Investing.com -- Customer visits to Taco Bell locations fell sharply Friday following a parasite outbreak that health authorities connected to lettuce from one of the chain's suppliers. The outbreak has affected Taco Bell, which serves as the primary growth engine for parent company Yum! Yum shares have fallen roughly 10% since July 10, when reports first emerged linking Taco Bell to the outbreak. Health officials traced cases of cyclosporiasis, a gastrointestinal illness caused by a microscopic parasite, to lettuce served at Taco Bell restaurants. Related articlesTaco Bell visits drop 19% after lettuce parasite outbreakThese 2 stocks are best positioned to benefit from higher uranium prices: analystAs Claude disrupts stock market, Anthropic researcher warns 'world is in peril'