TB rates in UK highest since 1987, but low, stable prevalence of MDR TB

The Health Protection Agency (HPA) last week published its first UK-wide annual report on tuberculosis (TB) in the UK, which finds that TB rates in the United Kingdom are higher now than at any other time since 1987, and are also higher than those in most other western European countries. However, rates of both resistant and MDR strains of TB have remained stable for the past few years, and MDR rates are lower than other countries in western Europe.

This is the first time the HPA’s annual TB report has included data on Scotland. A total of 8,113 cases of TB were reported in England, Wales and Northern Ireland in 2006, and 384 TB cases were reported in Scotland, bringing the UK-wide total to 8,497, a slight increase on 2005’s UK-wide reports (8,477), and a rate of 14.0 per 100,000.

Other headline findings include:

• The majority (61%) of cases occurred in young adults aged between 15 and 44.
• The majority (72%) of cases occurred in the non-UK born population, primarily those born in South Asia (47% of non-UK born cases) and sub-Saharan Africa (37% of non-UK born cases).
• London accounted for the largest proportion of cases (40%) and had the highest TB rate overall (44.8 per 100,000) followed by the West Midlands.
• Among TB cases with drug susceptibility testing results, 7.7% were resistant to at least one first-line drug; 6.9% were resistant to isoniazid and 1.1% were multi-drug resistant (MDR; resistant to at least isoniazid and rifampicin).

Since there was only an increase of 20 TB cases reported in 2006 compared with 2005, the HPA says it will need more years of data in order to assess whether or not these results indicate a slowing in the overall trend of increasing numbers of cases.

The report also includes data on TB treatment outcomes (available for 88% of cases reported in 2005). Overall, 79% of people diagnosed with TB in 2005 completed their treatment; this rate has remained stable since monitoring began in 2002. Men, older people and people born in the UK were more likely not to have completed their TB treatment. The most commonly reported reasons for not completing treatment were death (7%), loss to follow up (6%) and still being on treatment (4%).

The HPA notes that this 79% treatment completion rate is below the 85% recommended in the Chief Medical Officer's 2004 TB Action Plan. However, they note that is “this is in part due to a significant proportion of cases occurring among the elderly who die with, rather than of, tuberculosis. In addition some of the high risk populations for tuberculosis are hard-to-reach and hard-to-treat such as the homeless and problem drug users.”

Although the HPA has previously noted that there is an overlap between HIV and TB in the UK, the report does not include any data on the number of TB cases reported in HIV-positive individuals. However, earlier this year, a report from the UK Collaborative HIV Cohort (UK CHIC) found that Black Africans, and patients with a low CD4 cell count are the groups of HIV-positive individuals with the greatest risk of TB in the UK.

The full report can be obtained from the HPA website.