Q fever pneumonia: appearance on chest radiographs

Acute Q fever pneumonia: high-resolution computed tomographic findings in six patients

METHODS:

We analyzed high-resolution CT (HRCT) findings from six male patients (mean age, 22.6 years) with confirmed diagnoses of acute Q fever. Two chest radiologists analyzed the images and reached decisions by consensus. All patients presented fever, myalgia, prostation, headache, and dry cough. They also had common epidemiologic factors (recent travel for military service, where they had contact with sheep and capybara). Diagnoses were confirmed by the detection of C. burnetii DNA in clinical samples by polymerase chain reaction.

RESULTS:

The predominant HRCT findings were areas of consolidation (100%) and nodules (66.6%) with halos of ground-glass opacity, predominantly with segmental and peripheral distributions. Lesions affected all lobes, and predominated in the left upper and lower lobes. Involvement of more than one lobe was observed in four patients. No pleural effusion or lymph node enlargement was found.

CONCLUSION:

The predominant HRCT findings in patients with acute Q fever pneumonia were bilateral, peripheral areas of consolidation and nodules with irregular contours and halos of ground-glass opacity.

ADVANCES IN KNOWLEDGE:

Acute Q fever should be included in the differential diagnosis of lesions with the halo sign on HRCT.

Pulmonary manifestations of Q fever: analysis of 38 patients

Background

Lung involvement in both acute and chronic Q fever is not well described with only a few reported cases of pseudotumor or pulmonary fibrosis in chronic Q fever. The aim of this study was to better understand the pulmonary manifestations of Q fever.

Methods

We conducted a retrospective cohort study of patients with diagnosis of Q fever at Mayo Clinic Rochester. A total of 69 patients were initially identified between 2001 and 2014. Thirty-eight patients were included in this study as 3 were pediatric patients, 20 did not meet serologic criteria for Q fever, and 8 did not have imaging available at time of initial diagnosis. Descriptive analysis was conducted using JMP software.

Results

The median age was 57 years [interquartile range (IQR) 43, 62], 84% from the Midwest, and 13% worked in an occupation involving animals. The most common presentation was fevers (61%). Respiratory symptoms, such as cough, were noted in only 4 patients (11%). Twelve patients (29%) had abnormal imaging studies attributed to Q fever. Three patients (25%) with acute Q fever had findings of consolidation, lymphadenopathy, pleural effusions, and nonspecific pulmonary nodules. Radiographic findings of chronic Q fever were seen in 9 patients (75%) and included consolidation, ground-glass opacities, pleural effusions, lymphadenopathy, pulmonary edema, and lung pseudotumor.

Conclusions

Our results demonstrate that pulmonary manifestations are uncommon in Q fever but include cough and consolidation for acute Q fever and radiographic findings of pulmonary edema with pleural effusions, consolidation, and pseudotumor in those with chronic Q fever.

Chest radiography for predicting the cause of febrile illness among inpatients in Moshi, Tanzania

AIM

To describe chest radiographic abnormalities and assess their usefulness for predicting causes of fever in a resource-limited setting.

MATERIALS AND METHODS

Febrile patients were enrolled in Moshi, Tanzania, and chest radiographs were evaluated by radiologists in Tanzania and the United States. Radiologists were blinded to the results of extensive laboratory evaluations to determine the cause of fever.

RESULTS

Of 870 febrile patients, 515 (59.2%) had a chest radiograph available; including 268 (66.5%) of the adolescents and adults, the remainder were infants and children. One hundred and nineteen (44.4%) adults and 51 (20.6%) children were human immunodeficiency virus (HIV)-infected. Among adults, radiographic abnormalities were present in 139 (51.9%), including 77 (28.7%) with homogeneous and heterogeneous lung opacities, 26 (9.7%) with lung nodules, 25 (9.3%) with pleural effusion, 23 (8.6%) with cardiomegaly, and 13 (4.9%) with lymphadenopathy. Among children, radiographic abnormalities were present in 87 (35.2%), including 76 (30.8%) with homogeneous and heterogeneous lung opacities and six (2.4%) with lymphadenopathy. Among adolescents and adults, the presence of opacities was predictive of Streptococcus pneumoniae and Coxiella burnetii, whereas the presence of pulmonary nodules was predictive of Histoplasma capsulatum and Cryptococcus neoformans.

CONCLUSIONS

Chest radiograph abnormalities among febrile inpatients are common in northern Tanzania. Chest radiography is a useful adjunct for establishing an aetiologic diagnosis of febrile illness and may provide useful information for patient management, in particular for pneumococcal disease, Q fever, and fungal infections.

Computer-assisted detection of infectious lung diseases: a review

Respiratory tract infections are a leading cause of death and disability worldwide. Although radiology serves as a primary diagnostic method for assessing respiratory tract infections, visual analysis of chest radiographs and computed tomography (CT) scans is restricted by low specificity for causal infectious organisms and a limited capacity to assess severity and predict patient outcomes. These limitations suggest that computer-assisted detection (CAD) could make a valuable contribution to the management of respiratory tract infections by assisting in the early recognition of pulmonary parenchymal lesions, providing quantitative measures of disease severity and assessing the response to therapy. In this paper, we review the most common radiographic and CT features of respiratory tract infections, discuss the challenges of defining and measuring these disorders with CAD, and propose some strategies to address these challenges.

Q fever: clinical manifestations and treatment

Public awareness and advances in the diagnostic approach to Q fever have provided important information on epidemiological and clinical aspects of this zoonosis. Coxiella burnetii infection exhibits various acute or chronic clinical forms, and infection during pregnancy may jeopardize the integrity of the fetus. The presentation of infection is often nonspecific and this hinders prompt diagnosis. Therapeutic regimens vary, and treating Q fever during pregnancy and childhood is often challenging. Increasing clinical experience with C. burnetii infections has helped create treatment protocols and follow-up algorithms that have considerably improved management and prognosis. Vaccines are available, although their use is still limited.

Recurrent Jarisch-Herxheimer reaction in a patient with Q fever pneumonia: a case report

Q fever is a zoonotic disease caused by coxiella burnetii. The Jarisch-Herxheimer reaction (JHR) is associated with the antibiotic treatment of certain bacterial infections. We report a very rare case of a 36-year-old male with Q fever pneumonia that resulted in recurrent ARDS and presented the JHR during his treatment. The patient was admitted for treatment of community acquired pneumonia. He developed ARDS, was intubated and placed on mechanical ventilation. Doxycycline was empirically added to his antibiotic regiment. The patient presented an acute rise in temperature, tachycardia, tachypnea, hypoxia, hypotension and a temporary deterioration of his chest x-ray. The same 6-hour-long reaction which is known as JHR was presented another 3 times. Cultures were negative but antibodies against coxiella burnetii were positive. This case reminds us that any deterioration of a patient treated in the ICU should not be considered as a new septic episode and time should be allowed for the antibiotic regiments.

[Outbreak of Coxiella burnetii pneumonia]

OBJECTIVE

The aim of this study was to describe an outbreak of Q fever pneumonia in the North of Spain.

MATERIAL AND METHODS

We report 60 cases of Coxiella burnetii pneumonia in a rural area with 16,000 inhabitants during January and February 2003. The diagnosis was serologically confirmed by indirect immunofluorescence.

RESULTS

Mean age of the patients was 46 years and the male/female ratio was 2.5. Overall, 52% of the patients lived in urbanized areas and contact with animals was declared in only 7% of patients. Sixty percent of patients were hospitalized. The most frequent clinical presentation was an acute febrile process (100%) and headache (80%); respiratory symptoms were infrequent. The most common liver function alteration was elevated transaminase levels (35%). Radiologic evidence of a single lobar or segmental alveolar opacity was found in 87% of patients, and most commonly affected the lower lobes. Chest radiographs returned to normal in 70% of patients within the two first months. Empirical treatment consisted of beta-lactams and macrolides in 38%, macrolides alone in 8%, and quinolones in 23%; 27% were treated with beta-lactams alone. No deaths occurred.

CONCLUSIONS

Coxiella burnetii infection is very prevalent in the north of Spain and should be suspected and investigated when outbreaks of a pneumonic illness occur.

Pulmonary Disease from Biological Agents: Anthrax, Plague, Q Fever, and Tularemia

Anthrax, plague, Q fever, and tularemia are all potential inhalational bioterrorism agents. The pulmonary manifestations of these agents can be readily confused with each other as well as other more common diseases such as influenza and atypical pneumonia. This article reviews the threat potential, microbiology, pathogenesis, clinical features, diagnosis, and treatment of each of these agents and highlights the similarities and differences between their pulmonary presentations.

Clinical features of Q fever pneumonia

The aim of the study was to assess the clinical features of Q fever pneumonia in Japan. Four cases of Q fever pneumonia (a female aged 21 and males aged 53, 74 and 87 years) who were diagnosed using the PanBio ELISA test kit, were assessed and their clinical features are described. The frequency of Q fever pneumonia among our cases of community-acquired pneumonia was 1.4% (4/284). A 21-year-old female had a typical case of the disease with (i) a history of owning a cat, (ii) onset with fever and dry cough, (iii) multiple soft infiltrative shadows on CXR, (iv) a normal white blood cell count, and (v) good response to clarithromycin. The pneumonias in the other three cases were considered mixed infections with bacteria such as Streptococcus pneumoniae and Haemophilus influenzae. Their clinical features included the following: (i) an elderly person with an underlying disease, (ii) onset with fever and purulent sputum, (iii) coarse crackles on auscultation, (iv) infiltrative shadows and pleural effusion on CXR, (v) increased white blood cells with elevated BUN and hyponatraemia, and (vi) modest responses to combined therapy with carbapenem and minocycline. Our observations suggest that two types of pneumonia caused by Coxiella burnetti exist; one with the usual features of atypical pneumonia, and the other presenting with the clinical features of bacterial pneumonia in the elderly due to mixed bacterial infection.

Imagerie moderne des pneumonies infectieuses aiguës

Les pneumonies infectieuses aiguës constituent un problème de santé publique important, car elles sont une cause majeure de morbidité et de mortalité chez l’adulte. Si les données cliniques et radiographiques permettent le plus souvent de faire le diagnostic de pneumonie infectieuse, le diagnostic étiologique est plus difficile. En effet, de nombreux agents pathogènes peuvent être responsables de pneumonie et la réaction du parenchyme pulmonaire est peu variée, d’où la faible spécificité des lésions radiologiques observées en dehors de quelques cas particuliers. C’est pourquoi la compréhension des mécanismes physiopathologiques permet d’expliquer certains aspects radiologiques. De même, la connaissance des bases anatomocliniques et radiologiques autorise la reconnaissance de trois aspects radiographiques principaux. Quant à l’appréciation des contextes épidémiologique et immunitaire, ils peuvent permettre également d’approcher le germe en cause.

Q fever in adults: review of 66 clinical cases

Sixty-six cases of Q fever in adults, serologically confirmed by indirect immunofluorescence, were studied to analyze the epidemiological, clinical and therapeutic aspects of the disease. Eighty-three percent of the patients were male, and the mean age was 44.7 years. Contact with animals was recorded in 24 patients. The main clinical form of presentation was pneumonia (37 cases); eight patients had hypoxia, and five had respiratory failure. The empirical treatment consisted of macrolides in 36% of cases. Evolution was favorable in all cases.

Q fever pneumonia: CT findings

PURPOSE

To evaluate the computed tomographic (CT) features of Q fever pneumonia.

MATERIALS AND METHODS

The authors retrospectively reviewed the chest radiographs and CT scans obtained in 12 patients, who were selected on the basis of chest CT availability from a group of patients with a definite diagnosis of acute Q fever infection during an 8.5-year period.

RESULTS

In all cases, CT depicted lesions indicative of airspace involvement, which was expressed as lobar (n = 3), segmental (n = 3), patchy (n = 3), or a combination of these patterns (n = 3). Involvement of more than one lobe was observed in seven (58%) patients. In one patient with multiple patchy areas of consolidation, nodular lesions with a vascular connection and a halo of ground-glass opacity, which were suggestive of an angioinvasive process, were demonstrated. In addition, CT performed in a patient with acute Coxiella burnetii infection who abused alcohol revealed necrotizing pneumonia. Pleural effusions were seen at both CT and radiography in three patients, and mild lymph node enlargement in isolated regions was seen at CT in four patients. Chest radiography was less accurate than CT in the detection of segmental and patchy areas of consolidation.

CONCLUSION

The typical CT findings of Q fever pneumonia consisted mainly of multilobar airspace consolidation. A nodular pattern accompanied by a halo of ground-glass opacification and vessel connection, and necrotizing pneumonia in the setting of impaired immunity were less frequent.