Clinical Features and Radiological Findings of Adenovirus Pneumonia Associated with Progression to Acute Respiratory Distress Syndrome: A Single Center Study in 19 Adult Patients

Construction of a bivalent vaccine candidate against HAdV4/HAdV7 based on capsid-display strategy via Red-homologous recombination and counter-selection methodology

Human adenoviruses (HAdVs) are major respiratory pathogens. Specifically, human adenovirus type 4 (HAdV4) and human adenovirus type 7 (HAdV7) are known for causing fever and pneumonia, with documented cases of fatalities among the population. In recent years, HAdV4/HAdV7 has been implicated in causing substantial outbreaks, leading to increased morbidity in multiple countries. Most HAdV4 and HAdV7 infections have been reported in North America, Asia, Europe, Africa, South America, Oceania, and the Middle East. Most fatalities occurred in North America (the United States) and Asia (China and Singapore). Engineered recombinant adenoviruses have played a crucial role as vaccine vectors. In this study, we constructed a recombinant adenovirus, Ad4ITRmut-Ad7E3, and evaluated it in vitro and in vivo. We observed that the replication rate of Ad4ITRmut-Ad7E3 was lower than that of the RI-67 strain, indicating that the mutation of inverted terminal repeats (ITRs) weakened the replication ability of HAdV4. Immunization of BALB/c mice with the bivalent Ad4ITRmut-Ad7E3 vaccine strain, administered by intraperitoneal injection and oral gavage, resulted in the elicitation of neutralizing antibodies targeting HAdV4 and HAdV7. This finding not only provides a novel method and technique for the efficient construction of a polyvalent recombinant adenovirus vaccine candidate against HAdV4 and HAdV7 but also against other prevalent adenovirus serotypes such as HAdV3, HAdV11, HAdV14, and HAdV55, from various regions.

Viral Pneumonias

Viral pneumonia is usually community acquired and caused by influenza, parainfluenza, respiratory syncytial virus, human metapneumovirus, and adenovirus. Many of these infections are airway centric and chest imaging demonstrates bronchiolitis and bronchopneumonia, With the exception of adenovirus infections, the presence of lobar consolidation usually suggests bacterial coinfection. Community-acquired viral pathogens can cause more severe pneumonia in immunocompromised hosts, who are also susceptible to CMV and varicella infection. These latter 2 pathogens are less likely to manifest the striking airway-centric pattern. Airway-centric pattern is distinctly uncommon in Hantavirus pulmonary syndrome, a rare environmentally acquired infection with high mortality.

The risk factors involved in airway mucus plug in children with ADV Pneumonia

BACKGROUND

The risk factors for mucus plug in children with adenovirus (ADV) pneumonia.

METHODS AND MATERIALS

A retrospective analysis was conducted of children diagnosed ADV pneumonia and underwent fiberoptic bronchoscopy admitted to the Xiamen Children's Hospital from September 2018 to September 2021.The patients were divided into a mucus plug group (39 cases) and a non-mucus plug group (53 cases). The children's data including sex, age, clinical presentation, laboratory test parameters, imaging and bronchoscopic data were collected. The risk factors for the development of airway mucus plug were analysed by multifactorial logistic regression.

RESULTS

There were no statistically significant differences in sex, age, fever, hospitalization days, mixed infection, white blood cells (WBC) count, percentage of neutrophils (NE%), C-reactive protein(CRP), and D-dimer (all P > 0.05); Thermal range, procalcitonin (PCT), lactate dehydrogenase (LDH), Pleural effusion and associated decreased breath sounds was significantly higher in mucus plug group than in non-mucus plug group, and the differences were statistically significant (all P < 0.05); multifactorial logistic regression analysis showed that the duration of fever, PCT, and LDH were independent risk factors for the formation of mucus plugs. The critical values of ROC curves were pyroprocedure ≥ 6.5 d, PCT ≥ 0.705 ng/ml and LDH ≥ 478.5 U/L.

CONCLUSION

Duration of fever, PCT and LDH levels were the independent risk factors for the formation of an airway mucus plug in children with ADV pneumonia.

Clinical characteristics and severity prediction score of Adenovirus pneumonia in immunocompetent adult

BACKGROUND

Compared with children and immunocompromised patients, Adenovirus pneumonia in immunocompetent adults is less common. Evaluation of the applicability of severity score in predicting intensive care unit (ICU) admission of Adenovirus pneumonia is limited.

METHODS

We retrospectively reviewed 50 Adenovirus pneumonia inpatients in Xiangtan Central Hospital from 2018 to 2020. Hospitalized patients with no pneumonia or immunosuppression were excluded. Clinical characteristics and chest image at the admission of all patients were collected. Severity scores, including Pneumonia severity index (PSI), CURB-65, SMART-COP, and PaO2/FiO2 combined lymphocyte were evaluated to compare the performance of ICU admission.

RESULTS

Fifty inpatients with Adenovirus pneumonia were selected, 27 (54%) non-ICU and 23 (46%) ICU. Most patients were men (40 [80.00%]). Age median was 46.0 (IQR 31.0-56.0). Patients who required ICU care (n = 23) were more likely to report dyspnea (13[56.52%] vs 6[22.22%]; P = 0.002) and have lower transcutaneous oxygen saturation ([90% (IQR, 90-96), 95% (IQR, 93-96)]; P = 0.032). 76% (38/50) of patients had bilateral parenchymal abnormalities, including 91.30% (21/23) of ICU patients and 62.96% (17/27) of non-ICU patients. 23 Adenovirus pneumonia patients had bacterial infections, 17 had other viruses, and 5 had fungi. Coinfection with virus was more common in non-ICU patients than ICU patients (13[48.15%]VS 4[17.39%], P = 0.024), while bacteria and fungi not. SMART-COP exhibited the best ICU admission evaluation performance in Adenovirus pneumonia patients (AUC = 0.873, p < 0.001) and distributed similar in coinfections and no coinfections (p = 0.26).

CONCLUSIONS

In summary, Adenovirus pneumonia is not uncommon in immunocompetent adult patients who are susceptible to coinfection with other etiological illnesses. The initial SMART-COP score is still a reliable and valuable predictor of ICU admission in non-immunocompromised adult inpatients with adenovirus pneumonia.

Acute Respiratory Distress Syndrome Caused by Human Adenovirus in Adults: A Prospective Observational Study in Guangdong, China

Background

Viral causes of acute respiratory distress syndrome (ARDS) are mostly limited to influenza. However, adenovirus has been emerging as a cause of ARDS with a high mortality rate and described in adults are rare.

Methods

We conducted a prospective, single-center observational study of viral pneumonia with ARDS and confirmed adenovirus-associated ARDS in adults at our quaternary referral institution between March 2019 and June 2020. We prospectively analyzed clinical characteristics, laboratory test results, radiological characteristics, viral load from nasopharyngeal swabs and endotracheal aspirates, treatments, and outcomes for the study participants.

Results

The study enrolled 143 ARDS patients, including 47 patients with viral pneumonia-related ARDS, among which there were 14 adenovirus-associated ARDS patients, which accounted for 29.79% of the viral pneumonia-related ARDS cases. Among the adenovirus-associated ARDS patients, 78.57% were men with a mean age of 54.93 ± 19.04 years, younger than that of the non-adenovirus associated ARDS patients. Adenovirus-associated ARDS patients had no specific clinical characteristics, but they presented with decrease in the number of CD3+CD4+ T cells and higher serum creatinine during the early stage. The viral load and the positivity rate in the lower respiratory tract were higher than that of the upper respiratory tract in the patients with adenovirus-associated ARDS. All patients required invasive mechanical ventilation treatment. The average time from shortness of breath to the application of invasive ventilation was 24 h. Ten patients (71.43%) complicated by acute kidney injury, while 13 patients (71.43%) in the non-adenovirus associated ARDS group (P = 0.045). Additionally, 85.71% of the 14 adenovirus-associated ARDS patients survived. No significant differences were detected between the two groups regarding duration of ventilation, length of ICU stay and mortality.

Conclusion

Adenovirus infection is an important cause of virus-related ARDS. The positivity rate of adenovirus infection in lower respiratory tract secretions was higher than that in upper respiratory tract secretions in these patients. Age, lower CD3+CD4+ T cells, and high serum creatinine may be were associated with adenovirus induce ARDS in adults required mechanical ventilation. Early identification and intervention to prevent disease progression are essential for reducing the mortality rate in these patients.

Uncommon pathogens in an immunocompetent host: respiratory isolation of Cunninghamella bertholletiae, Aspergillus niger, Staphylococcus pseudintermedius and adenovirus in a patient with necrotising pneumonia

We present the unusual case of a 60-year-old immunocompetent woman with chronic obstructive pulmonary disease who developed a necrotising pneumonia with isolation of Cunninghamella bertholletiae, Aspergillus niger, Staphylococcus pseudintermedius and adenovirus. The patient recovered with antimicrobial therapy and supportive care in the intensive care unit. The current literature on diagnosis and treatment of these pathogens is reviewed.

Construction and Verification of a Predictive Model for Risk Factors in Children With Severe Adenoviral Pneumonia

OBJECTIVE

To construct and validate a predictive model for risk factors in children with severe adenoviral pneumonia based on chest low-dose CT imaging and clinical features.

METHODS

A total of 177 patients with adenoviral pneumonia who underwent low-dose CT examination were collected between January 2019 and August 2019. The assessment criteria for severe pneumonia were divided into mild group (N = 125) and severe group (N = 52). All cases divided into training cohort (N = 125) and validation cohort (N = 52). We constructed a prediction model by drawing a nomogram and verified the predictive efficacy of the model through the ROC curve, calibration curve and decision curve analysis.

RESULTS

The difference was statistically significant (P < 0.05) between the mild adenovirus pneumonia group and the severe adenovirus pneumonia group in gender, age, weight, body temperature, L/N ratio, LDH, ALT, AST, CK-MB, ADV DNA, bronchial inflation sign, emphysema, ground glass sign, bronchial wall thickening, bronchiectasis, pleural effusion, consolidation score, and lobular inflammation score. Multivariate logistic regression analysis showed that gender, LDH value, emphysema, consolidation score, and lobular inflammation score were severe independent risk factors for adenovirus pneumonia in children. Logistic regression was employed to construct clinical model, imaging semantic feature model, and combined model. The AUC values of the training sets of the three models were 0.85 (0.77-0.94), 0.83 (0.75-0.91), and 0.91 (0.85-0.97). The AUC of the validation set was 0.77 (0.64-0.91), 0.83 (0.71-0.94), and 0.85 (0.73-0.96), respectively. The calibration curve fit good of the three models. The clinical decision curve analysis demonstrates the clinical application value of the nomogram prediction model.

CONCLUSION

The prediction model based on chest low-dose CT image characteristics and clinical characteristics has relatively clear predictive value in distinguishing mild adenovirus pneumonia from severe adenovirus pneumonia in children and might provide a new method for early clinical prediction of the outcome of adenovirus pneumonia in children.

Accelerated Stack-of-Spirals Free-Breathing Three-Dimensional Ultrashort Echo Time Lung Magnetic Resonance Imaging: A Feasibility Study in Patients With Breast Cancer

PURPOSE

To investigate the clinical feasibility of accelerated free-breathing stack-of-spirals (spiral) three-dimensional (3D) ultrashort echo time (UTE) lung magnetic resonance imaging (MRI) using iterative self-consistent parallel imaging reconstruction from arbitrary k-space (SPIRiT) algorithm in patients with breast cancer.

METHODS

The institutional review board approved this prospective study and patients' informed consents were obtained. Between June and August 2018, 29 female patients with breast cancer underwent 3-T MRI including accelerated free-breathing spiral 3D UTE (0.98-mm isotropic spatial resolution; echo time, 0.05 msec) of the lungs and thin-section chest computed tomography (CT). Two radiologists evaluated the image quality and pulmonary nodules on MRI were assessed and compared, CT as a reference.

RESULTS

The pulmonary vessels and bronchi were visible consistently up to the sub-sub-segmental and sub-segmental branch levels, respectively, on accelerated spiral 3D UTE. The overall image quality was evaluated as good and excellent for 70.7% of accelerated spiral 3D UTE images (reviewer [R]1, 72.4% [21/29]; R2, 69.0% [20/29]) and acceptable for 20.7% (both R1 and R2, 20.7% [6/29]). Five patients on CT revealed 141 pulmonary metastatic nodules (5.3 ± 2.6 mm); the overall nodule detection rate of accelerated spiral 3D UTE was sensitivity of 90.8% (128/141), accuracy of 87.7%, and positive predictive value of 96.2%. In the Bland-Altman plot analysis comparing nodule size between CT and MRI, 132/141 nodules (93.6%) were inside the limits of agreement.

CONCLUSION

Accelerated free-breathing spiral 3D UTE using the SPIRiT algorithm could be a potential alternative to CT for oncology patients.

Acute respiratory distress syndrome: A study of autopsy findings

Context:

In this autopsy study, the various morphological patterns of acute respiratory distress syndrome (ARDS) have been analyzed and compared along with their etiopathogenesis.

Aims:

We aimed to study the prevalence and clinicopathological correlation of ARDS based on age, gender, hospital stay, symptoms, clinical diagnosis, gross, and microscopy findings.

Subjects and Methods:

Total 130 cases of ARDS were studied over a period of 5 years. Age, gender, hospital stay duration, symptoms, clinical diagnosis, gross and microscopic lung finding, clinicopathological correlation, and cause of death were documented and analyzed. Special stains were done whenever required.

Statistical Analysis:

This is an observational study, and simple statistics such as mean, median, and standard deviation have been used for continuous variables.

Results:

The prevalence of ARDS among the adult autopsy was 6.05%. Majority of the cases were in the age group of 18–30 years (36.9%), with a male: female ratio of 1.7:1. Chief complaints were fever (71%), breathlessness (54.6%), and chills (43.8%). The main clinical diagnoses were ARDS (41.6%), sepsis (28.3%), acute febrile illness (17%), and lower respiratory tract infection (12.5%). Most of the patients had a hospital stay of <1 day. Associated conditions mostly included chronic alcoholism (16.1%), pregnancy (16.1%), and chronic smoking (10.7%). Major findings on gross examination were intrapulmonary hemorrhage (38.5%), ARDS (33%), pulmonary edema (13%), and pneumonia (15.3%). On microscopy, major findings were hyaline membrane (84.6%), intrapulmonary hemorrhage (76.1%), pulmonary edema (75.3%), organizing fibrin (55.3%), and bronchopneumonia (36.2%).

Conclusion:

Infections were one of the major predisposing causes of ARDS. Due to the short interval, the underlying cause for ARDS often goes undiagnosed.

Pleural effusion as an indicator for the poor prognosis of COVID-19 patients

BACKGROUND

Coronavirus Disease 19 (COVID-19) is a global health concern that has become a pandemic over the past few months. This study aims at understanding the clinical manifestations of COVID-19 patients with pleural effusion.

METHODS

COVID-19 patients were retrospectively enrolled from the Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. Pharyngeal swabs from patients were tested using real-time polymerase chain reaction. Patients with COVID-19 were divided into two groups based on their computed tomography (CT) scans for the presence of pleural effusion at admission. We compared the clinical features, laboratory findings, scans and clinical outcomes between the two groups.

RESULTS

Pleural effusion was observed in 9.19% of the patients. Patients with pleural effusion were more likely to be severe or critical cases. Moreover, patients with pleural effusion were associated with increased mortality. Of the 799 discharged patients, patients with pleural effusion had longer hospital stays and duration of viral shedding since the onset of symptoms as compared with that for patients without pleural effusion. After discharge, 217 patients visited for a follow-up CT re-examination at the Union Hospital. The CT scans showed that patients with pleural effusion required a longer time to resolve the lung inflammation after the onset of COVID-19 as compared with the time required by patients without pleural effusion.

CONCLUSION

This population of patients requires special attention and pleural effusion may be an indicator of poor prognosis in COVID-19 patients.

Correlation between CT findings and outcomes in 46 patients with coronavirus disease 2019

The aim of this study was to analyze initial chest computed tomography (CT) findings in COVID-19 pneumonia and identify features associated with poor prognosis. Patients with RT-PCR-confirmed COVID-19 infection were assigned to recovery group if they made a full recovery and to death group if they died within 2 months of hospitalization. Chest CT examinations for ground-glass opacity, crazy-paving pattern, consolidation, and fibrosis were scored by two reviewers. The total CT score comprised the sum of lung involvement (5 lobes, scores 1–5 for each lobe, range; 0, none; 25, maximum). 40 patients who recovered from COVID-19 and six patients who died were enrolled. The initial chest CTs showed 27 (58.7%) patients had ground-glass opacity, 19 (41.3%) had ground glass and consolidation, and 35 (76.1%) patients had crazy-paving pattern. None of the patients who died had fibrosis in contrast to six (15%) patients who recovered from COVID-19. Most patients had subpleural lesions (89.0%) as well as bilateral (87.0%) and lower (93.0%) lung lobe involvement. Diffuse lesions were present in four (67%) patients who succumbed to coronavirus but only one (2.5%) patient who recovered (p < 0.001). In the death group of patients, the total CT score was higher than that of the recovery group (p = 0.005). Patients in the death group had lower lymphocyte count and higher C-reactive protein than those in the recovery group (p = 0.011 and p = 0.041, respectively). A high CT score and diffuse distribution of lung lesions in COVID-19 are indicative of disease severity and short-term mortality.

Respiratory Viral Infections in Sickle Cell Anemia: Special Emphasis on H1N1 Co-infection

Objectives

Patients with sickle cell anemia (SCA) are immunocompromised and at an increased risk of developing infections. Our aim was to establish the clinical, laboratory, and radiological manifestations of respiratory viral infections in SCA at Sultan Qaboos University Hospital (SQUH), Oman and assess its impact on disease morbidity and mortality, with special emphasis on H1N1.

Methods

We undertook a retrospective study in SCA patients with respiratory viral infections following up at the hematology department at SQUH. We collected demographic data and clinical, radiological, and laboratory parameters.

Results

In 84 SCA patients with 109 admission episodes for vaso-occlusive crisis (VOC), molecular diagnostic techniques confirmed 125 respiratory viral infections. Rhinovirus was the most prevalent infection (35.8%), whereas H1N1 virus infection was seen only in 10.1%. Laboratory investigations revealed a significant fall in mean hemoglobin levels, mean white blood cell, and platelet counts from baseline, whereas there was a significant rise in the mean lymphocyte and retic count, serum lactate dehydrogenase, and C-reactive protein levels during infective episodes (p < 0.050, Wilcoxon signed rank test). One-third (32.1%) of the VOC episodes progressed to acute chest syndrome (ACS), but in the H1N1 cohort, only two episodes of ACS was seen (18.2%).

Conclusions

Rhinovirus was the commonest respiratory virus infections in SCA patients, whereas parainfluenza 3 was associated with a significant adverse outcome. H1N1 was associated with a mild course. ACS was seen in approximately one-third of this group of patients.

Differentiating novel coronavirus pneumonia from general pneumonia based on machine learning

BACKGROUND

Chest CT screening as supplementary means is crucial in diagnosing novel coronavirus pneumonia (COVID-19) with high sensitivity and popularity. Machine learning was adept in discovering intricate structures from CT images and achieved expert-level performance in medical image analysis.

METHODS

An integrated machine learning framework on chest CT images for differentiating COVID-19 from general pneumonia (GP) was developed and validated. Seventy-three confirmed COVID-19 cases were consecutively enrolled together with 27 confirmed general pneumonia patients from Ruian People's Hospital, from January 2020 to March 2020. To accurately classify COVID-19, region of interest (ROI) delineation was implemented based on ground-glass opacities (GGOs) before feature extraction. Then, 34 statistical texture features of COVID-19 and GP ROI images were extracted, including 13 gray-level co-occurrence matrix (GLCM) features, 15 gray-level-gradient co-occurrence matrix (GLGCM) features and 6 histogram features. High-dimensional features impact the classification performance. Thus, ReliefF algorithm was leveraged to select features. The relevance of each feature was the average weights calculated by ReliefF in n times. Features with relevance larger than the empirically set threshold T were selected. After feature selection, the optimal feature set along with 4 other selected feature combinations for comparison were applied to the ensemble of bagged tree (EBT) and four other machine learning classifiers including support vector machine (SVM), logistic regression (LR), decision tree (DT), and K-nearest neighbor with Minkowski distance equal weight (KNN) using tenfold cross-validation.

RESULTS AND CONCLUSIONS

The classification accuracy (ACC), sensitivity (SEN), specificity (SPE) of our proposed method yield 94.16%, 88.62% and 100.00%, respectively. The area under the receiver operating characteristic curve (AUC) was 0.99. The experimental results indicate that the EBT algorithm with statistical textural features based on GGOs for differentiating COVID-19 from general pneumonia achieved high transferability, efficiency, specificity, sensitivity, and impressive accuracy, which is beneficial for inexperienced doctors to more accurately diagnose COVID-19 and essential for controlling the spread of the disease.

Characteristics of fever and response to antipyretic therapy in military personnel with adenovirus-positive community-acquired pneumonia

BACKGROUND

In 2014, an outbreak of adenoviral pneumonia occurred in the Korean military training center. However, there are limited data on the characteristics of the fever and its response to antipyretic therapy in immunocompetent adults with adenovirus-positive community-acquired pneumonia (CAP).

METHODS

The medical records of the patients who were admitted to the Armed Forces Chuncheon Hospital for the treatment of CAP between January 2014 and December 2016 were retrospectively analyzed. The patients were divided into three groups, namely, the adenovirus-positive (Adv) group, the adenovirus-negative (Non-Adv) group and the unknown pathogen group, according to the results of a polymerase chain reaction (PCR) test and sputum culture used to measure adenovirus and other bacteria or viruses in respiratory specimens. We evaluated and compared the demographics, clinicolaboratory findings and radiological findings upon admission between the two groups.

RESULTS

Out of the 251 military personnel with CAP during the study periods, 67 were classified into the Adv group, while 134 were classified into the Non-Adv group and 50 were classified into the unknown pathogen group. The patients in the Adv group had a longer duration of fever after admission (3.2 ± 1.6 vs. 1.9 ± 1.2 vs. 2.2 ± 1.5 days, P = 0.018) and symptom onset (5.8 ± 2.2 vs. 3.9 ± 2.5 vs. 3.7 ± 2.0 days, P = 0.006) than patients in the Non-Adv and unknown pathogen groups, respectively. The patients in the Adv group had a higher mean temperature at admission (37.8 ± 0.3 vs. 37.3 ± 0.3 vs. 37.3 ± 0.3, P = 0.005), and more patients were observed over 40 and 39 to 40(14.9% vs. 2.2% vs. 4.0%, 35.8% vs. 3.7% vs. 6.0%, P <  0.001) than those in the Non-Adv and unknown pathogen groups, respectively. The Adv group more commonly had no response or exhibited adverse events after antipyretic treatment compared to the Non-Adv group (17.9% vs. 1.5%, 35.0% vs. 4.3%, P <  0.001, P = 0.05, respectively). In addition, the time from admission to overall clinical stabilization was significantly longer in the patients in the Adv group than in those in the Non-Adv group (4.3 ± 2.8 vs. 2.9 ± 1.8 days, P = 0.034, respectively). Furthermore, no significant difference in the length of hospital stay was observed between the two groups, and no patient died in either group.

CONCLUSION

In this study, Adv-positive CAP in immunocompetent military personnel patients had distinct fever characteristics and responses to antipyretic treatment.

Successful Use of Cidofovir in an Immunocompetent Child With Severe Adenoviral Sepsis

Adenovirus infection is common in childhood and is generally associated with self-limited disease. Cidofovir, a viral DNA polymerase inhibitor, is used to treat adenovirus infection in select populations but is not often recommended for immunocompetent patients because of limited antiviral activity and nephrotoxicity. Here, we report a case of fulminant adenovirus infection associated with lymphopenia and multiple organ failure requiring extracorporeal membrane oxygenation support in a previously healthy child. After 1 week of supportive therapy, the patient had persistent organ failure and continued to have adenoviremia of >560 000 copies per mL. Weekly doses of cidofovir with concurrent probenecid for renal protection was initiated. Adenovirus blood load declined after the first cidofovir dose, becoming undetectable after 3 doses. The patient was successfully decannulated from extracorporeal membrane oxygenation, extubated, and eventually discharged at his functional baseline without need for ongoing respiratory support. Lymphopenia improved after viremia resolved, and a subsequent immunologic workup revealed no evidence of primary immunodeficiency. The viral isolate was genotyped as adenovirus type 7. This case reveals the successful use of cidofovir for management of severe adenovirus infection in a previously healthy child. To date, there are no universally accepted recommendations for the use of cidofovir in this population. Further study is warranted to determine the potential role of cidofovir in treating severe adenovirus infections in immunocompetent children.

Adenovirus Type 7 causing severe lower respiratory tract infection in immunocompetent adults: a comparison of two contrasting cases from an intensive care unit in North West England

Objectives

Severe lower respiratory tract infection caused by adenovirus is well described in immunocompromised hosts and can cause significant morbidity and mortality. We compare and contrast the clinical presentation, radiological, and virological features of two rare cases in immunocompetent adults admitted to an intensive care unit in a large, teaching hospital in North West England. We then provide a concise, comprehensive literature review.

Methods

The first case was a 35-year old female asthmatic who presented with respiratory distress and pneumonitis during peak influenza season, and recovered after a prolonged hospital stay. The second case was a 73-year old male who presented with diarrhoea, vomiting, and general malaise outside of influenza season, developed respiratory compromise, and died. Adenovirus type 7 was identified in bronchoalveolar lavages and plasma samples of both patients, each of whom received cidofovir. No other infectious aetiology was identified.

Results

Clinical and radiological features of severe lower respiratory tract adenoviral infection are similar to other infectious causes of pneumonia and ARDS, including severe influenza. This can create diagnostic uncertainty, especially during influenza season. Positive adenovirus polymerase chain reaction results can support a diagnosis of severe lower respiratory tract adenovirus infection in patients with a clinically compatible syndrome and no other identified aetiology, with higher viral loads being associated with worse prognosis. Although treatment is predominantly supportive, early use of cidofovir may improve outcomes.

Conclusions

These rare cases highlight that severe lower respiratory tract adenoviral infection should be considered in the differential diagnoses of immunocompetent patients presenting with pneumonia and ARDS.

Characteristics and Outcomes of Patients with Pulmonary Acute Respiratory Distress Syndrome Infected with Influenza versus Other Respiratory Viruses

Background

Although the frequency of respiratory viral infection in patients with pulmonary acute respiratory distress syndrome (ARDS) is not uncommon, clinical significance of the condition remains to be further elucidated. The purpose of this study was to compare characteristics and outcomes of patients with pulmonary ARDS infected with influenza and other respiratory viruses.

Methods

Clinical data of patients with pulmonary ARDS infected with respiratory viruses January 2014–June 2018 were reviewed. Respiratory viral infection was identified by multiplex reverse transcription–polymerase chain reaction (RT-PCR).

Results

Among 126 patients who underwent multiplex RT-PCR, respiratory viral infection was identified in 46% (58/126): 28 patients with influenza and 30 patients with other respiratory viruses. There was no significant difference in baseline and clinical characteristics between patients with influenza and those with other respiratory viruses. The use of extracorporeal membrane oxygenation (ECMO) was more frequent in patients with influenza than in those with other respiratory viruses (32.1% vs 3.3%, p=0.006). Co-bacterial pathogens were more frequently isolated from respiratory samples of patients with pulmonary ARDS infected with influenza virus than those with other respiratory viruses. (53.6% vs 26.7%, p=0.036). There were no significant differences regarding clinical outcomes. In multivariate analysis, acute physiology and chronic health evaluation II was associated with 30-mortality (odds ratio, 1.158; 95% confidence interval, 1.022–1.312; p=0.022).

Conclusion

Respiratory viral infection was not uncommon in patients with pulmonary ARDS. Influenza virus was most commonly identified and was associated with more co-bacterial infection and ECMO therapy.

The Repertoire of Adenovirus in Human Disease: The Innocuous to the Deadly

Adenoviridae is a family of double-stranded DNA viruses that are a significant cause of upper respiratory tract infections in children and adults. Less commonly, the adenovirus family can cause a variety of gastrointestinal, ophthalmologic, genitourinary, and neurologic diseases. Most adenovirus infections are self-limited in the immunocompetent host and are treated with supportive measures. Fatal infections can occur in immunocompromised patients and less frequently in the healthy. Adenoviral vectors are being studied for novel biomedical applications including gene therapy and immunization. In this review we will focus on the spectrum of adenoviral infections in humans.