Curbing the spread of disease Part 1

 

        

Once people came to understand that germs cause many diseases,
they started identifying and blocking the paths along which
the germs travel. In many cases, doing this was possible before
anyone had any detailed knowledge of the actual germs involved.

One strategy for blocking the spread of infectious disease is
quarantine, which involves identifying the people who have a contagious
disease and separating them from healthy people so that
the disease doesn’t spread. Quarantines have been used for
thousands of years. More recently quarantines have helped control
diseases like the supercontagious and deadly Ebola virus, which
has devastated several villages in Africa over the past few decades,
and SARS (severe acute respiratory syndrome).

Quarantines can be effective in controlling some contagious diseases.
But there are several big drawbacks. For one thing, it can
be hard to identify all the sick people. In many cases, a person
might be infected and still be able to spread the disease for quite a
while before developing any symptoms of the disease.
Second, some infected people never get sick at all. But in either
case, a person who looks healthy.





might still be able to pass on his or her germs to others. Quarantines
also can’t always block other ways that germs might spread—
for example, through infected water, food, animals, or insects.
Finally, quarantines can mean separating sick people from their jobs,
friends, and family, and that can be very hard to do. Today, big
quarantines involving lots of people are rare and are used
mainly in emergencies.

Another way to control the spread of disease is by controlling the
vectors that help it spread. A vector is a kind of middleman: a creature
which carries a germ that infects people. For example, mosquitoes
are the main vectors for malaria (a deadly disease common
in the tropics). For centuries, European explorers assumed that
the disease was caused by something in the tropical air (in fact,
the word “malaria” translates to (bad air”). But in 1895, the British
biologist Ronald Ross discovered that a tiny parasite (an organism
that lives off another organism) really causes the disease. Three
years later, a team of Italian scientists figured out that the parasite
was carried by mosquitoes and was spread through their bites.
Once people understood this, people in tropical cities were able to
reduce the threat of malaria by draining nearby swamps where
mosquitoes bred.

Understanding the role of germs Final Part

                                                                                                                                           

Louis Pasteur (1822–1895), a French chemist, was one of the most important scientists
in history. Many of his accomplishments and insights set the stage for modern medicine.
Pasteur increased our understanding of disease by proving the theory of spontaneous
generation—the belief that some life-forms, such as insects and microbes, could suddenly
materialize from nonliving matter—wasn’t true. For example, it was thought
that the mold that grew on spoiled milk just appeare there from nothing. People had believed in
spontaneous generation since ancient times, and although others before
Pasteur had raised objections, Pasteur’s experiments were the most convincing. He
proved that molds, fungi, and bacteria were actually present in
the air and that they wouldn’t grow on anything they couldn’t touch.

Not only did Pasteur show that germs were present everywhere,
but he also pioneered ways to get rid of them. He
proved that boiling liquids like wine and milk killed any germs
that were present, and then he demonstrated that quickly sealing
them off from air kept new germs from growing. This
process is called pasteurization, and it’s still used today. He
also suggested that surgeons boil their instruments before
doing surgery, but the idea didn’t catch on until later.
Pasteur’s work helped to convince other scientists that germs
were the cause of contagious diseases. Among his many
accomplishments, Pasteur pioneered vaccines for chicken pox,
cholera, diphtheria, anthrax, and rabies.


Physician Girolamo Fracastoro in the year 1546. But his idea didn’t
catch on. For one thing, nobody could see these germs—the microscope
hadn’t been invented yet! And by the time scientists finally
began to study bacteria and viruses, Fracastoro’s work had been mostly forgotten

The “germ theory” of disease was really popularized by the French
chemist Louis Pasteur in the 19th century. By then, Pasteur was able
to show that the presence of germs was linked to certain illnesses.
Once this idea was established, scientists started identifying the
bacteria and viruses that cause common diseases. As technology
improved, so did our ability to find, categorize, and study these
microscopic creatures .

Today, scientists have identified many of the germs that cause
known human diseases—even the ones that we can’t cure. Obviously,
knowing what causes an illness is incredibly important to doctors
and patients who are trying to fight it, and scientists are working
very hard to figure out the nature of more illnesses—like multiple
sclerosis—so they can identify and help eliminate the viruses
that may cause them. 

Understanding the role of germs (Part 2)

                                      
Garlic has long been used to fight off illness, but it is only recently that scientists
learned it can kill germs.



Ple, the bacteria in your intestines help you digest food.) But
other microbes have the potential to cause illness in the
human body. We call these disease- causing microbes germs.
Germs can be spread through food, water, the air, or the environment.
They can also be spread by physical contact
between two people. Sometimes germs can be spread by physical
contact with animals, although many germs that infect animals
are slightly different from the ones that make people sick.

Before people knew about germs, they didn’t understand how diseases started and spread.
Sometimes they blamed diseases on evil spirits—or, later, on “bad blood,” an idea without any medical source. They would come up with treatments based on these
ideas, such as performing exorcisms or deliberately cutting people
to drain the “bad” blood. These treatments often failed,
and even when they worked, doctors didn’t fully understand why.
For example, garlic was used for medical purposes in many
ancient cultures, but only recently have scientists discovered that
it can kill germs.

One of the earliest known suggestions that germs cause disease came from the Italian

To be continue....+