Histoplasmosis - the deep mycosis caused by a dimorphous barmy fungus of Histoplasma capsulatum which strikes fabric macrophages of lungs, a liver, a spleen, lymph nodes, skin and mucous membranes. Among various forms of a disease the sharp histoplasmosis of lungs which is characterized by fever, breast pains, cough, weakness, a limfadenopatiya, radiological changes prevails. In diagnosis of histoplasmosis cultural, microscopic, histologic researches are used; serological reactions, allergic tests. Protivomikotichesky medicines are appointed sick histoplasmosis ( In, sodium , , etc.)
Histoplasmosis (a disease of Darling, reticuloendothelial ) – the fungal disease causing damage to system of mononuclear phagocytes and proceeding with limited or generalized manifestations. Histoplasmosis is an endemic infection for the western and southern states of the USA, the countries of Central and South America, Africa; meets in Europe and Asia less often. Single episodes of incidence of histoplasmosis in Russia are known, however brought in cases of mycosis are not excluded. Men have histoplasmosis twice more often than women, children twice more often than adults.
On a clinical current allocate histoplasmosis of lungs, extra pulmonary histoplasmosis (skin, mucous membranes, TsNS, etc. bodies) and disseminirovanny histoplasmosis. The course of pulmonary histoplasmosis can be asymptomatic, sharp (clinically expressed) and chronic. The important factor defining weight of a current and the forecast of histoplasmosis is the condition of cellular immunity. Severe disseminirovanny forms of a disease of Darling usually arise at children, elderly people, HIV-positive people, patients with leukemia and lymphoma.
The dimorphous mushroom of Histoplasma capsulatum which is the causative agent of histoplasmosis can exist in 2 forms: fabric (barmy) and mitselialny (cultural). In a human body the fabric form of the microorganism striking cages of bodies of reticuloendothelial system meets (a liver, a spleen, lymph nodes, etc.). The cultural form of a mushroom develops out of an organism, at a temperature below 30 °C and well grows on nutrient mediums. Gistoplazma it is long remain in water and in the damp soil; quickly perish under the influence of disinfectants.
As the natural tank of a fungus serves the soil polluted by a dung and excrements of the infected animals and birds (bats, dogs, cats, hens, pigeons, etc.). The favorable environment for development of mushrooms are the thrown structures and wells, caves, grottoes, hollows of old trees, conditioners and so forth. Infection of the person with histoplasmosis happens in the air and dust way at inhalation of elements of a fungus to dust particles, is frequent when carrying out construction earthwork. In risk group on incidence of histoplasmosis there are villagers, farmers, workers of poultry farms, miners, geologists, tourists, cave explorers, etc. Transfer of histoplasmosis from animals to the person or from the person to the person is excluded.
In most cases as entrance gate of an infection serve airways. Having got into bronchial tubes and alveoluses, disputes turn into a fabric form and cause development of primary center in lungs and regionarny lymph nodes. In pulmonary fabric granulematozny process from the outcome develops in a necrosis, an ulceration or , is more rare – an abstsedirovaniye. Sharp pulmonary histoplasmosis on the pathogenesis is similar to primary tuberculosis of lungs. Getting to a system blood-groove of a gistoplazma cause a sensitization of an organism and development of specific antibodies. Sometimes pathological process is limited to it that corresponds to a subclinical form of histoplasmosis. In other cases hematogenic spread of a fungal infection causes development of disseminirovanny histoplasmosis.
Due to the aerogenic way of infection in clinic of histoplasmosis the pulmonary form prevails. Primary extra pulmonary forms of a disease of Darling meet seldom; usually damage of skin, mucous membranes, intestines serve as displays of disseminirovanny histoplasmosis. The incubatory period on average lasts 7-14 days, sometimes it is less or longer (from 4 to 30 days).
At 80% of the lungs infected sharp histoplasmosis has an asymptomatic current, being found by positive results of intracutaneous tests with gistoplazminy, serological reactions, to radiological changes in lungs. At the easy course of histoplasmosis the health of patients practically does not suffer; occasionally short-term fever, Qatar of the top airways, cough which are stopped within a week disturbs. For severe forms of pulmonary histoplasmosis typically sudden beginning, high fever (to 40-41 °C) with considerable daily changes of temperature; change of oznob by diffusion sweating; severe headache, ossalgiya and mialgiya. Thorax pains, cough with a purulent phlegm, a blood spitting are characteristic; nausea, diarrhea, belly-aches are possible. The feverish period proceeds from 2 to 6 weeks then there comes the long stage of a convalescence proceeding with subfebrilitety, astenisation, decrease in working capacity.
The chronic form of histoplasmosis of lungs has the long progressing current. It is characterized by moderate fever, cough with a phlegm, radiological changes (cavities, fibrosis, multiple kaltsinata in pulmonary fabric). Histoplasmosis is quite often combined with sarkoidozy, tuberculosis, leukoses, retikuleza.
At development of sharp disseminirovanny histoplasmosis against the background of fever and the expressed general intoxication there are multiple secondary centers of a fungal infection in various bodies. Damage of skin and mucous can be shown by various rashes (makulopapulezny, hemorrhagic, furunkulopodobny rash, eritemy), ulcer stomatitis and pharyngitis, abscesses of hypodermic cellulose, ulcers of genitalia, anus cracks. Among other organ displays of disseminirovanny histoplasmosis the limfadenopatiya, an encephalomeningitis can meet, retinit, horioidit, perikardit, the infectious endocarditis, ulcer colitis, a gepatosplenomegaliya, mezadenit, peritonitis. The course of chronic disseminirovanny histoplasmosis which was more erased and sluggish, however inevitably leading to polyorgan defeats.
The course of histoplasmosis has the features at children of early age and HIV-positive people - in these cases the disease develops as disseminirovanny process. At children sharply expressed gepatoliyenalny syndrome, a generalized limfadenopatiya, damage of lungs, skin and intestines is noted. HIV-positive persons have histoplasmosis approximately in 0,5% of cases i.e. less than candidiasis or aspergillomycosis. The Kliniko-rentgenologichesky picture is characterized by limfadenopatiy, high fever, a considerable gepatosplenomegaliya, cough and infiltrates in lungs. The lethality from histoplasmosis at this category of patients reaches 80%.
Diagnosis of histoplasmosis
Recognition of histoplasmosis is a difficult task for infectiologists, pulmonologists and other experts whom patients can address. The diagnosis is confirmed by allocation of Histoplasma capsulatum from a phlegm, washing waters of bronchial tubes; at a disseminirovanny form – from blood, urine, a calla, contents of abscesses, a sternalny punktat, tserebrospinalny liquid. In favor of histoplasmosis obtaining culture of a mushroom at crops of these materials on nutrient mediums testifies. For diagnosis of histoplasmosis serological reactions (RSK, reaction of a pretsipitation and latex of agglutination), a biopsy of a bronchial tube, lymph nodes, edges of ulcers with the subsequent histologic research are also used. As the highly specific test serves intracutaneous test with gistoplazminy.
At a X-ray analysis of lungs in a sharp stage of pulmonary histoplasmosis large and sredneochagovy infiltrates are found. Further on the place of infiltrates the centers of fibrosis and a kaltsinoz are formed. At suspicion of sharp pulmonary histoplasmosis the SARS, bacterial pneumonia, atypical pneumonia, ornithosis, Ku's fever, mycoplasmosis, tuberculosis are excluded. Chronic histoplasmosis of lungs demands differentiation with pulmonary forms of deep mycoses (nokardiozy, aspergillomycosis, koktsidioidomikozy, blastomikozy), limfogranulematozy. Disseminirovanny forms of mycosis should be differentiated with sepsis and miliarny tuberculosis.
Treatment, forecast and prevention of histoplasmosis
To persons with the asymptomatic or sharp localized histoplasmosis form antifungal treatment usually is not carried out. In these cases are limited to symptomatic therapy and the all-strengthening actions. At the long course or severe forms of histoplasmosis purpose of antimycotic medicines – an itrakonazol, a ketokonazol, an amfoteritsin In, a meglyumina of sodium of a suktsinat is shown. Along with system use of antimycotics, performing medicinal inhalations is expedient. Vitamins, antihistaminic medicines, good nutrition are in addition recommended. At development of complications of histoplasmosis surgical treatment can be required (a pericardium puncture, removal of lymph nodes, a resection of lungs, prosthetics of valves of heart, etc.).
Sharp histoplasmosis of lungs quite often proceeds in an asymptomatic form and usually comes to an end favorably for the patient. Fibrosis of lungs, arthritis, a knotty eritema can be the remote consequences of chronic histoplasmosis, uveit, encephalopathy, spasms, heart failure. Disseminirovanny forms pose the greatest threat for children, elderly people, patients with HIV infection. Nonspecific prevention of histoplasmosis has to include disinfecting of the soil, decrease in dust content of air, use of respirators when carrying out earthwork.