Botulism Linked to Fermented Tofu

Home-prepared fermented tofu, or soybean curd, was the culprit in 2 recent cases of foodborne botulism in an elderly Californian couple (MMWR. 2007; 56:96-97).

This is the first US report of botulism caused by the consumption of home-prepared fermented tofu. In China, home-fermented bean products were associated with 63% of the approximately 2000 botulism cases reported during 1958-1989.

In late November 2006, a 67-year-old Asian woman began experiencing double vision and bilateral ptosis. On December 4, she presented to her primary care physician with double vision, ptosis, dizziness, difficulty swallowing, slurred speech, drooling, and right-arm weakness.

Her 75-year-old husband reported 3 days of worsening double vision, dizziness, and difficulty swallowing. He also had mid-right ptosis and sluggish tongue movement. Both patients were admitted to the hospital, and Clostridium botulinum type A was found in their cultures.

A batch of home-prepared fermented tofu was identified as the culprit.

Primary care physicians should advise their patients that fermented tofu can result in foodborne botulism and that they should be extremely careful when preparing this product.