Institute for Microbiology, Medical Faculty of Masaryk University     and St. Anna Faculty Hospital
in Brno
Agents of neuroinfections

Central nervous system infections
•relatively rare
•can have a very serious course
•Incidence                                       bacterial meningitis: 2/100.000/year viral
meningitis:      10/100.000/year
•Lethality                                              bacterial meningitis, non-treated: >70 %
                                              treated: ~10 %

Penetration into CNS
•From a peripheral focus:
by means of blood (meningococci)
per continuitatem (pneumococci or
        haemophili from the middle ear)
along nerves (HSV, rabies virus)
•Directly:
after an injury  (pneumococci, staphylococci, nocardiae, aspergilli)

http://www.dcu.ie



 Etiology of CNS infections
...depends on the type and the duration of the disease, different in....
1. meningitis
- acute bacterial (purulent)/viral (aseptic)
- chronic
2. encephalitis
3. brain abscess – acute or chronic

 Cytology and biochemistry of CSF
marker
norm
purulent meningitis
aseptic meningitis
cells
0-6/μl
↑↑↑ (>1000)
↑↑(100-500)
proteins
20-50 mg/100 ml
↑↑ (>100)
↑ (50-100)
glucose
40-80 mg/100 ml
↓ (<30)
~ (30-40)

 Etiology of acute meningitis – I
Etiology of purulent meningitis by the age in %
age
GBS
0-1 m.
50
1-4 y.
5-29
30-59
≥60

www.bakteriologieatlas.de



 Etiology of acute meningitis – II
Etiology of purulent meningitis by the age in %
age
GBS
Haem. infl. b
0-1 m.
50
1-4 y.
70
5-29
30-59
≥60




 Etiology of acute meningitis – III
Etiology of purulent meningitis by the age in %
age
GBS
Haem. infl. b
Neiss. men.
0-1 m.
50
1-4 y.
70
5-29
45
30-59
≥60







 Etiology of acute meningitis – IV
Etiology of purulent meningitis by the age in %
age
GBS
Haem. infl. b
Neiss. men.
other
0-1 m.
50
1-4 y.
70
5-29
45
30-59
40
≥60

 Etiology of acute meningitis – V
Etiology of purulent meningitis by the age in %
age
GBS
Haem. infl. b
Neiss. men.
other
Str. pneu.
0-1 m.
50
1-4 y.
70
5-29
45
30-59
40
≥60
50

http://bioinfo.bact.wisc.edu



http://images.google.cz



 Etiology of acute meningitis – VI
Etiology of purulent meningitis by the age in %
age
GBS
Haem. infl. b
Neiss. men.
other
Str. pneu.
List. mono.
0-1 m.
50
33
10
1-4 y.
70
15
10
5-29
45
25
20
30-59
10
40
33
≥60
25
50
15




 Lethality and sequelae of purulent meningitis
 ....according to etiology

impor-tance
GBS
Haem. infl. b
Neiss. men.
other
Str. pneu.
List. mono.
letha-lity
â€
â€
seque-lae
+++
+
+
+

 Aseptic (viral) meningitis

mumps virus  (CNS infection is clinically silent)
enteroviruses: echoviruses (30 serotypes)
                          coxsackieviruses (23 + 6 serotypes)
tick-borne encephalitis virus (TBEV)
rarely HSV and VZV and other neuroviruses
rarely some bacteria
leptospirae, borreliae, M. tuberculosis

Etiology of chronic meningitis
Bacteria:  Mycobacterium tuberculosis
(meningitis basilaris)
Moulds and yeasts:
aspergilli
Cryptococcus neoformans
http://www.icu.cn

Etiology of encephalitis
Encephalitis – only acute, of viral origin:
- tick-borne encephalitis
- HSV
- enteroviruses
- mumps
Mumps parotitis with cervical and presternal edema and erythema

Cystic lesions resulting from accumulation of organisms in perivascular spaces
aapredbook.aappublications.org


Etiology of acute brain abscess
........always bacterial:
- mixed anaerobic and aerobic flora
- staphylococci (both S. aureus and coagulase negative staphylococci)
- group A and D streptococci

Etiology of chronic brain abscess
Bacteria:
Mycobacterium tuberculosis
Nocardia asteroides
Mycotic organisms:
Cryptococcus neoformans (yeast)
Parasites:
Cysticercus cellulosae (tissue form of pork tapeworm Taenia solium)

http://www.medicine.cmu.ac.th
Top: Taenia solium cysticerci in the brain of a nine-year-old girl who died during cerebrospinal
fluid extraction to diagnose her headaches.
This was in the 1970s - if it had happened 10 years later, noninvasive computerized tomography
would have given an accurate diagnosis, and the parasites could have been killed with drugs.
(Image courtesy of Dr. Ana Flisser, National Autonomous University of Mexico.)
Left: A pork tapeworm (T.solium) cysticercus,                  the form in which the tapeworm is
found in an infected brain.
(Colorized image by P. W. Pappas and S. M. Wardrop, courtesy of P. W. Pappas, Ohio State
University.)
http://eands.caltech.edu/articles/LXVI4/brainworms.html

 Leonardo da Vinci (1452-1519): Fetus in the Womb (between 1510-1512)