Warning of rising cases in London TB hotspot where 44 in every 100,000 residents have infection

With 44 in every 100,000 residents having active Tuberculosis (TB), Harrow is the borough with the second highest number in England, according to data from the National TB Surveillance System.

The incidence of TB in other areas of Northwest London is also high. However, this appears to be levelling off whereas in Harrow the cases “still seem to be rising”, according to the council. Because of this, Harrow’s Department of Public Health is in the process of developing a TB action plan.

Between January 2023 and December 2025, there was an average of 105 people per year diagnosed with active TB in Harrow – which has increased year on year from the 69 people per year between January 2017 and January 2019 when incidence were at their lowest.

During this period, 95 per cent of active cases in Harrow were in people who were born outside of the UK, with 69 per cent of those non-UK born people coming from India. Of the total number of incidents, 58 per cent had been living in the UK for less than five years, according to figures from Harrow’s Department of Public Health.

Speaking at a recent Health and Social Care Scrutiny meeting (March 10), Harrow’s Director of Public Health, Laurence Gibson, said the current cohort of residents with TB “are likely to have been infected before they travelled to the UK” and, whilst it is an issue across Northwest London, “it does seem to be affecting Harrow more than others”.

TB is an infection that normally affects the lungs, but can also affect other parts of the body, including the brain, spine and kidneys. It has two forms: active and latent. Active TB is where a person has symptoms – such as cough, tiredness, fever, and weight loss – whilst latent TB is where the bacteria that causes the disease has infected someone but the person does not have any symptoms.

Worldwide, TB remains one of the top ten causes of death. In England, approximately one in every 25 people diagnosed with active TB die within 12 months of diagnosis – equating to approximately 150 deaths per year.

People with active TB can infect others, whilst people with latent TB cannot. However, latent TB can ‘reactivate’ and become active TB for around one in every ten people. When people with active TB sneeze or cough they produce droplets containing the bacteria and it is these droplets that lead to the spread of TB from one person to another. People with active TB normally stop being infectious after about two weeks of effective treatment.

The incidence of TB in Harrow is continuing to increase, resulting in “significant morbidity and mortality for residents”, according to council documents. Data appears to show that this is largely driven by changes in migration patterns, missed opportunities to detect and treat latent infection in new migrants and an increase in the proportion of residents with diabetes mellitus and chronic kidney disease.

Harrow’s public health data shows that, of those eligible for latent TB screening, only 35 per cent were screened and of those screened only 10 per cent completed treatment. Mr Gibson said they “don’t know why this is” but understanding it will form a “vital part” of creating an action plan.