VIA HOW STUFF WORKS:
According to the U.S. Census Bureau, the average life expectancy at the beginning of the 20th century was 47.3 years. A century later, that number had increased to 77.85 years, due largely to the development of vaccinations and other treatments for deadly diseases. Of course, vaccines and treatments only work if they’re given, which is why many of these diseases still persist in poorer, developing countries. Despite the success of vaccines, only one of these diseases — smallpox — has been erased from the globe.
Here are some diseases that could be completely eradicated from the world if vaccines were made available to all.
. Chicken Pox
Before 1995, a case of the chicken pox was a rite of passage for kids. The disease, caused by the varicella-zoster virus, creates an itchy rash of small red bumps on the skin. The virus spreads when someone who has the disease coughs or sneezes, and a nonimmune person inhales the viral particles. The virus can also be passed through contact with the fluid of chicken pox blisters. Most cases are minor but in more serious instances, chicken pox can trigger bacterial infections, viral pneumonia and encephalitis (inflammation of the brain). According to the Centers for Disease Control and Prevention (CDC), before the chicken pox vaccine was approved for use in the United States in 1995, there were 11,000 hospitalizations and 100 deaths from the disease every year. Many countries don’t require the vaccination because chicken pox doesn’t cause that many deaths. They’d rather focus on vaccinating against the really serious diseases, so the disease is still common.
: Smallpox
Unlike other diseases on this list, which can still appear in outbreaks when vaccination vigilance weakens, smallpox has been wiped off the face of the earth, except for samples of the virus held in labs in the United States and Russia for research purposes. Symptoms of smallpox included a high fever, head and body aches, malaise, vomiting. The most marked characteristic of the diseases is a rash of small red bumps, which progress into sores that break open and spread the virus (the virus could also be spread via contact with shared items, clothing and bedding). Smallpox was an entirely human disease — it didn’t infect any other animal or insect on the planet. Thus, once vaccination eliminated the chances of the virus spreading among the human population, the disease disappeared; in fact, the United States hasn’t vaccinated for smallpox since 1972.Although smallpox was one of the most devastating illnesses in human history, killing more than 300 million people worldwide during the 20th century alone, scientists declared the world free of smallpox in 1979. The naturally occurring disease has been eradicated, but fears remain about the smallpox samples being used as bioweapons.
: Tetanus
Reproductive cells (spores) of Clostridium tetani are found in the soil and enter the body through a skin wound. Once the spores develop into mature bacteria, the bacteria produce tetanospasmin, a neurotoxin (a protein that poisons the body’s nervous system) that causes muscle spasms. In fact, tetanus gets its nickname — lockjaw — because the toxin often attacks the muscles that control the jaw. Lockjaw is accompanied by difficulty swallowing and painful stiffness in the neck, shoulders and back. The spasms can then spread to the muscles of the abdomen, upper arms and thighs. According to the CDC, tetanus is fatal in about 11 percent of cases, but fortunately, it can’t be spread from person to person — you need direct contact with C. tetani to contract the disease. Today, tetanus immunization is standard in the United States, but if you’re injured in a way that increases tetanus risk (i.e. stepping on a rusty nail, cutting your hand with a knife or getting bitten by a dog), a booster shot may be necessary if it’s been several years since your last tetanus shot.
: Yellow Fever
Yellow fever is spread by mosquitoes infected with the yellow fever virus. Jaundice, or yellowing of the skin and eyes, is the hallmark of the infection and gives it its name. Most cases of yellow fever are mild and require only three or four days to recover, but severe cases can cause bleeding, heart problems, liver or kidney failure, brain dysfunction or death.People with the disease can ease their symptoms, but there is no specific treatment, so prevention via the yellow fever vaccine is key. The vaccine provides immunity from the disease for 10 years or more and is generally safe for everyone older than nine months. Yellow fever occurs only in Africa, South America and some areas of the Caribbean, so only travelers who are destined for these regions need to be concerned about it. WHO estimates that there are 200,000 cases of yellow fever every year, and 30,000 of them are fatal. The elderly are at highest risk of developing the most severe symptoms. Although vaccination and mosquito-eradication efforts have made a great difference, WHO says yellow fever cases are on the rise again.
