David J. Lang

Demonstration of Cytomegalovirus in Semen

CYTOMEGALOVIRUS (CMV) infections of the female genital tract are common during pregnancy and probably represent an important source of neonatal infections.1 2 3 With recognition of CMV infections o...

Cytomegalovirus in semen. Persistence and demonstration in extracellular fluids.

Abstract Cytomegalovirus-infected semen derived from a patient who had previously recovered from heterophil-antibody-negative cytomegalovirus mononucleosis contained spermatozoa whose motility was initially depressed, but returned to normal while cytomegalovirus persisted in high titer. The virus was found primarily in extracellular fluid of the semen, and virus particles were demonstrable by electron microscopy as extracellular aggregates. Virus persisted in semen for 14 months while the subject remained asymptomatic and sexually active. Cytomegalovirus was recovered from the uterine cervix of a sexual contact. These studies indicate that cytomegalovirus may persist in semen, probably in extracellular fluids, unassociated with clinical symptoms or apparent impairment of sperm function. The prolonged asymptomatic presence of cytomegalovirus in semen may result in unrecognized venereal transmission of this virus. (N Engl J Med 291:121–123, 1974)

Cytomegalovirus infections in organ transplantation and post transfusion: An Hypothesis

The incidence and manifestations of cytomegalovirus (CMV) infections after organ transplantation and transfusion is reviewed. Since transfused individuals receive unmatched leukocytes, they share certain responses with recipients of organ grafts. In this regard enhanced replication of lymphoid elements, probably common to both groups, may be responsible for the frequent occurrence of primary as well as reactivated CMV infections in these patients. New CMV infections may be transmitted within transplanted cells — in blood leukocytes, wandering macrophages, infected and sloughed endothelial cells, or in carrier cells latently infected within an organ. Reticuloendothelial cells of the donor and the recipient receive a significant antigenic stimulus after transplantation or perfusion. This may lead to the replication and release of latent CMV if the virus is endogenous to the recipient or if it has been transmitted with leukocytes or within a donated organ. The nature of the resultant clinical illness depends in part upon the prior CMV antibody status of the recipient. Immunosuppressive regimens administered to organ recipients probably enhance the dissemination of CMV but not the acquisition of the virus.

Effectiveness of acycloguanosine and trifluorothymidine as inhibitors of cytomegalovirus infection in vitro.

The effectiveness of acycloguanosine (acyclovir) and trifluorothymidine (TFT) as inhibitors of cytomegalovirus (CMV) infection was tested using a plaque-reduction assay. Two laboratory strains and seven clinical isolates were employed. The results indicated that both acyclovir and TFT were ineffective in inhibiting viral cytopathic effect (CPE) below the concentration of 50 microM. At concentrations of 100 microM or more, greater than a 50 percent inhibition was achieved by both acyclovir and TFT on all clinical isolates. Although complete inhibition of plaque formation was seldom achieved even at a drug concentration as high as 200 microM, a reduction of plaque size was consistently observed at drug concentrations above 100 microM. When a low dose of virus was used for infection, ED50 could be achieved at an acyclovir concentration of 50 microM. Laboratory strains of CMV were found to be more resistant than the clinical isolates to inhibition of acyclovir.

Rapid diagnosis of herpes simplex infection: Amplication for electron-microscopy by short-term in vitro replication

Summary Herpes simplex virus (HSV) encephalitis was suspected in a three-year-old child on clinical grounds and on a computer tomography scan and an electroencephalogram. A brain biopsy was performed, and tissue was examined for confirmation. The use of immunoflorescence microscopy (IFM) and electron microscopy (EM) for the direct examination of a brain biopsy from a patient with presumptive herpes simplex virus (HSV) encephalitis yielded negative results. Nevertheless, Herpes virions were demonstrable by EM in tissue cultures inoculated with suspensions of this brain material prior to the appearance of specific light microscopic cytopathology. An embedding technique was devised whereby inoculated monolayers could be rapidly processed for EM and ultrathin sections examined two hours after cell harvest.

Herpesvirus morphology: visualization of a structural subunit.

The presence of spontaneously disrupted cytomegalovirus capsids has made it possible to visualize a subunit within the herpesvirus capsomere. The pattern resolved agreed well with the theoretical net based on the concept of a structural subunit at each apex of the hexon.

Viral Infection-Homograft Interactions in a Murine Model

The effects on some host defenses of murine cytomegalovirus (MCMV) and(or) EL(4), a mouse ascites homograft, were studied in mice. Assays of cellular and humoral immunity in response to either or both of these perturbations were carried out by quantitation of various immune activities.Limited studies demonstrated no effect of EL(4) inoculation on the host response to MCMV by organ viral titer, duration of viral persistence, or anti MCMV complement-fixing antibody titer. Prior infection with MCMV, however, resulted in greatly reduced numbers of splenocytes, the source in this study of immune effector cells. Residual splenocytes demonstrated less response to both phyto-hemagglutinin and lipopolysaccharide, particularly in the 2-3-wk interval after infection. Similarly, responder cells in mixed lymphocyte cultures were less reactive when derived from infected animals. Lymphocyte-mediated cytolysis of EL(4) was significantly less in mice infected on the day of and 7, 14, and 21 days before the tumor homograft with a return to control levels by 28 days. 90% of the cell-mediated cytolysis could be eliminated by treatment with anti-theta serum. Serum-mediated cytolysis of EL(4) was also reduced in infected animals. No suppressor cells or serum inhibitory factors could be identified in infected animals. Although alternative explanations exist, this study suggests that in infected animals there is a significant reduction in both the number and function of bone marrow-derived and thymus-derived cells directed against the alloantigens in EL(4).

CYTOMEGALOVIREMIA IN HEALTHY ASYMPTOMATIC PREGNANT ADOLESCENTS

Based upon clinical observations it has been deduced that human cytomegalovirus (HCMV) may be transmitted with blood. It has been estimated that approximately 5% of healthy individuals are asymptomatic carriers of HCMV in blood. Although isolation of this virus from blood is relatively easily accomplished in immunosuppressed individuals or from those with symptomatic HCMV-associated clinical conditions, efforts to recover virus from the blood of asymptomatic healthy carriers have been largely and repeatedly unsuccessful. Only one report has documented viremia in healthy individuals (in 1969 Diosi and associates reported recovery of HCMV from blood in 2 of 35 blood bank donors).¶In the course of studies of healthy pregnant adolescents in North Carolina and in Maryland, HCMV was recovered from the blood in 5 of 96 and 2 of 41 subjects respectively, or 5% in each population. There was no demonstrable association with prenatal transmission of HCMV, with subject well-being or outcome of pregnancy.¶The risk of HCMV reactivation in young pregnant women may relate to gestational and endocrine factors. It is also possible that reactivation of HCMV occurs most frequently soon after primary infection and that the risk of reactivation is inversely related to the elapsed time since virus acquisition. These observations may assist in defining risk factors for transfusion-related transmission as well as for reactivation and prenatal acquistion of HCMV.

10 CYTOMEGALOVIRUS (CMV) IN PREGNANT ADOLESCENTS AND THEIR OFFSPRING

A prospective study has been established of CMV among pregnant adolescents and their offspring. Results derived from studies of 53 mothers (mean age 15.6 yrs.) and 54 infants comprise this report. ¶ Thirty-seven of the 53 (81%) were CMV(CF) seropositive when first tested (mean estimated gestational age 23 wks). Twenty-three mothers (43% of total and 62% of seropositives) had one or more positive cultures for CMV and three of their infants (5.5% of total) were congenitally infected with CMV. ¶ The geometric mean (GMT) of maximum CMV titers among virus-positive mothers was 48.5 in contrast to 3.7 among those who were virus-negative (p<0.01). Twelve of 13 mothers with anti CMV titers of 64 or higher were virus-positive and three gave birth to congenitally infected infants. The CMV GMT was 39 in infants born to virus positive mothers compared to a CMV GMT of 4 in babies of virus-negative mothers (p<0.01). All (11) cord blood samples with a titer 64 were obtained from infants born to virus-positive mothers and included those congenitally infected. The determination of maternal and neonatal CMV antibody thus identified a particularly high risk subgroup. ¶ Pregnant adolescents and their offspring may experience frequent CMV infections (exogenous or endogenous in origin). The long term impact of these infections may be a factor in the poor outcome of some teenage pregnancies.