The laboratory diagnosis of lymphogranuloma venereum.

Although the literature on this subject is already quite considerable there is still some doubt as to the exact value of the different laboratory procedures available for the diagnosis of lymphogranuloma venereum. This does not, of course, apply to the demonstration of lymphogranuloma venereum virus in material from a suspected case of this disease, for this, as in any infective process, is of unequivocal value. Unfortunately the isolation and identification of lymphogranuloma venereum virus, though always worth undertaking, particularly in the early stages of the disease, is time-consuming and, in our limited experience, not nearly so readily achieved as some other workers have found (Wall, 1946). In the work here reported we have been more concerned with those laboratory tests, the Frei test and the lymphogranuloma venereum complement fixation test, which are of easy application and give an answer in a relatively short time. Much of the earlier work with these tests was done before Rake and his colleagues (1941) had drawn attention to the close relationship which exists between the viruses of the psittacosis-lymphogranuloma group. The extensive sharing of antigens, which is one of the important features of this relationship, is responsible for a high degree of cross reaction in complement fixation tests made with these viruses and their antisera (Rake. Eaton, and Shaffer, 1941) reducing them to a group specificity. The consequences for the Frei test are similar; a positive reaction to this test as at present practised is not confined to lymphogranuloma venereum but can also occur in infections with viruses of the psittacosis group (Rake, Eaton, and Shaffer, 1941). And although some of the more recent work on the Frei test and the complement fixation test in lymphogranuloma venereum has been done with Rake's important findings in mind the precise value of these two tests in the diagnosis of lymphogranuloma venereum is still far from clear. It was in an endeavour to remedy this deficiency and to find out if it would be possible to devise intra-