Transmission of Influenza Virus-Influenza virus shedding (the time during which a person can transmit the virus to others) beginning one day before symptoms appear and the virus will be released for between 5 to 7 days, although some people may shed virus for a longer period. People who contract influenza are most invective between the second and third days after infection. The amount of virus shed appears to correlate with fever, the amount of virus shed when temperatures are highest. Children are much more infectious than adults and shed virus before they develop symptoms until two weeks after infection. The transmission of influenza can be modeled mathematically, which helps predict how the virus will spread in a population.
Influenza can spread in three main ways:
a. through direct transmission (when an infected person sneezes, there are nasal mucous that enter directly in the eyes, nose, and mouth of another person);
b. through the air (when someone inhales the aerosols (small liquid grains in the air) that is produced when an infected person coughs, sneezes, or spits), and
c. through transmission of hand-to-eye, hand-to-nose, or hand-to-mouth, either from contaminated surfaces or from direct personal contact such as shaking hands.
The most important modes of transmission is still unclear, but they all contribute to the spread of the virus. On the route of transmission of the air, the size of the droplets that are small enough to be inhaled 0.5 to 5 μm in diameter and inhalation of droplets may be enough to cause infection. Although one sneeze can release up to 40,000 droplets most of these droplets are quite large and will disappear from the air quickly. How long can influenza virus can survive in the air droplets seems to be influenced by the levels of moisture and ultraviolet radiation: low humidity and lack of sunlight in winter aiding its survival.
Because the influenza virus can survive outside the body, the virus can also be transmitted by contaminated surfaces such as banknotes, doorknobs, light switches, and objects other households. The length of time the virus can survive on a variety of surfaces, the virus can survive for one or two days on hard surfaces and non-porous such as plastic or metal, for approximately fifteen minutes on a dry tissue paper, and only five minutes on the skin. However, if the virus found in mucous / slime, mucus so it can protect the virus to survive for a long time (up to 17 days on banknotes Bird flu virus can survive in the unknown while in a frozen state). Virus inactivated by heating to 56 ° C (133 ° F) for a minimum of 60 minutes, and also by acid (pH <2).
Influenza can spread in three main ways:
a. through direct transmission (when an infected person sneezes, there are nasal mucous that enter directly in the eyes, nose, and mouth of another person);
b. through the air (when someone inhales the aerosols (small liquid grains in the air) that is produced when an infected person coughs, sneezes, or spits), and
c. through transmission of hand-to-eye, hand-to-nose, or hand-to-mouth, either from contaminated surfaces or from direct personal contact such as shaking hands.
The most important modes of transmission is still unclear, but they all contribute to the spread of the virus. On the route of transmission of the air, the size of the droplets that are small enough to be inhaled 0.5 to 5 μm in diameter and inhalation of droplets may be enough to cause infection. Although one sneeze can release up to 40,000 droplets most of these droplets are quite large and will disappear from the air quickly. How long can influenza virus can survive in the air droplets seems to be influenced by the levels of moisture and ultraviolet radiation: low humidity and lack of sunlight in winter aiding its survival.
Because the influenza virus can survive outside the body, the virus can also be transmitted by contaminated surfaces such as banknotes, doorknobs, light switches, and objects other households. The length of time the virus can survive on a variety of surfaces, the virus can survive for one or two days on hard surfaces and non-porous such as plastic or metal, for approximately fifteen minutes on a dry tissue paper, and only five minutes on the skin. However, if the virus found in mucous / slime, mucus so it can protect the virus to survive for a long time (up to 17 days on banknotes Bird flu virus can survive in the unknown while in a frozen state). Virus inactivated by heating to 56 ° C (133 ° F) for a minimum of 60 minutes, and also by acid (pH <2).
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