Wound Botulism Associated With Black Tar Heroin Among Injecting Drug Users

Douglas J. Passaro, MD, MPH; S. Benson Werner, MD, MPH; Jim McGee, MSPH;
William R. Mac Kenzie, MD; Duc J. Vugia, MD, MPH

Context.—Wound botulism (WB) is a potentially lethal, descending, flaccid,
paralysis that results when spores of Clostridium botulinum germinate in a
wound and elaborate neurotoxin. Since 1988, California has experienced a
dramatic increase in WB associated with injecting "black tar" heroin (BTH),
a dark, tarry form of the drug.

Objective.—To identify risk factors for WB among injecting drug users (IDUs).

Design.—Case-control study based on data from in-person and telephone
interviews.

Participants.—Case patients (n26) were IDUs who developed WB from January
1994 through February 1996. Controls (n110) were IDUs newly enrolled in
methadone detoxification programs in 4 counties.

Main Outcome Measures.—Factors associated with the development of WB.

Results.—Among the 26 patients, the median age was 41.5 years, 15 (58%)
were women, 14 (54%) were non-Hispanic white, 11 (42%) were Hispanic, and
none were positive for the human immunodeficiency virus. Nearly all
participants (96% of patients and 97% of controls) injected BTH, and the
mean cumulative dose of BTH used per month was similar for patients and
controls (27 g and 31 g, respectively; P.6). Patients were more likely
than controls to inject drugs subcutaneously or intramuscularly (92% vs
44%, P<.001) and used this route of drug administration more times per
month (mean, 67 vs 24, P<.001), with a greater cumulative monthly dose of
BTH (22.3 g vs 6.3 g, P<.001). A dose-response relationship was observed
between the monthly cumulative dose of BTH injected subcutaneously or
intramuscularly and the development of WB (2 for linear trend, 26.5;
P<.001). In the final regression model, subcutaneous or intramuscular
injection of BTH was the only behavior associated with WB among IDUs (odds
ratio, 13.7; 95% confidence interval, 3.0-63.0). The risk for development
of WB was not affected by cleaning the skin, cleaning injection
paraphernalia, or sharing needles.

Conclusions.—Injection of BTH intramuscularly or subcutaneously is the
primary risk factor for the development of WB. Physicians in the western
United States, where BTH is widely used, should be aware of the potential
for WB to occur among IDUs.

JAMA. 1998;279:859-863

From the Division of Communicable Disease Control, California Department of
Health Services, Berkeley (Drs Passaro, Werner, and Vugia and Mr McGee),
and the Division of Infectious Diseases and Geographic Medicine, Stanford
University Medical School, Stanford, Calif (Dr Passaro), and the Division
of Field Epidemiology, Epidemiology Program Office, Centers for Disease
Control and Prevention, Atlanta, Ga (Drs Passaro and Mac Kenzie). Dr
Passaro is now with the Division of Infectious Diseases and Geographic
Medicine, Stanford University Medical Center. Dr Mac Kenzie is now with the
Division of Parasitic Diseases, Centers for Disease Control and Prevention.

[JAMA] EDITOR'S NOTE.—Despite the well-known hazards of injection drug use,
such as human immunodeficiency virus infection, endocarditis, and fatal
overdose, some substance abusers continue to inject heroin and other
illicit drugs. This case-control study evaluated injection drug users who
developed another dangerous complication, wound botulism, and examined risk
factors for this potentially fatal paralytic disorder. Injection of black
tar heroin (a dark, tarry form of the drug) subcutaneously or
intramuscularly (a practice known as skin-popping) was associated with an
increased risk for wound botulism, with a "dose-response" relationship
between the cumulative amount of black tar heroin injected via this route
and development of disease. Clinicians should add wound botulism to the
list of dangerous complications they may encounter in patients who inject
black tar heroin and other illicit drugs.

Phil B. Fontanarosa, MD, Senior Editor

© 1995-1998 American Medical Association.