Probable disseminated Mycobacterium abscessus subspecies bolletii infection in a patient with idiopathic CD4+ T lymphocytopenia: a case report

Epidemiology, clinical presentation, and predictors of outcome in nontuberculous mycobacterial central nervous system infection: a systematic review

BACKGROUND

CNS manifestations represent an emerging facet of NTM infection with significant mortality. Due to protean presentation and low index of suspicion, many cases are often treated erroneously as tubercular meningitis or fungal infections.

OBJECTIVES

Literature on NTM CNS disease is scarce, with most available data on pulmonary disease. This systematic review aimed to evaluate the epidemiology, clinical presentation, diagnostic modalities, and predictors of outcome in CNS NTM infection.

METHODS

The literature search was performed in major electronic databases (PubMed, Google Scholar, and Scopus) using keywords "CNS," "Central nervous system," "brain abscess," "meningitis," "spinal," "Nontuberculous mycobacteria," "NTM". All cases of CNS NTM infection reported between January 1980 and December 2022 were included.

RESULTS

A total of 77 studies (112 cases) were included in the final analysis. The mean age of all patients was 38 years, with most patients male (62.5%). Mycobacterium avium complex (MAC) was the most common aetiology, followed by M. fortuitum and M. abscessus (34.8%, 21.4% and 15.2%, respectively). The disseminated disease was found in 33% of cases. HIV (33.9%) and neurosurgical hardware (22.3%) were the common risk factors. Intracranial abscess (36.6%) and leptomeningeal enhancement (28%) were the most prevalent findings in neuroimaging. The overall case fatality rate was 37.5%. On multivariate analysis, male gender (adjusted OR 2.4, 95% CI 1.2-7.9) and HIV (adjusted OR 3.7, 95% CI 1.8-6.1) were the independent predictors of mortality). M. fortuitum infection was significantly associated with increased survival (adjusted OR 0.18, 95% CI (0.08-0.45), p value 0.012).

CONCLUSIONS

Current evidence shows the emerging role of rapid-grower NTM in CNS disease. Male gender and HIV positivity were associated with significant mortality, while M fortuitum carries favourable outcomes.

Non-tuberculous Mycobacteria in South African Wildlife: Neglected Pathogens and Potential Impediments for Bovine Tuberculosis Diagnosis

Non-tuberculous mycobacteria (NTM) are not only emerging and opportunistic pathogens of both humans and animals, but from a veterinary point of view some species induce cross-reactive immune responses that hamper the diagnosis of bovine tuberculosis (bTB) in both livestock and wildlife. Little information is available about NTM species circulating in wildlife species of South Africa. In this study, we determined the diversity of NTM isolated from wildlife species from South Africa as well as Botswana. Thirty known NTM species and subspecies, as well as unidentified NTM, and NTM closely related to Mycobacterium goodii/Mycobacterium smegmatis were identified from 102 isolates cultured between the years 1998 and 2010, using a combination of molecular assays viz PCR and sequencing of different Mycobacterial house-keeping genes as well as single nucleotide polymorphism (SNP) analysis. The NTM identified in this study include the following species which were isolated from tissue with tuberculosis- like lesions in the absence of Mycobacterium tuberculosis complex (MTBC) implying their potential role as pathogens of animals: Mycobacterium abscessus subsp. bolletii, Mycobacterium gastri, Mycobacterium species closely related to Mycobacterium goodii/Mycobacterium smegmatis, Mycobacterium brasiliensis, Mycobacterium sinense JMD 601, Mycobacterium avium subsp. avium, Mycobacterium sp. GR-2007, Mycobacterium bouchedurhonense, and Mycobacterium septicum/M. peregrinum. Mycobaterium brasiliensis, Mycobacterium gastri, Mycobacterium sp. GR-2007, and a potential novel Mycobacterium species closely related to Mycobacterium goodii were found for the first time in this study to be potential pathogens of animals. Mycobacterium simiae was isolated from a sample originating from a tuberculin skin test positive reactor, demonstrating its potential to elicit inappropriate immune responses in animals that may interfere with diagnosis of tuberculosis by immunology. Mycobacterium abscessus subsp. bolletti was the most frequently detected NTM identified in 37 of the 102 isolates. Other NTM species were also isolated from animals not showing any pathological changes. Knowledge gained in this study contribute to the understanding of NTM species circulating in wild animals in South Africa and the pathogenic potential of certain species, whose role in disease causation need to be examined, as well as to a certain extent the potential of M. simiae to hamper the diagnosis of bTB.

Severe Pneumocystis jirovecii pneumonia in an idiopathic CD4+ lymphocytopenia patient: case report and review of the literature

INTRODUCTION

When diagnosing Pneumocystis jirovecii pneumonia (PJP), the clinical suspicion must be confirmed by laboratory tests. PJP is rarely described in patients with idiopathic CD4⁺ lymphocytopenia (ICL), a rare T-cell deficiency of unknown origin with persistently low levels of CD4⁺ T-cells (<300 µl^-1 or <20 % of total lymphocytes) but repeated negative human immunodeficiency virus (HIV) tests. We retrospectively analysed a case of an ICL patient with severe PJP associated with multiple opportunistic infections (OIs). We also reviewed the literature since 1986.

CASE PRESENTATION

A laboratory-confirmed case of PJP associated with invasive candidiasis and cytomegalovirus infection was reported in an ICL patient. Despite early treatment, the patient died of respiratory failure under polymicrobial pneumonia. According to the literature, the mortality rate of ICL patients is 10.4 % (33/316). In ICL patients, the risk of OI is 83.2 % (263/316), with viral infections being the most prevalent (58.2 %, 184/316), followed by fungal infections (52.2 %, 165/316) and mycobacterial infections (15.5 %, 49/316). Dysimmunity is reported in 15.5 % (49/316) of ICL patients. Among the fungal infections, cryptococcal infections are the most prevalent (24.1 %, 76/316), followed by candidiasis (15.5 %, 49/316) and PJP (7.9 %, 25/316).

CONCLUSIONS

The high risk of OIs underlines the importance of more vigorous preventative actions in hospitals. The response to therapy and the detection of early relapse of PJP may be monitored by several laboratory tests including quantitative PCR. It is essential to treat the ICL and to follow the guidelines concerning therapy and prophylaxis of OIs as given to HIV patients.