Candidiasis and types of Candidiasis

Candidiasis is a fungal infection caused by a group of yeasts called Candida, usually Candida albicans . Candida is a normal part of the human microbiota and is commonly found in the mouth, gut, and female genital tract. However, when there is an overgrowth of Candida, it can cause infection.

Candidiasis can affect different parts of the body, such as the mouth, throat, esophagus, vagina, skin, nails, and internal organs . Candidiasis can be classified as mucosal, cutaneous, systemic, or antibiotic-associated depending on the site and type of infection.

Candidiasis is also known as moniliasis or yeast infection . It is a common cause of vaginal infections in women and oral infections in infants and people with weakened immune systems . Candidiasis can also occur in people who use antibiotics, corticosteroids, or immunosuppressive drugs that disrupt the normal balance of microorganisms in the body .

Candidiasis can be diagnosed by microscopic examination, culture, or blood tests depending on the location and severity of the infection . Candidiasis can be treated with antifungal drugs such as clotrimazole, nystatin, fluconazole, or amphotericin B . Candidiasis can be prevented by maintaining good hygiene, nutrition, and immune function .

Candidiasis is caused by a yeast-like fungus, known as Candida, and most commonly by a specific species known as Candida albicans . Candida albicans is a fungus that naturally lives on your body, especially in the gastrointestinal tract, mouth, skin and vagina . It is one of the few species of the genus Candida that causes the human infection candidiasis, which results from an overgrowth of the fungus.

Candida albicans is a dimorphic fungus, meaning that it can exist in two different forms: yeast and hyphae (filamentous cells) . The yeast form is oval or spherical and reproduces by budding. The hyphal form is elongated and branched and can penetrate into tissues and cells. Candida albicans can switch between these forms depending on the environmental conditions and the host immune response.

Candida albicans has several virulence factors that enable it to adhere to and invade the host tissues, such as adhesins, invasins, biofilm formation, proteases, phospholipases and lipases. These factors also help the fungus to evade or resist the host immune system and antifungal drugs.

Candida albicans can cause different types of infections depending on the site of colonization and the host factors. These include mucosal candidiasis (affecting the mouth, throat, esophagus, vagina and other mucous membranes), cutaneous candidiasis (affecting the skin, nails and hair), systemic candidiasis (affecting the blood and internal organs) and antibiotic candidiasis (caused by disruption of the normal microbiota by antibiotic therapy) .

Candida albicans is not a sexually transmitted infection, but it can be transmitted through sexual contact, childbirth, breastfeeding, medical devices and nosocomial transmission . Candidiasis is more common and severe in people with weakened immune systems, such as those with HIV/AIDS, cancer, diabetes, organ transplantation or corticosteroid use .

Candida albicans is a fungus that naturally lives on your body as part of your normal microflora. However, it can also be transmitted from one person to another through various routes, such as :

• Mother-to-infant transmission through childbirth, remaining as normal microflora, unless there is an overgrowth which can result in symptomatic disease, hence candidiasis.
• Child-to-mother transmission during breastfeeding, whereby the candida on the child’s tongue/mouth binds to the breast nipples on the mother during breastfeeding.
• Sexual transmission, this form is rare but it can occur and it has been listed by CDC as a sexually transmissible disease.
• Nosocomial transmission whereby immunocompromised patients acquire the yeast from healthcare workers, from invasive devices such as catheters and respirators. They account for 10% of nosocomial bloodstream infections.

Besides these modes of transmission, Candida albicans can also overgrow and cause infection if the balance of healthy bacteria and yeast in your body is disrupted by factors such as antibiotic use, hormonal changes, diabetes, pregnancy, immune suppression, or trauma.

Candidiasis is caused by the overgrowth and invasion of Candida species, especially Candida albicans, into the host tissues and organs. The pathogenesis and pathology of candidiasis depend on the virulence factors of the fungus, the immune status of the host, and the site of infection.

Some of the virulence factors of Candida albicans include:

• The dimorphic nature of the fungus, which allows it to switch between yeast and hyphal forms depending on the environmental conditions .
• The presence of adhesins and invasins, such as Als-3 proteins, that enable it to attach and invade the host cells .
• The ability to form biofilms on various surfaces, such as medical devices, which protect it from host defenses and antifungal drugs .
• The secretion of proteases, phospholipases, and lipases, which degrade the host cell membranes and tissues .

The pathology of candidiasis varies according to the type and location of infection. Some of the common types of candidiasis are:

• Mucosal candidiasis, which affects the mucosal lining of the mouth, throat, esophagus, vagina, and gastrointestinal tract. It causes inflammation, ulceration, whitish plaques, erythema, edema, and pain in the affected areas .
• Cutaneous candidiasis, which affects the skin, nails, and hair follicles. It causes redness, itching, scaling, vesicles, pustules, abscesses, and nail deformities in the affected areas .
• Systemic candidiasis, which affects the bloodstream and internal organs such as the kidney, heart, brain, eye, liver, spleen, and bone. It causes fever, chills, hypotension, shock, organ failure, disseminated intravascular coagulation (DIC), and death in severe cases .
• Antibiotic candidiasis, which is also known as iatrogenic candidiasis. It occurs when antibiotic therapy disrupts the normal flora of the host and allows Candida to overgrow in the gut or other sites.

The local histology of cutaneous and mucocutaneous lesions is characterized by inflammatory reactions varying from pyogenic abscesses to chronic granulomas. The fungal elements can be seen as budding yeasts or pseudohyphae in tissue sections stained with Gram stain or periodic acid-Schiff (PAS) stain. The systemic lesions are characterized by microabscesses containing neutrophils and fungal elements in various organs. The fungal elements can be seen as yeasts or true hyphae in tissue sections stained with silver stain or immunohistochemistry.

Candidiasis is a fungal infection caused by a yeast (a type of fungus) called Candida. Some species of Candida can cause infection in people; the most common is Candida albicans. Candida normally lives on skin and inside the body, such as the mouth, throat, gut, and vagina, without causing problems. Candida can cause infections if it grows out of control or if it enters deep into the body. For example, it can cause infections in the bloodstream or internal organs like the kidney, heart, or brain.

Based on these virulence factors and the site of colonization of the fungal agent, candida infections (candidiasis) can be classified as follows:

• Mucosal Candidiasis affects the mucosal lining of the host such as oral candidiasis, candidal vulvovaginitis, gastrointestinal candidiasis, and respiratory candidiasis . Mucosal candidiasis can be further divided into four subtypes:

  • Acute pseudomembranous candidiasis (thrush): The classic multiple white-flecks on the tongue, buccal mucosa, and palate
  • Chronic hyperplastic candidiasis: Thick white plaques on the buccal mucosa and labial commissures
  • Acute atrophic (erythematous) candidiasis: Erythematous patches on the palate
  • Chronic atrophic (denture stomatitis) candidiasis: Erythema and edema of the denture-bearing mucosa

• Cutaneous Candidiasis affects the skin, skin pores and nails, for example, candidal folliculitis, candidid, chronic mucocutaneous candidiasis, congenital cutaneous candidiasis, diaper candidiasis, candidal onychomycosis. Cutaneous candidiasis occurs in moist, warm parts of the body such as the axillae, groin, and intergluteal or inframammary folds; it is most common in obese and diabetic individuals forming red and moist vesicles.

• Systemic Candidiasis affects the deep-seated organs and the bloodstream, for example, candidemia, a form of fungemia that causes sepsis, invasive candidiasis, chronic systemic candidiasis (hepatosplenic candidiasis). Systemic candidiasis is associated with chronic administration of corticosteroids or immune-suppressive agents, especially in persons with leukemia, lymphoma, and aplastic anemia. Candidal endocarditis can occur when there are deposition and growth of yeast and pseudohyphae on the heart valves. Systemic kidney infection can also occur associated with urinary tract infection in persons with foley catheters, diabetes, pregnancy, and antibacterial antibiotics.
• Antibiotic Candidiasis is also known as iatrogenic candidiasis. It is caused by the disruption of the normal microbiota by antibiotic therapy, which allows Candida to overgrow and cause infection. Antibiotic candidiasis can affect any part of the body where Candida normally lives.

Candida albicans is a dimorphic fungus that can exist as both yeast and hyphal forms. The yeast form is the predominant mode of growth in the human body, where it colonizes various mucosal surfaces such as the mouth, throat, vagina and gut. The hyphal form is more invasive and can penetrate into tissues and blood vessels, causing systemic infections.

The disease cycle of Candida albicans depends on several factors, such as the host immune status, the presence of other microorganisms, the availability of nutrients and oxygen, and the environmental conditions. The following steps describe a general overview of how Candida albicans can cause infection:

• Candida albicans can be acquired from different sources, such as mother-to-infant transmission during childbirth or breastfeeding, sexual transmission, nosocomial transmission through contaminated medical devices or healthcare workers, or endogenous overgrowth due to disruption of the normal microbiota by antibiotics or other factors.
• Candida albicans adheres to the epithelial cells of the mucosal surfaces using various adhesins and invasins, such as Als-3 proteins. It also forms biofilms that protect it from host defenses and antifungal drugs.
• Candida albicans secretes enzymes such as proteases, phospholipases and lipases that degrade the host tissues and facilitate its invasion. It also switches from yeast to hyphal form in response to various stimuli, such as pH, temperature, serum and carbon dioxide. The hyphal form has more virulence factors and can penetrate deeper into the tissues and blood vessels.
• Candida albicans disseminates through the bloodstream or lymphatic system to various organs, such as the kidney, heart, brain and eye. It can also form abscesses or granulomas in the tissues. It causes inflammation and tissue damage by triggering host immune responses, such as cytokine production, complement activation and neutrophil recruitment.
• Candida albicans can evade host immune responses by various mechanisms, such as changing its surface antigens, hiding within host cells or biofilms, modulating host cell signaling pathways, or inducing immunosuppression or tolerance. It can also develop resistance to antifungal drugs by altering its cell wall or membrane composition, effluxing drugs out of the cell, or mutating drug targets.

The disease cycle of Candida albicans can be interrupted by various interventions, such as:

• Maintaining a healthy lifestyle and immune system that can prevent or control Candida overgrowth.
• Practicing good hygiene and avoiding contact with infected individuals or contaminated objects.
• Using antifungal drugs or natural remedies that can inhibit Candida growth or kill it.
• Restoring the normal microbiota balance by using probiotics or prebiotics that can compete with Candida for nutrients and space.

The following diagram illustrates the disease cycle of Candida albicans:

\begin{tikzpicture}
\node (acquire) {Acquire Candida albicans};
\node (adhere) {Adhere to mucosal surfaces};
\node (secrete) {Secrete enzymes};
\node (switch) {Switch to hyphal form};
\node (invade) {Invade tissues and blood vessels};
\node (disseminate) {Disseminate to organs};
\node (inflame) {Inflame and damage tissues};
\node (evade) {Evade immune responses};
\node (resist) {Resist antifungal drugs};
\draw (acquire) -- (adhere);
\draw (adhere) -- (secrete);
\draw (secrete) -- (switch);
\draw (switch) -- (invade);
\draw (invade) -- (disseminate);
\draw (disseminate) -- (inflame);
\draw (inflame) -- (evade);
\draw (evade) -- (resist);
\draw (resist) -| (acquire);
\end{tikzpicture}

Candidiasis can cause various symptoms depending on the site and type of infection. Some of the common clinical manifestations are:

• Oral candidiasis or thrush is a fungal infection of the mouth and throat that causes creamy white lesions on the tongue, inner cheeks, palate, gums, and lips. It can also cause soreness, burning, pain, and difficulty swallowing. Oral candidiasis is more common in infants, elderly, people with dentures, diabetes, dry mouth, or weakened immune systems.
• Vaginal candidiasis or yeast infection is a fungal infection of the vagina and vulva that causes itching, irritation, burning, redness, swelling, pain, and thick white discharge. It can also cause dyspareunia (pain during sex) and dysuria (pain during urination). Vaginal candidiasis is more common in women who are pregnant, diabetic, using antibiotics or hormonal contraceptives, or have a history of sexual transmission.
• Cutaneous candidiasis is a fungal infection of the skin, nails, and hair follicles that causes redness, itching, scaling, cracking, and blistering. It can also cause nail deformity and loss. Cutaneous candidiasis is more common in areas that are moist and warm, such as the armpits, groin, under the breasts, and between the fingers and toes. It can also occur in people who have burns, wounds, diabetes, obesity, or compromised skin barriers.
• Systemic candidiasis is a serious and potentially life-threatening fungal infection that spreads through the bloodstream to various organs such as the kidneys, heart, brain, eyes, bones, and joints. It can cause fever, chills, shock, organ failure, and death. Systemic candidiasis is more common in people who have weakened immune systems due to conditions such as HIV/AIDS, cancer, leukemia, lymphoma, or organ transplantation. It can also occur in people who have invasive medical devices such as catheters, intravenous lines, or artificial heart valves.
• Chronic mucocutaneous candidiasis is a rare and complex disorder that causes persistent and recurrent fungal infections of the skin and mucous membranes. It can affect any part of the body but usually involves the mouth, nose, ears, scalp, nails, and genitals. It can cause disfiguring lesions that are resistant to treatment. Chronic mucocutaneous candidiasis is associated with genetic defects in the immune system that impair the ability to fight Candida infections.

Candidiasis can affect different parts of the body, such as the mouth, throat, vagina, skin, and blood. Therefore, different types of specimens and tests may be needed to confirm the diagnosis. Some of the common methods for laboratory diagnosis of candidiasis are:

• Microscopic examination: This involves taking a sample of the affected area, such as a swab from the mouth or vagina, a scraping from the skin or nail, a biopsy from the tissue, or a centrifuged spinal fluid. The sample is then stained with Gram stain or KOH (potassium hydroxide) and examined under a microscope for the presence of yeast cells and pseudohyphae (branching filaments) of Candida albicans . This method is quick and inexpensive, but it may not be very sensitive or specific.

• Culture: This involves growing the sample on a special medium that supports the growth of fungi, such as Sabouraud dextrose agar or CHROMagar Candida. The culture is incubated at room temperature or 37°C for several days and then observed for the appearance and color of the colonies. Candida albicans usually produces white to cream-colored colonies that may form chlamydospores (thick-walled spores) or germ tubes (short projections) when exposed to certain conditions . This method is more sensitive and specific than microscopic examination, but it takes longer and requires skilled personnel.

• Serological tests: These involve detecting antibodies or antigens in the blood or other body fluids that are produced in response to Candida infection. For example, latex agglutination test can detect Candida mannan antigen in serum or cerebrospinal fluid. Enzyme-linked immunosorbent assay (ELISA) can measure Candida-specific IgG or IgM antibodies in serum. These tests can help diagnose systemic candidiasis, but they may not be very reliable or accurate.

• Molecular tests: These involve using techniques such as polymerase chain reaction (PCR) or DNA sequencing to identify the genetic material of Candida species in the sample. These tests can provide rapid and accurate identification of Candida species, especially those that are difficult to distinguish by culture or microscopy. However, these tests are expensive and require specialized equipment and expertise.

Depending on the type and severity of candidiasis, your doctor may use one or more of these methods to confirm the diagnosis and guide the treatment. It is important to get a proper diagnosis of candidiasis because it can cause serious complications if left untreated.

Candidiasis is treated with antifungal drugs that target the yeast cells and prevent them from growing and spreading. The choice of antifungal drug depends on the type, location, and severity of the infection, as well as the patient`s medical history and immune status.

Some of the common antifungal drugs used for candidiasis are:

• Clotrimazole: A topical cream or lozenge that is applied to the affected area of the skin, mouth, or vagina. It is effective for mild to moderate cases of cutaneous, oral, and vaginal candidiasis.
• Nystatin: A topical or oral suspension that is used to treat oral and intestinal candidiasis. It is also available as a vaginal tablet or cream for vaginal candidiasis. Nystatin works by binding to the fungal cell membrane and disrupting its integrity.
• Fluconazole: An oral or intravenous drug that is used to treat various types of candidiasis, including esophageal, systemic, and invasive infections. Fluconazole belongs to a class of drugs called azoles, which inhibit the synthesis of ergosterol, a vital component of the fungal cell membrane.
• Voriconazole: An oral or intravenous drug that is used to treat severe or resistant cases of candidiasis, especially those caused by Candida species other than Candida albicans. Voriconazole is also an azole antifungal that interferes with ergosterol synthesis.
• Amphotericin B: An intravenous drug that is used to treat life-threatening or disseminated candidiasis. Amphotericin B binds to ergosterol and creates pores in the fungal cell membrane, leading to cell death. Amphotericin B has serious side effects and is usually reserved for patients who do not respond to other antifungals.
• Echinocandins: A class of intravenous drugs that include anidulafungin, caspofungin, and micafungin. They are used to treat invasive candidiasis, especially in immunocompromised patients. Echinocandins inhibit the synthesis of beta-glucan, a major component of the fungal cell wall.

The duration and dosage of antifungal treatment depend on the type and severity of the infection, as well as the patient`s response and tolerance. Some infections may require a single dose, while others may require several weeks or months of therapy. Antifungal treatment should be continued until the symptoms resolve and the fungal culture is negative.

Antifungal drugs may have some side effects, such as nausea, vomiting, diarrhea, headache, rash, liver toxicity, kidney damage, allergic reactions, and drug interactions. Therefore, patients should inform their doctor about any medical conditions or medications they are taking before starting antifungal treatment. Patients should also follow their doctor`s instructions and report any adverse effects or signs of worsening infection.

Antifungal treatment may not be enough to cure candidiasis if there are underlying factors that predispose the patient to recurrent or chronic infections. These factors may include diabetes mellitus, HIV/AIDS, cancer chemotherapy, corticosteroid use, antibiotic use, pregnancy, hormonal imbalance, poor hygiene, or wearing tight-fitting clothing. Therefore, patients should also address these factors and adopt preventive measures to reduce the risk of candidiasis.

Some preventive measures include:

• Maintaining good oral hygiene by brushing teeth twice a day and flossing daily.
• Rinsing mouth with water or saltwater after eating or drinking sugary or acidic foods or beverages.
• Avoiding smoking or chewing tobacco.
• Eating a balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats.
• Avoiding excessive intake of sugar, alcohol, caffeine, and processed foods.
• Drinking plenty of water to stay hydrated and flush out toxins.
• Taking probiotics or yogurt with live cultures to restore the balance of healthy bacteria in the gut and vagina.
• Wearing loose-fitting cotton underwear and changing it daily.
• Avoiding douching or using scented feminine products that may irritate or alter the vaginal pH.
• Practicing safe sex by using condoms and avoiding multiple partners.
• Seeking medical attention promptly if there are any signs or symptoms of candidiasis.

Candidiasis is a common fungal infection that can affect various parts of the body. It can be treated with antifungal drugs that target the yeast cells and prevent them from growing and spreading. However, antifungal treatment may not be enough to cure candidiasis if there are underlying factors that predispose the patient to recurrent or chronic infections. Therefore, patients should also address these factors and adopt preventive measures to reduce the risk of candidiasis.

Candidiasis is a fungal infection caused by an overgrowth of Candida, a type of yeast that normally lives in the body without causing any problems. Candidiasis can affect various parts of the body, such as the mouth, throat, esophagus, skin, vagina, and bloodstream. Candidiasis can be prevented and controlled by following some simple measures:

• Maintain good physical and oral hygiene. Brush your teeth at least twice a day, floss regularly, and rinse your mouth with water or mouthwash after eating or drinking. Avoid sharing toothbrushes, dentures, or oral appliances with others. Keep your skin clean and dry, especially in areas where yeast can grow, such as the armpits, groin, and under the breasts. Change your underwear and socks daily and avoid wearing tight-fitting or synthetic clothing that traps moisture. Wash your hands frequently with soap and water or use an alcohol-based hand sanitizer.

• Minimize unhealthy foods from your diet like refined carbohydrates and sugar. These foods can feed the yeast and promote its growth. Instead, eat a balanced diet that includes plenty of fruits, vegetables, whole grains, lean proteins, healthy fats, and probiotics (such as yogurt or kefir) that can help restore the normal balance of bacteria in your gut.

• Manage your stress. Stress can weaken your immune system and make you more susceptible to infections. Try to find healthy ways to cope with stress, such as exercise, meditation, relaxation techniques, hobbies, or social support.

• Treat current medical conditions like diabetes, cancer or HIV. These conditions can impair your immune system and increase your risk of candidiasis. Follow your doctor`s advice on how to manage your condition and take your medications as prescribed. If you have diabetes, monitor your blood sugar levels regularly and keep them under control.

• Talk with your healthcare provider about current medications you are taking that might cause candidiasis as a side effect. Some medications, such as antibiotics, corticosteroids, birth control pills, and chemotherapy drugs, can disrupt the normal balance of microorganisms in your body and allow Candida to grow. If you need to take these medications, ask your doctor if you can also take antifungal drugs to prevent or treat candidiasis.

• Be a safe patient. If you are hospitalized or have a medical procedure that involves invasive devices such as catheters or respirators, be aware of the risk of nosocomial candidiasis (candidiasis acquired in a healthcare setting). Ask your healthcare provider if you need a central venous catheter (central line) and how long it should stay in place. Tell your doctor if the skin around the catheter becomes red or painful. Make sure everyone who touches you cleans their hands before and after contact. Washing hands can prevent the spread of germs.

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