Written or medically reviewed by a board-certified physician. See About.com's Medical Review Policy.

Updated September 07, 2015.

Rates of heroin use have been climbing in the US over the last decade. Heroin overdose deaths have increased almost 4 fold. Over 8000 die in the US from overdoses each year. Rates of abuse have doubled among women and have risen 50% among men in the US.

Infections though account for much of the harm.

Beyond deaths directly from overdoses, heroin use is also associated with infections which may -directly or indirectly - affect people long after the drug has cleared the system.


 Treatment for addiction may reduce the risk of overdose, but some infections may remain while others have created scars of sort.

The fact that heroin is often injected is the reason why it causes infections to spread.  Some may start by abusing prescription drugs before moving to using the less expensive heroin. This move may be between drugs that are not injected and a drug that is.

Prescription drug use alone is dangerous, of course. 44 die in the US a day as a result of prescription drug overdose. Roughly 10 a day die from heroin overdose.

There are 3 main ways in which heroin can lead to these infections

a) shared needles and other injecting equipment - leading to infections spreading by blood

b) non-sterile injection practices - leading to infections from bacteria on the skin

c) contaminated heroin - leading to some unusual infections

Infections spread by shared injection equipment.

Hepatitis C

Hepatitis C is a virus that causes liver damage. It can occur with acute presentation that sends those infected to the hospital, but most infected have chronic infections that they do notice until the liver disease has progressed.

There are new treatments that offer new promise for treating this disease.

The disease is often spread by shared injection equipment - such as shared needles. It's thought worldwide that globally about 90% of Hepatitis C infections are related to intravenous drug use, though roughly half (54%) of cases in the US. Hepatitis C cases have also risen over the last few years. Around 2000 develop new acute, symptomatic infections each year in the US and slightly under 30,000 are thought to develop the infection each year (as most cases are silent and not symptomatic when they first occur). There are approximately 2.7 million cases of chronic Hepatitis C in the US. Most infections occurred in the 1970s and 1980s and persist, as only about 15-25% clear the virus and do not become chronically infected. It is thought 1 in 3 young intravenous drug users (IDUs) (ages 18-30) are infected, while 70-90% of older chronic or former IDUs are infected.

Hepatitis B

Hepatitis B is a virus unrelated to hepatitis C, but which is also transmitted by sharing needles and also causes liver damage. Hepatitis B (HBV) infection in IDUs was reported to be as high as 20 percent in the United States in 2010

HIV

HIV can be spread through a variety of ways - through sex, birth, blood transfusions, and through shared needles and other injection equipment. Worldwide, it is thought about 30% of HIV infections outside of sub-Saharan Africa are from shared needles and injection equipment.

Likewise, HTLV and even Malaria, where it is present, can spread through IVDU.

Infections spread by lack of sterile technique

There are a number of infections that spread because the needles, though not shared, are used without sterile technique. The use of needles requires practice and protocols to avoid spreading infections, as health professionals learn. They pierce through skin that is normally covered in bacteria, taking the bacteria under the skin and possibly into the bloodstream. That is to say, our skin is covered in bacteria normally, as part of our microbiome. 

MRSA

One of the common bacteria spread this way is Staph Aureus, including MRSA (which is a drug resistant form of Staph Aureus). There are other infections caused by bacteria -like Group A streptococci (GAS tied to a number of infections) - that can lead to invasive infections. However, the main culprit is MRSA (and to some extent MSSA, Staph Aureus that isn't resistant to the important antibiotics that MRSA is). 

The infections caused by these bacteria can spread through skin-popping, where needles spread the bacteria below the skin, creating infections, such as skin infections, like cellulitis, or small pockets, like furuncles (or boils), or larger pockets like abscesses. Some types of cellulitis can be mild, while others can lead to soft tissue and muscle infections and to more severe infections like necrotizing fasciitis. IV drug use can send the drug, and hence the bacteria, directly into the bloodstream. This can cause an infection in the blood, leading to sepsis and severe illness depending on the bacteria. The bacteria can spread in the blood and seed other parts of the body including heart valves (endocarditis), bones (osteomyelitis), joints (septic arthritis), as well abscesses internally, such as in the liver. These infections can lead to life long damage, such as heart valve damage that can lead to heart failure or permanent and painful damage to bones and joints.

Treatment of MRSA - as well as many of the serious infections, like endocarditis, that it causes, usually requires prolonged IV treatment. This can be particularly dangerous for those who are addicted to IV drugs.

Infections caused by contaminants to the drugs used

Drugs injected are not usually 'pure' but are generally mixed with other substances. For medications used in hospitals, any drugs that is injected into patients needs to have the ingredients be carefully assured to be sterile. However, with drug use, the substances mixed with drugs may include a number of other microorganisms that can infect those who inject drugs.

These infections can be due to unusual bacteria that are not usually seen on the skin. Many of these infections are caused by spores that can last a long time.

Others may mix drugs with tap water, which is not sterile, leading to infections from microbes in the tap water (such as pseudomonas). More unusual colonization can also occur, especially in close quarters, leading to unexpected infections in the bloodstream, such non-toxinogenic Corynebacterium diphtheriae.

Botulism

Botulism is a rare bacterial infection that is potentially fatal but is now not usually seen now because of safety measures in food canning and preparation. Clostridium botulinum spores can contaminate heroin, especially "black tar heroin". It can be spread by skin popping or IV drug use leading to infections of wounds at injection sites. It can cause weakness, drooping eyelids, blurred vision, and difficulty speaking and swallowing. Because it is a rare infection and those using IV drugs may delay seeking care, diagnoses may be delayed. However, because the spores may contaminates batches of heroin before distribution it can lead to multiple cases in an outbreak among those who use the same batch of heroin.

Tetanus

Tetanus spores can contaminate heroin injection - either during production and distribution or during injection. Clostridium tetani are found naturally in the environment such as in dirt or on rusty equipment. In the US, bout 15% of cases of tetanus occur each year in persons who inject drugs, like heroin. In the UK, a sudden rise of tetanus occurred, associated with heroin injection in 25 people in 2003-2004.

Tetanus is largely avoidable with the full course of vaccination for tetanus (5 shots) and boosters every 10 years or a repeat booster if exposure (high risk injury) and no vaccine booster for 5 years.

Anthrax

Although anthrax often brings up the image of bioterrorism, the spores causing anthrax can be found naturally in some environments. There were in fact 82 cases of Bacillus anthracis (anthrax) in Scotland in 2009-2010 among individuals who used heroin. Most had soft tissue infections but some had serious infections.

Other spores infections caused by spores have also been reported - Bacillus cereus (a relative of Bacillus anthracis) and Clostridum sordellii (a relative of Clostridium botulinum and Clostridium tetani)

Others may be more likely to develop other infections, such as Tuberculosis, because of cramped living conditions and because TB can spread easily where more are immunocompromised, such as with HIV or even malnutrition.

For information on help with dealing with heroin abuse, the CDC recommends calling: 1-800-662-HELP or seek information from the National Institute for Drug Abuse webpage