2. Bacteria - small single-celled organisms. Bacteria are found almost
everywhere on Earth and are vital to the planet's ecosystems.
Infections - invasion and growth of germs in the body. The germs may
be bacteria, viruses, yeast, fungi, or other microorganisms.
Virus - an infectious agent that can only replicate within a host
organism. it can infect a variety of living organisms, including bacteria,
plants, and animals.
Viral Infection - any illness you get from a virus (a small germ that
uses your cells to reproduce)
Cytokine Storm - various inflammatory cytokines are produced at a
much higher rate than normal.
Dormant Infections - an infection by an organism that lies hidden or
inactive in the body.
Genital Warts - small growths or bumps on the genital or anal area
Definition of Terms
3. Olfactory nerve - the first cranial nerve (CN I). It enables the sense
of smell and taste.
Olfactory Neuroepithelium - is a specialized epithelial tissue inside
the nasal cavity that is involved in smell
Hemolymphatic - early stage of disease
Meningo-encephalitic - second stage
Definition of Terms
4. BACTERIAL Infections
Bacterial infections are any illness or condition caused by bacterial growth
or poisons (toxins). You can get sick from getting harmful bacteria in your
skin, gut (GI tract), lungs, heart, brain, blood or anywhere else in your body.
5. Common bacterial infections include:
1. Legionnaires'Disease
- Legionnaires' disease is a type of pneumonia caused by Legionella bacteria.
- There are many different species of legionella bacteria found in damp
environments. The two most common are legionella pneumophila (found in
water) and legionella longbeachae (found in soil).
- There are 2 main types: one is caused by contact with contaminated
water, the other is by air-borne bacteria.
- People with Legionnaires' disease usually get sick between 2 and 10 days
after being infected. The symptoms are similar to those of the flu, including:
fever, fatigue, chills dry cough, shortness of breath, chest pain, headache,
muscle pain, tiredness, nausea, vomiting and diarrhoea
6. Common bacterial infections include:
2. Meningococcal Disease
- is a contagious disease caused by a type of bacteria
called Neisseria meningitidis (also known as
meningococcal bacteria).
- People spread meningococcal bacteria to other
people by sharing respiratory and throat secretions
(saliva or spit). Generally, it takes close (for example,
coughing or kissing) or lengthy contact to spread these
bacteria.
7. Common bacterial infections include:
2. Meningococcal Disease
- Meningococcal infections can cause invasive meningococcal disease, which
can include:
septicaemia (when bacteria enter your bloodstream and cause blood
poisoning)
sepsis (a life-threatening condition that occurs when the body damages its
own tissues and organs in response to infection)
meningitis (inflammation of the membranes surrounding your brain and spinal
cord)
- Symptoms of invasive meningococcal disease can include: fever, headache,
neck stiffness, light sensitivity, nausea and vomiting, or loss of appetite,
drowsiness and confusion, leg pain or other muscle or joint aches and pains.
8. Common bacterial infections include:
3. Q Fever
- Q fever is an infection caused by a type of bacteria that you usually catch
from animals.
- Q fever is caused by the Bacterium coxiella burnetii, which is mostly found
in farm animals such as cattle, sheep and goats. It is also found in other
animals including dogs, cats and kangaroos.
- Symptoms of Q fever are similar to symptoms of the flu, including:
high fevers (up to 41°C ) with chills or sweats, which may last up to 4 weeks,
bad headaches, general feeling of being unwell, fatigue or muscle aches, dry
cough, sore throat, nausea, vomiting, diarrhoea or abdominal pain, chest pain
when you breathe and confusion.
- If you work with animals, you have a higher risk of being infected, for
example, if you are a meat worker, shearer, farmer or vet.
9. Common bacterial infections include:
4. Tuberculosis
- Tuberculosis (TB) is an infectious disease that most often damages your
lungs, but can affect any part of your body. It can cause serious illness and
death if it’s not treated. TB is caused by the bacterium Mycobacterium
tuberculosis.
- There are 2 types of TB:
Latent TB infection — this is when someone is infected with TB but does not
get sick, because their immune system is able to control the infection.
Active TB disease — this is when the TB bacteria multiply and the immune
system is not able to control them. Active TB causes symptoms.
- People with TB may: feel tired, lose weight without trying to, have a fever,
sweat in bed at night, lose their appetite, a cough that lasts at least 3
weeks and sputum (phlegm) containing blood and chest pain.
10. Common bacterial infections include:
5. Whooping Cough
Whooping cough is a bacterial infection that spreads from one person to
another. It causes severe bouts of coughing. The ‘whoop’ refers to the
sound you may make if you take a quick breath between coughs. Pertussis,
or the ‘hundred-day cough', are other names for whooping cough.
- Bacteria called Bordetella pertussis causes whooping cough. Having
contact with an infected person’s breathing fluids spreads it. For example,
if you have direct contact with an infected person or they cough or sneeze
near you.
- Whooping cough usually begins with cold-like symptoms including: runny
nose, sneezing, mild dry cough and fever. After these mild symptoms appear,
the cough worsens. When the cough is severe, it may cause vomiting,
fainting, and poor bladder control (urinary incontinence).
11. Viruses often start infecting tissues outside the nervous system before
potentially moving into it. These viruses can establish long-term infections
in the peripheral nervous system (PNS) and occasionally cause severe
problems in the CNS.
Viral Infections
12. How Viral Infections Begin?
It starts in peripheral tissues like epithelial or
endothelial cells.
If the virus isn't controlled:
It can spread to other
tissues
Leading to an excessive
immune response known as
a "cytokine storm"
various inflammatory cytokines are
produced at a much higher rate
than normal - leads to organ
damage
13. Body’s Initial Response:
Intrinsic Immune Response (cellular) - Cellular
mechanisms that combats virus within the infected cells
1.
Innate Immune Response (tissue-level) - Non-specific
defense mechanisms that act to limit the spread of the
virus and activate the adaptive immune system.
2.
Acquired Immune Response - Highly specific to the
particular virus and involves the production of antibodies
by B cells and the activation of T cells.
3.
15. ENTEROVIRUS
Can cause: Aseptic meningitis,
Poliomyelitis, Encephalitis
Symptoms: fever, headache, stiff
neck, and sensitivity to light
Spread: Person to person
Treatment: No specific treatment
only treatment of specific symptoms
19. ENTEROVIRUS
Can cause: Aseptic meningitis,
Poliomyelitis, Encephalitis
Symptoms: fever, headache, stiff
neck, and sensitivity to light
Spread: Person to person
Treatment: No specific treatment
only treatment of specific symptoms
20. Can cause: Encephalitis and ultimately
death if untreated.
Symptoms: Weakness or discomfort,
fever, or headache, itching
Spread: Saliva of infected animals
Treatment: There's no effective
treatment. Must get a series of shots to
prevent the infection from taking hold.
RABIES
21. Can cause: Neurological complications in
Immunocompromised individuals, such as
Encephalitis, Ventriculitis, and Myelitis.
Symptoms: High temperature, aching muscles,
skin rash, sore throat, swollen glands
Spread: Person to person through body fluids,
such as blood, saliva, urine, semen and breast
milk
Treatment: No cure, but there are medications
that can help treat the symptoms.
Cytomegalovirus
25. Can cause: Neurological complications in
Immunocompromised individuals, such as
Encephalitis, Ventriculitis, and Myelitis.
Symptoms: High temperature, aching muscles,
skin rash, sore throat, swollen glands
Spread: Person to person through body fluids,
such as blood, saliva, urine, semen and breast
milk
Treatment: No cure, but there are medications
that can help treat the symptoms.
Cytomegalovirus
26. PROTOZOAL Infections
Protozoal Infections are infectious diseases which
spread through travel. For a number of these organisms, the
nervous system is only one of the many systems involved;
however, this localization may often be the most severe and
incompatible with the survival of the patient. The CNS may be the
only affected system; when not, it is often the most severely
affected.
27. Amoebiasis:
•Cerebral Amoebic Abscess
Causative Agent: Entamoeba histolytica infection
Symptoms: HIV/AIDS and heart defects.
Gastrointestinal Infection, swelling of the brain,
headache, and seizures.
Transmission: Ingestion of cysts in infected faeces.
The bacteria or fungi make their way into your brain,
either through your bloodstream or from an infected
area in your head, such as your ears or sinuses.
29. Amoebiasis:
•Primary Amoebic Encephalitis (Free Living
Amoebae)
Causative Agent: Naegleria fowleri, “Brain-eating amoeba"
Symptoms: immunodeficiency and diabetes. Malnutrition,
changes in smell or taste, headaches, nausea, vomiting to
confusion, and death.
Transmission: The amoebas can enter the brain through
the nose when people swim in contaminated warm, fresh
water.
31. Amoebiasis:
•Primary Amoebic Meningoencephalitis
Caused by: Naegleria fowleri, “Brain-eating amoeba"
Causes: destroys brain tissue, causing severe brain
swelling and death in most cases within 2–7 days.
Headache, hallucinations, and coma.
Transmission: It is found in swimming pools, lakes, and
rivers. It invades the nasal mucosa and enters the brain by
travelling along the olfactory nerves.
33. Amoebiasis:
•Granulomatous Amoebic Encephalitis (GAE)
Caused by: Acanthamoeba castellanii, A. polyphaga, and
Balamuthia mandrillaris
Symptoms: HIV infection, lymphoma, malnutrition, cirrhosis, and
diabetes. Headache and seizures.
Transmission: Amoebae enter into the lungs via the nasal route,
where they cross the blood-brain barrier and enter into the CNS.
Skin lesions may provide direct entry into the bloodstream,
bypassing the lower respiratory tract. The olfactory
neuroepithelium may provide an alternative route of entry into the
CNS.
35. Cerebral Malaria:
•Cerebral Malaria
Causative Agent: Plasmodium: Plasmodium falciparum, P.
vivax, P. malariae, and P. ovale
Symptoms: P. falciparum causes the most severe morbidity
and mortality and is responsible for the syndrome of
cerebral malaria (CM), seizures, and coma
Transmitted by: anopheline mosquito, parasite-filled blood
cells block small blood vessels in the brain
39. Toxoplasmosis:
•Congenital Toxoplasmosis
Causative Agent: transplacental acquisition of
Toxoplasma gondii
Symptoms: premature delivery, chorioretinitis, minor
brain calcifications, and fetal death
Transmission: occurs only if maternal infection is
acquired during pregnancy, and is transmitted
through the placenta
41. Trypanosomiasis:
•Human African Trypanosomiasis (Sleeping
Sickness)
Causative Agent: Trypanosoma brucei rhodesiense and
Trypanosoma brucei gambiense, blood-feeding insects
Symptoms: sleep disruption, confusion, lethargy,
convulsions, and swollen lymph nodes.
Transmission: man to man or cattle to man by Glossina spp
tsetse flies, it evolves in a first hemo-lymphatic stage,
progressing to a second meningo-encephalitic stage when
the parasites cross the blood-brain barrier.
43. RICKETTSIAL INFECTIONS
Rickettsiae are bacteria that can
only survive inside cells
Most bacteria are spread through
ticks, fleas or lice
Spotted fever group, Typhus group,
Scrub typhus group
52. Viral Lymphatic Infections
Lymphadenitis occurs when one or more lymph nodes are
infected by a bacteria, a virus, or a fungus. When lymph nodes
become infected, it's usually because an infection started
somewhere else in your body.
53. Types of Viral Lymphatic
Infections
Yellow fever is a viral disease of the
bloodstream transmitted by the mosquito
Aedes aegypti. After injection by the
mosquito, the virus spreads to the lymph
nodes and blood, where it persists in the
bloodrich organs such as the liver. Very
high fever, nausea, and jaundice
accompany the disease.
54. Types of Viral Lymphatic
Infections
Dengue fever is transmitted by the Aedes
aegypti mosquito and caused by an RNA virus.
The viruses enter the bloodstream, where
they cause fever and severe muscle, bone,
and joint pains, leading to breakbone fever.
Successive exposures to the virus may result
in dengue hemorrhagic fever, in which
extensive hemorrhaging occurs in the blood-
rich organs.
55. Infectious mononucleosis is caused by a herpes virus
believed to be the Epstein-Barr virus. This virus has DNA
and an envelope and the ability to remain latent in the B-
lymphocytes. Symptoms of infectious mononucleosis include
sore throat, mild fever, enlarged spleen, and an elevation
of infected B-lymphocytes known as Downey cells. The
viruses are often transmitted by saliva. Treatment usually
consists of extensive bed rest, and recurrences are
possible.
Types of Viral Lymphatic
Infections
57. HIV Infection and AIDS
HIV IS A VIRUS THAT ATTACKS THE BODY'S IMMUNE
SYSTEM.
WHILE AIDS IS A SEVERE, LIFE-THREATENING SYNDROME
THAT REPRESENTS THE LATE CLINICAL STAGE OF
INFECTION WITH HIV.
IF HIV IS NOT TREATED, IT CAN LEAD TO AIDS.
INITIAL SYMPTOMS INCLUDES, FEVER,HEADACHE, RASH,
SORE THROAT
58. Two types :
▪︎Type 1 (HIV1), which is the most
common type
▪︎Type 2 (HIV-2) HIV viruses are single-
stranded RNA viruses in the family.
Mode of Transmission:
Transmission occurs via direct sexual
contact.
Sharing of contaminated needles and syringes.
Contaminated blood and blood.
Mother to child
59. MUMPS
MUMPS IS AN ACUTE VIRAL
INFECTION CHARACTERIZED BY FEVER AND SWELLING AND
TENDERNESS OF THE SALIVARY GLANDS.
COMPLICATIONS CAN INCLUDE ORCHITIS, OOPHORITIS,
MENINGITIS, ENCEPHALITIS, DEAFNESS, PANCREATITIS,
ARTHRITIS,MASTITIS, NEPHRITIS, THYROIDITIS, AND
PERICARDITIS.
60. Mode of Transmission:
• Transmission occurs via droplet
spread and direct contact with
the saliva of an infected
person.
Mumps is caused by mumps
virus, an RNA virus
in the genus Rubulavirus, family
Paramyxoviridae.
61. VIRAL HEMORRHAGIC INFECTIONS
VIRAL HEMORRHAGIC DISEASES
ARE EXTREMELY SERIOUS, ACUTE VIRAL ILLNESSES.
INITIAL SYMPTOMS INCLUDE SUDDEN ONSET OF
FEVER, MALAISE, MYALGIA,
AND HEADACHE, FOLLOWED BY PHARYNGITIS,
VOMITING, DIARRHEA, RASH, AND INTERNAL
HEMORRHAGING.
62. Mode of Transmission:
• Infected African green monkeys
• Person to person via direct contact with infected blood,
secretions, internal organs, or semen, or by needlestick.
• The risk is highest when the patient is vomiting, having
diarrhea, or hemorrhaging.
Viral hemorrhagic fevers are caused
by many different viruses, including
dengue virus, yellow fever virus,
Crimean-Congo hemorrhagic fever
virus, Lassa virus, Ebola
virus, and Marburg virus.
63. Infectious Mononucleosis
(ALSO
CALLED “MONO” OR THE “KISSING DISEASE”) IS
AN ACUTE VIRAL
DISEASE THAT MAY BE ASYMPTOMATIC OR
MAY BE CHARACTERIZED BY FEVER, SORE
THROAT, LYMPHADENOPATHY (ESPECIALLY
POSTERIOR CERVICAL LYMPH NODES),
SPLENOMEGALY (ENLARGED
SPLEEN), AND FATIGUE.
64. Mode of Transmission:
• Transmission occurs from person to person
by
direct contact with saliva. Kissing facilitates
spread among
adolescents.
• Can be transmitted via blood transfusion.
The etiologic agent of infectious
mononucleosis is
Epstein-Barr virus (EBV), which is
also known as human
herpesvirus 4.
