Knowing Botulism

  • Data Source:Ministry of Health and Welfare
  • Created:2016-03-23
  • Last Updated:2017-01-10

In March 2016, the Taiwan Food and Drug Administration (TFDA) received a report of a suspected botulism case from the Pingtung County Public Health Bureau. On receiving the report, the TFDA requested the Bureau to investigate the dietary history of the patient and collect suspected food residue samples for examination immediately. 

Clostridium botulinum prefers an anaerobic growing environment. It releases a neurotoxin that mainly attacks peripheral nerves, causing symptoms including blurred or double vision, drooping eyelids, dilated pupils, loss of facial expression, disturbances of salivary secretion, a dry mouth and throat, swallowing problems and difficulties in breathing and talking. There are mainly four types of infections: 

(1) Intestinal botulism (infant botulism): The human intestines provide an anaerobic environment that can lead to the growth of the bacteria. When they are intruded, intestinal tracts are inhabited by their spores that release a toxin. Botulinum spores can sometimes be found in other anaerobic environments such as honey or soil. It is therefore recommended that honey should not be fed to infants less than one year old since their intestinal immune systems are not fully developed. The making of complementary root crop foods also requires a thorough rinsing, skinning and heating process. 

(2) Foodborne botulism (classical botulism): This is caused by the intake of food which is contaminated with the botulinum bacteria, such as cured meat products that are privately made without proper disinfection and storage conditions. 

(3) Wound botulism: This is mostly caused by improper wound care, such as open wounds coming into contact with dust or dirt that is contaminated with the botulinum bacteria. 

(4) Others: These may be caused by over-injection of Botox or using illegal Botox products for cosmetic purposes. 

The samples taken from the patient in this case were examined by the Taiwan Centers for Disease Control (Taiwan CDC), showing a negative test result of the stool specimen. Despite a positive result in the serum detection, the serotype was not identified. In addition, food residue samples tested by the TFDA did not show any sign of the botulinum bacteria and botulinum toxin. 

The TFDA advises the public against making cured or canned food themselves out of safety concerns. When purchasing food which has been preserved in an anaerobic environment, such as vacuum-packed instant soybean products, the public should choose products with the vacuum packaging logo approved by the Ministry of Health and Welfare (MOHW) (see appendix); when purchasing cured or canned products, the public should choose comprehensively specified products and avoid those with inflated or damaged cans. Since the clostridium botulinum toxin cannot survive in high temperatures and can be destroyed by heating for 10 minutes at 100oC, it is best to heat any food thoroughly before consumption in order to ensure food safety. The TFDA has made and posted a promotional page, “Prevention of Food Poisoning – Knowing Botulism”, on its official website for the public to download and read.