Brill-Zinsser Disease; the Possibility of its Occurrence in Britain.

1. Of 318 Polish refugees now living in this country 30% gave a history of typhus fever; nearly half of these had complement-fixing antibodies to a titre of 1–5 or more to epidemic typhus. A further 12% without such a history similarly had these antibodies making a total of 22% of 318 refugees. None of the 174 British born controls had antibodies up to this titre. 2. Brill-Zinsser disease may occur from time to time among immigrants or visitors from typhus endemic areas to this country, but it is unlikely to be a serious problem. 3. The clinical diagnosis of Brill-Zinsser disease may not be easy because the characteristic rash is not always to be seen. Any patient of Eastern European origin or who has a history of typhus complaining of fever and severe headache should be examined serologically by the rickettsial agglutination or the complement-fixation test for specific epidemic typhus antibodies. The Weil-Felix reaction may be positive, but a negative result will not exclude a diagnosis of Brill-Zinsser disease. We acknowledge with gratitude the help, interest and advice of Dr E. S. Murray, of the School of Public Health, Harvard University and Dr Janet Niven and also the technical assistance of Mr J. P. Brooks, FIMLT. We have to thank Messrs Lederle for their kindness in supplying the rickettsial antigens and in addition those who helped us to obtain the specimens and the volunteers who supplied them.