Despite advances in technology, one of the biggest threats to human survival comes from primitive life forms.

Infectious diseases are caused by microorganisms, such as bacteria, virus and parasites.

These organisms have no access to education or technology, but they present a huge challenge to humanity.

That’s because they are adaptable.

Just as adaptability has helped humans survive, it makes it more difficult to control infectious diseases.

As conditions change, the organism which caused these diseases adapt and become stronger.

There are several kinds of infectious diseases.

Bacterial infections such as pneumonia, are caused by bacteria.

These infections can be treated by antibiotics, which kill the bacteria.

Viral infections are caused by the virus, such as the influenza virus.

These can sometimes be prevented by vaccines, such as the flu vaccines.

An example of parasitic infection is malaria.

Malaria is caused by parasites transmitted to humans by infected mosquitoes.

Once inside the body, the parasites can be difficult to kill or control.

And of course, these parasites are also adaptable.

How serious are infectious diseases?

Consider what happened in 1918, the influenza pandemic.

It started in the fall of 1918 with what seemed to be something no more serious than a common cold.

In the next two years, however, it infected a fifth of the world’s population.

In fact, it turned out to be the most deadly epidemic in history, killing between 20 and 40 million people.

The influenza virus that caused it was much stronger than previous influenza viruses.

Its molarity rate was 2.5% compared to 0.1%in previous influenza epidemic.

Its struck quickly without mercy, sometimes killing people within hours.

School and business closed in many places, and people wore masks to prevent the transmission of the virus through the air.

What was unusual about this pandemic was that it was most deadly for people age 20 to 40, rather than the elderly and young children.

Now a century later, we have flu vaccines that have reduced the severity of the epidemics.

These vaccines needed to be updated every year because the virus changes and new strains emerge.

What researchers fear is that a new strain of the virus will develop and cause another pandemic.

Once an outbreak occurs, transmission of the disease will be even faster than before.

An unattended consequence of our improved transportation system will be the speed at which an epidemic can spread.

Experts predict that the public health systems will be overwhelmed and unable to react quickly enough.

So the best defence will be to prevent an outbreak from occurring.

This will require global cooperation and the sharing of data.

It may also require changes in how humans interact with animals.

Animals such as birds and pigs carry viruses that may mutate into a strain that can infect humans.

Such a new strain could lead to another pandemic well before a new vaccine could be developed.

Since diseases and epidemic don’t stop at national borders, this is a global issue requiring global action.

The threat of a global epidemic is another example of why we must learn to live together.

A new strain of a virus is one that has mutated from the original.