Infections among injecting drug users in the United Kingdom 2004. An update: October 2005

The prevalence of HIV infection among injecting drug users (IDUs), in England & Wales at least, has probably increased in recent years. Overall HIV infection among IDUs in the UK remains, when compared to other countries, relatively rare with around one in every 65 injectors infected. The prevalence of HIV among IDUs has remained substantially higher in London than the rest of the country with around one in 25 IDUs having HIV in the capital. Overall more than two in five IDUs in the UK have been infected with hepatitis C. In England and Wales hepatitis C transmission among IDUs is high with one in six of those who had started to inject since the beginning of 2002 having become infected. In Glasgow, transmission was higher with one in two IDUs, who had been injecting for less than two years in 2004, having been infected with hepatitis C. Uptake of testing for hepatitis C among IDUs in contact with drug services has increased in recent years. It is estimated, however that around half of those IDUs with hepatitis C in contact with these services still remain unaware of their infection. There will also be substantial numbers of current and former IDUs who are not in contact with services that will be unaware that they have hepatitis C. Those who report injecting crack-cocaine have higher prevalences of HIV and hepatitis C infection. Whilst crack-cocaine use is associated with increased injecting risk behaviours, the underlying factors for the higher levels of blood borne virus infection are not as yet clear, but it is a cause for concern as crack-cocaine use has become more widespread. The continuing occurrence of wound botulism cases indicates that environmental contamination of heroin with bacterial spores remains a problem. Whilst there are continuing problems with injecting site infections associated with methicillin resistant Staphylococcus aureus and severe group A streptococcal infection. Transmission of both hepatitis A and B continues among IDUs even though there are effective vaccines. The proportion of IDUs reporting uptake of the hepatitis B vaccine has increased markedly in recent years, with the prison vaccination programmes being a major factor in this increase. Needle and syringe sharing increased in the late 1990s, and since then has been stable with around one in three IDUs reporting this activity in the last month. The sharing of other injecting equipment is more common, whilst few IDUs swab injecting sites prior to injecting. (Editor' s abstract)