Lung abscess: an update on the current knowledge and call for future investigations.

PURPOSE OF REVIEW: Lung abscess is a severe and complex respiratory infection. The purpose of this review is to discuss recent publications on lung abscess, covering topics such as epidemiology, clinical presentation, diagnosis, and treatment and prevention. RECENT FINDINGS: Risk factors associated with lung abscess include structural lung disease, poor dental hygiene, and ventilator-associated pneumonia, while concerns are now raised regarding the potential of electronic cigarettes use as a risk factor. The complexity of lung abscess is reflected by the relative high number of case reports describing rare and complex cases. Early transthoracic drainage could improve in-hospital outcomes, while next-generation sequencing could become an important tool in diagnostics and future clinical studies. SUMMARY: High-quality evidence and guidelines to support treatment of lung abscess are lacking. Despite advancements, we call for prospective studies to evaluate the use of invasive procedures and antibiotic treatment regimens.

The first case report: diagnosis and management of necrotizing fusobacterium lung abscess via BALF next-generation sequencing.

BACKGROUND: Fusobacterium necrophorum (F. necrophorum)-induced necrotizing pneumonia is a rare but severe pulmonary infection. Insufficient microbiological detection methods can lead to diagnostic difficulties. METHODS: We report a case of F. necrophorum lung abscess diagnosed by next-generation sequencing (NGS) of bronchoalveolar lavage fluid (BALF). RESULTS: BALF-NGS detected F. necrophorum, guiding subsequent targeted antibiotic therapy. With active drainage and metronidazole treatment, the patient's condition was effectively treated. CONCLUSION: BALF-NGS is a valuable tool for the rapid diagnosis of infections caused by difficult-to-culture bacteria. It played a decisive role in the early identification of F. necrophorum, enabling timely and targeted antibiotic intervention. Early diagnosis and appropriate treatment are crucial for the management of F. necrophorum pneumonia.

Intrathoracic Ewing's sarcoma in an adult masquerading as lung abscess.

Intrathoracic extraskeletal Ewing's sarcoma (EES) is a relatively uncommon malignant tumour. Here, we present a scenario involving an adult man in his 20s with a large intrathoracic EES that manifested as a lung abscess. Preoperative diagnostic tests were inconclusive; hence, the patient underwent an exploratory thoracotomy for the excision of the mass. Histopathology revealed a small round blue cell tumour, and immunohistochemistry, along with fluorescence in situ hybridisation, confirmed the diagnosis of Ewing's sarcoma. Adjuvant chemoradiotherapy was recommended, but the patient did not comply. A year later, he presented with a recurrence of the intrathoracic mass and subsequently received adjuvant chemotherapy. Currently, he is in remission.

A pulmonary abscess caused by Porphyromonas endodontalis infection:A case report and literature review.

Porphyromonas endodontalis is an oral anaerobic bacterium associated with periodontitis but seldomly been detected in other diseases. Only one case of respiratory disease caused by Porphyromonas endodontalis, pyopneumothorax, has been reported so far. A 53-year-old man with refractory periodontitis was admitted due to an indeterminate lung space-occupying lesion. Following mNGS analysis of the liquefaction necrotic area and solid component of the lesion through biopsy, Porphyromonas endodontalis and Parvimonas micra were detected. Therefore, the patient was diagnosed with an aspiration lung abscess and discharged after receiving effective antibacterial treatment. The Chest computed tomography (CT) scan revealed a remarkable improvement during outpatient follow-up. In this study, we applied mNGS to diagnose a case of lung abscess attributed to an uncommon bacterium successfully, suggesting that when patients complicated with periodontal diseases and clinical respiratory symptoms, the possibility of inhalation disease caused by oral pathogens should be considered.

[A Combination Therapy with Antibiotic and Surgical Treatment in a Patient with Patent Ductus Arteriosus with Pulmonary Vegetation:Report of a Case].

We present a case of a 24-year-old female who presented with a history of fever and back pain. She had no particular medical history and was not taking any medication. Transthoracic echocardiology and computed tomography showed a patent ductus arteriosus with vegetation in the pulmonary artery. She was treated with penicillin G;however, the vegetation embolized into the left pulmonary artery. After the antibiotics was changed to clindamycin and ceftriaxone, the resolution of the lung abscess was shown by computed tomography( CT). Two months later, a surgical repair of the patent ductus arteriosus was successfully performed. Patent ductus arteriosus-associated infectious endocarditis is relatively rare in adulthood.

Successful treatment of Rhodococcus lung abscess and empyema thoracis in a heart transplant recipient.

Rhodococcosis is an uncommon cause of pulmonary infection in thoracic organ transplant recipients. We describe a heart transplant recipient diagnosed with Rhodococcus equi left upper lung abscess with empyema thoracis complicated by bacteremia. The patient was successfully treated with appropriate antibiotics, adequate surgical resection, and optimization of immunosuppressants.

Lung abscess: Clinical characteristics of 222 Danish patients diagnosed from 2016 to 2021.

INTRODUCTION: Lung abscess (LA) is a serious respiratory infection often followed by several weeks of antibiotic treatment. This study described the clinical presentation of LA, treatment duration and mortality in a contemporary Danish population. METHODS: In a retrospective multicenter cohort study at four Danish hospitals, patients diagnosed with LA were identified using the International Classification of Diseases and Related Health Problems 10th revision (ICD-10) between 2016 and 2021. A predefined data collection tool was used to extract data on demographics, symptoms, clinical findings and treatment. RESULTS: Of 302 patients, 222 with LA were included after review of patient records (76%). Mean age was 65 years (54-74), 62.9% was male and 74.9% were ever-smokers. Chronic obstructive pulmonary disease (COPD) (35.1%), use of sedatives (29.3%) and alcohol abuse (21.8%) were common risk factors. Dental status was reported in 51.4%, whereof 41.6% had poor dental status. Patients presented with cough (78.8%), malaise (61.3%) and fever (56.8%) Patients were hospitalized for a median of 14 days (interquartile ranges, IQR 7-21) and median duration of antibiotic treatment was 38 days (IQR 30-51). All-cause mortality after 1, 3 and 12 months was 2.7%, 7.7% and 15.8%, respectively. CONCLUSION: Risk factors for LA include COPD and use of sedatives, alcohol abuse, and poor dental status. Despite long-term antibiotic treatment, long-term mortality is markedly high.

Lung abscess as a secondary infection of COVID-19: A case report and literature review.

A 16-year-old male was admitted with persistent fever, diarrhea, and anorexia 8 days after the diagnosis of coronavirus disease-2019 (COVID-19). Radiological examination of the lungs showed a cavitary lesion with an air-fluid level, but no apparent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia. The lesion was diagnosed as a lung abscess after COVID-19. Treatment with antimicrobials was initiated, which attenuated symptoms and the lung lesion. Specific pathogens were not detected despite repeated sputum cultures, which suggested that lung abscess was caused by oral bacteria as a secondary infection of COVID-19. To date, several cases of lung abscess as a complication of COVID-19 have been reported. However, the majority of cases occurred after intubation to treat COVID-19, and there have been no cases involving young adults. This healthy young patient may have developed lung abscess due to COVID-19.

Multiple pneumatoceles and lung abscesses caused by early-onset E. coli sepsis in a preterm neonate.

Early-onset sepsis (EOS) is a serious and fatal illness in neonates, Group B Streptococcus and Escherichia coli are major causative pathogens. We report a case of EOS and pneumonia caused by E. coli in a preterm neonate with multiple pneumatoceles and lung abscesses. A male neonate weighing 1670g was delivered at 33 6/7 weeks' gestation by a mother with clinical chorioamnionitis. He showed respiratory distress soon after birth and developed septic shock. He was intubated and mechanical ventilation was started. E.coli was detected in blood culture obtained from both the patient and his mother. He developed multiple pneumatoceles and lung abscesses. Surgical drainage was complicated, cefotaxime was thus continued until day 74. Pneumatoceles and lung abscesses are complications of neonatal pneumonia, rarely reported by E. coli. Multiple lung abscesses in our patient are distinct from single abscesses in previous case studies of neonatal lung abscesses. We speculate that bacteremia along with pneumatoceles led to multiple lung abscesses in our patient. These complications require long-term antibiotic therapy, to minimize morbidity and mortality, and should thus be considered when managing EOS caused by E. coli.

[Surgical ulcerative colitis complicated by multiple lung abscesses secondary to septic pulmonary embolism after multidrug immunosuppressive therapies].

This is a case implying a serious infectious complication risk during intensive severe ulcerative colitis treatment. A 26-year-old man developed diarrhea and bloody stool who was diagnosed with ulcerative colitis in 2018. He was managed with 5-aminosalicylic acid, but intolerance reaction resulted in discontinuation of treatment. He relapsed with severe abdominal pain and bloody stools in February 2019. He was referred to our department for intensive therapy. He had been treated with steroids, tacrolimus, granulocyte and monocyte apheresis, infliximab or tofacitinib, which temporarily improved his clinical symptoms. However, his medical condition could not be controlled. Hand-assisted laparoscopic subtotal colectomy was then performed in October 2019. He developed intermittent fever on postoperative day 3. Enhanced computed tomography (CT) revealed multiple deep vein thromboses and pulmonary embolism. Antibiotics and anticoagulation therapy were initiated, but postoperative day 13 CT showed multiple pulmonary cavities containing fluids and air, which were diagnosed as pulmonary abscess. His intermittent fever was over 38.0°C. Severe cough and hemoptysis lasted 3 weeks, the clinical symptoms and laboratory data then gradually improved after the fourth week.

A 45-Year-Old Man With Acute Chest Pain, Fever, and Dyspnea After Tooth Extraction.

CASE PRESENTATION: A 45-year-old Japanese man underwent wisdom tooth extraction. He developed right chest pain 2 days later, followed by continuous fever with dyspnea 2 weeks after the tooth extraction, and then came to our hospital. He complained of cough and purulent sputum.

Primary lung abscess due to multidrug-resistant Klebsiella pneumoniae.

Primary lung abscess as a complication of necrotising community-acquired pneumonia due to multidrug-resistant (MDR) Klebsiella pneumoniae is rare. A 63-year-old man with a medical history of type 2 diabetes mellitus and chronic kidney disease was diagnosed with lung abscess due to MDR Klebsiella pneumoniae, a rare organism as a causative agent for community-acquired pneumonia. This unusual case revealed therapeutic challenges faced owing to factors such as drug-resistant pathogen, longer duration of antibiotics required for lung abscess and the chronic kidney status of the patient limiting the dosage of antibiotics. The clinical nuggets discussed in this case might pave the way in the future for management guidelines to be formulated in optimising the selection and duration of therapy for lung abscesses with MDR aetiology and in early recognition of this rare but dreaded entity.

Lung abscess secondary to lung cancer with a coinfection of Granulicatellaadiacens and other bacteria: a case report.

BACKGROUND: Granulicatella adiacens is facultative anaerobic Gram-positive bacteria, which mainly involve bacterial endocarditis and bacteremia, but there are few reports of local suppurative infection. A case of lung abscess with a coinfection of Granulicatella adiacens and other bacteria in a lung cancer patient will be reported in this paper. To our knowledge, this is the first case report describing lung abscess due to G.adiacens. CASE PRESENTATION: A 52-year-old Chinese woman was admitted to the hospital, She complained of coughing and expectoration for 1 month, shortness of breath for half a month, and dyspnea for 1 day. After a series of examinations, she was diagnosed with lung abscess, pleural effusion, and bronchogenic carcinoma. Draining pus culture demonstrated Granulicatella adiacens. After more than 5 weeks of antibiotic therapies in total, she gradually recovered to fight against lung cancer. CONCLUSION: This is the first reported lung abscess caused by G.adiacens. In immunosuppressed hosts, G.adiacens is a virulent pathogen associated with a spectrum of intrathoracic suppurative. Earlier diagnosis and proper drainage surgery with effective antibiotics treatment are very important, and antimicrobial treatment should be more than 5 weeks. When complex pulmonary infection interferes with the CT diagnosis, clinical suspicion of lung cancer should be increased if G.adiacens or Eikenella corrodens is detected from a pulmonary infection.

[Bacterial lung abscesses].

A lung abscess is a necrotising infection leading to loss of healthy lung tissue. It develops over several weeks, and the typical presentation includes cough, fever, and general deterioration. The clinical work-up includes contrast-enhanced CT-scans, and frequently flexible bronchoscopy with broncho-alveolar lavage as described in this review. The infection commonly represents aspiration of oral bacterial flora, including anaerobic microbes. Penicillin resistance is common. A lung abscess generally requires long-term, tailored antibiotic treatment. The patient should consult a dentist to identify possible dental foci.

Legionella pulmonary abscess and pleural space infection in an immunocompetent patient.

A 34-year-old woman is admitted to the hospital with dyspnoea, dry cough and left-sided flank pain. Her Legionella urinary test was positive and CT imaging demonstrated multifocal pneumonia with pulmonary abscesses. Although she had initial clinical improvement on appropriate antibiotic therapy, her hospital course was complicated by worsening flank pain, hypoxemia and leucocytosis, prompting clinical re-evaluation and assessment for development of complications involving the pleural space. CT imaging revealed interval development of a loculated complicated parapneumonic effusion. Successful treatment required chest tube drainage assisted by fibrinolytic therapy. This case highlights the importance of considering Legionella in patients with pulmonary abscess, demonstrates an approach to a patient with a non-resolving pneumonia and illustrates the management of parapneumonic effusions.

An unusual case of multiple hepatic and pulmonary abscesses caused by Aggregatibacter aphrophilus in a young man: a case report.

BACKGROUND: Aggregatibacter aphrophilus, formerly known as Haemophilus aphrophilus, belongs to the HACEK organisms, a group of pathogens classically associated with infectious endocarditis. A. aphrophilus is a rarely found pathogen, though abscess formation in various organs has been described, typically due to spread from an infected heart valve. Here we describe the unusual case of multiple hepatic abscesses caused by A. aphrophilus. CASE PRESENTATION: A 33-year-old Caucasian man presented at our hospital with fever and malaise, elevated inflammatory markers, and liver enzymes. Imaging was compatible with multiple liver and pulmonary abscesses, without evidence of endocarditis. Cultures of blood and liver abscess material remained without growth. Polymerase chain reaction finally revealed Aggregatibacter aphrophilus in the liver tissue. The patient recovered fully within 6 weeks of doxycycline treatment. CONCLUSIONS: There are only a few case descriptions of liver abscesses caused by A. aphrophilus. As a ubiquitous organism in the gastrointestinal tract, A. aphrophilus may reach the liver via the portal venous system, as well as through hematogenous spread from the oropharynx. HACEK organisms are notoriously difficult to grow on culture, which highlights the diagnostic importance of eubacterial PCR.