UNIT 12A-INFECTOUS AND NON-INFECTOUS
DISEASES
[RABIES & COVID-19]
[Emmanuel Aire Benant]
[BTEC Level 3 Applied Science]
[Samantha Watters]
[27/02/2023]
,A pathogen is a microorganism (such as a virus, bacteria, fungus, or parasite) that causes
disease. Pathogens can be spread through contact with an infected person, animal, or object,
or through contaminated food or water. Pathogens can also enter the body through the air,
such as when someone inhales contaminated dust particles.
Pathogens cause a wide range of illnesses, from mild to severe. Common symptoms of an
infection include fever, rash, nausea, vomiting, and diarrhea. Other symptoms may include
muscle aches, headaches, and coughing. Some illnesses caused by pathogens can be treated
with antibiotics or antiviral medications, while others may require hospitalization and
supportive care.
Pathogens can also be spread through vectors, such as mosquitoes, ticks, and fleas, which
transmit them from one person or animal to another. This can lead to the spread of serious
diseases, such as malaria. Vaccines are available for some illnesses, such as measles and
polio, which can help prevent the spread of these diseases.
In summary, a pathogen is an infectious agent that can cause disease. Pathogens can be
spread through contact with an infected person or object, through contaminated food or
water, or through vectors such as mosquitoes and ticks. Vaccines are available for some
illnesses, which can help prevent the spread of disease.
Characteristics of viruses
Viruses are a type of microscopic infectious agent that can only replicate inside the cells of
other living organisms. They are composed of genetic material, either DNA (deoxyribonucleic
acid) or RNA, surrounded by a protein coat. Viruses can infect organisms ranging from
bacteria and plants to animals, including humans.
Viruses have a few distinct characteristics that define them. They are not considered to be
living organisms because they cannot replicate on their own, but instead must rely on the
host cell to carry out the synthesis of their components. Viruses also obligate intracellular
parasites, which mean they must invade a host cell to multiply.
Viruses are exceedingly small, ranging from 20 to 300 nanometers in diameter. They can only
be seen through an electron microscope and are one of the smallest known infectious agents.
They are also highly diverse and can infect many diverse types of organisms.
Viruses can cause a wide range of diseases, from mild colds to more serious illnesses such as
polio or smallpox. They can also be used to deliver genetic material into cells, making them
useful tools for gene therapy.
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,Viruses are also highly adaptable and can quickly evolve to overcome host defenses and cause
disease. In addition, they can spread rapidly and be difficult to control. Viruses move by
attaching to, entering, and hijacking the reproductive machinery of the host cell. This allows
the virus to replicate itself and spread to other cells. Some viruses move through the
bloodstream, while others can travel through the air.
[COVID-19]
1. SARS-CoV-2 is a positive-sense single-stranded RNA virus.
2. It is the causative agent of the coronavirus disease 2019 (COVID-19).
3. It is a member of the family of Coronarias and is related to the SARS-Cove virus that
caused the SARS outbreak in 2002-2004.
4. Its genome is about 30,000 base pairs in length.
5. It has four major structural proteins: spike (S), envelope (E), membrane (M) and
nucleocapsid (N) proteins.
6. It has an estimated incubation period of up to 14 days (about 2 weeks).
7. The virus is highly contagious and can spread through contact with an infected person,
respiratory droplets, and contaminated surfaces.
8. Symptoms of infection include fever, cough, difficulty breathing and fatigue.
9. It can cause severe illness and death, especially in the elderly and those with
underlying health conditions.
10. It is highly susceptible to environmental conditions such as heat and humidity.
[RABIES]
1. Lyssavirus is a genus of viruses in the family Rhabditida.
2. Lyssaviruses are composed of a single-stranded, negative-sense RNA genome.
3. Lyssaviruses are known to cause a range of diseases in mammals, including rabies in
humans.
4. Lyssaviruses can be transmitted through direct contact with infected animals or
through contact with animal saliva.
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,5. Lyssaviruses have been found in a wide range of mammals, including bats, cats, dogs,
horses, and monkeys.
6. Infection with lyssavirus typically results in acute, progressive encephalitis.
7. There is currently no known cure for lyssavirus infection, though preventative
measures such as vaccination can help reduce the risk of transmission.
8. Lyssavirus is a disease that is spread through the bite or scratches
of an infected animal and can be fatal if left untreated.
LIFE CYCLES
[COVID-19]
SARS-CoV-2 is the virus responsible for the current pandemic of coronavirus disease
(COVID-19). The virus has a distinct life cycle consisting of seven stages.
Stage 1: Attachment and Entry – The SARS-CoV-2 virus attaches to a host cell by binding
its spike proteins to specific receptors on the cell’s surface. It then enters the cell by
using its own fusion proteins to fuse the cell’s membrane with its own.
Stage 2: Uncoating – Once inside the host cell, the virus’s genome is released, and the
virus’s core is disassembled. The virus’s genome is then transcribed into mRNA.
Stage 3: Protein Translation – The mRNA is translated into proteins, which are used to
replicate the virus’s genetic material.
Stage 4: Genome Replication – The virus’s genome is replicated in the host cell’s
cytoplasm.
Stage 5: Assembly – The viral proteins and genome assemble in the host cell’s cytoplasm
to form new virus particles.
Stage 6: Release – The new virus particles are released from the host cell by either
budding or lysis.
Stage 7: Infection: The newly released virus particles can infect other cells, starting the
cycle again.
The life cycle of SARS-CoV-2 is quickly a few hours to complete. As such, it is important to
identify and contain potential sources of infection as quickly as possible to prevent the
virus's spread.
SARS-CoV-2 is a type of virus known as a coronavirus that is responsible for causing
COVID-19. It is believed to have originated from an animal source, with bats being the
most likely source. The virus is spread through droplets when an infected person coughs,
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,sneezes, or talks, and it can also be spread through contact with infected surfaces. Once
it is inside the body, it attaches to cells and replicates, causing an infection. The virus
binds to ACE2 receptors present on the surface of human cells, those in the lungs, and
enters the cells. Inside the cells, the viral RNA is translated into viral proteins which help
the virus to replicate and spread. The viral proteins also induce an immune response
which leads to inflammation and tissue damage in the affected areas. This inflammation
and tissue damage causes the symptoms of Covid-19, such as fever, coughing, and
shortness of breath.
[RABIES]
The life cycle of lyssavirus involves an initial attachment and entry into a host cell
followed by replication, transcription, translation, and assembly of new virus particles.
The newly formed virus particles are then released from the host cell and infect other
cells, leading to a full cycle of lyssavirus replication.
Attachment and Entry: Lyssavirus binds to cell surface receptors and enters the host cell
through endocytosis.
Penetration: the virus penetrates the epithelial cells of the mucous membranes, where it
replicates and spreads rapidly throughout the body.
Replication: Once inside the cell, the virus takes over the host cell machinery and
replicates its own genetic material.
Transcription and Translation: Lyssavirus transcribes its genetic material into mRNA,
which is then translated into viral proteins.
Assembly: The newly formed viral proteins assemble into new virus particles.
Release: Newly formed virus particles are released from the host cell either through cell
lysis or exocytosis.
Infection of New Cells: The released virus particles infect new cells, leading to a full cycle
of lyssavirus replication.
Rabies is a viral disease caused by Lyssavirus. It is a zoonotic virus, meaning it can be
transmitted from animals to humans. The virus is found in the saliva of infected animals
and is typically transmitted through a bite or scratch. Once inside the body, the virus
travels along nerves to the brain, where it multiplies and causes encephalitis
(inflammation of the brain). The virus enters the body through the wound caused by the
bite or scratch. It then travels through the nerves to the brain, where it multiplies and
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,causes encephalitis. The virus can also spread to other parts of the body, including the
salivary glands, where it can be secreted in the saliva. This is how the virus spreads from
animals to humans.
This can result in various symptoms, including seizures, confusion, paralysis, and
hydrophobia (fear of water). In severe cases, rabies can be fatal.
EFFECTS ON THE BODY
Covid-19 is a virus that has had a significant impact on the human body. The most
common symptoms of Covid-19 are fever, dry cough, and fatigue. In more severe
cases, the virus can cause pneumonia, acute respiratory distress syndrome, and
even death. Also, Covid-19 has been linked to other health complications,
including heart and lung damage, kidney failure, and neurological problems. The
long-term effects of Covid-19 are still unknown, but the virus has had a major
impact on the human body. ´
Covid-19 is known to cause inflammation in the body, which can lead to damage to the
lungs, heart, and other organs. Inflammation can also increase the risk of developing
blood clots, which can cause strokes and heart attacks. Additionally, Covid-19 has been
linked to an increased risk of developing diabetes, as the virus can cause damage to the
pancreas and other organs.
Covid-19 can also affect the immune system, making it more difficult for the body to fight
off other infections. Additionally, the virus can cause inflammation of the brain, which
can lead to neurological problems such as confusion, memory loss, and difficulty
concentrating.
Finally, Covid-19 has been linked to an increased risk of mental health disorders. People
who have been infected with the virus are more likely to suffer from depression, anxiety,
and other mental health issues.
Overall, Covid-19 has had a significant impact on the human body. It is important to
remember that the long-term effects of the virus are still unknown, and it is important to
take all necessary precautions to protect yourself and your loved ones.
Rabies: The virus enters the body through a bite or other wound, typically on the face or
hands. Over several days, the virus spreads throughout the body, infecting the central
nervous system. As it does so, it causes a wide range of symptoms.
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,In the initial stages, the person may experience fever, headache, fatigue, and confusion.
As the virus continues to spread, the person will experience increased agitation and
anxiety, hallucinations, delirium, and muscle spasms. Eventually, the person may
experience paralysis, difficulty breathing, coma, and death.
Once the virus is in the body, it is exceedingly difficult to treat. In most cases, the only
effective treatment is a course of post-exposure prophylaxis (PEP), which involves a
series of vaccinations and immunoglobulin injections. The sooner the PEP is started, the
better the chances of survival. If the PEP is started within 24 hours of exposure, it is
effective in preventing symptoms.
In some cases, even if the PEP is started within 24 hours, the virus can still cause severe
neurological symptoms. If the person is not treated within a few days, they can
experience paralysis and death. Because of this, it is important to seek medical attention
as soon as possible after potential exposure to rabies.
People who are infected but asymptomatic or people with mild COVID-19 should isolate
through at least day 5 (day 0 is the day symptoms appeared or the date the specimen was
collected for the positive test for people who are asymptomatic).
Asymptomatic Covid 19 patients may have symptoms and, without knowing, can spread
the virus to others.
People who are infected but asymptomatic or people with mild COVID-19 should isolate
through at least day 5 (day 0 is the day symptoms appeared or the date the specimen was
collected for the positive test for people who are asymptomatic). They should wear a
mask through day 10.
Rabies is a deadly virus that is mostly spread through the saliva of an infected animal,
typically a dog or bat. The virus can spread to other animals and humans through a bite,
or if the saliva of an infected animal meets a person’s mucous membrane or an open
wound. Once the virus is contracted, it progresses over time in a series of stages.
1. Prodromal stage: This is the first stage of rabies and is characterized by the onset of
flu-like symptoms such as fever, headache, generalized weakness and malaise. The
patient may also experience anxiety, confusion, agitation, and insomnia.
2. Excitative stage: This is the second stage of rabies and is characterized by violent
movements, hypersensitivity to touch and sound, confusion and aggression.
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,3. Paralysis stage: This is the third stage of rabies and is characterized by paralysis of the
muscles of the face, throat, and limbs, resulting in difficulty talking, swallowing, and
breathing.
4. Coma stage: This is the fourth stage of rabies and is characterized by a deep coma and
eventually death.
5. Death stage: This is the fifth and final stage of rabies and is characterized by death. It
is usually caused by respiratory failure or cardiovascular collapse.
Write about the stages COVID 19
Stage 1: Exposure and Early Symptoms
This is the stage when a person is exposed to the virus, either through contact with
someone infected or with a contaminated surface. This stage can last from 2 days to 2
weeks. During this stage, the person may experience mild symptoms, such as a fever,
cough, sore throat, and other flu-like symptoms.
Stage 2: Progression of Symptoms
This is the stage when the virus begins to spread in the body, causing more severe
symptoms. These can include high fever, difficulty breathing, chest pain, and other more
serious symptoms. This stage can last anywhere from 1 to 4 weeks.
Stage 3: Recovery
This is the stage when the body begins to fight the virus, and the person begins to
recover. During this stage, the person may experience fatigue, body aches, and other
symptoms as the body works to fight the virus. This stage can last from 1 to 2 weeks.
Stage 4: Post-Recovery
This is the stage when the person recovers from the virus. During this stage, the person
may still experience fatigue or other lingering symptoms, but the virus should no longer
be active in the body. This stage can last from 1 to 6 months.
highlight, in detail the most crucial factors associated with damage caused to various body
systems by Covid-19
Rabies & Covid-19 can affect human body systems, including:
The Respiratory system:
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,Rabies is a virus that affects the nervous system, while Covid-19 affects the respiratory
system. Both viruses are spread by contact with an infected individual, animal, or object.
However, while rabies is primarily transmitted through saliva, Covid-19 is primarily
spread through contact with respiratory droplets.
Rabies can cause inflammation in the respiratory system, which can lead to difficulty
breathing and difficulty swallowing. In severe cases, it can also cause paralysis of the
respiratory muscles, leading to respiratory failure.
Covid-19, on the other hand, primarily affects the lower respiratory tract, leading to
inflammation and the production of mucus. This can cause difficulty breathing, coughing,
and chest pain. In severe cases, it can cause respiratory failure and even death.
Both viruses can cause long-term damage to the respiratory system, leading to permanent
damage and decreased lung function.
The Lymphatic system: Rabies and Covid-19 both affect the lymphatic system in diverse
ways.
Rabies is a virus that is spread through the saliva of an infected animal, usually a bat,
raccoon, fox, or skunk. The virus travels through the nerves and into the lymph nodes,
where it replicates and spreads to other parts of the body. The virus can cause
inflammation of the lymph nodes and can lead to a swelling of the lymph nodes, known as
lymphadenopathy (increased size of lymph nodes).
Covid-19 is caused by the SARS-CoV-2 virus, which is spread through contact with an
infected person or by respiratory droplets. The virus can travel through the blood stream
and into the lymph nodes, where it can cause inflammation. This inflammation can lead to
swollen lymph nodes and can cause lymphadenitis, which is a condition where the lymph
nodes become enlarged and tender. In some cases, the lymph nodes may become
infected, leading to an infection called lymphadenitis.
Both rabies and Covid-19 can lead to inflammation of the lymph nodes and can cause
swelling and tenderness. In severe cases, the inflammation can lead to an infection and
can be potentially life-threatening. It is important to seek medical attention if you have
any symptoms of either of these viruses, as prompt treatment is essential.
The Circulatory system: Rabies affects the circulatory system by attacking the nerve cells
of the autonomic nervous system, which is responsible for controlling involuntary body
functions such as blood pressure, heart rate and breathing. This can lead to a high fever,
muscle spasms, and paralysis of the diaphragm which can cause difficulty breathing and
even death.
Covid-19 affects the circulatory system by causing inflammation and damage to the walls
of the blood vessels. This can lead to clotting and a decrease in oxygen-rich blood
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, delivered throughout the body. This can cause a decrease in organ function, including the
heart, and can even lead to stroke or a heart attack. In addition, Covid-19 has been linked
to an increased risk of heart failure and other cardiovascular complications.
The Digestive system: Rabies affects the digestive system by causing nausea, vomiting,
and abdominal pain. In severe cases, it can cause paralysis of the digestive tract, which
can lead to severe dehydration, malnutrition, and even death.
Covid-19 affects the digestive system in a variety of ways. In some people, it can cause
diarrhea, nausea, vomiting, and abdominal pain. In more severe cases, it can cause
inflammation of the gastrointestinal tract, which can lead to poor absorption of food and
nutrients, weight loss, and even death. It can also cause a decrease in appetite and
difficulty swallowing. Additionally, Covid-19 can cause inflammation of the pancreas,
leading to pancreatitis and other associated symptoms
1. Age: Older individuals are at increased risk of severe disease and death from Covid-19.
2. Comorbidities: People with underlying health conditions such as diabetes, heart
disease, obesity, and chronic lung disease are at greater risk for severe illness and death
from Covid-19.
3. Genetics: Research suggests that certain genetic variants may increase the risk of
severe illness from Covid-19.
4. Gender: Men are at higher risk of severe disease and death from Covid-19 than women.
5. Exposure: Exposure to the virus increases the risk of developing severe Covid-19.
6. Smoking: Smoking increases the risk of severe Covid-19.
7. Immunosuppression: Individuals on immunosuppressive medications or with
immunosuppressive diseases are at greater risk of severe Covid-19.
8. Nutrition: Poor nutrition increases the risk of severe Covid-19.
9. Pregnancy: Pregnant women are at increased risk of severe Covid-19.
10. Mental Health: Severe Covid-19 may be more likely to occur in people with mental
health conditions.
Statistics
Cases
Vaccines
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