An epidemic is an especially - infectious disease which affects a large portion of the population. It's a fad: quick, widely disseminated, short. Trough our great mobility infections can quickly travel worldwide.
A pandemic is an epidemic that reaches across borders, and is caused by a virus against which no or a reduced resistance is.
Also among plants or animals may a pandemic break out. The avian influenza virus and HIV (AIDS) are examples.
Most countries have statutory measures to prevent and combat epidemics: education and prevention, travel ban, quarantine, vaccination.

Quarantine or isolation is used to prevent the spread of infection.
To avoid rabies, imported dogs and other animals were first 6 months in quarantine in the UK. In the 21st century, this directive was replaced by a new system of animal passports.

A inoculation is done with an attenuated vaccine of a sick maker that elicits an immune response without making the receiver ill. Therefore the vaccinated is more resistant to the pathogen.

Immune: resistant, impervious to infection by the resistance built up after an illness or vaccination. The body has then created the appropriate antibodies.
The immune system is a defense of its own cells and molecules against intruders or altered own cells. Especially white blood cells are active in this.
The barriers of the saliva, tears, and mucus layers contain protective proteins, such as the enzyme lysozyme, which breaks down the cell walls of bacteria.
AIDS is caused by the HIV virus and causes no, or insufficient functioning immune system. AIDS has mainly in African and other third world countries a devastating impact on the population and the economy. (Human immunodeficiency virus infection / acquired immunodeficiency syndrome (HIV/AIDS)

An epidemic may have serious social consequences. Additional to and by many individual human dramas are tourism, transport and the economy falling still. Due to shortages civil disobedience and possible looting, as malnutrition, weakness and starvation.
Plague and smallpox, and those consequences have in the course of history several times decimated throughout communities and cities.
Diseases that whites brought in America cost life at places of 90% of the population which hadn’t any defense or immunity against it, and destroyed complete cultures.

Soon after (and distributed by) the First World War (1918) was the world affected by the pandemic Spanish flu (epidemic influenza) that with 20 to 100 million deaths probably made ​​twice as many casualties as the war.
She arose and was spread through U.S. military barracks, in a few days came death. Unlike other flu epidemics mainly young adults between 14-21 years were affected. That especially those with the strongest immune died was due to a strong counter- reaction of the immune system.

The swine flu, or influenza A (H1N1) is an influenza virus that caused a pandemic in 2009. The virus belongs to a new strain of the H1N1 swine flu virus.

Flu or influenza is similar, but is heavier and more painful than a cold. It is a disease that is caused by the influenza virus.
Each year, approximately 820,000 Dutch get the flu and 250 to 2,000 people die of the flu or the consequences, especially the elderly (65 +).
The 'normal' flu is thus 4 to 35 times more dangerous than swine flu. You never know in advance what impact a new flu strain will have.

In humans, influenza is caused by the influenza type A and B viruses.
Type A causes the most morbidity and mortality.
Type C viruses cause only one type of common cold, especially in children.

Influenza viruses are classified based on two proteins on their surface: hemagglutinin (HA or H) and neuraminidase (NA).
In humans are 3 different HAs and 2 NAs: HA1, 2 and 3, and NA1 and 2. The HA will ensure that the virus can penetrate the cells of infected individuals.
The combination of HA and NA indicates a name of the subtype of the virus, for example,
H1N1 Spanish flu of 1918.
H2N2 for the Asian flu of 1957 and 1958, which killed at least 1 million people.
H3N2 caused the epidemic of 1968 and the Hong Kong flu in 1969 with 750,000 dead.
Passing the flu will make one builds defenses against the corresponding subtype.
The HA and NA proteins are constantly changing.

About sixteen HA subtypes and nine NA subtypes are known in birds.
Bird flu is most common in gallinaceous birds, with drowsiness, watery eyes and swollen throats and / or staining comb as a symptom. Some birds die immediately after the initial infection. The incubation period is from three days to two weeks. The disease is lethal to chickens, turkeys and ducks.
Bird flu (avian influenza) is pandemic in Asia, with in October 2005 a stopover on a chicken farm in Romania. The to people potentially dangerous strain of bird flu is caused by the H5N1 virus.

The causative influenza A virus is highly variable, with new variants. At one in 10,000 cases (possibly dangerous) mutation in a host cell can occur.

The World Health Organization proposes to enter, because the hands carry and spread lots of germs and viruses, elbow greeting with a bird flu pandemic. Lots and thorough hand washing therefore invariably belongs to the preventive measures.

Mutations are small changes in the genetic material (DNA or RNA) of an organism or virus. They are important in the course of evolution, the development of resistance in bacteria and viruses, hereditary diseases, the development of cancer and aging.

Cancer is often caused by an accumulation of mutations in genes with regulating functions. This creates unrestrained cell division, with more chance of new mutations, allowing the cancer cells to be more aggressive and invasive. Before a cell develops to cancer are at least seven mutations needed.

Ebola is rare but dangerous. There is no effective vaccine nor a cure for people. The Ebola virus causes in simians, including humans, a severe abnormality in the blood causing internal bleeding. The average incubation period is one week. After the first symptoms (fever, severe headache and strong pains) takes on average 48 to 72 hours before the patient dies.
The virus is transferred through all body fluids. Not everyone who is infected dies, the estimated mortality range from 50% to over 90%.
The (Franquet's Epauletted Fruit Bat (Epomops franqueti) and other types of fruit bats may be the spreaders of the virus.

The similar Marburg virus is of the same family of filoviruses (Filoviridae) and causes heavy bleeding from all orifices. Outbreaks of the disease are known in 1967, 1975, 1980, 1987, 1998, 2004 and 2005.

We now live in a more densely populated and globalized world with few and decreasing natural barriers and more and more highways (including air traffic), also for viruses.

In 2017, the Coalition for Epidemic Preparedness Innovation (CEPI) was established to prepare scenarios and technologies for a new disease. In SARS and MERS, it took several weeks to map the genome of the virus. Now we can do that within a few days.

The Global Virome Project aims to create a database of all naturally occurring viruses. About 260 are able to infect humans. But there are more than 1.2 million as yet unknown viruses (in birds and mammals) worldwide, of which more than five hundred thousand could pass to humans.

The Covid-19 virus demonstrated that there is still no global and coordinated approach in 2020, and that each country is acting more or less successfully with its own measures and priorities. And that it can spread worldwide very quickly, and available efficient treatment takes (too) long.

In the 80s, the then Soviet Union experimented with the preparation of the Marburg virus for biological warfare.
In aerosol form are just a few virions (virus particles) needed in order to infect a victim. You can with an SS -18 intercontinental ballistic missile –scale such an event. After Dr. Nikolai Ustinov had injected himself accidentally with Marburg, his colleagues could isolate a more lethal version of the virus from his body and cultivate it. After 1991, little or nothing is known about the recent Russian research and / or development of biological weapons.
A cost analysis per square kilometer affected shows that the conventional cost ratio: Nuclear: Chemical: Biological relates as 2000:800:600:1. One dollar to biological weapons can thus cause as much damage as $ 2,000 in conventional weapons. Biological weapons are so attractive, even for poorer countries and terrorists.
Various micro - organisms, viruses, and toxins are eligible. The U.S. Centers for Disease Control and Prevention showed six pathogens as the most dangerous: anthrax, botulinum (the poison of the bacterium Clostridium botulinum), the plague bacterium Yersinia pestis, smallpox, the tularemia bacteria and the Ebola virus.

Biological weapons have already been used previously.
South American Indians covered their weapons with curare poison or the poison dart frog.
Mongol conquerors under Genghis Khan and European besiegers forced unruly cities sometimes by shooting bodies of plague victims over the city walls with catapults primarily to spread the disease via drinking water.

English archers raised their arrows into the ground. So they could shoot faster in succession, but the arrows were also infected with bacteria such as tetanus.
In 1767, the British distributed blankets infected with smallpox among the Indians.
The Japanese used during World War II with the plague infected fleas on China's population which caused 200,000 to 440,000 deaths.

Thanks to our civilization and development, we can do this now much better and more efficiently, such as with viruses or bacteria that are resistant to drugs, or for which there are no (timely) vaccines or remedies.

Cholera is an infectious disease caused by the bacterium Vibrio cholerae. The incubation of the bacteria varies from six hours to two days. The disease is transmitted through contaminated water, fish, feces and it causes severe diarrhea and dehydration.

EHEC is a collective name for enterohaemorrhagic Escherichia coli, bacteria that produce a toxin with food poisoning, serious infections, and bloody diarrhea as result. A well-known variant is the EHEC O157: H7.
In 2011 came EHEC in the news by outbreak and spread through soy sprouts and vegetables and others of a rare and apparently aggressive EHEC variant, O104: H4.

Hospital bacteria is a collective name for several bacteria that resist antibiotics. Especially in hospitals, with many antibiotics and weak patients they cause many infections.
MRSA stands for Methicillin - Resistant Staphylococcus Aureus. The Staphylococcus aureus is a skin bacterium that in approximately 30 percent of all people occers, for example, in nasal cavity or mucous membranes.

The insensitivity to methicillin and other antibiotics began in 1960, and the resistance was increasing. Antibiotics that do work are usually more expensive and cause more side effects.
Through the use of antibiotics, MRSA was also introduced in livestock farms.
It seems indestructible, is genetically flexible and adapts easily under new circumstances. A solution is still not found.

The symptoms are not always the same and sometimes not even visible and therefore difficult to determine. The consequences can range from skin and wound infections to urinary tract infections and pneumonia.

Resistant ill makers, high mobility, high dependence on centralized water distribution and food production, and terrorism threaten large areas and populations.
Remedies often don’t exist, or are too late. Survivors usually: (almost) none. The only preventive measure seems to consist of a good hygiene and ensuring a healthy and strong body that provides adequate resistance. And hope that you can be at the x% survivalist.

Worms that were frozen 40,000 years ago in a Siberian layer of ice turned out to be able to come back to life in a warm lab of about 20 degrees, as Russian biologists discovered. It will certainly be possible for micro-organisms.

Some people are so touchy that they feel shortchanged as an epidemic wouls miss them. (Kin Hubbard)