Recent changes in the official botulism websites of the Centers for Disease Control and Prevention (CDC) and the California Department of Public Health caught our attention.

Both are attributing an increase in the number of wound botulism cases to an "epidemic" of Mexican black tar heroin abuse in California.  CDC puts it this way:

In the United States, an average of 145 cases are reported each year.  Of these, approximately 15 percent are foodborne, 65 percent are infant botulism, and 20 percent  are wound.  Adult intestinal colonization and iatrogenic botulism also occur, but rarely. Outbreaks of foodborne botulism involving two or more persons occur most years and usually caused by eating contaminated home-canned foods. The number of cases of foodborne and infant botulism has changed little in recent years, but wound botulism has increased because of the use of black-tar heroin, especially in California. 

The California Department of Public Health is even more pointed in its summary:  "The number of cases of food-borne and infant botulism has changed little in recent years, but wound botulism has increases because of the injection of black tar heroin.  In recent years, California has experienced an epidemic of this form of botulism and we now report nearby three-quarters of the wound botulism cases in the country.

We first reported on wound botulism cases in California here.

Here’s the official answer from CDC to the question: "What is botulism?"

Botulism is a rare but serious paralytic illness caused by a nerve toxin that is produced by the bacterium Clostridium botulinum. There are three main kinds of botulism. Foodborne botulism is caused by eating foods that contain the botulism toxin. Wound botulism is caused by toxin produced from a wound infected with Clostridium botulinum. Infant botulism is caused by consuming the spores of the botulinum bacteria, which then grow in the intestines and release toxin. All forms of botulism can be fatal and are considered medical emergencies. Foodborne botulism can be especially dangerous because many people can be poisoned by eating a contaminated food.