Fungal Infections: Meaning, Types, Examples, Treatment, Symptoms

Fungi are the organisms that are classified separately from plants and animals. They propagate by spreading spores into the air or environment. They live naturally in our body, but can also overgrow under certain conditions. Fungal infections are diseases caused by fungi. The organisms are classified under the Kingdom Fungi and have varied morphology.

This Story also Contains

1. What are Fungal Infections?
2. Classification of Fungi:
3. Types of Fungal Infections
4. Causes and Spread of Fungal Infection
5. Diagnosis of Fungal Infections
6. Treatment of Fungal Infections
7. How Can I Lower My Risk of Fungal Infections?
8. Comparison table of different Fungal diseases
9. MCQs on Fungal Infections

They are most common on the skin and nails, mouth, throat, lungs, urinary tract, and many other parts of the body. The infections look red, swollen, or bumpy. They might look like a rash or kind of a lump under the skin. Fungal infections in the nails can make them discoloured, thick or cracled. Fungal diseases are the topic of the chapter Human Health and Disease. It is a chapter in the biology subject.

What are Fungal Infections?

Mycoses, or fungal infections, are diseases produced by organisms in the kingdom Fungi that can develop in the human body and its diverse regions. These infections can be normal skin conditions or can advance to severe systemic diseases. It is significant in human health because some types of fungal infections lead to severe morbidity and, in some cases, mortality, most affecting immunocompromised patients.

Classification of Fungi:

The classification of fungi into yeasts, moulds and dimorphic fungi is based on the morphology and the mode of growth of the fungus. The classification is given below-

• Yeasts are a group of single-celled fungi with the ability to reproduce through a process called budding.

• Moulds are more complex and have branching, thread-like structures known as the hyphae.

• Dimorphic Fungi are the kind of fungus that, in some cases, may look like yeast, but under certain conditions, they can form moulds.

Types of Fungal Infections

Fungal infections can be classified into three main types: Superficial, Subcutaneous, and Systemic. Such infections, along with examples, are given below-

Superficial Fungal Infections:

These are skin, hair, and nail infections.

Tinea (Ringworm)

• Causative Agents: Sporulating fungi are: Dermatophytes such as Trichophyton, Microsporum and Epidermophyton.

• Symptoms: yellow, scaly, ring-shaped rashes.

• Diagnosis and Treatment: This is done through the conditions presented during clinical examination and through a minute examination of skin scrapings. It is cured through the use of topical antifungal drugs such as clotrimazole or oral antifungal drugs such as terbinafine

Candidiasis

• Causative Agent: These include Candida species.

• Types: Some of the common conditions include Oral thrush and vaginal yeast infection.

• Symptoms: Coatings of white in the mouth, stinging, and secretion in vaginal infections.

• Diagnosis and Treatment: Its diagnosis is done through clinical examination as well as culture; it is treated with antifungal agents such as fluconazole or nystatin.

Pityriasis Versicolor

• Causative Agent: The most common genus of yeast implicated in your skin conditions is the Malassezia species.

• Symptoms: Lesions on the skin; a change in colour of the skin or the hair.

• Diagnosis and Treatment: Through clinical examination coupled with microscopic examination, with treatment involving topical antifungal shampoos or topical creams.

Subcutaneous Fungal Infections:

These diseases run subcutaneously and infest the skin with lesions, cuts and bruises.

Sporotrichosis

• Causative Agent: Sporothrix schenckii is a thermally dimorphic fungus responsible for the disease sporotrichosis, or rose gardener’s disease.

• Mode of Transmission: by contact with plants or soil and consequent skin injuries.

• Symptoms: The clinical presentation of leprosy includes skin lesions, which are erythematous, raised patches and nodules that are predisposed to ulcerate.

• Diagnosis and Treatment: diagnosed through culture of lesion samples; managed with oral itraconazole.

Chromoblastomycosis

• Causative Agents: The important genera are Fonsecaea and Cladophialophora.

• Symptoms: Squamous epithelium tumour that evolves with time.

• Diagnosis and Treatment: Identified by biopsy and culturing; the treatment includes antifungal drugs like itraconazole and surgical intervention in cases of severe fungal infections.

Systemic Fungal Infections:

These are infections that occur in tissues and organs internal in the body and are mostly terminal in immunocompromised clients

Aspergillosis

• Causative Agent: Aspergillus species. In the case of Influenza, there is no identified Aspergillus species that causes this disease in humans.

• Risk Factors: include immunosuppression and lung diseases. Many animals are slaughtered, and their bodies are butchered to serve as food for human beings.

• Symptoms: These include the common flu symptoms such as fever, cough, chest pain, and acute breathing problems.

• Diagnosis and Treatment: Diagnosed with imaging, diagnostic cultures and serologies; treated with antifungal agents such as voriconazole.

Histoplasmosis

• Causative Agent: Histoplasma capsulatum.

• Mode of Transmission: Ingestion of contaminated dust and food, contact with contaminated water, and direct skin contact with contaminated soil.

• Symptoms: SAR-like symptoms; pneumonia-like illness.

• Diagnosis and Treatment: Diagnosed by culturing the organism, performing serological tests, and making histopathological examinations, it can be treated with itraconazole or amphotericin B in serious situations

Cryptococcosis

• Causative Agent: Cryptococcus neoformans is a yeast that is found in the environment and causes cryptococcosis. It is a fungal infection that affects people with compromised immunity and immune systems and is characterised by lung infection, the formation of cysts, and processes that lead to manifestations of the disease.

• Symptoms: These signs include headache, fever, and neck stiffness, especially those affecting the lungs and central nervous system.

• Diagnosis and Treatment: Diagnosed by a lumbar puncture- CSF sample; treated with antifungals such as amphotericin B and flucytosine.

Coccidioidomycosis (Valley Fever)

• Causative Agent: Coccidioides species;

• Symptoms: Patients present with fever, cough, fatigue and, in the severe form, disseminated disease.

• Diagnosis and Treatment: Diagnosed by serum tests and culture; Antifungal agents and drugs such as fluconazole can be used in the treatment of this skin disease.

Causes and Spread of Fungal Infection

Fungal infections occur when people come into contact with pathogenic fungi through inhalation, touching surfaces with fungus, or rigorous skin contact with surfaces through cuts and abrasions. Their reproduction occurs through spores, which are either aerial, through the soil or found on substrates.

Fungus also survives best in warm and moist conditions, such as skin folds, feet, and groin areas. Any kind of cuts, burns, or open wounds on the skin also allows fungus to enter the body and cause infection. Persons with a compromised immune system are also susceptible to fungal infection. Poor and inadequate hygiene practices can trap moisture and help in fungal growth.

Diagnosis of Fungal Infections

Fungal infections need to be diagnosed early enough to be treated. Fungal infections are diagnosed using various techniques:

• Microscopic Examination: This involved the identification of fungal elements in various samples taken.

• Culture Methods: Sub-culturing fungi from clinical specimens to the species level.

• Serological Tests: Serological testing is used to find the presence of certain fungal antigens or antibodies in the patient’s bloodstream.

• Molecular Techniques (PCR): PCR for the Identification of Fungal Genus in Clinical Specimens.

Treatment of Fungal Infections

Fungal infections are some of the most common diseases that affect people today, and it becomes important to know the cures for fungal infections. Antifungal treatment should be started immediately after the identification of the epidemiological factors and clinical signs associated with a specific fungal infection.

Medications Used:

• Oral Medication (Pills): For systemic infections (e.g., fluconazole, itraconazole ), it reduces the concentration by about 50%.

• IV Medication: Used in serious cases, for example, amphotericin B.

• Topical Treatments: For superficial infections, it is used in the form of creams, lotions, or powders.

• Mouthwash or Lozenges: In regard to oral thrush.

• Eye Drops: For fungal eye infections,

• Shampoo: In children with infections like tinea capitis

How Can I Lower My Risk of Fungal Infections?

People should follow proper hygiene practices and adopt preventive measures to lower their risk of fungal infection. The following could be followed-

• Hygiene and Sanitation Practices: Hand washing with soap; avoiding dampness in skin; dry skin.

• Avoiding Exposure: Minimising exposure of the human body to the fungal spores in high-risk areas.

• Antifungal Prophylaxis: Immunosuppressed persons.

• Public Health Strategies: Education, Map basics to enhance sanitation, Campaign

Comparison table of different Fungal diseases

The following table describes certain fungal diseases, with their causative organism, mode of transmission, symptoms, diagnosis and their treatments.

MCQs on Fungal Infections

Q1. Ringworm in humans is caused by

Option 1: Viruses

Option 2: Bacteria

Option 3: Fungi

Option 4: Nematodes

Correct answer: (3) Fungi.

Explanation:

Ringworm is a type of fungal infection with characteristics such as red or silvery ring-shaped rashes. It may affect any of the following body parts: the feet, armpits, scalp, thighs, and groin. The symptoms differ depending on the location but include:
Itchy, scaly patches that may appear as rings with raised borders.
In the groin, it manifests as red, itchy spots.
On the scalp, it can cause bald patches and inflammation.
Nail infections can cause thickened, discoloured nails.
Treatment is usually done with antifungal drugs to relieve symptoms and eradicate the infection.

Hence, the correct answer is Option (3) Fungi.

Q2. The pathogen Microsporum responsible for ringworm disease in humans belongs to the same kingdom of organisms as that of

Option 1: Taenia, a tapeworm

Option 2: Wuchereria, a filarial worm

Option 3: Rhizopus, a mould

Option 4: Ascaris, a roundworm

Correct answer: 3) Rhizopus, a mould

Explanation:

The pathogen Microsporum, known for causing ringworm in humans, is classified under the kingdom Fungi. It is a specific type of dermatophyte that affects the skin, hair, and nails, resulting in symptoms such as itchy, red, circular lesions. This genus exemplifies the nature of fungi, which are eukaryotic organisms distinct from bacteria and viruses due to their nucleated cells. The kingdom of Fungi also encompasses other notable species like Aspergillus, Candida, and Penicillium, highlighting the diversity within this distinct life domain.

Hence, the correct answer is option 3) Rhizopus, a mould

Q3. Read the following statements and select the correct option.

Statement 1: Many fungi belonging to genera Microsporum, Trichophyton, and Epidermophyton are responsible for the disease ringworm.

Statement 2: Ringworm infection is generally acquired from the soil by using towels, clothes, comb, etc. of infected individuals.

Option 1: Both statements 1 and 2 are correct.

Option 2: Statement 1 is correct but statement 2 is incorrect .

Option 3: Statement 1 is incorrect but statement 2 is correct .

Option 4: Both statements 1 and 2 are incorrect.

Correct answer: 1) Both statements 1 and 2 are correct.

Explanation:

Ringworm is caused by fungal infections, specifically by dermatophytes. These fungi thrive in warm and moist environments, which makes areas like skin folds such as those in the groin, between the toes, or under the breasts deal with their growth. Contributing factors include poor hygiene, excessive sweating, tight clothing, and damp conditions, all of which can promote the spread of these fungi.

Hence, the correct answer is option 1) Both statements 1 and 2 are correct.

Also read:

• Practice MCQs on Fungal Diseases

• Viral Diseases

• Diseases Caused by Nematodes