Asymptomatic infection with EB virus

Abstract

Positive Paul-Bunnell-Davidsohn reactions in sera from healthy individuals, usually blood donors (where the incidence may be 0-9 to 1 6%), have been described on several occasions (Barratt, 1941;Hobson, Lawson, and Wigfield, 1958;Virtanen, 1962). The significance of these observations is obscure and whether such heterophile antibodies represent subclinical infectious mononucleosis or are chance findings, to be dismissed as 'false-positive reactions', is not clear. The association of the EB virus with infectious mononucleosis (Henle, Henle, and Diehl, 1968;Evans, Niederman, and McCollum, 1968) sheds some light upon this problem, for the high incidence of antibodies to this virus in the community showed that asymptomatic infection with the probable causative agent of infectious mononucleosis was widespread. Holborow, Hemsted, and Mead (1973) have recently observed that a high proportion of patients with active infectious mononucleosis possessed antibodies to smooth muscle. Our own unpublished data support this observation but we were surprised that some of our control medical students and nurses also had smooth muscle antibodies. These antibodies are usually found in patients with some degree of liver damage (Johnson, Holborow, and Glynn, 1965) but our medical students and nurses were, apparently, quite healthy. Their sera were therefore tested for EB virus antibodies and, in the following report, we outline our findings and suggest that subclinical EB virus infection, associated with the development of smooth muscle antibodies, may be not uncommon in young adults.

Mechanisms of smooth muscle antibody production: a clinical study in children with infections, haemolytic syndromes, and idiopathic thrombocytopenic purpura.

“…In chickenpox, although SMA was found in about half of the patients (9/19), the incidence was not significantly raised, but this may be due to the smaller number examined. These prevalence findings for SMA in viral hepatitis and infectious mononucleosis in children are similar to those reported for adults, viz, up to 81 % in viral hepatitis (Farrow et al, 1970;Ajdukiewicz et al, 1972;Vittal et al, 1974) and up to 75 % in infectious mononucleosis (Holborow et al, 1973;Sutton et al, 1974b). The incidence of SMA in healthy adults, ranging from 12 % to 20% (Whitehouse and Holborow, 1971;Holborow et al, 1973;Sutton et al, 1974a;Shu etal., 1975), is similar to that in a random population sample in Greece (19 4%).…”

Measurement of heterophil antibody and antibodies to EB viral capsid antigen IgG and IgM in suspected cases of infectious mononucleosis.

“…EB IgM and HA tests on sera taken from small children for other laboratory investigations might reveal the clinical pattern associated with EB infection and show whether a positive HA test is indeed often absent when EB virus infection occurs at an early age. It is possible that it may often be asymptomatic as positive EB IgM and HA tests have been found in sera from students taken during routine sampling when no recent illness has been reported (PHLS unpublished and Sutton et al, 1974b).…”

Screening tests for hepatitis B antigen and antibody in two colleges of education and studies on the relationship between nonspecific positive antibody tests and EB virus infection.

“…They were therefore likely to be convalescent from recent EB virus infection. It is known that EB virus infection in the university age group can occur either with or without characteristic symptoms of infectious mononucleosis (University Health Physicians and Public Health Laboratory Service Laboratories, Joint Investigation, 1971) and that heterophil antibody can be detected in those without typical symptoms (Edwards and McSwiggan, 1974;Sutton et al, 1974). Two of these students gave recent histories suggestive of infectious mononucleosis when questioned at the time of sampling.…”