Are there still effects on Indian Subcontinent ethnic tuberculosis of return visits?: a longitudinal study 1978-97

Objective: To assess whether return visits to the Indian Subcontinent (ISC) are associated with increased risks of developing clinical tuberculosis.

Methods: Descriptive analysis of epidemiological records over a period of 1978-97 inclusive in Blackburn, Hyndburn and Ribble Valley for individuals of ISC ethnic origin notified with tuberculosis. Those cases diagnosed through local contact tracing exercises were excluded.

Results: Of 1032 eligible individuals notified with tuberculosis, 228 (22.1%) reported prior visits to the ISC. Of these 151 (66%) reported having visits within 3 years of that notification, including 60% of the United Kingdom (U.K.) born without prior exposure to the ISC.

Conclusion: The clinical observations are consistent with the hypothesis that return visits to the ISC carry a risk of acquiring tuberculosis. This cannot be confirmed, however, without information about the return visits in the ISC population as a whole. A case-control study may be required to confirm the hypothesis.