Coccidioidomycosis

Introduction to coccidioidomycosis Coccidioidomycosis, also known as San Joaquinfever or Valleyfever. Is a disease caused by Coccidioides, often manifested as acute benign asymptomatic or self-limiting primary respiratory infection; occasionally disseminated, in the skin, subcutaneous tissue, lymph nodes, bones, liver, kidney , meninges, brain or other tissues form focal lesions. basic knowledge The proportion of sickness: 0.004% - 0.009% Susceptible people: young and middle-aged workers Mode of infection: respiratory transmission Complications: meningitis pleural effusion

The cause of coccidioidomycosis

Coccidioides is a biphasic fungus that lives in the soil and is highly infectious. It can cause skin test positive by sucking only a single spore. Humans mainly by injecting joint spores in soil or spores cultured in the laboratory. Infection, a small number may also be transmitted through pollutants.

Coccidioidomycosis prevention

There is still no way to prevent coccidioidomycosis. It is recommended that people try to avoid activities that generate a lot of dust in the environment, such as construction. If you have to work in this area, you need to take some measures, such as Wear a mouth bag or mask.

Coccidioidomycosis complications Complications meningitis pleural effusion

The infection can spread to tissues outside the respiratory tract, mainly skin, bone, joints and meninges, and there may be complications such as meningitis and pleural effusion.

Symptoms of coccidioidomycosis Common symptoms Low fever with cough, slightly... Lymph node enlargement Neutrophil increased chronic cough and cough with chest pain eosinophilia

From the culture of infected body fluids or tissue specimens, or directly in the sputum, pleural fluid, cerebrospinal fluid, draining sinus lesions, or in tissue biopsy specimens stained with silver or PAS, the detection of Coccidioides The small sphere can be diagnosed. The diameter of the intact small sphere is usually 20~80m. The thick wall is filled with small endospores (2~4m in diameter). The endospores released from the ruptured small sphere and entering the tissue can be mistaken for Budless yeast.

The complement binding assay to detect anti-coccidial IgG antibodies is still the most useful test, with serum titers 1:4 indicating the presence of current or recent infections, and higher titers (1:32) indicate that lungs are most likely to have occurred External infection, however, immunosuppressed patients may have low titers, successful treatment titers should be reduced, and complement-binding antibodies in cerebrospinal fluid can confirm the diagnosis of coccidioidomalitis, which is important because only a very small number of cases can be Positive culture.

Other antibody tests, including newer, more sensitive and specific immunological tests, cannot judge the prognosis. They are of little use. People with normal immune function usually have skin caused by coccidiostat or globular voxel within 10 to 21 days after infection. Delayed allergic reactions, but progressive disease is characteristically deficient in this response, and because the test is positive for most people in endemic areas, it is mainly used for epidemiological studies rather than for diagnosis.

Clinical features:

a. The incidence of young adults and wild workers is mostly, more men than women.

b. The disease is caused by infection with Coccidioides.

c, the primary lesions are more than 1 week to 3 weeks after the infection, sputum-like lesions, after the formation of nodules, along the lymphatic vessels, like sporotrichosis, lymphangitis and lymphadenopathy, most can self-heal .

d, secondary skin lesions occur in the nose, cheeks and scalp, etc., manifested as multiple painless nodules, central rupture, or sputum hyperplasia.

e, mucosa and all organs of the body can be affected, but generally do not involve the muscles and digestive tract, lungs, heavy can be fatal.

f, divided into primary coccidioidomycosis, and secondary coccidioidomycosis.

g, fungal microscopic examination showed that the round thick-walled spores are called spheres, which can be filled with endospores, and the fungi are cultured as biphasic bacteria.

h, coccidiostat skin test positive, serological test positive.

i, the number of blood leukocytes increased, especially the number of neutrophils increased, the number of eosinophils increased significantly, and the erythrocyte sedimentation rate continued to accelerate.

Examination of coccidioidomycosis

1, laboratory inspection

Direct microscopic examination of the fungus revealed spore-forming sporangia, fungal culture at room temperature, visible hyphae, joint spores.

2, serological examination

(1) Acid-detecting IgM is a diagnostic index for acute infection of the disease. Most patients can detect specific IgM within 4 weeks before infection, and disappear at 2 months, suggesting that the patient has developed disseminated infection.

(2) IgG antibody: increased from 4 to 12 weeks after infection, after disseminated infection, the IgG antibody continued to be positive, and the disease disappeared upon recovery.

3, histopathological examination

Primary cutaneous sporozoites are chronic granulomas. There are neutrophils, eosinophils, lymphocytes and plasma cells infiltrating, sometimes small abscesses, spore sacs containing spores inside; The sporozoite disease is an abscess formation, which can be seen in casein necrosis, and endospores can be seen in the heterogeneous giant cells.

Diagnosis and diagnosis of coccidioidomycosis

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory findings.

Differential diagnosis

Primary lung infection should be differentiated from colds, bronchial pneumonia, etc.

Secondary infection should be differentiated from tuberculosis, tumors and other fungal infections, syphilis.

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