Epidemiological Trends and Therapeutic Strategies for Fungal Infections: A technical Report

Majedul Hoque, Iftear Kazim Rafi

^1,2Department of Pharmacy, Jahangirnagar University, Dhaka, Bangladesh

Corresponding author’s contact: +8801896301786

Abstract

Fungi are primarily opportunistic pathogens that can only enter the body if its natural defence are drastically depleted. The majority of risk factors for an invasive fungal infection cannot be avoided since they are entwined with the underlying illnesses and the therapies used to treat them. In individuals with chronic illnesses and immune-compromised patients, fungi are a significant predictor of mortality. Bangladesh has a wide range of fungi infections, and numerous studies have shown how common they are there. Although viruses and bacteria are the primary causes of these illnesses, opportunistic fungal infections in humans and animals are becoming more common on a global scale. To achieve better results, it is essential to comprehend the epidemiology, clinical characteristics, and diagnostic process of fungal infection. In this report, we examine the emergence of fungus infections as well as the clinical signs, prognosis, and care of several fungi that are widespread in our nation. It will give a brief understanding of infectious diseases and creating awareness among people.

Keywords: Infection, fungus, aspergillus, clotrimazole

1. Background: Much of the time, humans and the microbes that surround them coexist peacefully; infections only occur when the immune system is compromised or when the pathogen population reaches very high densities. The majority of infections go unnoticed, but occasionally the infecting organisms do cause the body to react, which results in clinically evident signs and symptoms, a condition known as an infectious disease. Why did fungi develop to become such potent adversaries of critically ill patients? First off, it is obvious that fungi, despite their ability to make bread rise, provide us beer and wine, and impart flavour to cheese and other foods, are mostly associated with the end of biological existence[1]. Following cardiovascular disorders, infectious diseases are the second biggest cause of death worldwide [2]. Even though fungal infectious propagules are abundant in the environment, making contact with them inevitable, fungal infections are relatively infrequent diseases in healthy and immunocompetent humans and animals compared to bacterial and viral infections [3,4]. It is believed that dermatophyte fungi are the primary cause of superficial skin, hair, and nail fungal infections in nearly one-fourth of the world’s population. A staggering 75% of women will experience at least one vulvovaginal fungal infection caused by a Candida species over their lifetime, making oral and genital mucosal fungal infections extremely prevalent[5]. 3 million cases of chronic obstructive pulmonary disease and 10 million cases of fungal-associated asthma are directly caused by Aspergillus species. Although far less frequent, invasive fungal illnesses brought on by the species of Cryptococcus, Candida, Aspergillus, and Pneumocystis are linked to extremely high fatality rates, ranging from 30% to 90%, depending on the fungus and patient group[6]. Like all other living things, fungi are recognised and classified according to their shapes, structures, and behavioural traits. Moulds (also known as hyphal fungi) are the common name for fungi that exist primarily as independent single cells and are known as yeasts for those that are founded on hyphal threads. Yeast and hyphae are almost invariably tiny cell types. A mycelium is a collection of hyphal strands, hyphal branches, and any related spore-bearing structures. Both yeast and hyphae grow vegetatively through asexual, mitotic cell division, generally as a daughter-burst from an already-existing fungal cell[7]. Numerous formerly harmless fungus species have evolved to become infectious agents as a result of climate changes brought on by anthropogenic pressure[8,9]. Globally, there are different categories into which fungal infections might be placed[10]. Opportunistic fungi prefer environments that are apart from the host organism and only accidentally breach host-immune defence barriers to spread infections [11]. Contrarily, truly pathogenic fungi depend on the host, and many obligate-pathogen species depend on the host organism for development, reproduction, and the acquisition of nutrients[12]. There are several ways for infectious pathogens to spread between people and from animals to people, including fecal-oral contact, direct or indirect contact, and vector-borne routes[12-14]. Additionally, reports about the potential transfer of fungal diseases from people to animals have been published in the literature[15]. It’s also crucial to consider the potential for silent infections and the animal carriers of fungal diseases that could serve as an ambiguous source of infection[16–18]. Thus, FIs are growing with time and turning into a major worldwide health issue with high rates of morbidity and mortality and dire socioeconomic repercussions.

2. Risk of fungal infection: The most common conditions that lead to allergic bronchopulmonary aspergillosis (ABPA) are cystic fibrosis and asthma. People who have other lung disorders like tuberculosis frequently develop aspergillomas[19]. Known also as a “fungus ball.” Chronic obstructive pulmonary disease (COPD), sarcoidosis, and tuberculosis are among the additional lung conditions that frequently coexist with chronic pulmonary aspergillosis [20]. People with compromised immune systems are more susceptible to invasive aspergillosis, such as those who have undergone organ or stem cell transplantation, are undergoing chemotherapy for cancer, or are taking high amounts of corticosteroids. Severe influenza patients admitted to hospitals have been reported to have invasive aspergillosis [21]. Patients on immunosuppressants, those getting chemotherapy for cancer, and those with persistent, incapacitating illnesses. patients who have been using tocilizumab or high dosages of steroids for a long time. COVID-19 severity cases. Patients who needed nasal prongs, a mask, or ventilator support and were on oxygen.

3. Different types of fungal infection: According to the location of the infection, the kind of virulence, and the method of acquisition, fungi infections are divided into three groups. They are further divided into four categories: superficial, cutaneous, subcutaneous, and deep, depending on the site of infection. Mycoses are referred to as “Superficial mycoses” when they merely affect the stratum corneum and do not cause inflammation. Infections of the integuments and appendages, such as the hair and nails, are known as cutaneous infections. Infection of the subcutaneous tissues occurs with subcutaneous mycoses typically at the site of traumatic inoculation. Internal organs such as the lungs, central nervous system, abdominal viscera, and bones are affected by deep mycoses. The gastrointestinal system, blood arteries, and respiratory tract are the three most typical entrance points for fungal infections. Mycoses are classified as exogenous or endogenous depending on the method of acquisition. Exogenous infections can spread by the air, the skin, or a percutaneous route. An endogenously acquired fungal infection is caused by the colonization or reactivation of a fungus from a dormant infection. Additionally, fungi can be categorized as primary or opportunistic pathogens based on their level of pathogenicity. A primary pathogen may start an infection in a host with a healthy immune system, whereas an opportunistic pathogen needs to undermine the host’s defences in order to start an infection[22].

Figure 1. several types of fungal infection with example (Source: academia)

There are over 180 different species of Aspergillus, but only about 40 of them are known to infect people. The most typical source of human Aspergillus infections is Aspergillus fumigatus. The common species A. flavus, A. terreus, and A. nigeria are also present[23]. Anywhere on the body might develop fungal skin infections. Among the most prevalent are yeast infections, jock itch, athlete’s foot, and ringworm[24].

4. Diagnosis & treatments: A doctor can diagnose athlete’s foot by looking at the skin symptoms. A small patch of skin can be scraped off and checked for the fungus if the doctor is unsure. Aspergillus is a living organism. Most individuals inhale fungal spores every day because Aspergillus, the mould (a type of fungus) that causes aspergillosis, is quite widespread both inside and outdoors[25]. Most likely, it is difficult to totally avoid inhaling Aspergillus spores. Inhaling Aspergillus is safe for those with strong immune systems. Breathing in Aspergillus spores, however, can result in an infection in the lungs or sinuses that can spread to other regions of the body in persons with compromised immune systems[26]. Diagnosis is primarily clinical but may be aided by imaging, histopathology, specimen staining,culture and Galactomannan antigen test on serum and bronchoalveolar lavage fluid.

Antifungal medications, often known as topical medications, are frequently used to treat fungi infections. These medications are applied topically to the diseased area. Creams, gels, lotions, solutions, shampoos, and creams are all examples of topical medications. Antifungal medications can also be ingested orally. In addition to drugs, people may use measures to keep the affected areas dry, such as applying powders or wearing open-toed shoes. Some available antifungal drugs are Amorolfine, Butoconazole, Butenafine, Ciclopirox, Clotrimazole, Econazole, Gentian violet, Ketoconazole, Sulconazole, Terbinafine, Terconazole, Tioconazole, Tolnaftate, Undecylenate, Oxiconazole, Miconazole, Naftifine,Voricanazole, Amphotericin B, Capsofungin etc.

5. Summary: Even if the list is limited to only those species for which there is available proof of infection, the total number of fungi that have been implicated as opportunistic human pathogens may likely approach 400 species. Fewer than 100 fungal species are close to the position of common human infections since many of the species listed would have been encountered clinically on very infrequent times, frequently only once or twice. A critical point has been reached in the epidemiology of invasive fungal diseases. Fungi have developed into a big worldwide health issue from being rare in the early 20th century when the world was beset by bacterial diseases. If these are identified and treated early, the morbidity and mortality from deep fungal infections can be effectively decreased. All indicators point to an increase in the burden of fungi-related diseases in the twenty-first century, necessitating additional funding for research into this class of infectious diseases in order to better prepare people for this epidemic.

Compliance with ethical standards

Disclosure of conflict of interest 

There is no conflict of interest regarding this paper. 

Availability of data and materials 

The data and materials used to support the findings of this study are publicly available. 

Author contribution 

All author contributed significantly to design and development of this work.

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