Very often, an infection will not manifest any symptoms. Furthermore, some types of HPV go away on their own, while others increase the risk of developing cancer. The HPV vaccine offers good protection against infections.
Measles is an extremely contagious virus transmitted by droplets from an infected person who has sneezed or coughed. The virus responsible for this disease remains in the air for some time, increasing the degree of contagion. Measles is one of the major causes of child mortality in the world, despite the existence of an effective and safe vaccine that could prevent it.
Between 1. Without treatment, the disease can be fatal in just a few hours. In fact, between 21, and , deaths are reported each year. Cholera is extremely contagious in many parts of the world that lack effective water treatment systems. Most patients have no symptoms. In severe cases, however, diarrhea, nausea, and vomiting can rapidly lead to dehydration.
Dengue is particularly virulent in tropical and subtropical regions. The first symptoms usually appear after 3 to 14 days and are similar to those of the flu. Each year, approximately 50 million people worldwide contract dengue fever.
Mumps is a highly contagious disease, especially in children, and often causes swollen salivary glands. This virus is transmitted mainly through saliva and infectious airborne droplets. In other words, you can get mumps by kissing an infected person or touching a contaminated surface or object. Before the introduction of a vaccine, case numbers were quite high.
For example, , cases of mumps were reported in the United States in Bubonic plague is transmitted through the bite of fleas contaminated by the Yersinia pestis bacteria , a parasite often found in small rodents and mammals. It can also be contracted by inhaling the bacteria or infected respiratory droplets. Direct contact with infected human tissue is yet another way to catch the disease. Its most characteristic symptoms include inflammation and swelling of the lymph nodes, a phenomenon known as a "bubo.
Pneumonic plague, another form of plague, is highly contagious and particularly lethal. Death generally occurs only two days after the onset of symptoms. Unlike bubonic plague, this version is not transmitted by flea bite, but rather by airborne particles.
Shortly after the first symptoms appear high fever, chills, chest pain, headache, and rapid heartbeat , patients develop a cough that eventually produces a secretion resembling raspberry syrup. Caused by a microbe known as Mycobacterium tuberculosis , this disease is spread through infectious airborne droplets. For example, a tuberculosis patient who sneezes will blow the bacteria into the air, which can then infect others in the vicinity.
However, only the active, rather than the latent form is contagious. Tuberculosis usually affects the lungs first, causing a persistent cough, pain in the chest, and other problems. Highly contagious, poliomyelitis is caused by the poliovirus.
In countries where the disease is still active, namely in Afghanistan and Pakistan, polio is transmitted orally via water and food contaminated by the stool of an infected person. The virus then multiplies in the intestines. In addition to causing fever, nausea, vomiting, and generalized malaise, polio can, in some cases, leave patients with permanent paralysis of the limbs usually the legs.
While vaccines eradicated polio back in in America, the virus has only recently disappeared from the African continent. Eradicated since , smallpox was one of the most contagious diseases of the last century. One person contaminated with the variola virus could infect up to 10 others. This infectious disease is transmitted mainly by the projection of contaminated droplets into the air or via contaminated objects, such as clothing, sheets, and blankets. Unlike many infectious diseases, the Ebola virus is not usually trasmitted by air.
You can also get sick by touching an object needles, bedding, etc. Fever accompanied by chills, extreme fatigue, headache, and muscle aches are among the first symptoms of Ebola. Other manifestations may appear a few days later, such as internal and external bleeding.
The Spanish flu first appeared in and has since become one of the most infectious diseases in history. The virus targeted the lungs and immune system. Like other contagious diseases, the Spanish flu was spread by airborne droplets or contact with contaminated surfaces. When Flu Spreads People with flu are most contagious in the first three to four days after their illness begins.
Period of Contagiousness You may be able to pass on flu to someone else before you know you are sick, as well as while you are sick. People with flu are most contagious in the first days after their illness begins. Some otherwise healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Some people, especially young children and people with weakened immune systems, might be able to infect others with flu viruses for an even longer time.
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