Candida fungi: diagnosis and medical treatment

2021-07-23 11:37 PM

Candida fungi that cause disease in humans are mainly Candida albicans, a symbiotic fungus, usually residing in the skin, mucous membranes of the mouth, intestines, and vagina.

Candida refers to the range of infections caused by species of the fungus Candida; These infections can be acute or chronic, local or systemic. Disseminated candidiasis is life-threatening. The majority of candidiasis is caused by Candida albicans. C. Albicans is a reviving organism common in the oropharynx, gastrointestinal tract, and vaginal cavity of humans but capable of causing opportunistic infections following disruption of the normal system, breach of the mucosal cell barrier. C. Albicans can be detected as normal microbiota in about 50 percent of individuals.

Candida includes about 200 species. They can be found among humans and other mammals, birds, insects, arthropods, fish, animal waste, plants, fungi, naturally high sugar substrates (eg. , honey, nectar, grapes) and fermentation products, dairy products, soil, freshwater, seawater and on airborne particles.

Human infection was first described as thrush by Hippocrates in the fifth century BC. In 1853, Charles Robin microscopically observed budding cells and filaments in epithelial scrapes, and he named this fungus Oidium albicans. Subsequently, more than 160 synonyms, including Monilia albicans, were used before Candida albicans became the accepted name for the species.

At least 30 species of Candida have caused infections in humans. The most common of these are C. albicans, C. glabrata, C. krusei, C. parapsilosis and C. tropical. C. parapsilosis has been recognized as a heterogeneous species, and it has been proposed that it be divided into three morphologically and physiologically indistinguishable species: C. parapsilosis, C. metapsilosis and C. orthopsis . Phylogenetic analyzes show that C. glabrata is more closely related to Saccharomyces cerevisiae than to C. albicans, and future taxonomic modifications are possible.

Candida fungi that cause disease in humans are mainly Candida albicans, a symbiotic fungus, usually residing in the skin, mucous membranes of the mouth, intestines, and vagina. Candidiasis often occurs when the patient has a weakened immune system (such as young children, pregnant women, antibiotic use, prolonged use of corticosteroids, diabetes, especially people with HIV/AIDS). . In these people, the disease often recurs persistently, or recurs, causing discomfort and great impact on health.

Candida fungi often cause disease in the skin and mucous membranes, in the form of oral thrush, vulvovaginitis, vaginitis, periostitis... The disease can spread through the bloodstream, which can cause damage to other organs such as kidneys, spleen, lungs, liver, eyes, meninges, brain, or around the heart valve. Intravenous drug use, vascular catheterization, and parenteral nutrition are all factors involved in the entry of Candida into the bloodstream and cause of bacteremia.

Clinical symptoms

Oral candidiasis

Thrush is sporadic or banded together as white patches on the lining of the mouth and throat, usually painless.

Throat examination revealed many spots or clusters of white, spongy, mushy, flaky pseudomembranous tissue on the tongue, gums, inner cheeks, nasopharynx, anterior tonsils, and posterior walls of the throat.

Diagnosis is mainly clinical. Fungal culture should only be performed when clinical evidence is atypical, or treatment is unsuccessful.

Esophageal Candida

Common in HIV-infected people with severe immunodeficiency (CD4 < 100/mm3).

Characteristic signs are dysphagia and pain behind the sternum.

Diagnosis is mainly clinical. Esophageal endoscopy typically shows white patches along and around the esophagus.

Genitourinary Candida

Common in women.

Patients have symptoms of itching, burning in the external genitalia, The discharge forms white patches like whey.

Vulva-vaginal redness, swelling, and painful urination.

The disease is recurrent.

Candida infection in blood

Fever.

Manifestations of infection and intoxication.

Enlarged liver and spleen.

May present with endocarditis, retinitis, pneumonia.

Test:

Blood culture.

Microscopically for fungi or classified cultures: if clinical atypical or ineffective treatment.

Subclinical

Candidiasis of the skin and mucous membranes: testing is not required.

Esophagoscopy in patients with esophagitis unresponsive to antifungal therapy and in need of differential diagnosis from esophagitis of other etiologies (Herpes, Cytomegalovirus, aphthous ulcers).

Echocardiography in suspected Candida endocarditis; corresponding tests for suspected meningitis, arthritis, and fungal urinary tract infections.

Differential diagnosis

Throat thrush should be distinguished from diphtheria and hairy leukoplakia:

Diphtheria: common disease in unvaccinated children; pseudomembranous, sticky, difficult to peel off; have diphtheria epidemiological factors.

Tongue hairy leukoplakia: lesions are grooves on both sides of the tongue, difficult to peel.

Esophageal thrush requires a differential diagnosis from Herpes simplex (HSV) or Cytomegalovirus (CMV) esophagitis.

Vaginal thrush should be differentiated from genital infections of other etiologies. In these diseases II, vaginal discharge may be purulent, often with a foul odor; Patients rarely experience itching as in Candida vaginitis.

Sepsis is difficult to distinguish from sepsis of other etiologies, which can only be confirmed by blood culture.

Definite diagnosis

Diagnosis of skin and mucosal candidiasis (thrush, esophageal, vaginal candidiasis) is mainly based on clinical evidence; Test and culture only when the patient does not get better after 5-7 days of antifungal therapy, is suspected of resistant Candida, or the disease is caused by other etiologies.

Blood culture isolates the causative fungus when a fungal infection is suspected.

Treatment

Oral candidiasis

Fluconazole 100-150mg/day x 7 days; or

Ketoconazole 200mg twice daily for 7 days.

Esophageal Candida

If the patient is able to drink, use oral medication:

Fluconazole 200-300mg/day x 14 days, or

itraconazole 400mg/day x 14 days; or

Ketoconazole 200mg 2 times/day x 14 days.

If the patient is unable to swallow, a nasogastric tube can be inserted, and the patient is given the above medication. If the patient's condition is too severe: use amphotericin B at a dose of 0.3mg/kg/day intravenously.

Nutritional support for patients: feeding through a catheter; local and systemic pain relief.

Genitourinary Candida

Fluconazole 150-200mg orally as a single dose; if the patient is severely immunocompromised, use higher doses and longer duration, or

Itraconazole 100mg orally 2 tablets/day x 3 consecutive days; or:

Clotrimazol 100mg or miconazole 100mg vaginally 1 tablet/day for 3-7 days, or:

Clotrimazol 500mg 1 time, nystatin 100,000 units, vaginal 1 tablet / day x 14 days.

Candida bacteremia

Amphotericin B intravenously, 0.5-1.0mg/kg/day x 2 weeks.

If the patient cannot tolerate amphotericin B, administer fluconazole 200-400 mg/day intravenously.

Pay attention to the removal of infectious agents such as catheters, treatment of existing diseases.

Prevention

Strengthen body immunity. Hygiene of the body, especially the genitals in women.

Eliminate factors that favor fungal growth such as discontinuing interventions such as catheterization and hospital-acquired infections.

For HIV/AIDS patients, early treatment and good adherence to antiretroviral drugs is required.

Prophylactic fluconazole can be used in severely immunocompromised patients.