Benjamin P Turner, Kambiz Boomla, and Klaus Schmierer
Ethnicity and prevalence of multiple sclerosis in east London
Background: Incidence and prevalence rates of multiple sclerosis (MS) are generally higher in White populations than in other ethnic groups. Relevant studies in the United Kingdom were conducted over 30 years ago.
Objectives: To provide updated ethnicity-specific MS prevalence rates in the United Kingdom.
Methods: Electronic records from general practices (GPs) in four east London boroughs were queried for the number of people diagnosed with MS, grouped by ethnicity, into 5-year age bands. Compared against total registered GP patients in the area (c. 900,000), the age-standardised MS prevalence was calculated by ethnic group.
Results: The overall age-standardised prevalence of MS was 111 per 100,000 (152 for women and 70 for men), and 180, 74 and 29 for the White, Black and South Asian populations, respectively. The sex ratios (female:male) were 2.2:1, 2.1:1 and 2.8:1, respectively.
Conclusion: MS prevalence was considerably lower among Black and South Asian populations, compared to the White population, by 59% and 84%, respectively. However, compared to available data in Africa and South Asia, MS is several times more prevalent among Black people and South Asians living in the United Kingdom than their territorial ancestry.
Ethnicity-specific prevalence of MS in east London: crude (white bars) and age standardised (filled bars).
Our medical students have been busy getting all People with MS attending Barts Health onto the BartsMS Database, however for this study we also teamed up with Kambiz Boomla and his colleagues at the Centre for Primary Care and Public Health of the Blizard Institute.
Even the highest prevalence reported for any
sub-Saharan African country, 0.24/100,000 in Ghana, is a small fraction of the
prevalence of MS in Black people in east London (74/100,000). MS prevalence for
people living in India (7/100,000) or Pakistan (5/100,000) was also much lower
than for South Asians living in east London (29/100,000).
While prevalence differences could be explained
by fewer MS diagnoses occurring in less resourced countries, it is unlikely to explain the gulf in prevalence between these territories. As summarised by The Times “Within one generation of
being here the likelihood of them getting MS has multiplied… This strongly suggests an environmental factor.”
Or several thereof. The next question is how to test – robustly and within an achievable time frame – whether altering factors for which there is strong evidence, such as EBV infection and low vitamin D, impacts on the risk of getting MS.