mating and producing more microfilaria. The adult worms can live up to 17 years in the human host.
It is better not to slap any creepy crawly it might just be a Blister Beatle …
They squash easily and … emit cantharidin. Blisters and slight irritation will appear quite soon after contact with cantharidin. RESIST the temptation to rub or scratch AT ALL COSTS as this will spread the problem. Fullblown blisters will develop, accompanied by inflammation and an aching pain as the poison penetrates deeper.
The liquid from the blisters will itself cause new blisters if allowed to come in contact with fresh skin!
And the mosquito, of course, is the most dangerous animal in Africa. Children under five are especially vulnerable to malaria. The WHO tells us that somewhere in Africa a child dies every 30 seconds.
In the Congo McGee wore long-sleeved shirts and long pants, all his clothing was soaked in permethrin prior to leaving home. DEET was spread on exposed skin. He took his Malarone every day and slept under a mosquito net whenever one was available. His flesh may well have been rendered unfit for human consumption but he actually doesn’t give a shit for the welfare of anyone wishing to eat him.
And he made it safely back to Australia where …