The American journal of medicine
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The acute respiratory illnesses are the most common type of acute illness in the United States today. The respiratory viruses--which include influenza viruses, parainfluenza viruses, respiratory syncytial virus (RSV), rhinoviruses, coronaviruses, and adenoviruses--cause the majority of these illnesses. Some of these viruses cause illness throughout the year, whereas others are most common in winter. ⋯ At MDACC, pneumonia occurred in 58-78% of infected patients, and 22-44% died. The role of the virus infection in many cases of pneumonia is uncertain, but death from pure viral pneumonia is well documented. A number of immune deficiencies in this patient population and options for control of these infections have been described that can, respectively, account for the medical problem and provide ways to approach prevention and treatment.
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Among immunocompromised adults, such as bone marrow transplant recipients, more than half of respiratory viral infections are complicated by pneumonia, with an associated mortality rate > 50%. Nosocomial transmission of respiratory viral pathogens, such as respiratory syncytial virus (RSV) and influenza, in the immunocompromised patient has been reported frequently and usually occurs during a community outbreak. In view of the poor outcome in this subset of patients, intensive efforts should be directed at instituting prevention measures that would interrupt nosocomial transmission. ⋯ In highly immunocompromised patients, prophylactic use of antiviral agents should be considered during an outbreak or when the frequency of nosocomial transmission is high. An aggressive multifaceted infection control strategy appears to be effective in reducing the frequency of nosocomial transmission of respiratory viral infections in immunocompromised patients. Universal and timely influenza vaccination of hospital personnel who care for immunocompromised patients is necessary.
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Community respiratory viruses, such as respiratory syncytial virus (RSV), influenza viruses, parainfluenza viruses, adenoviruses, and picornaviruses, are an important cause of respiratory disease in the immunocompromised adult with cancer. Recent studies have demonstrated that a minimum of 31% of adult bone marrow transplant (BMT) recipients and 18% of adults with leukemia who are hospitalized with an acute respiratory illness have a community respiratory virus infection. The temporal occurrence of these infections in immunocompromised patients tends to mirror their occurrence in the community. ⋯ Defining effective prophylactic and therapeutic strategies will be a challenge, given the diversity of viruses, the wide spectrum of immunocompromised patients with varying vulnerability to serious community respiratory virus disease, and the frequent presence of other opportunistic infections and medical problems. A combination of antiviral drugs and immunotherapy may need to be considered for their potential additive effect as well as to prevent the emergence of resistant virus, as occurs during monotherapy for influenza with amantadine or rimantadine. The optimal therapies need to be defined in controlled trials; however, it appears that a favorable response will hinge on the initiation of therapy at an early stage of the respiratory illness.
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Respiratory viruses, particularly influenza viruses, respiratory syncytial virus (RSV), parainfluenza viruses, and adenoviruses, are ubiquitous pathogens among humans, especially among young children. However, relatively little is known about the impact of these common infections on individuals with the human immunodeficiency virus (HIV). A review of the literature identifies three key areas that need further exploration. ⋯ Increased HIV-1 replication has been demonstrated in vitro in T lymphoma cells exposed to genetic material from adenovirus. Increased HIV replication in peripheral blood from adults following inactivated influenza vaccination has been reported. The impact of natural respiratory viral infection (and perhaps vaccination against these pathogens) on HIV replication and disease progression will be an important area of study.
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Clinical Trial
Respiratory virus infections after marrow transplant: the Fred Hutchinson Cancer Research Center experience.
Respiratory virus infections are becoming increasingly appreciated causes of morbidity and mortality in bone marrow transplant recipients. Fred Hutchinson Cancer Research Center (FHCRC) has had considerable experience with respiratory syncytial virus (RSV), parainfluenza, influenza, and rhinovirus infections in these patients over the past decade. Overall, RSV accounted for the majority of community-acquired respiratory virus infections (35%), followed by parainfluenza virus (30%), rhinovirus (25%), and influenza virus (11%). ⋯ In one study conducted at FHCRC, intravenous ribavirin was not effective against established RSV pneumonia. In another, ongoing study, however, short-course aerosolized ribavirin appears to reduce progression of upper respiratory tract infection to pneumonia, but further study is needed. Neither strategy had an obvious impact on viral shedding, although persistence of viral shedding did not correlate with either the development or the outcome of pneumonia.