Measles (Latin Morbilli.) – An acute infectious viral disease with high sensitivity (index of contagiousness is close to 100%), which is characterized by high fever (up to 40,5 ° C), inflammation of the oral mucous membranes and upper respiratory tract, conjunctivitis, and characteristic maculopapular rash of the skin, general intoxication does doxycycline work.
Measles is known since ancient times. His detailed clinical description is made Arab physician Rhazes (IX century), the British Sidnem T. and R. Morton (XVII century). Since the XVIII century, measles is treated as an independent nosology. The viral etiology of the disease proved A. Anderson and D. Goldberger (1911). Pathogen isolated D. Enders and TK Peebles (1954). Effective seroprevention measles developed Degkvitts R. (1916-1920). Live vaccines used since 1967 for routine vaccination, developed an AA Smorodintsev et al. (1960).
What Causes / Causes Corey
Measles is caused by an RNA virus genus morbilliviruses paramyxovirus family, has a spherical shape and a diameter of 120-230 nm. It consists of a nucleocapsid – RNA helix plus three proteins and an outer shell formed by the matrix proteins (surface glycoprotein) of two types – one hemagglutinin and one “dumbbell” protein.
All known strains belong to the same serovar; antigenic structure similar to pathogens parainfluenza and mumps. The most important antigens – hemagglutinin, hemolysin, nucleocapsid and a membrane protein.
Maloustoychiv virus in the environment, dies quickly outside the body from exposure to various chemical and physical factors (irradiation, boiling, treatment with disinfectant). At room temperature, it preserves the activity of about 1-2 days at a low temperature – within a few weeks. The optimum temperature for preservation of the virus – (-15) – (- 20) ° C.
Despite the instability to the impact of the external environment there are cases of the virus over long distances with the air current on the ventilation system – in the cold season in one particular building. Attenuated strains of measles virus used for the production of live measles vaccine.
Pathogenesis (what’s going on?) During Cory
Way measles transmission – airborne virus released into the environment in large quantities sick man with mucus during coughing, sneezing, etc…
The source of infection – patients with measles in any form that is contagious to others with the last days of the incubation period (last 2 days) before the 4th day of rash. On the 5th day of rash the patient is considered to be non-contagious.
Measles suffer mostly children aged 2-5 years and much less adults do not recover from the disease in childhood. Newborn babies have colostral immunity transmitted to them from their mothers if they had been ill with measles earlier. This immunity lasts the first 3 months of life. There are cases of congenital measles when transplacental infection of the fetus virus from the sick mother.
After this illness develops a strong immunity, repeated human measles, without concomitant diseases of the immune system, it is doubtful, although such cases are described. Most cases of measles occur in winter and spring (December-May) period with the rise of incidence every 2-4 years.
Currently, in the countries conductive total measles vaccine, the disease occurs as sporadic cases or mini-epidemic.
Infection atriums are the mucous membranes of the upper respiratory tract and possibly of the conjunctiva. After initial replication in the epithelial cells and regional lymph nodes of the pathogen enters the bloodstream, the primary viremia has been developing in the incubation period. As a result of disseminated virus, fixed in various organs and secondarily it accumulates in the cells of macrophage system. The organs (lymph nodes, tonsils, lungs, intestines, liver, spleen, bone marrow myeloid tissue) develop small inflammatory infiltrates retikuloendoteliya proliferation and the formation of polynuclear giant cells. The incubation period, the number of viruses in the body still relatively small and can be neutralized introduction of measles immunoglobulin persons in contact with patients with measles, no later than the 5th day after exposure.
With the catarrhal symptoms of the disease is the same occurrence of a second wave of viremia. The maximum concentration of virus in the blood is maintained throughout the period of catarrhal and rashes first day, and then drops sharply. By the 5 th day of lesions in the blood appear neutralizing antibody, a virus is not detected.
With a tropism to the epithelial cells of the mucous membranes and central nervous system, the virus mainly affects the upper respiratory tract (sometimes the bronchi and lungs), the conjunctiva, to a small extent the gastrointestinal tract. Inflammation develops with the appearance of giant cells in lymphoid formations of the intestine, as well as in the central nervous system, so that there is a possibility of complications such as meningitis and meningoencephalitis. Protein components of the virus, and biologically active substances that are released in response to the circulation of the virus, give catarrhal inflammation in the affected organs infectious-allergic character. Specific focal inflammatory process with an allergic reaction, degeneration of the epithelium, increased vascular permeability, perivascular infiltration and edema formation underlies enantemy Measles, Koplik spots Filatova-Belsky, on the mucous membrane of the cheeks and lips, and later exanthema.