This document discusses meningitis, including the different types (bacterial, viral, fungal), their causes and risk factors, how they spread, and details about lumbar puncture and CSF glucose testing. Bacterial meningitis is the most serious type and can be deadly if not treated promptly. Viral meningitis is the most common type and usually less severe. Fungal meningitis is rare and usually affects those with weakened immune systems. Lumbar puncture is used to collect CSF for glucose and other tests to help diagnose meningitis. Abnormal glucose levels in the CSF can indicate infection or other issues.

1. By
Dr KHALED ALGARIRI
International Medicine School – MSU
May 2017

2. What is the meningitis and what are the
types?
Meningitis is an inflammation (swelling) of the protective membranes
covering the brain and spinal cord. A bacterial or viral infection of the fluid
surrounding the brain and spinal cord usually causes the swelling. However,
injuries, cancer, certain drugs, and other types of infections also can cause
meningitis. It is important to know the specific cause of meningitis because
the treatment differs depending on the cause.

4. What is Bacterial Meningitis?
Bacterial meningitis is very serious and can be deadly.
Death can occur in as little as a few hours. Most people
recover from meningitis. However, permanent
disabilities (such as brain damage, hearing loss, and
learning disabilities) can result from the infection.

5. How B. Meningitis spread?
 Generally, the germs that cause bacterial meningitis spread from one person to another. Certain
germs, such as Listeria monocytogenes, can spread through food.
 How people spread the germs often depends on the type of bacteria. It is also important to know
that people can carry these bacteria in or on their bodies without being sick. These people are
“carriers.” Most carriers never become sick, but can still spread the bacteria to others.
 Here are some of the most common examples of how people spread each type of bacteria to each
other:
 Mothers can pass group B Streptococcus and Escherichia coli to their babies during labor and
birth.
 People spread Hib and Streptococcus pneumoniae by coughing or sneezing while in close
contact with others, who breathe in the bacteria.
 People spread Neisseria meningitidis by sharing respiratory or throat secretions (saliva or spit).
This typically occurs during close (coughing or kissing) or lengthy (living in the same
household) contact.
 People can get Escherichia coli by eating food prepared by people who did not wash their hands
well after using the toilet.
 People usually get sick from Escherichia coli and Listeria monocytogenes by eating contaminated
food

6. Risk factors of B. Meningitis
 Age
 Babies are at increased risk for bacterial meningitis compared to people in other
age groups. However, people of any age can develop bacterial meningitis. See
section above for which bacteria more commonly affect which age groups.
 Community setting
 Infectious diseases tend to spread where large groups of people gather together.
College campuses have reported outbreaks of meningococcal disease, caused by
N. meningitidis.
 Certain medical conditions
 There are certain medical conditions, medications, and surgical procedures that
put people at increased risk for meningitis.
 Working with meningitis-causing pathogens
 Microbiologists routinely exposed to meningitis-causing bacteria are at
increased risk for meningitis.

8. What is Viral Meningitis? How it spread?
Viral meningitis causesd by viruses , it is the most common type of meningitis, an
inflammation of the tissue that covers the brain and spinal cord. It is often less
severe than bacterial meningitis, and most people get better on their own (without
treatment). However, it’s very important for anyone with symptoms of meningitis
to see a healthcare provider right away because some types of meningitis can be
very serious, and only a doctor can determine if you have the disease, the type of
meningitis, and the best treatment, which can sometimes be lifesaving.
If you have close contact with a person who has viral meningitis, you may become
infected with the virus that made that person sick. However, you are not likely to
develop meningitis. That’s because only a small number of people who get
infected with the viruses that cause meningitis will actually develop viral
meningitis.

9. Risk Factors of V. Meningitis
 children younger than 5 years old, and
 people with weakened immune systems caused by diseases,
medications (such as chemotherapy), and recent organ or bone
marrow transplantations.
 Babies younger than 1 month old and people with weakened immune
systems are more likely to have severe illness.

11. What is Fungal Meningitis ? How it spread?
 Fungal meningitis is rare and usually caused by fungus spreading through
blood to the spinal cord. Although anyone can get fungal meningitis,
people with weakened immune systems, like those with an HIV infection
or cancer, are at increased risk.
 The most common cause of fungal meningitis for people with weak
immune systems is Cryptococcus. This disease is one of the most common
causes of adult meningitis in Africa.
Fungal meningitis is not spread from person to person. Fungal
meningitis can develop after a fungus spreads through the bloodstream
from somewhere else in the body to the brain or spinal cord or from an
infection next to the brain or spinal cord.

12. Risk factors of F. Meningitis
Certain diseases (such as diabetes , cancer and HIV),
medications, and surgical procedures may weaken the
immune system and increase your risk of getting fungal
infection, which can lead to fungal meningitis. Premature
babies with very low birth weights are also at increased risk
for getting Candida blood stream infection, which may spread
to the brain.

13. CSF glucose test
A CSF glucose test measures the amount of sugar
(glucose) in the cerebrospinal fluid (CSF). CSF is a
clear fluid that flows in the space surrounding the
spinal cord and brain.

14. How the Test is Performed
LUMBAR PUNCTURE
A lumbar puncture is a medical procedure where a needle is
inserted into the lower part of the spine to test for conditions
affecting the brain, spinal cord or other parts of the nervous
system

15. CSF is collected by lumbar puncture
between third, fourth, fifth lumbar vertebrae.
It requires certain precautions and careful
technique to prevent the introduction of
infection or the damaging of neural tissue.
Lumbar puncture

16. Risk Factors

17. CSF is collected in three sterile tubes
• Tube 1 – used for chemical and serologic test: centrifuge
and use supernatant for chemistry analysis (glucose, protein, enzymes and
chloride) kept in freezer till performed.
• Tube 2 – used for microbiology lab kept in room
temperature
• Tube 3 – used for hematology (cell count) Cell counts done
as soon as possible after the fluid is collected as cellular degradation occurs
rapidly. If postponed, refrigerate for up to one hour.

18.  Normal Values
 The glucose level in the CSF should be 50 - 80 mg/100 mL (or greater than
2/3 of the blood sugar level).
 Note: Normal value ranges may vary slightly among different laboratories.
Talk to your doctor about the meaning of your specific test results

19. What abnormal results mean?
Abnormal results include increased and decreased glucose levels. Abnormal
results may be due to:
 Infection (bacterial or fungus)
 Inflammation of the central nervous system
 Tumors

21. CSF/blood glucose ratio
Normal CSF glucose/ plasma glucose ratio is
approximately 0.6-0.7
 (N.B. Ratio is decreased if plasma glucose is more than 500
mg/dl
 due to saturation of the glucose carrier system to CSF
CSF/blood glucose ratio may be a better single indicator for
bacterial meningitis. Since the CSF glucose and blood glucose
values are promptly and easily obtained from a lumbar puncture

22. Thank you