That page says "The outbreak in Constantinople was thought to have been carried to the city by infected rats on grain boats arriving from Egypt.[7] To feed its

That page says "The outbreak in Constantinople was thought to have been carried to the city by infected rats on grain boats arriving from Egypt.[7] To feed its citizens, the city and outlying communities imported massive amounts of grain—mostly from Egypt. Grain ships may have been the original source of contagion, as the rat (and flea) population in Egypt thrived on feeding from the large granaries maintained by the government."