It is a highly contagious disease transmitted through water and food containing the pathogen. Even after the fever recovered person can for many years to be a carrier of bacteria that cause typhoid fever. At untimely treatment of the disease can threaten the patient's life antibacterials in the.
Despite the fact that humanity in the last century was able to significantly reduce the number of reported cases of typhoid fever, decided to end this problem, can not be called. The likelihood of developing the disease exists, especially in countries with troubled military situation and poor hygiene standards for life. Therefore, unsanitary conditions are the main prerequisite for the spread of the disease.
Typhoid fever refers to diseases, exclusively, the human population. Infection occurs after discharge from the feces of sick people carriers and pathogens into the environment. About this they contaminate water, food, household items. Not the last value belongs to flies as external carriers of pathogenic. A healthy person can become sick after consuming infected food or after direct contact with patients.
The causative agent of typhoid fever
A pathogen that causes the occurrence of typhoid fever is a type of Salmonella - Salmonella typhi. Is a family of Gram-negative enterobacteria wand capable of propagation only in the human body. The morphological differences from other Salmonella has not. Strict aerobic, so it can only exist in a living form, does not form spores. Do not demanding on the surrounding environment and thus are well cultivated on common nutrient media. This type of Salmonella quite stable in the environment, is perfectly adapted to the low temperatures and can survive even prolonged freezing.
Not resistant to high temperatures and instantly killed by boiling. Good saves pathogenic properties in running and stagnant water and food (dairy products, vegetables, minced meat).
Typhoid Salmonella Pathogenicity is due to their antigenic structure and endotoxin. The most important of these are the surface antigen virulence (in Vi-antigen) and lipo-protein complex saccharide cell wall (endotoxin). If the first results in the ability of the pathogen to hit the organs and tissues, as well as the intensity of the immune response, the second turn on the destruction of Salmonella immune cells with a powerful release of their toxic components. Features antigen virulence of pathogens of typhoid are such that they allow him to change their antigenic properties, moving in different forms, including L-shaped, resistant to antimicrobials. This enables long-circulating pathogen, supporting the spread of the epidemic.
The life cycle of typhoid salmonella after contact with a susceptible organism can not pass without the participation of the reticular and lymphoid tissues. Therefore Atrium campaigners accumulation of lymphatic cells of the intestine (Peyer's patches) in the submucosal layer. Of these bacteria spread to mesenteric lymph nodes and into the portal circulation. The most important breeding site typhoid Salmonella becomes the liver and spleen. Over time, the immune mechanisms are able to neutralize pathogens completely, as produced by specific antibodies.
Typhoid fever must be differentiated from diseases associated with prolonged fever and development of signs of intoxication, -. Typhus, malaria, brucellosis, pneumonia, sepsis, tuberculosis, Hodgkin's disease, and others should be based on such symptoms in the clinical differential diagnosis of typhoid fever as high prolonged fever, pallor face, pain and rumbling palpation in the right iliac region, gepatolienalnyi syndrome, bradycardia, increase in the size of the language, overlaid on the center, the emergence of 8-9-day sickness sparse rozeolёznoy rash on the abdomen and the lower part of the chest, at a heavy current - the development of typhoid status. Correct diagnosis causes significant difficulties, especially in atypical forms of typhoid fever. Therefore, each case is more than 3 days duration unclear fever requires appropriate laboratory studies, including the allocation of the pathogen from the blood and faeces, identifying the pathogen antigen in the serum and stool. Getting typhoid blood culture - the absolute confirmation of the diagnosis of typhoid fever. Detection of typhoid sticks in the stool less informative.
The most reliable method for the diagnosis of typhoid fever - abjection. To conduct this seeding 10 ml of blood per 100 ml of medium containing bile (10-20% bile broth Rappaport medium). Isolation of blood culture is most effective in the first week of illness, but for diagnostic purposes a study carried out at all times of the temperature of the reaction. Crops feces (stool culture) and urine (urinokulturu) also hold in all periods of the disease, especially for 2-3 weeks. However, we must remember that typhoid coli from faeces and urine can not only identify patients with typhoid fever, but also from bacteria carriers in different fevers. Crops of feces and urine tests performed on solid nutrient media.
In addition to the bacteriological examinations from the very first days of illness can be identified typhoid O-Ar in the stool or blood serum in RSA, RLA, and the methods of ELISA and immunofluorescence microscopy.
Serological diagnosis (Phragmites in paired serum samples with erythrocyte typhoid O-diagnostic tools) is performed at the end of the first week of illness, but the minimum diagnostic titre of the AT (1: 200) for the first time can be detected in the later stages of the disease (in the 3rd week of illness). Phragmites with erythrocyte typhoid Vi-diagnosticum in patients with typhoid fever has an auxiliary value (minimum diagnostic titre 1:40). Most often, the reaction is used for the selection of persons suspected bacteriocarrier. When the credits AT 1:80 and above these individuals spend multiple bacteriological examination.