Transcript Bacterial meningitis

 Bacterial
 Aseptic
 Viral
 Parasitic
 Non-infectious


Acute bacterial meningitis is the most common form of
meningitis
Bacterial Meningitis occurs when pathogenic bacteria enter the
subarachnoid space and cause an inflammatory response.


There are several pathogens that can cause bacterial
meningitis.


This in turn interferes with blood flow and can result in paralysis
or even stroke
In the United States these include Haemophilus influenzae,
Streptococcus pneumoniae, group B Streptococcus, Listeria
monocytogenes, and Neisseria meningitidis.
In the United States, about 4,100 cases of bacterial meningitis,
including 500 deaths, occurred each year between 2003–2007
(CDC)




The bacteria most often responsible for bacterial meningitis are
common in the environment and can also be found in your nose
and respiratory system without causing any harm.
Sometimes meningitis occurs for no known reason.
Other times it occurs after a head injury or after you have had an
infection and your immune system is weakened.
Common causes of bacterial meningitis vary by age group:
Age Group
Causes
Newborns
Group B Streptococcus, Escherichia coli, Listeria monocytogenes
Infants and Children
Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus
influenzae type b
Adolescents and Young Adults
Neisseria meningitidis, Streptococcus pneumoniae
Older Adults
Streptococcus pneumoniae, Neisseria meningitidis, Listeria
monocytogenes


Age – infants are at higher risk for bacterial meningitis
Community setting -infectious diseases tend to spread quickly within
large cohabitating groups. College students and military personnel are at
increased risk for meningococcal meningitis.

Certain medical conditions - there are certain diseases, medications, and
surgical procedures that may weaken the immune system or increase risk
of meningitis in other ways. (ETOH abuse, sickle cell, splenectomy,
corticosteroids.)

Working with meningitis-microbiologists who are routinely exposed to
meningitis-causing pathogens are at increased risk.

Travel-travelers to Africa and travelers to Mecca during annual
pilgrimages.


Pregnant women are at increased risk of developing listeriosis
(caused by the bacterium Listeria monocytogenes).

Pregnant women typically experience only a mild, flu-like illness with Listeria
infection.

Infections during pregnancy can lead to miscarriage, stillbirth, premature
delivery, or life-threatening infection of the newborn, including meningitis.
Pregnant women who test positive for group B Streptococcus (group
B strep) can pass the bacteria to their baby, most often during labor
and birth.




A newborn infected with group B strep bacteria can develop meningitis or
other life-threatening infections soon after birth.
The risk of meningitis during pregnancy caused by Listeria
monocytogenes can be reduced by learning what foods to avoid
and how to safely prepare and refrigerate food.
Pregnant women should get screened for group B strep at 35-37
weeks.
Women who test positive for group B strep will be given antibiotics
during labor to prevent infection in a newborn.




Onset of symptoms is rapid and severe and usually within 24 hours. Bacterial
meningitis can cause serious complications such as brain damage, hearing loss or
learning disabilities. Most people with meningitis recover however; if allowed to
progress may be fatal.
Signs and Symptoms include:
 Headache
 High Fever
 Neck Rigidity
 Sensitivity to light
 Upset stomach
 Fatigue
 Body Rash
 Sore throat
Adult & Older Children
 Confusion, irritability, increasing drowsiness
 Seizure and stroke may occur
Young Children
 Vomiting or loss of appetite
 Very irritable, crying
 Seizure or hydrocephalus may occur


The pathogens that cause bacterial meningitis can be contagious.

Can spread through the exchange of respiratory and throat secretions (e.g.,
airborne, kissing).

Not spread by casual contact or by simply breathing the air where a person with
meningitis has been

Other meningitis-causing bacteria are not spread person-to-person, but can
cause disease because the person has certain risk factors .

Most of the bacteria that cause meningitis are not as contagious as diseases like
the common cold or the flu.

Unlike other bacterial causes of meningitis, you can get Listeria monocytogenes
by eating contaminated food.
Sometimes the bacteria that cause meningitis spread to other people.



Usually happens when there is close or long contact with a sick person in the
same household or daycare center, or if they had direct contact with a patient's
oral secretions .
Those who had close contact with meningococcal or Haemophilus influenzae
type b meningitis are at higher risk of getting disease and may need antibiotics
Close contacts of a person with meningitis caused by other bacteria, such as
Streptococcus pneumoniae, do not need antibiotics.




If meningitis is suspected, samples of blood or cerebrospinal
fluid are collected and sent to the laboratory for testing.
To know the specific cause of meningitis is important
because that helps doctors understand how to treat the
disease, and possibly how bad it will get.
In the case of bacterial meningitis, antibiotics can help
prevent severe illness and reduce the spread of infection
from person to person.
If bacteria are present, they can often be cultured.


Growing the bacteria in the laboratory is important for confirming the
presence of bacteria, identifying the specific type of bacteria that is
causing the infection, and deciding which antibiotic will work best.
Other tests can sometimes find and identify the bacteria if
the cultures do not.

CAT Scans, X-Rays,






It is important that treatment be started as soon as possible. Bacterial
meningitis can be treated effectively with antibiotics.
Appropriate antibiotic treatment reduces the risk of dying from
meningitis, although the risk remains higher among young infants and the
elderly.
The most effective way to protect against certain types of bacterial
meningitis is to complete the recommended vaccine schedule.
There are vaccines available for three types of bacteria that can cause
meningitis:

Haemophilus influenzae type b (Hib)

Neisseria meningitidis (meningococcus)

Streptococcus pneumoniae (pneumococcus)
Antibiotics may also be recommended for the entire family if a family
member develops severe Hib infection and there’s a high risk person in
the house.
Maintaining healthy habits, like not smoking and avoiding cigarette
smoke, getting plenty of rest, and not coming into close contact with
people who are sick, can also help.




The CDC recommends the meningococcal vaccine for:

All children and adolescents ages 11 through 18

College freshmen living in dormitories

Military recruits

Scientists routinely exposed to meningococcal bacteria

Anyone traveling to or living in a part of the world where the disease is common, such as Africa

Anyone with a damaged spleen or who has had his or her spleen removed

Anyone who has terminal complement component deficiency (an immune system disorder)
The CDC does not recommend the vaccine for:

Anyone who has ever had a severe (life threatening) allergic reaction to a previous dose of
meningococcal vaccine.

Anyone who has a severe (life threatening) allergy to any vaccine component. Tell your doctor
if you have any severe allergies.
The CDC recommends that the following individuals wait before receiving the
vaccine:

Anyone who is moderately or severely ill at the time of their scheduled appointment to receive
their shot should wait until they recover.

Anyone who has ever had Guillain-Barre syndrome should discuss getting the vaccine with his or
her doctor.
Pregnant women should only get the vaccine if it is clinically indicated



The term aseptic meningitis refers loosely to all cases of
meningitis in which no bacterial infection can be
demonstrated.
This is usually due to viruses, but it may be due to
bacterial infection that has already been partially treated,
with disappearance of the bacteria from the meninges, or
by infection in a space adjacent to the meninges (e.g.
sinusitis).
Endocarditis (infection of the heart valves with spread of
small clusters of bacteria through the bloodstream) may
cause aseptic meningitis.




Aseptic meningitis may also result from infection with
spirochetes, a type of bacteria that includes Treponema
pallidum (the cause of syphilis) and Borrelia burgdorferi
(known for causing Lyme disease).
Meningitis may be encountered in cerebral malaria
(malaria infecting the brain).
Fungal meningitis, e.g. due to Cryptococcus neoformans, is
typically seen in people with immune deficiency such as
AIDS.
Amoebic meningitis, meningitis due to infection with
amoebae such as Naegleria fowleri, is contracted from
freshwater sources.
 Viruses
that can cause meningitis include
enteroviruses, herpes simplex virus type 2
(and less commonly type 1), varicella zoster
virus (known for causing chickenpox and
shingles), mumps virus, HIV, and LCMV.
A
parasitic cause is often assumed when
there is a predominance of eosinophils (a
type of white blood cell) in the CSF.
 The most common parasites implicated are
Angiostrongylus cantonensis, Gnathostoma
spinigerum, Schistosoma, as well as the
conditions cysticercosis, toxocariasis,
baylisascariasis, paragonimiasis, and a
number of rarer infections and noninfective
conditions.
Meningitis may occur as the result of several
non-infectious causes: spread of cancer to the
meninges (malignant or neoplastic meningitis)
and certain drugs (mainly non-steroidal antiinflammatory drugs, antibiotics and intravenous
immunoglobulins).
 It may also be caused by several inflammatory
conditions such as sarcoidosis (which is then
called neurosarcoidosis), connective tissue
disorders such as systemic lupus erythematosus,
and certain forms of vasculitis (inflammatory
conditions of the blood vessel wall) such as
Behçet's disease.

Epidermoid cysts and dermoid cysts may cause
meningitis by releasing irritant matter into the
subarachnoid space.
 Mollaret's meningitis is a syndrome of recurring
episodes of aseptic meningitis; it is thought to
be caused by herpes simplex virus type 2.
 Rarely, migraine may cause meningitis, but this
diagnosis is usually only made when other causes
have been eliminated.
