I have hesitated positing this but feel it should be posted to help people become aware of
problems they might encounter.
I have always used a visa card for everything for my safari and use in Kenya. I have never had a problem.
My safari company has kept my card information confidential and locked up over 10 years, and when I would write them to charge an upcoming trip only 1 or 2 people had access to the number. They could then send the charge to my visa company and were paid directly.
Last year I obtained a Delta Skymiles card through American Express. Very few people in Africa use American Express. I asked my tour operator to charge my trip and was told that with American Express they needed a copy of the card which I sent them. They had to take that to Barclay's bank to process the charge. They cannot just swipe a card in a machine as one can do with Visa or Master Charge.
Well, I got a call from American Express asking if I had made a $2,500.000 for Kenya Airways or a
$1,700.00 charge for Turkish Airlines. I had not. Obviously someone swiped all my card information and
fraudulently misused it. I trust the tour operator completely as they've had my information for 10 years and never has anyone misused it. I have come to the conclusion that is most likely someone at Barclay's Bank who got a copy of the card who 'robbed' my account.
Thus just to be safe and protect yourself, don't use American Express in Africa.