第1个回答 2022-06-09
Infectious Diseases
Despite advances in technology, one of the biggest threats to human survival comes from primitive life forms.
Infectious diseases are caused by micro-organisms, such as bacteria, viruses 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 cause these diseases adapt and become stronger.
One of the biggest threats to human survival comes from primitive life forms.
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 viruses, such as the influenza virus.
These can sometimes be prevented by vaccines, such as the flu vaccine.
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.
Antibiotics attack and kill bacteria.
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 the 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 mortality rate was two and a half percent compared to a point one percent in previous influenza epidemics.
It struck quickly and without mercy, sometimes killing people within hours.
Schools and businesses closed in many places, and people wore masks to prevent transmission of the virus through the air.
What was unusual about this pandemic was that it was most deadly for people aged 20 to 40, rather than the elderly and young children.
Now, a century later, we have flu vaccines that have reduced the severity of epidemics .
These vaccines need 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 unintended 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.
A new strain of a virus is a mutated form of the virus.
A new strain of a virus is one that has mutated from the original.
So the best defense 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 epidemics don’t stop at national boarders , 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.
It allows epidemics to spread more quickly.
Epidemics don't stop at national borders.
One danger is that an animal virus may mutate into a strain that can infect humans.
An improved transportation system allows epidemics to spread more quickly.
Animals, such as birds and pigs carry viruses that may mutate into a strain that can infect humans.
Experts predict that public health systems will be overwhelmed and unable to react quickly enough.
One of the most interesting books of the 20th century was the novel, Catch 22. In the novel, the term 'a catch 22 situation' was introduced. The term has nothing to do with catching anything. It has a much deeper meaning, and it describes a kind of logical conundrum that’s worth exploring.
First, it’s important to put the phrase into context. In the novel, a group of American bomber pilots is on an island in the Mediterranean. They face death almost every day when they fly their bombing missions. Many have already lost their lives. The remaining pilots know that it is only a matter of the time before they will be the next victims.
One of the characters in the novel is a doctor. It is his job to see that the pilots are fit to fly. In particular, there is rule that says he has to ground anyone who is crazy. To ground them means to remove them from active duty so that they don’t fly.
Some of the men believed in the principles they were fighting for. They were willing to give their lives for their country. But to others , this was crazy. They thought the whole thing was insane . One of them, Yossarian, wanted out. He was friends with the doctor, and he wanted the doctor to ground him.
When Yossarian asked the doctor to ground him, the doctor replied: “you’re wasting your time, you’re not crazy”.
Yossarian told him to ask one of the other pilots, Clevinger, to tell him how crazy he was.
“There is no point. He’s crazy.” The doctor replied.” Crazy people can’t decide whether you are crazy or not .”
“Clevinger isn’t crazy! he’s one of the sanest pilots here.”
“So he’s obviously out of his head,” said the Doc. “He’s got to be insane to keep on flying combat missions after all the close calls he’s had .”“well, if he’s crazy, why don’t you ground him?”
“I can’t unless he asks to be grounded. That’s part of the rule.”
“So all he has to do is ask?”
“no, then I can’t ground him.”
“So there is a catch,” said Yossarian, trying to get things straight.
“Sure, there’s a catch,” said the Doc, with a slight smile. “Catch 22. If he asks, then he can’t be crazy. Only those who are crazy are grounded”.
“there’s some catch,” obs erved Yossarian.
“it’s the best there is,” the Doc replied.
If he asks to be grounded he isn't crazy.
To be sane means to be in a healthy state of mind.
A close call is a narrow escape from danger, such as surviving a serous accident.