Status of pulmonary fungal pathogens among individuals with clinical features of pulmonary tuberculosis at Mbarara University Teaching Hospital in Southwestern Uganda

Prevalence of Oropharyngeal Candidiasis and distribution of Candida species among People Living with Human Immunodeficiency Virus in Africa: a systematic review and meta-analysis

Background

The incidence of oropharyngeal candidiasis among people living with human immunodeficiency virus in Africa is on the rise. Oropharyngeal candidiasis is mainly caused by C.albicans; however, a shift in the etiology towards non-Candida albicans species is increasing. In addition, there are variations in the epidemiological distribution of Candida species causing oropharyngeal candidiasis among people living with human immunodeficiency virus in Africa.

Objective

This review aimed to determine the prevalence of oropharyngeal candidiasis and the distribution of Candida species among people living with human immunodeficiency virus in Africa.

Materials and Methods

This systematic review protocol was registered in the base PROSPERO database prior to its conduct (CRD42021254473). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines (PRISMA-P) were followed for this study. The PubMed, Scopus and EMBASE databases were searched to identify published studies published between 1st January 2000 and 8th October 2022. The eligible studies were included in the meta-analysis and analyzed using a random effects model. The risk of bias of the included studies was assessed using the Joanna Briggs Institute quality assessment tool for prevalence studies.

Results

The database search yielded 370 titles from PubMed (n=192), EMBASE (n=162) and SCOPUS (n=16). Fourteen studies with a total of 3,863 participants were included in the meta-analysis. The pooled prevalence of oropharyngeal candidiasis was 49.0% (95% CI: 37% - 62%). A total of 2,688 Candida isolates were reported; approximately 76.6% (n=2,060) were C. albicans, and 21.7% (n=582) were non-C. albicans. Among the non-Candida albicans species, C. glabrata was the most common isolate (29.6%), followed by C. tropicalis (27.7%), C. krusei (17.0%), C. parapsilosis (8.1%) and C. dubliniensis (5.2%). Out of 14 studies, 7 (50.0%) had a low risk of bias, 5 (35.7%) had a moderate risk of bias, and 2 (14.3%) had a high risk of bias.

Conclusion

Almost half of people living with HIV in Africa have oropharyngeal candidiasis, and C. albicans remains the most frequent cause of oropharyngeal candidiasis.

Investigating Metabolic and Molecular Ecological Evolution of Opportunistic Pulmonary Fungal Coinfections: Protocol for a Laboratory-Based Cross-Sectional Study

BACKGROUND

Fungal-bacterial cocolonization and coinfections pose an emerging challenge among patients suspected of having pulmonary tuberculosis (PTB); however, the underlying pathogenic mechanisms and microbiome interactions are poorly understood. Understanding how environmental microbes, such as fungi and bacteria, coevolve and develop traits to evade host immune responses and resist treatment is critical to controlling opportunistic pulmonary fungal coinfections. In this project, we propose to study the coexistence of fungal and bacterial microbial communities during chronic pulmonary diseases, with a keen interest in underpinning fungal etiological evolution and the predominating interactions that may exist between fungi and bacteria.

OBJECTIVE

This is a protocol for a study aimed at investigating the metabolic and molecular ecological evolution of opportunistic pulmonary fungal coinfections through determining and characterizing the burden, etiological profiles, microbial communities, and interactions established between fungi and bacteria as implicated among patients with presumptive PTB.

METHODS

This will be a laboratory-based cross-sectional study, with a sample size of 406 participants. From each participant, 2 sputa samples (one on-spot and one early morning) will be collected. These samples will then be analyzed for both fungal and bacterial etiology using conventional metabolic and molecular (intergenic transcribed spacer and 16S ribosomal DNA-based polymerase chain reaction) approaches. We will also attempt to design a genome-scale metabolic model for pulmonary microbial communities to analyze the composition of the entire microbiome (ie, fungi and bacteria) and investigate host-microbial interactions under different patient conditions. This analysis will be based on the interplays of genes (identified by metagenomics) and inferred from amplicon data and metabolites (identified by metabolomics) by analyzing the full data set and using specific computational tools. We will also collect baseline data, including demographic and clinical history, using a patient-reported questionnaire. Altogether, this approach will contribute to a diagnostic-based observational study. The primary outcome will be the overall fungal and bacterial diagnostic profile of the study participants. Other diagnostic factors associated with the etiological profile, such as incidence and prevalence, will also be analyzed using univariate and multivariate schemes. Odds ratios with 95% CIs will be presented with a statistical significance set at P<.05.

RESULTS

The study has been approved by the Mbarara University Research Ethic Committee (MUREC1/7-07/09/20) and the Uganda National Council of Science and Technology (HS1233ES). Following careful scrutiny, the protocol was designed to enable patient enrollment, which began in March 2022 at Mbarara University Teaching Hospital. Data collection is ongoing and is expected to be completed by August 2023, and manuscripts will be submitted for publication thereafter.

CONCLUSIONS

Through this protocol, we will explore the metabolic and molecular ecological evolution of opportunistic pulmonary fungal coinfections among patients with presumptive PTB. Establishing key fungal-bacterial cross-kingdom synergistic relationships is crucial for instituting fungal bacterial coinfecting etiology.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN33572982; https://tinyurl.com/caa2nw69.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48014.

Relationship Between Invasive Fungal Infection and Hypostatic Pneumonia: A Prospective Cohort Study

Background

The short-term mortality of hypostatic pneumonia (HP) is very high, and the treatment outcome is poor. The clinical diagnosis and treatment are primarily focused on bacterial and viral infection, ignoring the role of fungal infection at present. This study aims to validate the relationship between Invasive Fungal Infections (IFI) and HP.

Methods

In the cross-sectional study, a total of 11,371 participants have been enrolled. In the prospective cohort study, 4,441 individuals have been included at baseline and followed up from 2015 to 2019 with a total person years of 8,484.65. The standard procedures were used to assess questionnaire investigations, laboratory testing, and anthropometric indicators. For data analysis, logistic regression, restricted cubic spline, log-rank regression, Cox regression, and linear mixed effects model were applied to assess the relationship between IFI and HP risk longitudinally.

Results

In the cross-sectional study, elevated β-D-Glucan (BDG) concentrations are associated with a higher risk of HP prevalence in the total population, men, and women (OR_{T3 vs}._T1 [95% CIs]: 2.12 [1.55, 2.91]; 2.01 [1.35, 2.99]; 2.34 [1.39, 3.94]), which were verified by a dose–effect relationship in the restricted cubic spline model. In the cohort study, Cox and Log-rank regression showed that the elevated BDG concentrations are associated with a significantly higher risk of HP incidence than participants with lower BDG concentrations (HR_{T3 vs}._T1 [95% CIs]: 2.72 [1.36, 5.43], p_Log–rank = 0.0086). During 5 years, the globulin (GLB) and C-reactive protein (CRP) were always on the top in the highest category of BDG concentrations. Between low and high BDG concentration, the total trend of GLB concentration was falling and the total trend of CRP concentration was rising with the increase of years (all the p-values < 0.0001).

Conclusion

In this study, IFI is associated with a higher risk of HP, with time sequence and related mechanisms requiring further investigation in the future.