A study of diseases caused by atypical mycobacteria in Japan

Metagenomic next-generation sequencing assistance in identifying Mycobacterium avium meningoencephalitis: A case report and literature review

Nontuberculous mycobacteria associated intracranial infection is a rare disease that mainly occurs in HIV-infected patients. The disease has a poor prognosis. The authors report a case of non-tuberculous mycobacterial meningoencephalitis in a non-AIDS patient, but long history of poorly controlled type 2 diabetes mellitus. A 55-year-old, right-handed, male patient presented with an 8-day history of fever, episodes of severe headache with signs of meningeal irritation. MRI showed hyperintensities/contrast enhancement in the visual pathways, basal ganglia sellar region and leptomeninges. No etiological diagnosis was reached until metagenomic next-generation sequencing (mNGS) was used, showing the presence of Mycobacterium avium. The patient was cured with aggressive antimycobacterial therapy. The authors discuss the clinical manifestations and drug therapy of nontuberculous mycobacteria-related intracranial infections by reviewing relevant literature. As meningoencephalitis by Mycobacterium avium has a high mortality an early diagnosis and appropriate therapeutic interventions are warranted. For this reason, the use of mNGS can be helpful to avoid therapeutic delay.

Pulmonary infection with opportunist mycobacteria on Merseyside 1974-1983

During a 10 year period 49 patients were recorded as having pulmonary infection caused by opportunist mycobacteria. Six different species were identified of which M. kansasii (65%) and M. avium-intracellulare (20%) were the most common. Cough and sputum (82%) or haemoptysis (26%) were frequent symptoms on presentation and over two thirds of patients had pre-existing respiratory disease. Chest radiographs showed predominantly apical disease with the right apex (44%) being twice as commonly affected as the left (22%). In 30% the radiograph showed bilateral disease. Clinicians had an individual approach to treatment with no uniform pattern of drug prescribing. A majority of patients (59%) received rifampicin for at least 9 months and those patients with M. kansasii infection responded well with no bacteriological relapses in 20 patients followed for a mean period of 3.9 years. M. avium-intracellulare, M. malmoense and M. xenopi were less responsive to treatment and in four patients receiving chemotherapy death was attributed to mycobacterial infection.