Antiviral prophylaxis and treatment (excluding HIV therapy)

Aseptic meningitis caused by reactivation of varicella-zoster virus in two immunocompetent patients

Varicella-zoster virus (VZV) may be a more frequent causative factor of aseptic meningitis than previously anticipated. Here we present 2 cases of reactivation of VZV in immunocompetent individuals, resulting in meningitis and affection of multiple cranial nerves, and discuss the incidence, clinical spectrum, pathogenesis, diagnostics and options for treatment.

Cidofovir and foscarnet for treatment of human herpesvirus 6 encephalitis in a neutropenic stem cell transplant recipient

We report a stem cell transplant recipient who developed human herpesvirus 6 encephalitis. Human herpesvirus 6 load indicated massive intrathecal viral replication. Administration of cidofovir followed by foscarnet was associated with total clearance of human herpesvirus 6 infection. Cidofovir and foscarnet combination therapy may be beneficial for reducing mortality of (neutropenic) stem cell transplant recipients with human herpesvirus 6 encephalitis.

Brote nosocomial de gripe en pacientes hematológicos de alto riesgo. Eficacia de las medidas de control y del uso de zanamivir

INTRODUCTION

This study describes a nosocomial outbreak of influenza in high-risk-hematological patients, and the usefulness of epidemiological measures and zanamivir administration for its control.

METHODS

Fifteen patients who had been in contact with a patient with influenza A were included in the study. Viral culture of nasopharyngeal exudate was performed and the epidemiological data, risk factors and clinical outcome were evaluated. The efficacy of early therapy and preventive use of zanamivir was also assessed.

RESULTS

Seven out of 15 patients (46.6%) developed symptoms and in 5 of these 7 cases (71.4%), influenza A virus was isolated. Eight patients did not develop symptoms and viral culture was sterile. All symptomatic patients were isolated, and treatment with inhaled zanamivir (10 mg/12 h, 5 days) was initiated as soon as possible; only one patient developed respiratory failure; the remaining cases had self-limited upper respiratory tract symptoms. There was no associated mortality. Zanamivir prophylaxis was used in three non-symptomatic patients considered to be at high risk. Tolerance to zanamivir was excellent. No new cases were observed after initiation of the preventive measures and use of zanamivir.

CONCLUSION

The attack rate in a nosocomial influenza outbreak can be very high in immunocompromised patients. Prompt initiation of preventive measures, early treatment and prophylaxis with zanamivir may help to limit the extension of these outbreaks.

The clinical importance of the nomenclature, evolution and taxonomy of human papillomaviruses

Human papillomaviruses (HPVs) are formally described by isolation of their circular double-stranded DNA genomes and establishment and comparison of the nucleotide sequence of these genomes. Alternatives such as serological diagnosis and maintenance of HPVs in culture are neither clinically useful nor consistently feasible. Novel HPV isolates have traditionally been described as “types”. The analysis of specific HPV types is of medical importance, because HPV types typically induce type-specific lesions, i.e. they may be specific for cutaneous or mucosal epithelia, or give rise to benign warts or malignant carcinomas. Recently, it was formally decided that papillomaviruses are a virus family separate from the polyomaviruses. Within the papillomavirus family, closely or remotely related types form species or genera. These formal agreements were important as they brought the taxonomy of papillomaviruses in line with that of other viruses, bacteria and higher organisms, although their impact on medical practice and terminology used in clinical studies is limited. Notably, however, HPV types that are closely related (i.e. form “species”) are associated with similar lesions. Confusion of the terms “type” and “subtype” should be avoided, as the latter term refers to some specific but rare taxonomic assemblages. In contrast to many RNA viruses, HPV types evolve very slowly, and diverged since the origin of humans only by about 2%. These divergent isolates are called “variants”. HPVs evolved together with humankind and Homo sapiens was never without HPVs, and consequently never without warts and cervical cancer. Variants of the same HPV type may have different pathogenicity and may account for part of the worldwide disparities in the occurrence of genital cancers.

Características de los fármacos antivirales

This article summarizes the principal characteristics of the drugs used to treat viral infections, with the exception of human immunodeficiency virus infection. It includes antiviral agents active against herpes virus, cytomegalovirus, hepatitis B and C virus, and respiratory viruses, such as influenza and respiratory syncytial virus. Dosage according to the indication, dose adjustment in the case of renal or hepatic insufficiency, significant pharmacokinetic characteristics, and the main adverse effects and interactions are described.