Education and imaging. Gastrointestinal: Mycobacterium genavense enteritis in an immunosuppressed patient

Disseminated Mycobacterium genavense infection in a patient with a history of sarcoidosis

We present a case of Mycobacterium genavense infection in a man in his 60s with a history of sarcoidosis, treated for 24 years with systemic corticosteroids and later methotrexate as monotherapy. He presented with low grade fever, dyspnoea and right-sided thoracic pain and was admitted due to a treatment-refractory infection. After a prolonged period of symptoms and diagnostics, acid-fast bacilli were demonstrated in pleural fluid and PCR revealed M. genavense The patient was treated with intravenous amikacin, peroral azithromycin, rifampicin and ethambutol for a total of 18 months, with a good clinical and radiological treatment response. Infection with M. genavense is rare in HIV-negative immunocompromised hosts. Diagnosing and treating mycobacterial infections, especially for more rare species, remains a challenge as clinical evidence is sparse. Nonetheless, the disease-causing infection must be considered in symptomatic and immunocompromised patients.

An unusual case of abdominal mycobacterial infection: Case report and literature review

This article presents a case of an HIV-infected paediatric patient with an unusual Mycobacterium genavense infection with predominantly abdominal organ involvement.

Mycobacterium genavense infections in non-HIV immunocompromised hosts: a systematic review

BACKGROUND

Mycobacterium genavense is a non-tuberculous mycobacterium which can rarely cause disease in non-HIV immunocompromised hosts. We describe our experience with this unusual infection and perform a systematic review of the literature to describe the features of M. genavense infection in non-HIV immunocompromised hosts.

METHODS

All cases of Mycobacterium genavense infection in non-HIV patients at our institution were reviewed. In addition, we conducted a systematic review of the literature to identify previously published cases of M. genavense infections in non-HIV hosts.

FINDINGS

Two cases of M. genavense were identified at our center; a 51-year-old renal transplant recipient with a prosthetic knee joint infection and a 66-year-old woman with idiopathic CD4 lymphocytopenia with gastrointestinal tract disease. The systematic review identified 44 cases of M. genavense infection in non-HIV hosts. The most common underlying conditions were solid organ transplantation (40%), sarcoidosis (14%) and hematopoietic stem cell transplantation (7%). Disease most commonly involved the gastrointestinal tract, spleen, liver or bone marrow. Diagnosis was challenging with PCR required for identification in nearly all cases. Over one-third of patients died, which may reflect the combination of infection and underlying comorbidities. Overall cure was achieved in 61% with a mean duration of antimycobacterial therapy of 15.5 months (range 10-24).

CONCLUSION

M. genavense infection is a rare mycobacterial infection in non-HIV immunocompromised hosts. It should be suspected in immunocompromised patients presenting with disseminated mycobacterial infection, acid fast bacilli on smear or histopathologic examination, with poor or no growth in mycobacterial cultures.

Mycobacterium genavense Infections in a Tertiary Hospital and Reviewed Cases in Non-HIV Patients

Mycobacterium genavense is a relatively new species of nontuberculous mycobacterium reported to cause disseminated infections in patients with AIDS and later on in non-HIV immunosuppressed patients. We describe clinical and laboratory features and response to therapy in 7 patients, three of them with HIV infection and four non-HIV-three organ transplant recipients and one with hyper-IgE syndrome-in Valencia, Spain, in a ten years period. We then summarize the published cases of M. avium complex infection, with invasion of peripheral blood, liver, spleen, bone marrow, lymph nodes, and lungs. In clinical samples a large number of acid-fast bacilli were observed. M. genavense grew only from liquid media and after a prolonged incubation period. Its identification was accomplished through molecular methods. Patients were treated with prolonged combinations of antimicrobial agents. There was clinical favourable outcome in 4 patients.

Mycobacterium genavense in the Netherlands: an opportunistic pathogen in HIV and non-HIV immunocompromised patients. An observational study in 14 cases

Mycobacterium genavense is an opportunistic non-tuberculous mycobacterium previously mostly associated with HIV-infected patients with CD4 counts below 100/μL. In this retrospective observational study of medical charts we studied all Dutch patients in whom M. genavense was detected between January 2002 and January 2010. Of the 14 patients identified, 13 (93%) showed clinically relevant M. genavense disease. All patients with M. genavense disease were severely immunocompromised, including HIV-infected patients, solid organ transplant recipients, those with chronic steroid use in combination with other immune modulating drugs, recipients of chemotherapy for non-Hodgkin lymphoma, and those with immunodeficiency syndromes. Two patients had non-disseminated pulmonary M. genavense disease. Of the 12 patients treated, eight (75%) showed a favourable outcome. Four patients died in this study, three despite treatment for M. genavense disease. We conclude that M. genavense is a clinically relevant pathogen in severely immunocompromised patients that causes predominantly disseminated disease with serious morbidity and mortality. M. genavense is increasingly seen among non-HIV immunocompromised patients.

Mycobacterium genavense infections: a retrospective multicenter study in France, 1996-2007

Mycobacterium genavense, a nontuberculous mycobacterium, led to devastating infections in patients with acquired immunodeficiency syndrome (AIDS) before highly active antiretroviral therapy (HAART) was available, as well as in other immunocompromised patients. We conducted the current study to describe the features of this infection in patients infected with human immunodeficiency virus (HIV) in the HAART era and in non HIV-infected patients.We conducted a retrospective cohort survey in France. All patients with M. genavense infection diagnosed from 1996 to 2007 at the National Reference Center, Institut Pasteur, Paris, were identified and their clinical, laboratory, and microbiologic data were centralized in a single database. Twenty-five cases of M. genavense infection originating from 19 centers were identified. Twenty patients had AIDS, 3 had solid organ transplantation, and 2 had sarcoidosis. Sixty-four percent (n = 16) were male, mean age was 42 years, and median CD4 count was 13/mm (range, 0-148/mm) in patients with AIDS. Twenty-four patients had disseminated infection with fever (75%, n = 18), weight loss (79%, n = 19), abdominal pain (71%, n = 17), diarrhea (62.5%, n = 15), splenomegaly (71%, n = 17), hepatomegaly (62.5%, n = 15), or abdominal adenopathy (62.5%, n = 15). M. genavense was isolated from the lymph node (n = 13), intestinal biopsy (n = 9), blood (n = 6), sputum (n = 3), stool (n = 3), and bone marrow (n = 5). Eleven patients (44%) died, 8 (32%) were considered cured with no residual symptoms, and 6 (24%) had chronic symptoms. The 1-year survival rate was 72%.The prognosis of M. genavense infection in HIV-infected patients has dramatically improved with HAART. Clinical presentations in HIV and non-HIV immunocompromised patients were similar.