What is the environment for measles virus?

Answer 1

Measles virus is the causing agent for the disease. He is present in the sick man's blood and respiratory and nasal secretions and in the rash's elements. The measles virus is not present in healthy persons, because there are no human carriers with inactive measles virus.

Isolation of measles virus was done on tissue culture (human kidney, or monkey), using blood or pharyngeal secretions from patients suffering from measles.

Morphology-measles virus is a spherical particle of 120 - 128?m in diameter, with small surface projections acicular. Structurally, it contains a nucleon capsule, the RNA and an outer sheath composed of lipids, glycoprotein and polypeptides. Infectivity is related to the skin. Antigen for complement fixation is present in the nucleon capsule, and specifically stated are given coating. Unlike other related viruses, measles virus does not possess neuraminidase. There is only one antigenic type.

Resistance in the external environment and physical factors-measles virus is least resistant to the external environment, especially at high temperatures. It lasts for a few weeks in the refrigerator and several months in a frozen state at 790 C. From 150 to 370 degrees C loses half of infectivity within 2 hours. In a room with normal temperature and low humidity, resists better, but loses 50-70% of infectivity in conditions of high humidity. It is quickly destroyed by radiation. The exposure to formalin (1 / 4000) for 4 days to 370, results in virus inactivation (complete loss of infectivity). Measles virus is sensitive to any antibiotic.

The measles virus enters the human's body through the nasal and eye mucosa. Some authors have argued that the gate would only virus eye mucosa (children receptive to the measles, brought into contact with patients suffering from measles, the disease did not, if they were applied to glasses, covering the entire orbital region or if they convalescent serum ).

After penetration through the mucosal, the virus reaches the lymphoid tissue, where it multiplies (incubation period). The virus could be isolated from blood during this period. When he made the maximum number of multiplication the measles virus invades the blood and organs, causing the first symptoms of disease. Measles virus during this period isolates itself in the blood, nasal secretions and urine. In blood, measles virus is located mainly in leukocytes where it multiplies (which would explain the leucopenia and frequent changes measles cromozoms).