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 1 978-97 inclusive in Blackburn, Hyndburn and Ribble Valley for individuals o f ISC ethnic origin notified with tuberculosis. Those cases diagnosed throu gh 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 vis its within 3 years of that notification. including 60%, of the United Kingd om (U.K.) born without prior exposure to the ISC. Conclusion: The clinical observations are consistent with the hypothesis th at return visits to the ISC carry a risk of acquiring tuberculosis. This ca nnot be confirmed. however, without information about the return visits in the ISC population as a whole. A case-control study may be required to conf irm the hypothesis. (C) 2001 The British Infection Society.