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Negeriosis: Causes, Symptoms, Diagnosis, Treatment
Last reviewed: 23.04.2024
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[Epidemiology of non-gliosis
Young people and children are most often infected with negligens, mainly when swimming in open water, swimming pools and hot tubs. Apparently, this is due to the presence of flagellate stages of development in the water, which facilitates human contact with amoebas.
Cysts of negleries can also penetrate into the nasal cavity when inhaled aerosols containing them. Negglies are widespread enough, but are more common in areas with a tropical and subtropical climate. Prior to 1985, the literature contained information on 128 cases of CNS nongeriosis in the world, of which 50 were registered in the United States.
What causes non-gliosis?
Negleria is a free living amoeba, in the life cycle of which there are 3 morphological forms: amoeboid trophozoite, flagellate stage and cyst. The sizes of trophozoites are 15-40 μm. The energetic pulsation of the contractile vacuole distinguishes it from the host cells. The core (5 μm) has an endosome. Pseudopodia transparent and broad. Like all amoebas, the cytoplasm is subdivided into ecto- and endoplasm, but neglerias have the Golgi plate complex, a pronounced endoplasmic reticulum and contractile vacuole. Cysts are round, with a smooth double wall, 10-20 microns in size.
Biology of Negeriosis
N. Fowleri is a free living amoeba that lives in freshwater reservoirs (sewage, swimming pools, thermal springs, etc.). With an increase in temperature to 35 ° C, non-gluens begin to multiply actively, and their numbers increase significantly. Part of the amoebas with sharp fluctuations in temperature and changes in pH of the environment forms two flagella and actively floats in the water column during the day, then again turns into an amoeboid form.
In the event of unfavorable conditions, amoeba are easily encysted. Unlike acanthamoeb, cysts of negleres are less resistant to drying.
Pathogenesis of non-gliosis
Infection of a person with amoebae occurs, apparently, when they get into the mouth and nose cavity with contaminated water. From the nasopharynx through the olfactory epithelium, amoebas penetrate the richly vascularized subarachnoid space, from where they spread to all parts of the brain. In the brain tissues they are localized around blood vessels and are rapidly multiplying. As a consequence, hemorrhages and necrosis occur both in the gray and white matter of the brain. Primary amoebic meningoencephalitis develops.
Symptoms of Negeriosis
The incubation period of non-gliosis lasts 2-3 days, more rarely 7-15 days. The onset of the illness is sudden. In the beginning, often there are violations of taste or olfactory sensations. Symptoms of non-gliosis appear: headaches, high fever, nausea, vomiting, convulsions. There is stiff neck. On the mucous membrane of the pharynx ulcers are often formed. Neurological symptoms of non-gliosis due to meningitis and encephalitis are revealed . Developed pulmonary edema. Soon comes a coma. In most cases, within a week after the onset of the first symptoms, patients die due to pulmonary edema and respiratory arrest. N. Fowlen, as well as acanthamoeba, can cause damage to the skin, lungs and eyes.
Complications of non-gliosis
The most formidable complication of non-gliosis is the development of meningoencephalitis as a result of dissemination of pathogens from the primary lesion on the skin or eye to the central nervous system.
Diagnosis of non-gliosis
Clinical diagnosis of non-gliosis is difficult due to the similarity of symptoms of primary amoebic brain damage with meningitis and meningoencephalitis of bacterial or viral etiology. Anamnesis data are taken into account (bathing in rich muddy water bodies with warm water, contact with sewage, etc.). The final diagnosis of primary amoebic meningoencephalitis is established microscopically when N. Fowlen is detected in the sediment of the cerebrospinal fluid or in brain biopsy specimens. They differ from surrounding cells by mobility. The culture method is also used. Nemlerii are aerobic organisms, they, like acanthamoeba, can grow on a simple agar, on which bacteria are previously sown. When water is added to the culture of negligia, flagellate forms are formed, which serves as their distinguishing feature from acanthamoebas. Differential diagnosis of negleriosis in CNS lesions is performed with encephalitis and meningitis of another etiology.
What do need to examine?
What tests are needed?
Treatment of non-gliosis
Treatment of non-gliosis is not developed. Amphotericin B is used in a dose of 0.25-1.5 mg / kg / day IV in the drip, subarachnoid or directly into the ventricles of the brain. Sometimes it is administered in combination with miconazole and (or) rifampin. Intravenous injections of sulfadiazine (0.5 g / day), levomycetin (2-4 million IU / day) are used. As symptomatic means used anticonvulsants, glucocorticoids, etc. After non-glandular meningitis, only patients who received amphotericin B. Survived.
Negeriosis has an unfavorable prognosis for CNS damage.
How to prevent nongeriosis?
Prevention of non-gliosis is to observe the rules of personal hygiene. Particular attention is paid to preventing infection during swimming in swimming pools and open water reservoirs where the water temperature is 35 ° C or more.