Tick-borne typhus in England.

uncomplicated viral hepatitis patients with a high E.S.R. are likely to be of the short incubation period type.Giles and her colleagues6 found that in about one-third of their patients the anti- gen could only be demonstrated during the incubation period, so that it is possible that patients with a low E.S.R. who are antigennegative by the double-diffusion test may be of the long incubation period type.Further investigation is necessary, using more sen- sitive tests, to show whether this is so.Krugman et al. found that the thymol tur- bidity test was usually normal in the long incubation period type and high in the short incubation period type.'These findings, and those of the E.S.R., could be explained by changes in the serum proteins.Most laboratories are unable to do the simple double-diffusion test because of the scarcity of the specific antibody.The E.S.R. can be done in all types of hospital and it is hoped that may prove an additional help in the differentiation of the two types of viral hepatitis.-Iam, etc.,