In the face of deadly viruses the only weapon humanity has is proper hand washing and disinfectant, but preventive measures may not be enough for the 10 deadliest viruses. A virus is a small infectious agent that replicates inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to bacteria and archaea. Science has not yet determined whether viruses constitute life because they lack key characteristics of life, such as cell structure. They have often been described as 'organisms at the edge of life.' What is known about viruses is that they cause serious illnesses and can destroy lives if not dealt with properly. The following viruses are not listed in any particular order but don't be fooled, they are all equally deadly. Also they are not just the only most dangerous, there are many more viruses that have brought humanity to its knees causing panic and terror in the hearts of many.
The Ebola virus is one of five known viruses within the genus Ebolavirus. Four of the five known ebola viruses cause severe, and often fatal, hemorrhagic fever in humans and other mammals. The 2013–2014 Ebola virus epidemicin West Africa has resulted in at least 13,567 suspected cases and 4,922 confirmed deaths. The 2014 Ebola epidemic is the largest in history, affecting multiple countries in West Africa. Thomas Eric Duncan was the first person to succumb to the Ebola virus within the United States. CDC and partners are taking precautions to prevent the further spread of Ebola within the United States.
Recovery from Ebola is dependent on proper supportive care and the patient’s immune system. People who recover from Ebola infection develop antibodies that last for at least 10 years. It is not known if people who recover are immune for life or if they can become infected with a different strain of Ebola. Some people who have recovered from Ebola have developed long-term complications, such as joint and vision problems.
On the forefront of the fight against Ebola is the international non-governmental organization, Doctor's Without Borders. The NGO is the only aid organization treating people affected by the virus. Some of its staff have died from Ebola. Since the beginning of the Ebola outbreak, the organization has treated 470 patients in specialized centers. Doctors Without Borders has 300 international and national staff working in West Africa. It has sent more than 40 tons of equipment and supplies to the region to help fight the epidemic. However, it cannot deal with the size of the epidemic.
H5N1 Bird Flu
Influenza A virus subtype H5N1, or simply H5N1, is a subtype of the influenza A virus which can cause illness in humans and many other animal species. H5N1 is becoming increasingly common but is being held in check by vaccination. Around 60 percent of humans known to have been infected with the current Asian strain of H5N1 have died from it, and H5N1 may mutate into a strain capable of efficient human-to-human transmission.
In general, humans who catch the virus have symptoms that include fever, cough, sore throat, muscle aches,conjunctivitis, and, in severe cases, breathing problems and pneumonia. The severity of the infection depends in large part on the state of the infected persons immune systems and whether they have been exposed to the strain before. Eleven outbreaks of H5N1 were reported worldwide in June 2008 in five countries (China, Egypt, Indonesia, Pakistan and Vietnam) compared to 65 outbreaks in June 2006 and 55 in June 2007. In July 2013 the WHO announced a total of 630 confirmed human cases which resulted in the deaths of 375 people since 2003.
At least 12 companies and 17 governments are developing per-pandemic vaccines in 28 different clinical trials that, if successful, could turn a deadly pandemic infection into a non-deadly one. Full-scale production of a vaccine that could prevent any illness from the strain would require at least three months after the virus's emergence.
Crimean-Congo Hemorrhagic Fever
Crimean-Congo hemorrhagic fever (CCHF) is caused by infection through a tick-borne virus. The disease was first characterized in Crimea in 1944 and given the name Crimean hemorrhagic fever. It was then later recognized in 1969 as the cause of illness in the Congo, thus resulting in the current name of the disease. Crimean-Congo hemorrhagic fever is found in Eastern Europe, particularly in the former Soviet Union, throughout the Mediterranean, in northwestern China, central Asia, southern Europe, Africa, the Middle East, and the Indian subcontinent.
The onset of CCHF is sudden, with initial signs and symptoms including headache, high fever, back pain, joint pain, stomach pain, and vomiting. Symptoms may also include jaundice, changes in mood, and alternated sensory perception. As the illness progresses the infected develops large areas of severe bruising, nosebleeds, and uncontrolled bleeding to make an episode of Z Nation look tame. In documented outbreaks of CCHF, fatality rates in hospitalized patients have ranged from nine percent to as high as 50 percent.
Treatment for CCHF is primarily supportive. Care should include careful attention to fluid balance and correction of electrolyte abnormalities, oxygenation and appropriate treatment of secondary infections. Since the 1970s, several vaccine trials around the world against CCHF have been scrapped due to high toxicity. Vaccines are still being developed but because of the sporadic nature of the disease it is difficult to conduct large trials.
The 1918 flu pandemic (January 1918 – December 1920) was an unusually deadly influenza virus and the first of the two pandemics involving the H1N1 influenza virus. It infected 500 million people across the world, including remote Pacific islands and the Arctic, killing 50 to 100 million people—three to five percent of the world's population —making it one of the deadliest natural disasters in human history. The pandemic has been described as "the greatest medical holocaust in history," and may have killed more people than the Black Death.
Most influenza outbreaks disproportionately kill juvenile, elderly, or already weakened patients. In contrast, the 1918 pandemic predominantly killed healthy young adults. Modern research, using viruses taken from the bodies of frozen victims, has concluded the virus kills by overworking the body's immune system. The strong immune reactions of young adults ravaged the body, whereas the weaker immune systems of children and middle-aged was too weak.
To maintain morale in World War I, wartime censors minimized early reports of illness and mortality in Germany, Britain, France, and the United States, but papers were free to report the epidemic's effects in neutral Spain, creating a false impression that Spain was especially hard hit—thus the pandemic's nickname.
Humans catch the rabies virus from another animal through a bite or scratch. In countries where dogs commonly have rabies more than 99 percent of human cases are the result of dog bites. In the United States less than five percent of cases are the result of dogs, and bats are the primary vector. The virus can only be identified in humans after symptoms begin to appear. It is notorious for transforming animals into violent creatures, as if they were famous murderers.
Rabies is a virus causing inflammation of the brain in humans and other warm-blooded animals. Typically, symptoms of the disease do not become apparent until one to three months after being infected. The amount of time depends on the distance the virus must travel to reach the central nervous system. Early symptoms include fever and the sensation of tingling at the site of exposure, and eventually violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, and eventual loss of consciousness. Unlike some diseases infecting the brain neurological damage from rabies cannot be relieved through music. Once symptoms appear, it nearly always results in death. Between 26,000 and 55,000 deaths every year are the result of rabies, with more than 95 percent of those deaths occurring in Asia and Africa. More than 3 billion people live in regions of the world where the virus can be found.
Animal control and vaccination programs have decreased the risk of rabies from dogs in a number of regions around the world. Immunizing people before they are exposed is recommended in those who are at high risk, such as people who work with bats or spend prolonged periods in areas of the world where the disease is common. In those who have been exposed to rabies, a rabies vaccine and sometimes rabies immunoglobulin are effective in preventing the disease if administered before symptoms appear. Washing bites and scratches for 15 minutes with soap and water also appears to be somewhat effective. Unless animals are replaced with robotic doppelgängers like in Do Androids Dream of Electric Sheep rabies will continue to pose a threat to humanity.
The human immunodeficiency virus (HIV) is a lentivirus that causes acquired immunodeficiency syndrome(AIDS), a condition in humans in which progressive failure of the immune system allows life-threatening infections and cancers to thrive. Without treatment, the average survival time after infection with HIV is estimated to be nine to 11 years.
Infection with HIV occurs through the transfer of blood, semen, vaginal fluid, pre-ejaculate, and breast milk. Within these bodily fluids, HIV is present as both free virus particles and a virus within infected immune cells. HIV is still considered a worldwide epidemic. According to WHO, 35.3 million people are living with the HIV virus and 1.6 million people die of AIDS related illness each year.
Currently, there is no cure for HIV/AIDS. The most universally recommended method for the prevention of HIV/AIDS is to avoid blood-to-blood contact between people and to practice safe sex. It is much safer than trying to have sex in zero gravity.
West Nile Virus
West Nile Virus (WNV) is a mosquito-borne virus found in temperate and tropical regions of the world. It was first identified in Uganda but has spread across the globe. Prior to the mid-1990s WNV was considered sporadic and a minor threat to humans, until an outbreak in Algeria in 1994. Since then, WNV has spread globally, with the first case in New York City in 1999. In 2012, WNV killed 286 people in the United States primarily in Texas, making it the deadliest year on record for the United States.
Symptoms of WNV typically include fever, headaches, muscle pain, nausea, vomiting and rash. In less than one percent of cases the infected suffer a neurological disease when the virus reaches the central nervous system, leading to inflammation of the brain.
Currently, there is no vaccine against WNV infection available. The only way to fight the virus is for municipalities to create effective mosquito control programs, while businesses and citizens work to reduce breeding populations of mosquitoes. Eliminating stagnant pools of water found in old tires, buckets and unused swimming pools prevents mosquitoes from reproducing. Numerous books have been written to teach people effective methods of combating the deadly disease.
Marburg virus (MARV) causes a form of viral hemorrhagic fever in humans and nonhuman primates. Marburg virus was first recognized in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia). Thirty-one people became ill. Seven deaths were reported. The first people infected had been exposed to imported African green monkeys or green monkey tissues while conducting research.
After an incubation period of five-10 days, symptom onset is sudden and marked by fever, chills, headache, andmyalgia. Nausea, vomiting, chest pain, a sore throat, abdominal pain, and diarrhea may then appear. Symptoms become increasingly severe and can include jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive hemorrhaging, and multiple organs failing.
In 2009, expanded clinical trials of an Ebola and Marburg vaccine began in Kampala, Uganda. As of October 2014, no vaccine has been approved for use in the United States.
Yellow Fever is a virus spread by mosquitoes that only infects humans, other primates, and several mosquito species. It can be difficult to detect because symptoms are not apparent in the early stages of infection. To confirm a suspected case blood sample testing with a polymerase chain reaction is required. Symptoms typically improve within five days. In some people, within a day of improving the fever returns, abdominal pain occurs, and liver damage begins causing yellow skin.
In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains, and headaches. Symptoms typically improve within five days.Yellow fever causes 200,000 infections and 30,000 deaths every year, with nearly 90 percent occurring in Africa. Nearly a billion people live in an area of the world where the disease is common. Since the 1980s, the number of cases of yellow fever have been increasing. The increase is believed to be due to fewer people being immune, more people living in cities, people moving frequently, and the lack of global cooperation on climate change.
A safe and effective vaccine against yellow fever exists and some countries require vaccinations for travelers. In areas where yellow fever is common and vaccination is uncommon, early diagnosis and immunization of large parts of the population is important to prevent outbreaks. Once infected, management is symptomatic and no specific measures are effective against the virus. Death occurs in approximately half of people who do not receive treatment.
Severe Acute Respiratory Syndrome (SARS) is a viral respiratory disease caused by the coronavirus, and is believed to have originated from bats. Between November 2002 and July 2003, an outbreak of SARS in southern China caused 8,096 cases and 774 deaths in multiple countries, with the majority of cases in Hong Kong. On March 12, 2003 the World Health Organization (WHO) issued a global alert, followed by a health alert by the United States Centers for Disease Control and Prevention (CDC). Local transmission of SARS took place in Toronto, Ottawa, San Francisco, Ulan Bator, Manila, Singapore, Taiwan, Hanoi and Hong Kong whereas within China it spread to Guangdong, Jilin, Hebei, Hubei, Shaanxi, Jiangsu, Shanxi, Tianjin, and Inner Mongolia.
Initial symptoms are flu-like and may include fever, muscle ache, lethargy, cough, sore throat, and other nonspecific symptoms. The only symptom common to all patients appears to be a fever above 38 °C (100 °F). SARS may occasionally lead to pneumonia, either direct viral pneumonia or secondary bacterial pneumonia.
To date there is no effective vaccine for SARs. The most effective way to combat an outbreak is through isolation and quarantine to prevent the viruses spread. Suspected cases of SARS must be isolated in negative pressure rooms, similar to the rooms featured in The Strain. Hand washing and disinfection of surfaces along with the use of surgical masks are highly recommended in the event of a SARS epidemic.