Dozens of cases of tuberculosis were reported in Calderdale in recent years, figures reveal.
Health experts say incidents of the disease, also called TB, have declined nationwide, though rates remain higher than those on the continent.
Public Health England statistics show there were 39 cases of TB in Calderdale between 2016 and 2018, the latest period for which data is available.
That's a rate of 6.2 cases for every 100,000 people – slightly lower than the 9.2 average across England.
Tuberculosis is a bacterial infection spread by inhaling the tiny droplets from an infected person's coughs and sneezes.
The disease, which usually affects the lungs, is curable using antibiotics but can be fatal if left untreated.
Of the six people with a form of TB sensitive to drugs in Calderdale in 2017, six completed treatment in 12 months.
The treatment rate had risen from the previous year, when 94 per cent of those infected finished treatment within a year.
Nationally, TB rates have dropped to their lowest since records began, after concerted efforts to reduce a sustained increase in cases between the mid-1980s and the turn of the millennium.
Despite the general decline of TB across England, it still lingers in poverty-stricken areas.
According to Public Health England, cases of TB continue to grow among marginalised communities and infection rates are seven times higher among the poorest 10% of the population than the richest 10 per cent.
The London borough of Newham reported the highest rate in England between 2016 and 2018, at 49.3 cases per 100,000 people, while Eden, Ryedale and the Isles of Scilly reported no cases.
Social factors such as debt and unemployment are known to increase the risk of tuberculosis, warns charity TB Alert.
Mike Mandelbaum, the organisation's chief executive, said: "People are most at risk if they came to the UK from countries where there are high levels of TB, or if their general health or living conditions make them more vulnerable to airborne TB bacteria, for example being homeless.
"If TB is not treated it is life threatening and can also be passed on to other people."
Infection rates in the UK remain higher than most other European countries, he added.
A Public Health England spokeswoman said: "Overall, the geographic variation is largely due to differences in demographics between different areas.
"Urban areas are associated with variations both in deprivation and in the diversity of their populations; most TB cases (72 per cent) occurring in people who were born outside the UK."
She added: "We are working towards the World Health Organisation's End TB Strategy target of a 90% reduction in new cases of TB by 2035."