Tuberculosis Consultant Services

Asians who developed tuberculosis in London were divided into two groups.  The first group consisted of persons who had immigrated to the United Kingdom and never returned to their country of origin.  The occurrence of tuberculosis in this group is shown in the top panel.

The second group consisted of persons who, after immigration, returned one or more times to their country of origin.  The occurrence of tuberculosis relative to the first entry to the United Kingdom is shown in the middle panel.  The occurrence of tuberculosis of tuberculosis relative to the last re-entry is shown in the bottom panel.

Persons who never returned to their country of origin had the highest risk immediately following immigration. This suggests that most of disease in these persons was the result of progression from recent infection acquired in the country of origin.

The distribution among those who did return shows an even distribution of case emergence over time when analyzed relative to the first entry. When arranged relative to re-entry, the distribution resembles that among those who never returned.

This analysis strongly suggests the importance of recently acquired infection and points to the differences in infection risk in low and high incidence countries.