Ocular manifestations of disseminated Mycobacterium chimaera infection after cardiothoracic surgery

Recurrent Choroidal Neovascular Membrane as the Initial Presentation of Mycobacterium chimaera-Associated Serpiginoid Choroiditis

PURPOSE

To report a rare presentation of a proven case of Mycobacterium chimaera infection presenting as multifocal choroiditis with recurrent choroidal neovascular membrane (CNVM) in one eye, initially misdiagnosed as punctate inner choroidopathy and later developed serpiginous-like choroiditis in the other eye.

METHODS

Retrospective case report with a review of existing literature.

RESULTS

A 30-year-old women presented with metamorphopsia (OD) and best-corrected visual acuity (BCVA) of 6/24 (OD) and was diagnosed to have punctate inner choroidopathy with CNVM (OD). Since then, she had received four intravitreal anti-vascular endothelial growth factor injections over 3 years. Two years later, she developed a slowly progressing choroidal lesion radiating from the disc in a serpiginoid manner in the left eye. There was no vitritis. Labs revealed a positive QuantiFERON-TB Gold test. High-resolution computed tomography of the thorax showed sub-centimetre noncalcified lymph nodes in subcarinal and perivascular regions, minimal pleural thickening in left lower zone, minimal pericardial effusion, bronchiectatic changes, and fibrotic strands in right middle and left lower lobes. Bronchoalveolar lavage grew M. chimaera intracellularae (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). She was given a course of clarithromycin, moxifloxacin, rifampicin, and doxycycline for 12 months. Though the right eye remained stable, choroidal lesion in the left eye continued to progress threatening the fovea, requiring oral steroids, methotrexate, and an intravitreal dexamethasone implant. At the last follow-up, her BCVA was 6/18 (OD) and 6/6 (OS). Both eyes were stable.

CONCLUSION

This case highlights a rare presentation of proven M. chimaera infection presenting as multifocal choroiditis with recurrent CNVM in one eye and serpiginous-like choroiditis in the other eye, requiring aggressive treatment to salvage the vision.

Mycobacterium chimaera chorioretinitis preceding central nervous system lesions: a case report and review of the literature

Background

Mycobacterium chimaera ocular infection is a rare disease that is linked to bypass devices used during cardiothoracic surgeries. Reported cases in the literature of ocular involvement preceding CNS involvement are based on clinical exam with no neuroimaging. Here we present a case of M. chimaera ocular infection with no CNS M. chimaera lesions on brain magnetic resonance imaging (MRI).

Case presentation

A 59-year-old female presented with altered mental status and blurred vision in February 2021. Her past medical history was significant for aortic valve replacement and ascending aortic aneurysm repair in 2017 complicated by known M. chimaera infection. She had been receiving azithromycin, ethambutol, rifampin, and amikacin as systemic anti-mycobacterium treatment. Her dilated fundus exam showed numerous yellow placoid circular lesions scattered throughout the macula and peripheral retina in both eyes with associated vitritis. Systemic workup, including brain MRI showed no acute infectious lesions. Her infections workup was unremarkable except for a positive toxoplasma IgM, for which she was treated with sulfamethoxazole/trimethoprim. One month later, a head computed tomography showed new numerous scattered round foci of hyperdensity throughout the cerebrum and brainstem thought to be foci of M. chimaera infection. Clofazimine was added per culture and sensitivity. MRI brain 1 month later showed mild decrease in conspicuity and number of these intensities while on anti-mycobacterium treatment. Her cognition had improved at that time as well. She was seen in retina clinic 2 months later where her exam showed similar retinal lesions with no associated vitritis or anterior chamber cell in bilateral eyes, suggesting a lack of active infection. Optical coherence tomography macula showed parafoveal cystoid macular edema bilaterally. She was started on steroidal and non-steroidal anti-inflammatory eye drops.

Conclusions

To the best of our knowledge, this is the first case in the literature to report M. chimaera chorioretinitis with concomitant negative neuroimaging. Chorioretinal M. chimaera lesions should motivate high suspicion of CNS involvement prompting early neurological work up.

Pharmacologic management of Mycobacterium chimaera Infections: A Primer for Clinicians

Mycobacterium chimaera, a member of the Mycobacterium avium complex, can cause infections in individuals after open heart surgery due to contaminated heater-cooler units. The diagnosis can be challenging, as the incubation period can be quite variable, and symptoms are nonspecific. In addition to aggressive surgical management, combination pharmacologic therapy is the cornerstone of therapy, which should consist of a macrolide, a rifamycin, ethambutol, and amikacin. Multiple second-line agents may be utilized in the setting of intolerances or toxicities. In vitro susceptibility of these agents is similar to activity against other species in the Mycobacterium avium complex. Drug–drug interactions are frequently encountered, as many individuals have chronic medical comorbidities and are prescribed medications that interact with the first-line agents used to treat M. chimaera. Recognition of these drug–drug interactions and appropriate management are essential for optimizing treatment outcomes.

Differences between Mycobacterium chimaera and tuberculosis Using Ocular Multimodal Imaging: A Systematic Review

Due to their non-specific diagnostic patterns of ocular infection, differential diagnosis between Mycobacterium (M.) chimaera and tuberculosis can be challenging. In both disorders, ocular manifestation can be the first sign of a systemic infection, and a delayed diagnosis might reduce the response to treatment leading to negative outcomes. Thus, it becomes imperative to distinguish chorioretinal lesions associated with M. chimaera, from lesions due to M. tuberculosis and other infectious disorders. To date, multimodal non-invasive imaging modalities that include ultra-wide field fundus photography, fluorescein and indocyanine green angiography, optical coherence tomography and optical coherence tomography angiography, facilitate in vivo examination of retinal and choroidal tissues, enabling early diagnosis, monitoring treatment response, and relapse detection. This approach is crucial to differentiate between active and inactive ocular disease, and guides clinicians in their decisional-tree during the patients’ follow-up. In this review, we summarized and compared the available literature on multimodal imaging data of M. chimaera infection and tuberculosis, emphasizing similarities and differences in imaging patterns between these two entities and highlighting the relevance of multimodal imaging in the management of the infections.