The Most Lethal Viruses Known To Mankind

Though we cannot see them, viruses are scarier than spiders and any creepy-crawling bug anyone can imagine. Many of them have wiped out millions of individuals before a vaccine was established and survivors are often left with permanent reminders of their illness. One particularly scary virus does not even make affected individuals feel sick and it comes with up to a seventy percent chance of death for those who catch it. Here are some of the most lethal viruses known to mankind that will have you washing your hands every chance you get.

Influenza

According to the World Health Organization, up to five hundred thousand individuals worldwide will die during the typical influenza season each year. A flu pandemic occurs when a new strain of the flu emerges. The worst ever recorded flu pandemic was the Spanish flu in 1918, which killed fifty to 100 million individuals in two years, including individuals in remote locations, such as the Arctic. This unusually deadly pandemic was the first of two influenza pandemics involving the H1N1 strain. Flu vaccines are available now; however, these only cover the most likely strains to appear in a given year, and may not always prevent the flu entirely, though they will shorten the illness and make it less severe should the patient still fall ill.

Rabies

The story of rabies dates back to 2300 B.C. when Babylonians who were bitten by dogs went mad and died. While exposure to the virus is rare in North America today, rabies is still a serious problem in parts of Africa and India. Vaccines are available to prevent the sickness associated with bites from infected animals. If left untreated, the rabies virus attacks the central nervous system and death will ensue. Symptoms may include hallucinations, raging, and violent behavior, along with hydrophobia, which is the fear of water.

Smallpox

Before the World Health Assembly declared the world free of smallpox in 1980, the virus killed one in every three individuals it infected. More than three hundred million individuals died from smallpox in the twentieth century alone before an effective vaccination came to the rescue. The smallpox patients who survived often went blind and were left with permanent scars. Mortality rates were highest in civilizations in Europe. Symptoms of smallpox included issues like a severe rash, blistering, high fever, and oozing skin sores.

HIV

Since the human immunodeficiency virus (HIV) was first formally recognized in the 1980s, it has killed more than thirty-six million individuals worldwide. Since then, powerful antiviral drugs have become available to help infected individuals live longer, though there is currently no cure for the condition. The virus tends to spread throughout low and middle-income countries, where ninety-five percent of new infections develop. The virus, which attacks the immune system, is spread through body fluid contact of infected persons by means of sexual intercourse or by sharing needles.

Rotavirus

Rotavirus is the main cause of severe diarrhea in young children and infants. According to the World Health Organization, more than four hundred and fifty-three thousand children under the five years old died from the virus in 2008 alone. Researchers believe the virus spreads through the fecal-oral route, or when small feces particles are consumed. There are two vaccines available to protect children in the developed world from rotavirus; however, the virus remains a killer in parts of the world where treatment is not widely available.

Dengue Fever

Dengue is a virus carried by mosquitoes that can cause an Ebola-like disease known as dengue hemorrhagic fever. It is the leading cause of death in subtropical and tropical regions of the world. Although there is currently no vaccine available for dengue hemorrhagic fever, it is not contagious and is treatable. According to the World Health Organization, dengue affects up to one million individuals a year. Symptoms of this condition include a fever, severe headache, and death if it is left untreated.

Hantavirus

Hantavirus is an airborne virus transmitted through an individual's exposure to infected mice droppings. Different strains of the virus are carried by different mice species. Two of the more prominent strains of hantavirus are hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The two strains may cause issues such as edema and acute kidney failure. If infected, there is a one in fifteen percent mortality rate with severe hemorrhagic fever with renal syndrome, while hantavirus pulmonary syndrome has a thirty-eight percent mortality rate.

Lassa

Lassa is a virus carried by a West African species of rats known as Mastomys. The virus can be picked up by inhaling air near an infected rat's feces and humans can spread it through body fluid contact. Lassa fever is responsible for approximately five thousand deaths a year in the West African areas of Liberia and Sierra Leone. Although there is no vaccine currently available, medical professionals have found some success in treating their patients with antiviral drugs during the early stages of the infection. Otherwise, Lassa fever has a fifteen to twenty percent mortality rate.

Marburg

The Marburg virus, also known as BSL-4, was first identified in 1967 when a group of German and Serbian lab workers contracted a hemorrhagic fever from African green monkeys being used to research vaccines for polio. The Marburg virus, tragically, has no cure and is spread through human contact. Symptoms start with a headache, fever, rash, and then develop into internal bleeding, organ failure, and death. The mortality rate associated with the Marburg virus has progressed from twenty-five percent during the initial outbreak to eighty percent in recent cases.

Ebola

First discovered in the sub-Saharan African nations in 1976, Ebola is a deadly virus named after its location of origin near the Ebola River in the Democratic Republic of the Congo. Symptoms and complications of this virus include bleeding from the eyes, hemorrhagic fever, headache, sore throat, internal bleeding, organ failure, and death. One strain of the Ebola virus does not even make patients feel sick before progressive internal bleeding and organ failure begin. According to the World Health Organization, the mortality rate of Ebola is between fifty and seventy percent. There is no cure for Ebola, although it has been successfully treated in some cases.

Measles

Also known as rubeola, measles is a highly contagious virus that can be prevented through vaccination. Symptoms of measles include runny nose, fever, conjunctivitis, and a rash. The rash associated with this condition typically begins on the face, and it consists of tiny red blotches that occur in clusters. The rash gradually spreads across the torso and arms, eventually spreading to the thighs, legs, and feet. When the rash is present, the patient's fever will often rise, and it could be as high as 104 to 105.8 degrees Fahrenheit.

A blood test can be used to diagnose measles, and treatment consists of post-exposure vaccination and the use of immune serum globulin. Fever reducers and antibiotics may also be used. Even with treatment, measles can cause serious complications, including ear infections, bronchitis, pneumonia, and encephalitis. If contracted during pregnancy, the virus may trigger early labor, and it is associated with low birth weight in the newborn. To prevent measles, two doses of vaccine are required, and these are normally given before a child enters elementary school. Without the vaccine, measles can be incredibly dangerous and often results in death.

Hepatitis C

Hepatitis C is a type of viral infection that can become chronic. The virus triggers liver inflammation, and it can lead to liver disease. Signs of hepatitis C include fatigue, easy bruising or bleeding, jaundice, reduced appetite, itchy skin, and swelling in the legs. Some patients may also deal with weight loss, spider angiomas, dark-colored urine, and fluid accumulation in the abdomen. Hepatitis C can be diagnosed through a blood test. Patients born between 1945 and 1965 have an increased risk of this condition, and doctors recommend that they consider being screened for hepatitis C.

Individuals who received a blood transfusion prior to 1992 may also wish to be screened. If hepatitis C is diagnosed, doctors may perform MRI scans and special ultrasounds to assess the patient's liver health and plan treatment. A number of oral medications are available for treatment, and doctors typically recommend that patients receive vaccinations for hepatitis A and hepatitis B to protect the liver as much as possible.

Yellow Fever

Yellow fever is a type of viral infection transmitted by mosquitoes and is most prevalent in parts of Africa, Central America, and South America. This condition typically has an incubation period of three to six days, and many patients never experience any symptoms. If symptoms do occur, they begin after the incubation period and include fever, muscle pain, back pain, headaches, and loss of appetite. Some individuals might also develop nausea or vomiting. Thankfully, in the majority of cases, symptoms will resolve on their own within four days. A small percentage of patients with this illness may enter a second phase, which can be severe.

Symptoms experienced during this phase generally include high fever, jaundice, dark-colored urine, and abdominal pain. Liver and kidney damage are common in this stage, and fifty percent of patients with this more severe form of yellow fever will die within ten days. A vaccination is available to prevent yellow fever, and patients traveling to certain countries may be required to show proof of vaccination. The vaccine should be used with caution in individuals over sixty years old.