From 1987 to 2008, 13% of tetanus cases and 29% of tetanus deaths occurred in people sick with diabetes. Diabetics suffer from tetanus three times more often than the rest, and die four times more often. 15% of tetanus cases occur in intravenous drug users.
Even if one were to assume that tetanus antibodies effectively neutralize the toxin, they would still need to get to the place of injury. And if the injury were to occur in a place with no sufficient blood supply, antibodies would not be able to get there. This is why diabetics suffer from tetanus much more often.
Since 1955, 90% of tetanus cases in New York were heroin addicts. Same in Chicago.
A case of brother and sister who got tetanus from heroin is described here. The brother had a severe form of tetanus and the sister had a mild one. They both recovered – the brother in three weeks and the sister in two weeks. Since the sister received the vaccine 15 years ago, the authors concluded that was the reason she got the mild form. They also concluded that the brother was most likely never vaccinated, and that is why he got severe tetanus, although his antibodies level was never tested, and if he was ever vaccinated remained unclear.
From 1984 to 1994, 40 people died of tetanus in the Lazio region in Italy (population of 5.1 million). 48% of them were elderly people, and among the younger ones, mostly intravenous drug users died. In the age group of under 30 years old, no death were recorded. Among those who were not drug users, only one person under the age of 40 died, and two more people under the age of 50. The risk of death in elderly people was 27 times higher, in farmers – 167 times higher, and in drug users – 186 times higher.Tetanus in Injecting Drug Users, United Kingdom. 2006, Hahné, Emerg Infect Dis
Until 2003, tetanus was a rare disease in Great Britain, and mostly happened among the elderly. After 2003, drug users began to get infected with tetanus. In 2003, there were 35 cases of tetanus, and two of them died. The authors researched for common factors and found out that they got sick from infected heroin from Liverpool. The authors urge the doctors and prison staff to vaccinate drug users.Tetanus in Injecting Drug Users. 2005, Beeching, BMJ
Cases of tetanus in drug users were already described in Victorian era. They injected morphine under the skin then.
In Chicago, in the ‘50s, before the vaccination began, most patients were heroin addicts. Out of the 22 cases of tetanus, 12 were drug users, and they all died. Only four of the rest died. CDC reports that 55% of tetanus cases in California were intravenous drug users.
It is reported here that five out of five tetanus patients in three years in Saudi Arabia, were heroin addicts.