Before we get started with the real killers of the virus kingdom let us clarify what is considered a virus. In laymen’s terms a virus is a small living particle which attaches itself to cells and drastically changes the way they function. This can lead anywhere from irritating but fairly harmless diseases to death. There are literally thousands of different viruses which are often easily spread between human and animals alike. Gratefully most of these viruses can be treated or prevented with vaccinations these days. Medical Science has had immense break troughs over the last couple of centuries and has done an amazing job to safeguard us from virus attacks.
Advanced practices and knowledge of hygiene has helped the prevention of viruses being spread between humans. Yet no matter how hard we try some viruses are still the cause of hundreds of thousands of death in the global human population.
Here are 10 of the most potent and potentially lethal viruses still current.
Smallpox has been known as one of the bigger killers of our time with a death rate of 30% to 35% of infected victims. The spread of this virus is not dependent on season or climate. This is an airborne virus which means it is highly contagious and can spread over a large region in an extremely short time. Smallpox is one of the oldest known viruses with evidence of its existence being traced back to 10,000 BC and it is believed to be the pustular rash on the mummy of Ramses V of Egypt. Smallpox alone was responsible for 300 to 500 million deaths in the 20 Centuries. This disease has two versions to it known as Variola major and Variola minor. With Variola minor being the lesser of the two with only a 1% historical death rate.
Smallpox localized its attack in the small blood vessels and the mouth / throat area. Its incubation between contraction and first visible signs is around 12 Days. Signs and Symptoms are described as following:
Resources quote from wikipedia:
Around the 12th day, lysis of many infected cells occurs and the virus is found in the bloodstream in large numbers (this is called viremia), and a second wave of multiplication occurs in the spleen, bone marrow, and lymph nodes. The initial or prodromal symptoms are similar to other viral diseases such as influenza and the common cold: fever (at least 38.5 °C (101 °F)), muscle pain, malaise, headache, prostration, and as the digestive tract is commonly involved, nausea and vomiting and backache often occur. The prodrome, or preeruptive stage, usually lasts 2-4 days. By days 12-15 the first visible lesions-small reddish spots called enanthem-appear on mucous membranes of the mouth, tongue, palate, and throat, and temperature falls to near normal. These lesions rapidly enlarge and rupture, releasing large amounts of virus into the saliva.
Smallpox virus preferentially attacks skin cells, causing the characteristic pimples (called macules) associated with the disease. A rash develops on the skin 24 to 48 hours after lesions on the mucous membranes appear. Typically the macules first appear on the forehead, then rapidly spread to the whole face, proximal portions of extremities, the trunk, and lastly to distal portions of extremities. The process takes no more than 24 to 36 hours, after which no new lesions appear. At this point Variola major infection can take several very different courses, resulting in four types of smallpox disease based on the Rao classification: ordinary, modified, malignant (or flat), and hemorrhagic. Historically, smallpox has an overall fatality rate of about 30%; however, the malignant and hemorrhagic forms are usually fatal.[
In December 1979 the WHO (World Health Organization) proclaimed the eradication of Smallpox and vaccination against this disease ended in the USA in 1972. To this day it is the only human virus / disease which is thought of as eradicated. However in my mind the threat of Smallpox is not over by a long shot, since in 1980 Russia successfully adapted and produced large quantities of this deadly virus for the use in biological warfare. The natural cause of Smallpox may no longer be a threat, but the virus is still in existence somewhere in a laboratory which means a renewed outbreak and after the adeption has no developed into a new strain which we are not at all familiar with, is more then possible.
AIDS / HIV
Welcome to another super killer which has scared and killed human beings off in large numbers. As far as we know HIV which causes AIDS has first been transferred to human from monkeys in Africa as early as 1884. It seemed to have remained fairly stationary in the African Continent until roughly 1966 when if first entered Haiti. It wasn’t until 1970 that the first signs of HIV were documented in the United States, but even at this time scientist and doctors are naïve to the impending danger it brings to humankind.
The real awareness of this lethal virus started in the 80’s with it being misnamed as a gay or drug user plague. Yet very shortly there after cases of HIV / AIDS were reported in haemophiliacs, American resident Haitians and non-drug using women. Several cases of HIV / AIDS were reported throughout European Countries which kicked off the heightened awareness of this virus.
It wasn’t until 1982 that the Name AIDS which stands for Acquired Immune Deficiency Syndrome was coined. By 1983 1 out of every 3 reported AIDS cases ends in death.
It isn’t until 1985 that the first cases are reported in China, which now closes the global circle of infection.
Now scientists are starting to work feverishly on this wide spreading killer virus and in 1987 AZT is released as the first Drug to supposedly treat AIDS, but in 1993 it is being acknowledged as being useless for treatment of HIV patience in early stages. The good news however is that it helps to reduce the HIV transferance from mother to unborn child which causes a drop in HIV positive born infants. By 1996 a Combination antiretroviral treatment shows itself as affective against HIV and by 1997 it shows its first decline in HIV cases.
Over the next 10 years several trial studies for treatments are being started and discontinued.
There are two different types of HIV. HIV-1 which is the most frequently spread type, with HIV-2 being predominantly found in West Africa being the lesser the lethal type and mostly related to the 2 strains found in Monkeys.
HIV is spread through the transfer of infected blood, sexual intercourse, anal intercourse (both homosexual and hetrosexual), oral sex as well as from infected mother to unborn child. However HIV is not spread via kissing unless an open sores or cuts are present on in the mouth. Direct contact of infected blood can sadly be via blood transfusion, but since a very strong blood screening is now in affect this risk is minimal.
Sharing of needles of drug users is a big risk. A small risk is also the transfer from infected patient to health care provider, but those cases are extremely seldom.
It is important to realize that you can not spread the HIV Virus through touching or hugging (as long as no blood or open cuts are present), sharing of household items, sharing facilities such as swimming pools, hot tubs, saunas etc. and coughs or sneezes.
Remember that it takes direct contact of infected blood or bodily fluids. This means you can be around infected AIDS patience and interact with them in regular ways without fear of contracting the desease. Just use some common sense!
Severe acute respiratory syndrome short SARS has had a near pandemic from November 2002 to July 2004 with a case-fatality rate of 9.6%. During the short span of weeks SARS spread around 37 Countries. By 2006 WHO has proclaimed SARS as fully contained but has not been listed it as of yet as eradicated since it may still be present in animals and can be cause another outbreak in the future.
One of the many viruses transmitted by mosquitos. According to medical research you can contract Dengue multiple times due to its four serotypes. Once Dengue is contracted and should you have made it all the way through you will be immune to the particular serotype, but are still volnurable to the remain ones.
Dengue Fever is also known as “breakbone” or “dandyfever”. Those names are derived from the physical appearance of most sufferers who are plagued by contortions caused by the extensive muscle and join pains.
The more extreme form of Dengue is called “Dengue hemorrage fever” and can be potentially life-threatening. Some of its signs include black stool, bleeding in the nose and gums, high fever, rashes, blisters or easy bruising. Dengue hermorrage fever can lead into its most severe form “Dengue Shock Syndrome”.
Dengue fever is most common in the subtropic and tropics. Latest studies have shown a rise of it in Southeast Asia, Thailand, Vietnam, Singapore, and Malaysia. An estimated 100 million cases of Dengue fever are reported annually with several hundred thousand of them developing into Dengue hemorrhage fever which require hospitalization.
The good news is that this virus is not contagious, meaning it can not be spread on a human to human level. It is transferred via a mosquito bite to a human host body where it must take its course.
An average incubation period of this virus is five to eight days, but can take as long as 15 Days before the first symptoms appear. These first signs of Dengue usually begin with chills, pain when moving the eyes and headaches. Then it spreads to lower backaches, pain in the legs and joints. The first wave of fever can rise as high as 104 F and will be accompanied by low blood pressure and a relatively low heart rate. Eyes are starting to redden and a pink rash makes its appearance over your face which disappears fairly quickly. Another sign are the swollen glands in your neck and groin area. This can last for 2 to 4 days at which point this happy little virus lolls you into a moment of feeling better again. For about 1 Day you will have a moment of well being, causing you to belief that you are on your road to recovery. Think again my friends, because now comes phase to of this virus joy ride. Say hello again to the rash only now it spreads over your entire body except the face, the high rise of temperature returns quickly and we are going to add red and swollen soles and palms to the mix. Should you be lucky and it didn’t develop into any of the more severe variation of this delightful virus you are now on the road to recovery. Although the actual period of illness only last 1 to 2 Weeks, full recovery can take several weeks due to the weakened state of your body. The good news is that regular Dengue Fever is only fatal in about 1% of the cases reported.
Sadly DHF (Dengue Hemorrhage Fever) is not as forgiving and appears to target the younger children of ages 10 and under. The mortality rate for DHF is 6% up to 30% with the majority of it affecting infants under 1 year of age.
If you are planning on traveling into any regions which are known for the contraction of Dengue I advise you to visit http://www.cdc.gov/Dengue/ for further information and some guides for prevention.
Hanta Virus is yet another hemorrhage type virus which has several different regional specific strands. As with all viruses some of their strands or forms are more severe than others. The “Hantaan Virus” found mainly in Asia and the “Sin Nombre” found mainly in the USA are severe. Hanta Virus is transmitted via the inhalation of dust or dried particles which carry rodent saliva or dried waste products of an infected rodent.
The mortality rate of the “Sin Nombre” strand in severe cases is 70% – 80%, but in milder forms drops to about 40%. Quiet high in my estimation and not something to be taken lightly.
Although we don’t hear too much of this virus it is not a new virus. First outbreaks and documentations go as far back as 1951 in Korea. It is to be assumed that there were probably earlier cases, but these were the first to be actually documented when United Nations Soldiers succumb to it and were in need of hospitalizations.
Several outbreaks were documented between then and 2000, and even here in the USA during this period 277 cases hanta virus cases were reported with 100 of them being fatal.
This may not appear as a lot, but it is still enough to make the medical community to sit up and pay attention. If you are interested in a time line of outbreaks and case histories click here!
Largely a lot of information on this virus is still rather sketchy but one thing is common to all strands of the virus it causes kidney impairment or failure. Hospitalization is always required upon contraction.
This delightful little virus was named after the Ebola River Valley in the former Zaire. It is a viral genus and can be transmitted from human host to human host via bodily fluids. The first outbreak was recorded in 1976 with its form as Ebola Hemorrhage Fever and was found in Zaire and Sudan with a scary 90% death rate at that point. Over the following years and later outbreaks this mortality rate kept rising and falling until it settled around 50%.
So how does a human host contract this virus to begin with? It is assumed that the virus is transmitted via contact of an infected animal host to a human host. So yes folks once again a transmission from animals to humans.
What gets even more worrisome is the human ability to capitalize on such horrible viruses and turn them into potentially lethal biological warfare agents. According to various sources in 1992 Shoko Asahara Leader of Japan’s Aum Shinrikyocult led 40 of his people into Zaira to aquire a sample of this deadly virus. Of course he did so under the guise of a good will mission of medical aid for the ebola victims.
Since there is no approved method of treatment or vaccine available for this lethal virus it is now classified as a Category A Bioterrosismn agent and a biosafety level 4 agent.
E-Coli has been tormenting humans for quiet some time as well. The first documented case was in 1883 but it wasn’t until 1885 that it first truly gained recognition in the African Medical Medical Journal. E-Coli stands for Escherichia coli. Now since E-Coli is typically harmless just extremely uncomfortable leading to food poisoning, you may wonder why I have chosen to include it in this list.
I belief that it has earned its place due to the more and more frequent outbreaks of E-Coli, showing us that it is far from “undisruptive”. New strands of E-Coli are naturally mutating constantly which keeps our medical community fascinated with it.
Now I said that it is harmless, but that is not entirely correct. In developing countries this virus can be rather lethal to children. But not only there can it take its toll, even here in the USA it claim victims if it causes complications like hemolytic-uremic syndrome (HUS). Those at most risk are young children, the elderly and those with immunocompromised.
Eating of unwashed vegetables or undercooked meat is the best known cause of contracting E-Coli. It is advised to be vary cautious of proper food handling and preperation at all times.
E-Coli seems to be a “developing” virus which is becoming increasingly drug resistant. So we may hear more from it in the future. Keep an eye on it.
Welcome to yet another mosquito transmitted virus, in this case the bit of the female mosquito. It is originated to the tropics and subtropics like Africa and South America. It is believed to have originated in Afrika in the 16th Century and was spread to South America via slave trade.
Since the 17th Century it has traveled a bit more extensively and has been recorded with several large outbreaks in Africa, the Americas and Europe.
Yellow fever received its name from the potentially toxic stage which causes liver damage and shows as jaundice. It is yet another virus in the family of homorrahge fevers.
An estimated 200.000 cases with a mortality rate of 30,000 in unvaccinated populations are reported by the WHO, with 90% of those cases being in Africa.
The good news is that since the middle of the 20th Century a safe and effective vaccine has been in existence against this Virus. You have noticed I said vaccine, since there is no known cure for this desease to my knowledge. It is highly adviced and in some areas required that you get vaccinated before traveling to afflicted localities.
It is currently considered a reemerging desease since an increase in cases since the 1980’s.
Yellow fever strikes rather quickly upon contraction as well. The incubation is only 3 to 5 days before first symptons show. Within 1 Day the toxic phase sets in and within Jaundice will kick in within 2 to 3 Days. The symptoms are no fun either. Fever, chills, bleeding into the skin, headaches and back pains coupled with slowed heart rate.
Once again a desease with a wicked sense of humor, since one you have been through that stage you apparently are on your road to recovery and feel better for a day or two. Then it comes back with a vengeance, more severe before and leading finally into internal hemorraghing, dilirium, coma and at last death. This has a 50% chance of happening in infected patients.
Measels is one of the ancient deseases as well, it dates back to 165 to 180 A.D. Some of the best known and most wide spread outbreaks were during the Roman times where it killed large parts of the Roman Army, 1592 in Cuba causing the demise of 2/3 of the population, 1594 where it took large casualties in Honduras. An estimated count of 200 Million death have been reported over the last 150 Years. So yes, it can be considered one of the super killers of our time.
This is a highly contagious virus which is spread easily during the infectious period via transferrance of droplets. Gratefully there are affective treatments available and have been for some time now.
Vaccinations against this desease is done in young children around their first 1 year of life.
The H1N1 virus is part of the Type A Influenca family and had previous recorded outbreaks before the recent 2009 scare. It was the cause of the Spanish Influence pandemic in 1918. Unlike the pandemic in 1918 which was caused by birds, the more recent one was caused by swine.
Between 2009 and August 2010 when WHO declared the pandemic officially over it had caused 17.000 death world wide.
Quick actions on the part of the medical community brought this form of Influenza quickly under control by offering vaccinations against it. Sadly only limited numbers were available in the beginning.
It was transmitted by direct contact with infected animals or injection of undercooked meat of the infected animals.
It’s symptons are the typical Influenza symptoms of fever, chills, sore throat, muscle pains, back pains, coughing etc.
As you can see nature is more then able to defend herself and remind us that we are all mortal after all. For further and more detailed information please visit the following resource websites used to create this article.
Yellow Fever (1)
Yellow Fever (2)
Hanta – Virus (2)