Estimated Burden of Serious Fungal Infections in Malawi

A systematic review of epidemiology, risk factors, diagnosis, antifungal resistance, and management of invasive aspergillosis in Africa

Invasive aspergillosis (IA) affects more than 300,000 people annually worldwide with a case fatality rate reaching 80%. However, in Africa despite the presence of risk factors for the development of IA, the burden of these fungal infections remained unknown. This systematic review aimed to update the available information on the epidemiology and the therapeutic management of IA in Africa. The published papers were systematically searched on major medical databases from September 20 to October 10, 2021. The list of references of eligible articles and the Google scholar database were also checked in order to search for possible eligible articles. Results were reported following the Preferred Reporting Items for Systematic and Meta-analyses (PRISMA) guidelines. The search yielded 1864 articles of which 29 met the inclusion criteria. This systematic review showed the existence of IA in Africa. The prevalence of IA can reach 27% with a fatality rate of more than 60%. The most common clinical form of IA found was invasive pulmonary aspergillosis. The main predisposing conditions identified were neutropenia, HIV/AIDS, renal transplant recipients, and renal failure. Aspergillus section Flavi and Nigri were the main Aspergillus species identified and Aspergillus section Fumigati was uncommon. The main management strategy for IA cases was to start antifungal therapy only after a failure of broad-spectrum antibiotic therapy. This review provided evidence of the existence of invasive aspergillosis in Africa and especially a high rate of undiagnosed invasive aspergillosis cases.

Addressing Microbial Resistance Worldwide: Challenges over Controlling Life-Threatening Fungal Infections

Fungal infections are a serious global concern because of their ability to spread and colonize host tissues in immunocompromised individuals. Such infections have been frequently reported worldwide and are currently gaining clinical research relevance owing to their resistant character, representing a bottleneck in treating affected people. Resistant fungi are an emergent public health threat. The upsurge of such pathogens has led to new research toward unraveling the destructive potential evoked by these species. Some fungi-grouped into Candida, Aspergillus, and Cryptococcus-are causative agents of severe and systemic infections. They are associated with high mortality rates and have recently been described as sources of coinfection in COVID-hospitalized patients. Despite the efforts to elucidate the challenges of colonization, dissemination, and infection severity, the immunopathogenesis of fungal diseases remains a pivotal characteristic in fungal burden elimination. The struggle between the host immune system and the physiological strategies of the fungi to maintain cellular viability is complex. In this brief review, we highlight the relevance of drug resistance phenotypes in fungi of clinical significance, taking into consideration their physiopathology and how the scientific community could orchestrate their efforts to avoid fungal infection dissemination and deaths.

The impact of mucormycosis (black fungus) on SARS-CoV-2-infected patients: at a glance

The emergence of various diseases during the COVID-19 pandemic made health workers more attentive, and one of the new pathogens is the black fungus (mucormycosis). As a result, millions of lives have already been lost. As a result of the mutation, the virus is constantly changing its traits, including the rate of disease transmission, virulence, pathogenesis, and clinical signs. A recent analysis revealed that some COVID-19 patients were also coinfected with a fungal disease called mucormycosis (black fungus). India has already categorized the COVID-19 patient black fungus outbreak as an epidemic. Only a few reports are observed in other countries. The immune system is weakened by COVID-19 medication, rendering it more prone to illnesses like black fungus (mucormycosis). COVID-19, which is caused by a B.1.617 strain of the SARS-CoV-2 virus, has been circulating in India since April 2021. Mucormycosis is a rare fungal infection induced by exposure to a fungus called mucormycete. The most typically implicated genera are Mucor rhyzuprhizopusdia and Cunninghamella. Mucormycosis is also known as zygomycosis. The main causes of infection are soil, dumping sites, ancient building walls, and other sources of infection (reservoir words "mucormycosis" and "zygomycosis" are occasionally interchanged). Zygomycota, on the other hand, has been identified as polyphyletic and is not currently included in fungal classification systems; also, zygomycosis includes Entomophthorales, but mucormycosis does not. This current review will be focused on the etiology and virulence factors of COVID-19/mucormycosis coinfections in COVID-19-associated mucormycosis patients, as well as their prevalence, diagnosis, and treatment.

Determining the burden of fungal infections in Zimbabwe

Zimbabwe currently faces several healthcare challenges, most notably HIV and associated infections including tuberculosis (TB), malaria and recently outbreaks of cholera, typhoid fever and COVID-19. Fungal infections, which are also a major public health threat, receive considerably less attention. Consequently, there is dearth of data regarding the burden of fungal diseases in the country. We estimated the burden of fungal diseases in Zimbabwe based on published literature and 'at-risk' populations (HIV/AIDS patients, survivors of pulmonary TB, cancer, chronic obstructive pulmonary disease, asthma and patients receiving critical care) using previously described methods. Where there was no data for Zimbabwe, regional, or international data was used. Our study revealed that approximately 14.9% of Zimbabweans suffer from fungal infections annually, with 80% having tinea capitis. The annual incidence of cryptococcal meningitis and Pneumocystis jirovecii pneumonia in HIV/AIDS were estimated at 41/100,000 and 63/100,000, respectively. The estimated prevalence of recurrent vulvovaginal candidiasis (RVVC) was 2,739/100,000. The estimated burden of fungal diseases in Zimbabwe is high in comparison to other African countries, highlighting the urgent need for increased awareness and surveillance to improve diagnosis and management.

The global incidence and diagnosis of fungal keratitis

Fungal keratitis is a severe corneal infection that often results in blindness and eye loss. The disease is most prevalent in tropical and subtropical climates, and infected individuals are frequently young agricultural workers of low socioeconomic status. Early diagnosis and treatment can preserve vision. Here, we discuss the fungal keratitis diagnostic literature and estimate the global burden through a complete systematic literature review from January, 1946 to July, 2019. An adapted GRADE score was used to evaluate incidence papers-116 studies provided the incidence of fungal keratitis as a proportion of microbial keratitis and 18 provided the incidence in a defined population. We calculated a minimum annual incidence estimate of 1 051 787 cases (736 251-1 367 323), with the highest rates in Asia and Africa. If all culture-negative cases are assumed to be fungal, the annual incidence would be 1 480 916 cases (1 036 641-1 925 191). In three case series, 8-11% of patients had to have the eye removed, which represents an annual loss of 84 143-115 697 eyes. As fungal keratitis probably affects over a million people annually, an inexpensive, simple diagnostic method and affordable treatment are needed in every country.

Screening for invasive fungal disease using non-culture-based assays among inpatients with advanced HIV disease at a large academic hospital in South Africa

INTRODUCTION

Despite widespread access to antiretroviral therapy (ART), the burden of advanced HIV disease in South Africa is high. This translates into an increased risk of AIDS-related opportunistic infections, including invasive mycoses.

METHODS

Using a limited number of non-culture-based diagnostic assays, we aimed to determine the prevalence of invasive mycoses and tuberculosis among hospitalised adults with very advanced HIV (CD4 counts < 100 cells/µL) at a large academic hospital. We conducted interviews and prospective medical chart reviews. We performed point-of-care finger stick and serum cryptococcal antigen lateral flow assays; serum (1 → 3) ß-D-glucan assays; urine Histoplasma galactomannan antigen enzyme immunoassays and TB lipoarabinomannan assays.

RESULTS

We enrolled 189 participants from 5280 screened inpatients. Fifty-eight per cent were female, with median age 37 years (IQR: 30-43) and median CD4 count 32 cells/µL (IQR: 13-63). At enrolment, 60% (109/181) were receiving ART. Twenty-one participants (11%) had a diagnosis of an invasive mycosis, of whom 53% (11/21) had cryptococcal disease. Thirteen participants (7%) had tuberculosis and a concurrent invasive mycosis. ART-experienced participants were 60% less likely to have an invasive mycosis than those ART-naïve (adjusted OR: 0.4; 95% CI 0.15-1.0; P = .03). Overall in-hospital mortality was 13% (invasive mycosis: 10% [95% CI 1.2-30.7] versus other diagnoses: 13% (95% CI 8.4-19.3)).

CONCLUSIONS

One in ten participants had evidence of an invasive mycosis. Diagnosis of proven invasive fungal disease and differentiation from other opportunistic infections was challenging. More fungal-specific screening and diagnostic tests should be applied to inpatients with advanced HIV disease.

The Pathogenesis of Fungal-Related Diseases and Allergies in the African Population: The State of the Evidence and Knowledge Gaps

The prevalence of allergic diseases in the African continent has received limited attention with the allergic diseases due to fungal allergens being among the least studied. This lead to the opinion being that the prevalence of allergic disease is low in Africa. Recent reports from different African countries indicate that this is not the case as allergic conditions are common and some; particularly those due to fungal allergens are increasing in prevalence. Thus, there is need to understand both the aetiology and pathogenies of these diseases, particularly the neglected fungal allergic diseases. This review addresses currently available knowledge of fungal-induced allergy, disease pathogenesis comparing findings from human versus experimental mouse studies of fungal allergy. The review discusses the potential role of the gut mycobiome and the extent to which this is relevant to fungal allergy, diagnosis and human health.

Bridging the knowledge gap on mycoses in Africa: Setting up a Pan-African Mycology Working Group

Most African countries have poorly funded and overburdened health systems. Additionally, a high prevalence of HIV in Sub-Saharan Africa contributes to a high burden of opportunistic fungal infections. Data generated by GAFFI from 15 of 57 African countries revealed that an estimated 47 million Africans suffer from fungal diseases, of whom an estimated 1.7 million suffer from a serious fungal infection annually. Almost all African countries lack a surveillance system for fungal infections with the exception of South Africa. South Africa is also the only African country with a national mycology reference laboratory. Across the continent, there is a pervasive picture of inadequate/poor diagnostic capacity, low level of awareness among healthcare workers and policymakers and unavailability and non-accessibility to essential antifungal medications. Recent outreach efforts by the International Society for Human and Animal Mycology (ISHAM) and the European Confederation of Medical Mycology (ECMM) have aimed to increase involvement of African countries and experts in global initiatives such as "One World One Guideline" and also the ECMM Academy. Recently, under the auspices of ISHAM, the African sub-region created a network of mycology experts whose goal is to organise and engage African leaders in the field of medical mycology. The aim of this ISHAM Working Group was to facilitate interaction and synergy among regional leaders in order to develop educational programmes for capacity building to aid in the diagnosis and care of patients with fungal infections in Africa. The working group will also encourage country initiatives to develop clinical guidelines, to support surveys and to support the establishment of reference mycology laboratories.

Estimated Burden of Fungal Infections in Namibia

Namibia is a sub-Saharan country with one of the highest HIV infection rates in the world. Although care and support services are available that cater for opportunistic infections related to HIV, the main focus is narrow and predominantly aimed at tuberculosis. We aimed to estimate the burden of serious fungal infections in Namibia, currently unknown, based on the size of the population at risk and available epidemiological data. Data were obtained from the World Health Organization (WHO), Joint United Nations Programme on HIV/AIDS (UNAIDS), and published reports. When no data existed, risk populations were used to estimate the frequencies of fungal infections, using the previously described methodology. The population of Namibia in 2011 was estimated at 2,459,000 and 37% were children. Among approximately 516,390 adult women, recurrent vulvovaginal candidiasis (≥4 episodes /year) is estimated to occur in 37,390 (3003/100,000 females). Using a low international average rate of 5/100,000, we estimated 125 cases of candidemia, and 19 patients with intra-abdominal candidiasis. Among survivors of pulmonary tuberculosis (TB) in Namibia 2017, 112 new cases of chronic pulmonary aspergillosis (CPA) are likely, a prevalence of 354 post-TB and a total prevalence estimate of 453 CPA patients in all. Asthma affects 11.2% of adults, 178,483 people, and so allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) were estimated in approximately 179/100,000 and 237/100,000 people, respectively. Invasive aspergillosis (IA) is estimated to affect 15 patients following leukaemia therapy, and an estimated 0.13% patients admitted to hospital with chronic obstructive pulmonary disease (COPD) (259) and 4% of HIV-related deaths (108) — a total of 383 people. The total HIV-infected population is estimated at 200,000, with 32,371 not on antiretroviral therapy (ART). Among HIV-infected patients, 543 cases of cryptococcal meningitis and 836 cases of Pneumocystis pneumonia are estimated each year. Tinea capitis infections were estimated at 53,784 cases, and mucormycosis at five cases. Data were missing for fungal keratitis and skin neglected fungal tropical diseases such as mycetoma. The present study indicates that approximately 5% of the Namibian population is affected by fungal infections. This study is not an epidemiological study—it illustrates estimates based on assumptions derived from similar studies. The estimates are incomplete and need further epidemiological and diagnostic studies to corroborate, amend them, and improve the diagnosis and management of these diseases.

Burden of fungal asthma in Africa: A systematic review and meta-analysis

BACKGROUND

Asthma is one of the neglected diseases in Africa with a high prevalence. Allergic fungal diseases have been reported to complicate asthma progression and treatment outcomes. However, data about fungal asthma and its associated complications are limited in Africa. We aimed to estimate the burden of fungal asthma among adults and children in Africa using a systematic review.

METHODS

We first engaged the Institute for Health Metrics and Evaluation (IHME) to highlight the trend in morbidity and mortality attributed to asthma in Africa. We then searched PubMed, HINARI and Google Scholar for all studies of any design focusing on fungal asthma in any African country. Languages were restricted to English and French, but not year of publication. We estimated the weighted prevalence of allergic fungal infections among asthmatics with a 95% CI and pooled the results using a random effects model. This study is registered with PROSPERO, number CRD42019117319.

RESULTS

The IHME data showed that there has been a gradual increase in morbidity and mortality due to asthma in African adults with a prevalence of 4%. Our search retrieved 5233 citations. We retained 20 studies that met our selection criteria. These were from 13 African countries published between 1967 and 2018. There were eight cross-sectional studies and twelve review articles. The average asthma prevalence in Africa was 6% from these studies. The prevalence of fungal sensitisation was relatively high (3-52%) in the asthmatic population with an average of 28% and a pooled estimate of 23.3%, mostly due to Aspergillus species. Prevalence of Allergic bronchopulmonary apsergillosis was estimated at 1.6-21.2%. Diagnosis of fungal allergy was mostly made by skin prick tests. There was no data on the use of medication to manage fungal asthma. None of the studies evaluated the association between fungal allergy and asthma severity. Data were lacking in children.

CONCLUSION

There is a high prevalence of fungal sensitization among Africans with asthma. Fungal asthma is a significant problem in Africa but there remains a paucity of data on the epidemiology and associated complications. There is urgent need for national epidemiological studies to estimate the actual burden of fungal asthma in Africa.

Estimated Burden of Serious Fungal Infections in Ghana

Fungal infections are increasingly becoming common and yet often neglected in developing countries. Information on the burden of these infections is important for improved patient outcomes. The burden of serious fungal infections in Ghana is unknown. We aimed to estimate this burden. Using local, regional, or global data and estimates of population and at-risk groups, deterministic modelling was employed to estimate national incidence or prevalence. Our study revealed that about 4% of Ghanaians suffer from serious fungal infections yearly, with over 35,000 affected by life-threatening invasive fungal infections. Incidence of cryptococcal meningitis, Pneumocystis jirovecii pneumonia, and disseminated histoplasmosis cases in AIDS was estimated at 6275, 12,610 and 724, respectively. Oral and esophageal candidiasis collectively affect 27,100 Ghanaians and 42,653 adult asthmatics are estimated to have fungal asthma. We estimate a prevalence of 12,620 cases of chronic pulmonary aspergillosis (CPA and an incidence of 1254 cases of invasive aspergillosis (IA). Estimated cases of candidemia and candida peritonitis cases were 1446 and 217, respectively. The estimated prevalence of recurrent vulvovaginal candidiasis (RVVC) and tinea capitis was 442,621 and 598,840, respectively. Mucormycosis and fungal keratitis each may affect 58 and 810 Ghanaians. These data highlight the urgent need for intensified awareness to improve diagnosis and management.

Candida albicans-induced acute lung injury through activating several inflammatory signaling pathways in mice

Candida albicans infection-induced acute lung injury is one of the most prevalent diseases in immunosuppressive individual. Nevertheless, the mechanism by which Candida albicans induced acute lung injury remains unclear. The present study investigated the mechanism by which Candida albicans induced acute lung injury in mice. Mice were randomly divided into four groups and intratracheally injected with 60 μl Candida albicans (10⁶ CFU) or normal saline. Half of the mice were sacrificed at 6 h after Candida albicans. The rest of the mice for survival test were observed until 7 d after Candida albicans. As expected, immunosuppression aggravated Candida albicans-induced acute lung injury and death in mice. Additionally, Candida albicans infection elevated mRNA levels of pro-inflammatory and chemokines in lungs and the levels of IL-6, IL-1β and IL-17 in serum. Further study showed that Candida albicans promoted nuclear translocation of NF-κB p50 and p65 subunits in pulmonary epithelial cells and interstitial cells. Candida albicans induced pulmonary p38, ERK1/2 and Akt phosphorylation in normal and immunosuppressive mice. Moreover, Candida albicans infection activated pulmonary STAT3 signaling in normal and immunosuppressive mice. Overall, these results suggest that Candida albicans induced acute lung injury and death may be through activating several inflammatory signaling pathways.

Global Epidemiology of Mucormycosis

Mucormycosis is an angio-invasive fungal infection, associated with high morbidity and mortality. A change in the epidemiology of mucormycosis has been observed in recent years with the rise in incidence, new causative agents and susceptible population. The rise has been perceived globally, but it is very high in the Asian continent. Though diabetes mellitus overshadow all other risk factors in Asia, post-tuberculosis and chronic renal failure have emerged as new risk groups. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis in patients with haematological malignancy and transplant recipients. In immunocompetent hosts, cutaneous mucormycosis is commonly seen following trauma. The intriguing clinical entity, isolated renal mucormycosis in immunocompetent patients is only reported from China and India. A new clinical entity, indolent mucormycosis in nasal sinuses, is recently recognized. The causative agents of mucormycosis vary across different geographic locations. Though Rhizopusarrhizus is the most common agent isolated worldwide, Apophysomycesvariabilis is predominant in Asia and Lichtheimia species in Europe. The new causative agents, Rhizopus homothallicus, Mucor irregularis, and Thamnostylum lucknowense are reported from Asia. In conclusion, with the change in epidemiology of mucormycosis country-wise studies are warranted to estimate disease burden in different risk groups, analyse the clinical disease pattern and identify the new etiological agents.