UK report highlights homelessness link to IDUs acquiring hepatitis C, but not HIV

Homelessness, injecting into the groin or leg, and injecting crack-cocaine are associated with a higher risk of injecting drug users (IDUs) acquiring hepatitis C and other serious infections, according to a new report from the UK’s Health Protection Agency (HPA).

The report, Shooting up. Infections among injecting drug users in the United Kingdom 2006. An update: 2007 also highlights that hepatitis C is now affecting almost half of all IDUs; and that around one out of 75 IDUs in the UK is living with HIV.

The report’s authors highlight that around three-quarters of IDUs have been homeless at some point in their lives, and those who have been homeless had higher levels of injecting risk and associated infections, primarily due to needle-sharing and poor hygiene.

The report also found that:

• One in four of those who had been homeless reported the direct sharing of needles and syringes in the past month compared with only one in six of those who had not been homeless.
• Those who had been homeless during the last year were more likely to report an abscess, open sore or wound at an injecting site.
• A higher proportion of those who had been homeless had hepatitis C infection.

However, homelessness was not associated with a risk of HIV infection: IDUs who reported that they had ever been homeless had a similar prevalence of HIV infection compared to those who had not (1.3% vs. 1.2%).

Which drugs are being injected, and how many people use them?

The HPA reports that the drugs most commonly injected during the past four weeks by the almost 2000 IDUs participating in the 2006 Unlinked Anonymous Prevalence Monitoring Programme (UAPMP) survey were: heroin (87%, 1,730); crack-cocaine (33%, 657); and amphetamines (15%, 303). The report notes that “the use of crack-cocaine has become more widespread” and that “this is a cause for concern as those injecting crack-cocaine report more equipment sharing.”

Although the actual numbers of people who inject drugs in the United Kingdom remains uncertain, at least 140,000 people in England are thought to inject heroin or crack-cocaine (representing 0.42% of adults aged 15 to 64), although this may be an underestimate. Studies from Scotland suggest that the number of IDUs may have fallen from around 25,000 in 2000, to 19,000 in 2003 (representing 0.9% and 0.7% of adults aged 15 to 54 years, respectively).

Hepatitis C

Hepatitis C virus (HCV) affects almost half of all IDUs, making it, says the report, “the most important infectious disease affecting those who inject drugs.” With HCV treatments improving over time, the report suggests, “the uptake of diagnostic testing for hepatitis C by current and former IDUs is increasingly important. “

Although, 41% of IDUs in the 2006 UAPMP survey had HCV antibodies (which is similar to findings in their last report) there were, notes the report, some “very marked regional variations” in HCV prevalence throughout the UK. These ranged from 18% in Wales, 22% in the North East of England, and 29% in Northern Ireland; to 57% in London and 60% in the North West of England.

The 2006 UAPMP survey found that people who reported injecting crack-cocaine in the past four weeks were more likely to have HCV infection compared to those who did not (59% vs. 34%).

Similarly, those who had injected into their groins in the past four weeks were more likely to have HCV infection compared to those who had not (54% vs. 37%); and those who injected into their legs were also more likely to have HCV infection than those who had not (49% vs. 41%).

In addition, the survey found that IDUs who had ever been homeless were more like to be infected with HCV than those who had not (45% vs. 28%).

On a positive note, the report says that increasing numbers of IDUs with HCV are becoming aware of their infection. Three quarters of IDUs who took part in the UAPMP survey in England report having been tested for HCV, compared with 49% in 2000.

It also highlights a recent study which estimates that “as many as 4,500 hepatitis C infections had potentially been prevented in Glasgow during 1988-2000 as a result of harm-reduction measures.”

HIV

Althoug the report says that “the prevalence of HIV infection among IDUs, in England & Wales, is higher than at the start of the decade”, prevalence appears to have peaked compared with the results of the 2005 UAPMP survey.

The 2006 UAPMP survey found an overall HIV prevalence of 1.3%, although, as with HCV infection, there were some marked regional variations, notably in London which continues to have the highest HIV prevalence amongst IDUs, at 4.0%.

HIV prevalence appears to be higher in Northern Ireland (1.9%) and in Wales (1.1%) than in the rest of England, excluding London (0.65%). This is much lower than seen in 2005 (1.6%) and is a return to 2004 levels.

However, the prevalence of HIV among people who have recently begun injecting drugs – a measure of recent HIV transmission – has increased, suggesting that HIV incidence may be increasing among IDUs (0.77% in 2006 vs. 0.25% in 2002).

The report also found that although most IDUs in contact with health care services reported having had a test for HIV at some point, only two-thirds of those with HIV are aware of their infection.

So far, 156 new HIV diagnoses have been reported throughout the UK (72 in London, 16 in Scotland, and 68 elsewhere), where infection was probably acquired through injecting drug use.

Only two-thirds of these reports had information on probable country of infection: about half were probably acquired in the UK and about half were probably acquired outside of the UK, primarily in Southern Europe.

Hepatitis B and bacterial infections

The report notes that Hepatitis B virus (HBV) transmission is continuing among IDUs, and appears to be on the increase, despite the availability of an effective vaccine.

The UAPMP survey found that 10% of people who have recently begun injecting drugs had antibodies to hepatitis B core antigen compared with 7.1% in 2005.

However, the report notes that there has been a marked increase in the number of IDUs receiving the hepatitis B vaccine, with two-thirds now reporting vaccination.

Around one-third of IDUs report having had an abscess, sore or opened wound at an injecting site in the last year.

Many IDUs also report ongoing infections ranging from localised injection site infection to invasive meticillin resistant Staphylococcus aureus (MRSA) and severe group A streptococcal infection.

The report also notes that the “ongoing occurrence of wound botulism cases remains a concern.”

Recommendations

The report's authors make several recommendations based on their findings. These prioritise “preventing the spread of infections among IDUs and reducing the harm that these infections cause.”

Recommendations include:

• Continuing the development of high-quality needle exchange programmes for those unable to stop injecting.
• Ensuring that all services working with IDUs provide information and practical advice on safer injecting practices, avoiding injecting site infections, prevention of blood-borne virus transmission, and the safe disposal of used equipment.
• The continued provision of hepatitis B vaccination services, easy access to health checks, treatment for injection site infections, and diagnostic tests for hepatitis C and HIV.
• Continued provision of interventions to encourage behaviour change away from the sharing of injecting equipment and to decrease or stop injecting; as well as interventions that support entry into drug treatment, particularly to sustained quality substitute opioid treatment for heroin users which has been shown to be protective against infections.

The HPA’s Dr Fortune Ncube, who compiled the report, concludes by noting, “the recent increase in infections among IDUs indicates a need to re-examine the scope and range of harm reduction services provided for IDUs. Although a lot of work has been done in response to this, such as recent NICE guidelines and National Clinical Guidelines, much more is still needed to bring the levels of infection down.”