Influenza infection in patients before and after liver transplantation.

Infection with influenza virus poses specific problems in pediatric and adult liver transplant recipients, both before and after liver transplantation. These include a higher rate of pulmonary and extrapulmonary complications, development of rejection with graft dysfunction, prolonged shedding of influenza virus, and increased drug-resistance. Hepatic decompensation may occur during influenza infection in patients with cirrhosis. Current prophylaxis includes yearly vaccination with trivalent inactivated vaccine. Appropriate diagnosis and prompt treatment of any upper respiratory infections are indicated in these patients. In this review, we describe a case of influenza viral pneumonia in an adult liver transplant recipient, review basic and clinical aspects of influenza infection in this patient population, and discuss current modes of prevention and treatment in detail.

Double-blind placebo-controlled trial of oral acyclovir in first-episode genital herpes simplex virus infection.

One hundred nineteen patients with primary and 31 patients with nonprimary first-episode genital herpes were treated for ten days with 200 mg of acyclovir capsules or placebo capsules orally five times daily. Among acyclovir recipients with primary genital herpes, the median duration of viral shedding (two days), time to crusting of all lesions (seven days), time to healing of all lesions (12 days), and duration of local pain (five days) and constitutional symptoms (three days) were shorter than among placebo recipients (9, 10, 16, 7, and 6 days, respectively). Among patients with nonprimary first-episode genital herpes, oral acyclovir shortened the median duration of viral shedding but had no significant effect on the duration of lesions or symptoms. The time to first recurrence and frequency of recurrences were similar in acyclovir- and placebo-treated patients. Oral acyclovir treatment of primary first-episode genital herpes shortens the duration of viral shedding and symptoms and accelerates healing, but it does not appear to influence subsequent genital recurrences.

Rapid viral diagnosis.

The advent of antiviral chemotherapy provides a strong impetus to develop methods to diagnose viral infections rapidly and accurately. Several other potential contributions of rapid viral diagnoses to patient management also exist. Virus isolation remains the "gold standard" of viral diagnosis against which most newly developed diagnostic approaches--including serologic testing, viral-enzyme detection, microscopic techniques, radioimmunoassays, and enzyme immunoassays--must be compared. Since, as currently performed, enzyme immunoassays such as enzyme-linked immunosorbent assays have reached the limit of their sensitivity, fully satisfactory rapid viral diagnosis will require new approaches. Two such potentially useful approaches are the detection of viral antigen with a method that permits visual localization of virus-specific immunoenzymatic staining and the detection of viral nucleic acids in clinical specimens by hybridization with nucleic-acid probes.

Detection of herpes simplex virus in clinical specimens by DNA hybridization.

An assay to detect herpes simplex virus (HSV) DNA in clinical specimens has been developed. It utilizes nucleic acid hybridization with a 32P-labeled DNA probe prepared from a fragment of HSV DNA cloned in a plasmid vector. This assay can detect 5 X 10(4) plaque-forming units of cell-free HSV and as few as four virus-infected cells. The assay has a sensitivity of 78% and a specificity of 100% compared to virus culture for the detection of HSV in swab specimens from genital lesions. No hybridization is observed with uninfected, varicella-zoster virus infected, or cytomegalovirus infected cells, and specimens from herpes zoster lesions are uniformly negative. While hybridization with a 32P-labeled probe is not optimally suited for routine diagnostic use, this report establishes the feasibility of using nucleic acid hybridization to detect HSV in clinical specimens.

Enzyme immunofiltration technique for rapid diagnosis of herpes simplex virus eye infections in a rabbit model.

A rapid enzyme immunofiltration assay for herpes simplex virus (HSV) has been developed which is sensitive enough to detect viral antigens in eye swabs from rabbits with primary herpes keratitis. This assay employs a specially designed filter manifold to immobilize whole cells and cell debris dissociated from the swabs. Viral antigens trapped on the filters are then detected in an indirect immunoassay utilizing staphylococcal protein A conjugated with horseradish peroxidase. The assay required only 2.5 h to perform and could be read visually. Reconstruction experiments indicated that antigen from as few as 49 HSV-infected cells could be detected. Calcium alginate swabs were shown to recover more viral antigen than dacron swabs. The enzyme immunofiltration assay detected HSV antigens on 95% of the eye swabs from which infectious virus was recovered. In addition, HSV antigen was also detected in several swabs from infected eyes which did not yield infectious virus, presumably because the virus was neutralized by native antibody present in the lacrimal fluid. This enzyme immunofiltration assay technique lends itself to the elution of native antibody bound to the viral antigens, and this may be especially applicable in the diagnosis of recurrent HSV keratitis, where antiviral antibody in the lacrimal fluid may interfere with virus isolation and fluorescent-antibody or other virus detection assays.

Psoralen inactivation of influenza and herpes simplex viruses and of virus-infected cells.

Psoralen compounds covalently bind to nucleic acids when irradiated with long-wavelength ultraviolet light. This treatment can destroy the infectivity of deoxyribonucleic acid and ribonucleic acid viruses. Two psoralen compounds, 4'-hydroxymethyltrioxsalen and 4'-aminomethyltrioxsalen, were used with long-wavelength ultraviolet light to inactivate cell-free herpes simplex and influenza viruses and to render virus-infected cells noninfectious. This method of inactivation was compared with germicidal (short-wavelength) ultraviolet light irradiation. The antigenicity of the treated, virus-infected, antigen-bearing cells was examined by immunofluorescence and radioimmunoassay and by measuring the capacity of the herpes simplex virus-infected cells to stimulate virus-specific lymphocyte proliferation. The infectivity of the virus-infected cells could be totally eliminated without altering their viral antigenicity. The use of psoralen plus long-wavelength ultraviolet light is well suited to the preparation of noninfectious virus antigens and virus antigen-bearing cells for immunological assays.