Seminars in respiratory and critical care medicine
-
Semin Respir Crit Care Med · Aug 2011
ReviewInfluenza: epidemiology, clinical features, therapy, and prevention.
Influenza A and B are important causes of respiratory illness in all age groups. Influenza causes seasonal outbreaks globally and, less commonly, pandemics. In the United States, seasonal influenza epidemics account for >200,000 hospitalizations and >30,000 deaths annually. ⋯ Vaccines are the cornerstone of influenza control. Currently, trivalent inactivated vaccine (TIV) and live attenuated influenza vaccine (LAIV) are available. These agents reduce mortality and morbidity in high-risk patients (i.e., the elderly or patients with comorbidities), and expanding the use of vaccines to healthy children and adults reduces the incidence of influenza, pneumonia, and hospitalizations due to respiratory illnesses in the community.
-
Human metapneumovirus (hMPV) is a common pathogen that can cause both upper and lower respiratory tract infections, particularly in children, elderly adults, and immunocompromised hosts. Since its initial identification in 2001, hMPV has been isolated from individuals with acute respiratory tract infections (ARTIs) in virtually every continent. Serological studies indicate that it has caused human infection since 1958 or earlier. ⋯ Ribavirin has similar activity in vitro and in animal models against hRSV and hMPV, but its efficacy in vivo is unproven. Monoclonal antibodies have activity in murine models but are not available in humans. Several vaccines are promising in animal models, but their safety and efficacy have not yet been evaluated in humans.
-
The human Herpesviridae family consists of eight members: cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1 and 2 (HSV-1, -2), varicella-zoster virus (VZV), and human herpesvirus 6, 7, and 8 (HHV-6, -7, -8). Lifelong latency may develop in the host with reactivation during periods of relative immunosuppression that occurs in transplant recipients. These are pleiotropic viruses: in addition to their direct effects of tissue injury and clinical illness, they exhibit several indirect effects, including immunomodulation and effects on angiogenesis and tumorigenesis, which may result in long-term adverse sequelae in the lung allograft. ⋯ EBV and HHV-8 have proven oncogenic potential. HSV-1 and -2 and VZV are neurotropic, causing perioral fever blisters, genital ulcerations, and, rarely, encephalitis. This article discusses the individual pathogens, preventive strategies in the era of potent treatment regimens for established viral infection or disease and their potential impact on the indirect effects of these viruses on long-term allograft function, and the incidence, risk factors for, and impact of antiviral resistance.