Rickettsia typhi. A new causative agent of round pneumonia in adults

Spherical pneumonia caused by Ralstonia mannitolilytica: a case report and literature review

BACKGROUND

Spherical pneumonia is an extremely rare condition that is difficult to diagnose. It is a specific type of lung infection that often manifests as a round or round-like mass on chest imaging. Spherical pneumonia is easily misdiagnosed as a pulmonary tumor; therefore, awareness of this disease must be strengthened.

CASE PRESENTATION

The patient was a 29-year-old female who had persistent cough and sputum for approximately 1 month and fever for 5 days. Chest computed tomography (CT) at our hospital revealed a mass in the lower lobe of the right lung near the hilar region, with obstructive pulmonary atelectasis and obstructive pneumonia. Although lung cancer was suspected, Ralstonia mannitolilytica was detected by metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid, and no cancer cells or Mycobacterium tuberculosis were detected. Finally, the patient was diagnosed with spherical pneumonia caused by R. mannitolilytica. Anti-infective treatment, symptomatic treatment, and administration of a traditional Chinese medicine decoction were performed based on the syndrome differentiation. After 10 days of treatment, chest CT revealed few lesions in the lower lobe of the right lung, which were significantly reduced compared with those in the past.

CONCLUSIONS

Spherical pneumonia caused by R. mannitolilytica has not yet been reported and differential diagnosis is key in clinical diagnosis. When spherical pneumonia is difficult to diagnose, mNGS may be a better alternative.

A case of round pneumonia due to Enterobacter hormaechei: the need for a standardized diagnosis and treatment approach in adults

Round pneumonia is an unusual radiological manifestation of a bacterial lung infection. We present the case of an elderly male patient who arrived at the emergency room with a productive cough and exertional dyspnea. His chest x-ray and CT showed a round opacity and air bronchograms in the right upper lobe. Taken together, the patient's symptoms and images strongly suggest a pulmonary infection. Empirical antibiotic therapy with ceftriaxone and clarithromycin was started. The sputum culture was positive for Enterobacter hormaechei and the bacterium was sensitive to levofloxacin; therefore, the antibiotic therapy was changed. Despite the treatment, the patient progressed to respiratory failure and septic shock, dying six days after admission. Although round pneumonia is uncommon, it is a potentially curable disease and clinicians should always consider it in their differential diagnosis.

Outbreak of mycoplasmal round pneumonia in an adult population: A case series

BACKGROUND

Mycoplasmal pneumonia is a common type of adult community-acquired pneumonia in China, but round/spherical pneumonia caused by mycoplasma pneumoniae has rarely been reported. Here, we report an outbreak of mycoplasmal round pneumonia in a military dormitory in China.

METHODS

We analysed epidemiological, clinical, imaging and laboratory data from a series of adults affected by an outbreak of mycoplasmal round pneumonia in the dormitory of a military hospital (Fuzhou General Hospital) in Fuzhou, China. The dormitory included 2 separate buildings. Mycoplasma antibody was detected using a passive agglutination assay.

RESULTS

The first case in our series, a 23-year-old male intern, presented on July 16, 2015 with a 3-day history of low-grade fever, dizziness, fatigue and chest tightness. Chest computed tomography revealed spherical masses. Over the following 4 days, 11 individuals who had been in close contact with the first patient were found to have similar masses. All 12 cases were mildly symptomatic or asymptomatic, and fever was the only sign visible upon physical examination. Chest radiology revealed single, round consolidations in 3 cases and multiple round consolidations in 9 cases; consolidations ranged in size from 0.2 to 2.9 cm. Most cases had normal blood cell count, erythrocyte sedimentation rate and C reactive protein level. Nasopharyngeal swabs from all cases tested negative for 25 pathogens, including Mycoplasma pneumoniae, in a PCR-based assay performed on August 1, 2015. All 12 patients showed a 4-fold increase in the titre of anti-mycoplasmal pneumonia antibody in paired sera on August 13, 2015. Patients were given the antibiotic moxifloxacin or symptomatic treatment, and 11 of the 12 cases showed complete resolution of round pneumonia lesions within 4 weeks.

CONCLUSION

This case series illustrates the diversity of clinical manifestations as well as imaging findings for mycoplasmal pneumonia, to which clinicians should pay more attention. Mycoplasmal round pneumonia should be included in differential diagnosis of multiple pulmonary nodules in adults in order to enable accurate clinical identification of disease and successful treatment and resolution.