Sometimes the tiniest pests can be the most difficult to fight. One enemy - the tsetse fly - nearly destroyed milk merchant Abdullah Khalfan's business. It took a big technology - nuclear power - to fight it off.
These days Abdullah sells more than 300 hundred litres of milk and yoghurt from his stall in Zanzibar's historic Stone Town market. But a few years ago the 38-year-old milk merchant could only dream of business being so good. Cows on this island off the coast of Tanzania were not producing much milk due to a little insect called the tsetse fly that was biting them.
The tsetse fly looks very similar to its harmless relative, the housefly, but it is bloodsucking and deadly. Its bite transmits the parasite trypanasome, causing the neurological disease known as sleeping sickness. Sleeping sickness claims the lives of an estimated 100,000 Africans every year.
A strain of the same parasite causes bovine trypanosomiasis, a debilitating disease in cattle known as nagana in Swahili. Cows that become pregnant with the disease often abort before delivering their calves; bulls become sterile. The tsetse fly is also the reason horses have not been able to survive in many parts of Africa. "The tsetse made my cows very sick," says Abdullah.
"Only the scrawny local breed of cows could survive nagana," remembered a customer waiting to buy milk at Abdullah's stall. "But they are not good dairy cows." Milk became a luxury in Zanzibar.
Now that has changed. Cows on the island are no longer being infected with the parasite. Experts from the government of Tanzania, the United Nations International Atomic Energy Agency (IAEA) and several other UN agencies worked together for almost a decade to eradicate the tsetse fly from Zanzibar.
Scientists started by breeding millions of flies in captivity. The males were then separated and treated with low doses of radiation to make them sterile. Released into the wild, they mated with females who were 'tricked' into thinking they were pregnant but never produced any offspring. The tsetse fly simply died out.
Zanzibar's success inspired the African Union to launch a campaign throughout the continent. The fly infests an area of almost 10 million square kilometres that runs across the equator of sub-Saharan Africa and includes 37 African countries.
"It's no coincidence that the world's poorest countries are in tsetse infested regions," says Qian Jihui, IAEA's Deputy Director General. Not only does the tsetse fly reduce the supply of milk and beef, it also hampers crop production as cattle are traditionally used to till the soil. The insect also infests fertile land along the riverbanks, forcing farmers off the best land.
Officials in Zanzibar worry that flies could migrate back to the island as stowaways on cattle ships from the mainland. "The 30-kilometre journey from Tanzania is too far for the tsetse fly to travel on its own," says Udo Feldmann, an entomologist at IAEA. "The cattle have to be checked to ensure that the flies are not reintroduced."
Abdullah now produces most of the milk he sells with just eighteen healthy cows. Annual dairy production in Zanzibar has tripled from what it was five years earlier and is expected to increase further. "I'm buying more cows now because they are profitable," says Abdullah. "When the tsetse flies were around it didn't make sense."
"It's amazing to think that getting rid of a little insect could make such a difference to my life," he adds.
FIND OUT MORE how the UN Works with business and industry even at the local level, go to the links next to Abdullah.
قصص أخرى عن التجارة: