Recovery of viruses other than cytomegalovirus from bronchoalveolar lavage fluid

Constrictive bronchiolitis obliterans with a presumptive etiology of preceding feline herpesvirus infection in a cat

Background

Bronchiolar disorders are rarely recognized in cats. Constrictive bronchiolitis obliterans is characterized by concentric peribronchiolar fibrosis and inflammation of the bronchioles, but the underlying causes remain poorly understood in current small animal medicine.

Case presentation

A 9-year-old cat presented with paroxysmal tachypnea, infrequent cough and persistent labor breathing. Thoracic radiography showed lung hyperinflation and bronchointerstitial pattern, and pulmonary function assessment revealed flow limitation in the late-expiratory phase and poor response to short-acting bronchodilator. Dorsally distributed subpleural ground glass opacities with distinct margin and tree-in-bud opacities were observed on lung high-resolution computed tomography. The cat underwent bronchoalveolar lavage (BAL) and showed severe neutrophilic inflammation. Feline herpesvirus was the only pathogen detected in the BAL fluid. Multiple therapeutic attempts were unsuccessful and the cat died 8 weeks after the initial presentation. Necropsy revealed the infiltration of inflammatory cells, obstruction of the bronchiolar lumen, and submucosal concentric fibrosis suggesting constrictive bronchiolitis obliterans. Combining the pre- and post-mortem findings, as well as the time from symptom onset or BAL to necropsy, constrictive bronchiolitis obliterans was possibly triggered by a preceding feline herpesvirus infection in this case.

Conclusions

The history of nonvaccinated status, lower airway neutrophilic inflammation, and presence of feline herpesvirus in the BAL fluid without coexistence of other pathogens led to the presumption that constrictive bronchiolitis obliterans was induced by a preceding feline herpesvirus infection in this cat. The pathological changes of bronchiolitis obliterans induced by a preceding feline herpesvirus infection could be different from that of cats with acute herpesvirus pneumonia, such as intranuclear inclusions would disappear over time and were no longer found 7–10 days after inoculation. The presence of patchy distribution of subpleural ground glass opacities on lung high-resolution computed tomography should raise the suspicion of peribronchiolar fibrosis. Clinical awareness of bronchiolar disorders as a differential diagnosis is important in cats with lung hyperinflation and labored breathing who show poor reversibility to bronchodilator.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Clinical characteristics and outcomes of severe rhinovirus-associated pneumonia identified by bronchoscopic bronchoalveolar lavage in adults: comparison with severe influenza virus-associated pneumonia

BACKGROUND

Rhinoviruses (RVs) may cause pneumonia, but the characteristics of RV-associated pneumonia have not been adequately evaluated.

OBJECTIVE

We aimed to compare characteristics, complications, and outcomes between severe RV- and influenza virus (IFV)-associated pneumonia in adults.

STUDY DESIGN

We used prospective cohort data of adult patients with severe pneumonia who had been admitted to the medical intensive care unit of a tertiary care hospital over a 4-year period. The clinical features and outcomes of 27 patients with RV-positive bronchoscopic bronchoalveolar lavage (BAL) fluid were compared to those of 51 pneumonia patients with IFV-positive BAL fluid or IFV-positive nasopharyngeal specimens.

RESULTS

Of 356 patients who underwent bronchoscopic BAL and respiratory virus polymerase chain reaction (PCR), RV was the most commonly identified virus (8.1%) from BAL fluid. Patients with RV-associated pneumonia were more likely to be immunocompromised than patients with IFV-associated pneumonia (81.5% vs. 33.3%, p<0.001). Bacterial coinfection tended to be less common in the RV group (18.5% vs. 37.3%, p=0.09). Although septic shock was less common in the RV group (29.6% vs. 54.9%, p=0.03), other clinical manifestations, laboratory findings, and radiologic patterns were similar between the groups. The 28-day mortality of patients with severe RV- and IFV-associated pneumonia was similarly high (29.6% vs. 35.3% respectively, p=0.61).

CONCLUSIONS

Severe RV-associated pneumonia patients were more likely to be immunocompromised and less likely to present septic shock. Overall clinical features were similar and mortalities of both groups were comparably high. Studies of larger cohorts encompassing mild to moderate pneumonia patients are needed.

Utility of animal and in vivo experimental infection of humans with rhinoviruses in the development of therapeutic agents for viral exacerbations of asthma and chronic obstructive pulmonary disease

There is an association with acute viral infection of the respiratory tract and exacerbations of asthma and chronic obstructive pulmonary disease (COPD). Although these exacerbations are associated with several types of viruses, human rhinoviruses (HRVs) are associated with the vast majority of disease exacerbations. Due to the lack of an animal species that is naturally permissive for HRVs to use as a facile model system, and the limitations associated with animal models of asthma and COPD, studies of controlled experimental infection of humans with HRVs have been used and conducted safely for decades. This review discusses how these experimental infection studies with HRVs have provided a means of understanding the pathophysiology underlying virus-induced exacerbations of asthma and COPD with the goal of developing agents for their prevention and treatment.

What role do viruses play in nosocomial pneumonia?

PURPOSE OF THE REVIEW

Viruses are an increasingly recognized cause of community-acquired pneumonia (CAP), but their exact role in nosocomial pneumonia is still debated. This review focuses on the role of viruses as a cause of nosocomial pneumonia.

RECENT FINDINGS

Respiratory viruses may be responsible for healthcare-associated pneumonia, because affected patients and those with CAP have the same risk factors for viral disease. In mechanically ventilated patients, viruses belonging to the Herpesviridae family, namely herpes simplex virus (HSV) and cytomegalovirus, can be reactivated and cause bronchopneumonitis or ventilator-associated pneumonia, respectively. Recent results confirmed the high rate of HSV reactivation in the distal airways of mechanically ventilated patients, and that patients with high virus loads (>10(5)  copies/ml of bronchoalveolar lavage fluid) have poorer outcomes than those with low or no virus load. However, the responsibility of mimivirus, initially described as a possible cause of pneumonia, was not confirmed for nosocomial pneumonia.

SUMMARY

Respiratory viruses are mainly responsible for CAP, but they may also cause healthcare-associated pneumonia. HSV bronchopneumonitis and cytomegalovirus pneumonia are not rare diseases, and patients with Herpesviridae lung infections have worse prognoses than those without. Whether or not those Herpesviridae infections are responsible for true morbidity or morbidity remains to be determined.

Clinical severity of rhinovirus/enterovirus compared to other respiratory viruses in children

Background

Human rhinovirus/enterovirus (HRV/ENT) infections are commonly identified in children with acute respiratory infections (ARIs), but data on their clinical severity remain limited.

Objectives

We compared the clinical severity of HRV/ENT to respiratory syncytial virus (RSV), influenza A/B (FLU), and other common respiratory viruses in children.

Patients/Methods

Retrospective study of children with ARIs and confirmed single positive viral infections on mid-turbinate swabs by molecular assays. Outcome measures included hospital admission and, for inpatients, a composite endpoint consisting of intensive care admission, hospitalization >5 days, oxygen requirements or death.

Results

A total of 116 HRV/ENT, 102 RSV, 99 FLU, and 64 other common respiratory viruses were identified. Children with single HRV/ENT infections presented with significantly higher rates of underlying immunosuppressive conditions compared to those with RSV (37·9% versus 13·6%; P < 0·001), FLU (37·9% versus 22%; P = 0·018) or any other single viral infection (37·9% versus 22·5%; P = 0·024). In multivariable analysis adjusted for underlying conditions and age, children with HRV/ENT infections had increased odds of hospitalization compared to children with RSV infections (OR 2·6; 95% CI 1·4, 4·8; P < 0·003) or FLU infections (OR 3·0; 95% CI 1·6, 5·8; <0·001) and increased odds of severe clinical disease among inpatients (OR 3·0; 95% CI 1·6,5·6; P = 0·001) when compared to those with FLU infections.

Conclusions

Children with HRV/ENT had a more severe clinical course than those with RSV and FLUA/B infections and often had significant comorbidities. These findings emphasize the importance of considering HRV/ENT infection in children presenting with severe acute respiratory tract infections.

Diagnosis of influenza from lower respiratory tract sampling after negative upper respiratory tract sampling

In this retrospective cohort study, we demonstrate that PCR-confirmed diagnoses of influenza were made solely by lower respiratory sampling in 6.9% of cases, as traditional upper respiratory tract tests were negative, indeterminate or not performed. Clinical features of these cases are presented. Clinicians should consider lower respiratory tract sampling in select cases of influenza-like illness for diagnosis.

Infections respiratoires virales à herpesviridae en réanimation

Les herpesviridae, essentiellement l’herpes simplex virus (HSV) et le cytomégalovirus (CMV), sont fréquemment détectés dans les voies aériennes des malades non immunodéprimés sous ventilation mécanique. Bien que leur présence traduise le plus souvent une réactivation virale sans réelle atteinte parenchymateuse, celle-ci peut néanmoins exister chez un certain nombre de patients. Si le diagnostic d’atteinte parenchymateuse à herpesviridae doit être étayé par une preuve histologique (effet cytopathogène spécifique), l’utilisation des outils de virologie moléculaire (amplification par polymerase chain reaction en temps réel pour estimer la charge virale) pourrait remplacer l’examen histologique dans un futur proche. La survenue d’une bronchopneumonie à HSV est associée à une réactivation du virus au niveau oropharyngé et à la présence de lésions labiales. Cette maladie semble avoir un réel impact sur l’évolution, puisqu’elle est associée à une durée de ventilation mécanique et à un séjour en réanimation prolongés. L’intérêt d’un traitement par acyclovir dans cette indication reste cependant à déterminer. Si la réactivation du CMV dans le sang est facile à détecter et associée à une évolution défavorable, la pneumonie à CMV est difficile à prouver du fait de la lourdeur des techniques diagnostiques (biopsie pulmonaire), et son impact sur le pronostic incertain. L’intérêt d’un traitement par ganciclovir dans cette indication reste aussi à démontrer.

Viral infections in septic shock (VISS-trial)-crosslinks between inflammation and immunosuppression

BACKGROUND

Recent investigations provided evidence that herpes simplex virus (HSV-1) and cytomegalovirus (CMV) are reactivated in critically ill individuals. However, at this time, it remains unclear whether these viral infections are of real pathogenetic relevance or represent innocent bystanders.

MATERIALS AND METHODS

In total, 60 patients with septic shock were enrolled. Blood samples and tracheal secretion were collected at the time of sepsis diagnosis (T0) as well as 7 d (T1), 14 d (T2), 21 d (T3), and 28 d (T4) later. The following virologic diagnostics were performed: (1) Viral load of herpes simplex virus type1 (HSV-1) and cytomegalovirus (CMV) in blood samples as well as tracheal secretion using polymerase chain reaction (PCR). (2) Detection of CMV-antigen (pp65) in blood samples using immunofluorescence microscopy. Furthermore plasma levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were evaluated using ELISA-kits.

RESULTS

Thirty-one patients (51.7%) were found to be positive for HSV-1, whereas in 16 patients (26.7%) CMV could be identified. Patients with a positive PCR for HSV-1 and/or CMV showed a significantly prolonged length of hospital stay and absolute time of respirator-dependant ventilation. Furthermore, survival curves of patients with a high HSV-1-load (>10E8) in tracheal secretion in comparison with those with a lower HSV-1-load (<10E8) revealed a significantly impaired survival.

CONCLUSIONS

Viral superinfections with HSV-1 or CMV can frequently be observed in patients with septic shock, especially in those with increased disease severity and a prolonged need for respirator-dependant ventilation. In patients with a viral superinfection morbidity is increased, whereas differences in mortality seem to be dosage-dependant.

Diagnosis and management of infectious complications in critically ill patients with cancer

Cancer and its treatments lead to profound suppression of innate and acquired immune function. In this population, bacterial infections are common and may rapidly lead to overwhelming sepsis and death. Furthermore, infections caused by viral and fungal pathogens should be considered in patients who have specific immune defects. As cancer therapies have become more aggressive the risk for infection has increased and many patients require intensive care support. Despite improvements in long-term survival, infections remain a common complication of cancer therapy and accounts for the majority of chemotherapy-associated deaths. By understanding the host defense impairments and likely pathogens clinicians will be better able to guide diagnosis and management of this unique population.

Herpes simplex virus type 1 and respiratory disease in critically-ill patients: real pathogen or innocent bystander?

Herpes simplex virus type 1 (HSV-1) has been associated with pulmonary disease, mostly in severely immunocompromised patients. After reactivation and shedding in the oropharynx, the virus may reach the lower respiratory tract by aspiration or by contiguous spread. HSV-1 can be detected in clinical specimens by virus culture or quantitatively by nucleic acid amplification techniques. With these techniques, HSV-1 is often detected in the respiratory secretions of critically-ill patients. However, a clear diagnosis of HSV-1 pneumonia is difficult to establish because clinical criteria, radiological features and laboratory findings all lack specificity. Lower respiratory tract HSV-1 infections have not been associated with specific risk-factors. There is also an absence of consistent data concerning the effect of antiviral treatment on the outcome of critically-ill patients. Further studies are needed to better define the pathogenic role of HSV-1 in the lower respiratory tract of these patients, to improve the diagnosis, and, especially, to assess the need for antiviral treatment in the individual patient.

Detection of severe human metapneumovirus infection by real-time polymerase chain reaction and histopathological assessment

BackgroundInfections with common respiratory tract viruses can cause high mortality, especially in immunocompromised hosts, but the impact of human metapneumovirus (hMPV) in this setting was previously unknown

MethodsWe evaluated consecutive bronchoalveolar lavage and bronchial wash fluid samples from 688 patients—72% were immunocompromised and were predominantly lung transplant recipients—for hMPV by use of quantitative real-time polymerase chain reaction (PCR), and positive results were correlated with clinical outcome and results of viral cultures, in situ hybridization, and lung histopathological assessment

ResultsSix cases of hMPV infection were identified, and they had a similar frequency and occurred in a similar age range as other paramyxoviral infections. Four of 6 infections occurred in immunocompromised patients. Infection was confirmed by in situ hybridization for the viral nucleocapsid gene. Histopathological assessment of lung tissue samples showed acute and organizing injury, and smudge cell formation was distinct from findings in infections with other paramyxoviruses. Each patient with high titers of hMPV exhibited a complicated clinical course requiring prolonged hospitalization

ConclusionsOur results provide in situ evidence of hMPV infection in humans and suggest that hMPV is a cause of clinically severe lower respiratory tract infection that can be detected during bronchoscopy by use of real-time PCR and routine histopathological assessment

Respiratory Viruses and Severe Lower Respiratory Tract Complications in Hospitalized Patients

BACKGROUND

Acute respiratory viral infections are generally self-limited in healthy subjects but can lead to severe complications in immunocompromised hosts. We report the clinical impact of acute lower respiratory tract viral infections in hospitalized patients.

MATERIALS AND METHODS

Of 1,001 fiberoptic bronchoscopies performed during a period of 5 years, 33 BAL samples were positive for respiratory viruses by cell culture. The main diagnosis, length of hospitalization, response to initial treatment, and the mortality rate at 30 days were analyzed. Spirometry performed before and after infection was compared in lung transplant recipients.

RESULTS

The following respiratory viruses were identified in 33 cases: influenza A or B (n = 13), parainfluenza virus 1-3 (n = 7), rhinovirus (n = 5), respiratory syncytial virus (n = 4), and adenovirus (n = 4). All cases were immunocompromised patients who acquired new respiratory symptoms and/or radiologic abnormalities suggesting a pulmonary infection. Twenty-five patients (74%) did not respond to initial broad-spectrum antibiotics, and 11 patients (33%) required intensive care for respiratory failure. The overall mortality rate at 1 month was 24%. In patients with a sole viral pathogen identified in their BAL, the mortality rate was 39%. In lung transplant recipients (n = 10), the mean FEV(1) decreased from 2.2 to 1.9 L/s before and during the infection episode, respectively (p < 0.01); 3 months later, 60% of the patients had still not completely recovered to baseline values.

CONCLUSION

Respiratory viruses recovered in BAL samples of immunocompromised patients are associated with severe lower respiratory complications. In lung transplant recipients, we observed a persisting impairment of pulmonary function.

Herpes simplex virus pneumonia in a patient with ependymoma

The authors report a fatal outcome in a 4-year-old boy with herpes simplex virus (HSV) pneumonia and ependymoma. The patient had respiratory distress that worsened despite antibiotic treatment. Bronchoalveolar lavage showed intranuclear viral inclusions, and culture was positive for HSV type 1. His T-cell count was significantly decreased. Although acyclovir and foscarnet were given, the patient died. Postmortem examination showed HSV pneumonitis with severe alveolar damage and severe involutional changes of the thymus with absence of Hassall's corpuscles. HSV must be considered in the differential diagnosis of patients with interstitial pneumonia and T-cell deficiency, especially after craniospinal irradiation.

Herpes simplex pneumonia: Combination therapy with oral acyclovir and aerosolized ribavirin in an immunocompetent patient

BACKGROUND

Herpes simplex viruses (HSVs) are known to cause respiratory tract infections in immunocompromised hosts and, in rare instances, in immunocompetent hosts. Numerous in vitro and in vivo studies have shown that aerosolized administration of ribavirin can potently and selectively inhibit viral replication in pulmonary disease, thereby increasing the effectiveness of acyclovir in HSV.

OBJECTIVE

In this case study, we reported on a 46-year-old immunocompetent woman with HSV type 1 pneumonia with bilateral pulmonary infiltrates but without mucocutaneous lesions.

METHODS

The diagnosis was confirmed using cytology, viral culture, and serology. Because of the persistence of fever and dyspnea, we chose an antiviral therapy. The patient received oral acyclovir and aerosolized ribavirin to improve the antiviral effectiveness of the acyclovir and to reduce the symptoms and the time to resolution of the pulmonary disease.

RESULTS

After 3 days of therapy, dyspnea and fever decreased and hypoxemia improved. After 2 weeks, computed tomography showed complete resolution of pulmonary abnormalities. The patient did not report any adverse effects.

CONCLUSIONS

In our case study, we demonstrated that therapy with a combination of aerosolized ribavirin and oral acyclovir may be useful to reduce the severity of viral infection, the adverse effects, and the days of hospitalization. To our knowledge, this is the first report in the literature of the synergistic effects of the combination of aerosolized ribavirin and oral acyclovir in the treatment of an immunocompetent patient with HSV pneumonia.

Rhinovirus infections in hematopoietic stem cell transplant recipients with pneumonia

Little is known about the impact of human rhinovirus (HRV) and coronavirus infections in hematopoietic stem cell transplant (HSCT) recipients. We tested bronchoalveolar lavage (BAL) samples obtained from HSCT recipients with acute pulmonary infiltrates for HRV (n=122) and coronavirus (n=46) by reverse-transcriptase polymerase chain reaction. HRV RNA was detected in 6 (8%) of 77 patients, and coronavirus RNA was detected in 0 of 46 of BAL samples from HSCT recipients. The fatality rate in HRV-infected patients was high (83%), but all patients had significant coinfections, and the overall mortality rate was not different from that of patients who were negative for HRV in BAL samples. These results suggest that HRV may be a cause of lower respiratory tract infections in HSCT recipients and that its detection in BAL samples is associated with frequent copathogens. Whether the poor prognosis is due to HRV or the copathogen is not clear.

Herpesvirus type 1-8 in BAL fluid from HIV-1-infected patients with suspected pneumonia and from healthy individuals

Pneumonia is still a major problem in human immunodeficiency virus (HIV)-infected patients, and despite extensive investigation the aetiology remains unknown in many cases. The prevalence of the eight human herpesviruses was determined by polymerase chain reaction in 91 samples of bronchoalveolar lavage (BAL) fluid from 72 HIV-infected patients with 91 episodes of suspected pneumonia. The presence of herpesviruses was related to clinical and immunological findings and the prevalence of herpesviruses in HIV-infected patients was compared with the prevalence in BAL fluid from 50 healthy, immunocompetent individuals. Epstein-Barr virus, cytomegalovirus and human herpesvirus-8 (HHV8) were found in 5.5%, 36% and 5.5% of BAL fluid samples from HIV-infected patients. No herpesviruses were detectable in BAL fluid from healthy, immunocompetent individuals. The herpesviruses occurred mainly in patients with CD4+ counts <200 x 10(6) L(-1). All patients with herpesviruses recovered without specific antiviral treatment. Two patients with HHV8 had the diagnosis of Kaposi's sarcoma. It is concluded that cytomegalovirus, Epstein-Barr virus, and human herpesvirus-8 are frequently present in bronchoalveolar lavage fluid from severely immunocompromised human immunodeficiency virus-infected patients with pulmonary symptoms. In bronchoalveolar lavage fluid from healthy, immunocompetent individuals, herpesviruses are absent. Apart from human herpesvirus-8, the present results indicate that the herpesviruses do not play a serious pathogenic role in the development of pulmonary symptoms in human immunodeficiency virus-infected patients.

Clinical features of patients with acute respiratory illness and rhinovirus in their bronchoalveolar lavages

BACKGROUND

Several reports in selected populations suggest that human rhinovirus (HRV) may be responsible for lower respiratory tract infections or pneumonia. We describe clinical features of all patients with rhinovirus cultured from their bronchoalveolar lavage (BAL) during a 10-yr period in a tertiary care center.

METHODS

Results for viral culture of all lower respiratory specimens performed during a 10-year period at the University of Virginia Health Sciences Center were reviewed. A case was defined as any patient with a positive culture for HRV in a BAL specimen. A comprehensive review of the patients' medical records was performed. In one case, in situ hybridization (ISH) was performed in order to identify whether rhinoviral RNA was present in bronchial biopsy specimens.

RESULTS

During the 10-year study period viruses were identified in 431 lower respiratory tract specimens, and were most frequently cytomegalovirus or herpes simplex virus. Twenty patients (ages, 2.5-86 year) had a bronchoalveolar specimen culture positive for HRV. All had an abnormal chest radiograph, 60% were admitted to the intensive care unit, and 25% expired during their hospitalization. In 18 patients (90%) various severe underlying conditions were identified including solid organ transplants in seven, malignancies in four and AIDS in two. An immunosuppressive disease or condition requiring immunosuppressive therapy was present in all cases. In addition to HRV, one or more potential pathogens were identified in respiratory specimens from 14 patients (70%). Histopathological abnormalities, ranging from fibropurulent debris in alveoli to diffuse alveolar damage, were present in 6 of 13 bronchial biopsies. In two cases without any other significant pathogens than HRV, acute inflammations with fibropurulent debris in alveoli were observed. One lung transplant patient showed intermittent recovery of HRV in her respiratory specimens during a 15-week time period, but ISH did not show HRV RNA in bronchial epithelial cells.

CONCLUSION

Our observations suggest that HRV recovery from BALs or lower respiratory tract samples in highly immunocompromised patients is associated with severe lower respiratory tract illness. Whether HRV directly causes viral pneumonia or predispose to pulmonary injury and/or superinfection remains uncertain.

Diagnosis of lower respiratory tract infections: what we have and what would be nice

STUDY OBJECTIVES

To review the various methods used to diagnose lower respiratory tract infections.

DESIGN

Review of literature with appropriate references to various techniques proposed to diagnose pneumonia.

INTERVENTION

Compare and contrast different proposed approaches to diagnose pneumonia.

RESULTS

Bronchoscopic techniques appear more clear cut for certain nonbacterial pathogens. Their role in immunocompromised patients is more clear cut, while in the nonimmunocompromised patient, invasive diagnostic techniques probably provide a higher certainty of the final diagnosis of the patient. Recent interest has focused on nonbronchoscopic techniques for the mechanically ventilated patient. None of these techniques has been demonstrated to change clinical outcome.

CONCLUSIONS

Diagnosis of lower respiratory tract infection has to be tailored for the individual patient. Decision about which procedure to do is influenced by the patient's underlying immune status, level of illness, and response to empiric therapy.

Respiratory virus infections in bone marrow transplant recipients: the European perspective

The role of respiratory viruses in severe complications following bone marrow transplantation was examined in a survey of selected transplant centers in Europe belonging to the European Group for Blood and Marrow Transplantation. Information was collected on 57 cases of infections with respiratory viruses, including adenoviruses. In two centers that had conducted prospective studies of bone marrow recipients with respiratory symptoms, the frequency of these infections was 7.1% and 4%, respectively. The severity of these infections varied. Pneumonias caused by respiratory syncytial virus and adenovirus were associated with mortality rates of 60% and 75%, respectively, whereas pneumonia caused by parainfluenza had a mortality rate of 20%. Influenza infections progressed to fatal pneumonia in 17% of cases. Results of antiviral therapy varied. As the results of our survey showed, respiratory virus infections are not infrequent after bone marrow transplantation and are associated with significant morbidity and mortality.

Viruses and other miscellaneous organisms

Pulmonary infections caused by several types of viruses and other miscellaneous organisms may cause disease in HIV infection. Evidence suggests that pulmonary conditions may result from infections of the lung by HIV itself. Other viruses, most commonly cytomegalovirus, may be primary perpetrators of pneumonitis or may contribute to diseases caused by coexisting infections. Although diagnosis and assessment of the clinical significance of these infections may be difficult, their recognition is of practical importance because potentially effective therapeutic agents are available for several of them. Miscellaneous infections such as pulmonary toxoplasmosis and pertussis are other uncommon but potentially treatable complications of HIV disease.

Pulmonary disease

This article has presented the reader with an overview of the pulmonary disorders that develop during the course of HIV disease with special emphasis on the more commonly encountered entities. This information is intended to prepare the clinician to recognize the hallmark characteristics of the various diseases as well as atypical features. Despite the advances in basic understanding of the clinicopathologic consequences of infection with HIV, a cure has not been realized. There has, however, been success in controlling some of the major pulmonary problems that adversely affect both the quality and the length of life for persons with AIDS. For most complications of HIV infection, prognosis ultimately depends not only on treatment of the specific problem, but also controlling the relentless process of progressive immunosuppression. Continued research into treatment or prevention of HIV infection itself is needed, but at present prevention, rapid diagnosis, and treatment of recognized problems remain an intermediary goal.

Management of herpes simplex virus type 1 pneumonia following liver transplantation

Interstitial pneumonia caused by Herpes simplex virus type 1 (HSV-1) is a severe complication of orthotopic liver transplantation (LTX). The records of patients were reviewed who had an LTX at the age of 16 years or older between 1991 and 1994 with a mean follow-up of 21 months (range, 10 to 44 months). Six patients were included who had fever of > 38 degrees C, deterioration of arterial blood gases, radiological evidence of interstitial pneumonia and proof of HSV-1 in bronchoalveolar lavage fluid. All patients were anti-HSV-IgG positive before LTX. All patients were successfully treated with intravenous acyclovir, mechanical ventilation and reduced immunosuppression. Three patients who received cyclosporin A had a rejection which was successfully treated by switching to FK 506. Four patients were discharged in good health. One patient died 36 months after LTX of an unrelated cause. One patient died of urosepsis on postoperative day 139. Acyclovir together with mechanical ventilation and reduced immunosuppression proved to be an effective treatment for HSV-1 pneumonia following LTX.