<< Chapter < Page Chapter >> Page >

Learning objectives

  • Identify the most common acellular pathogens that can cause infections of the nervous system
  • Compare the major characteristics of specific viral diseases affecting the nervous system

A number of different viruses and subviral particles can cause diseases that affect the nervous system. Viral diseases tend to be more common than bacterial infections of the nervous system today. Fortunately, viral infections are generally milder than their bacterial counterparts and often spontaneously resolve. Some of the more important acellular pathogens of the nervous system are described in this section.

Viral meningitis

Although it is much more common than bacterial meningitis, viral meningitis is typically less severe. Many different viruses can lead to meningitis as a sequela of the primary infection, including those that cause herpes , influenza , measles , and mumps . Most cases of viral meningitis spontaneously resolve, but severe cases do occur.

Arboviral encephalitis

Several types of insect-borne viruses can cause encephalitis. Collectively, these viruses are referred to as arboviruses (because they are ar thropod- bo rne), and the diseases they cause are described as arboviral encephalitis . Most arboviruses are endemic to specific geographical regions. Arborviral encephalitis diseases found in the United States include eastern equine encephalitis (EEE), western equine encephalitis (WEE), St. Louis encephalitis, and West Nile encephalitis (WNE). Expansion of arboviruses beyond their endemic regions sometimes occurs, generally as a result of environmental changes that are favorable to the virus or its vector. Increased travel of infected humans, animals, or vectors has also allowed arboviruses to spread into new regions.

In most cases, arboviral infections are asymptomatic or lead to a mild disease. However, when symptoms do occur, they include high fever, chills, headaches, vomiting, diarrhea, and restlessness. In elderly patients, severe arboviral encephalitis can rapidly lead to convulsions, coma, and death.

Mosquitoes are the most common biological vectors for arboviruses, which tend to be enveloped ssRNA viruses. Thus, prevention of arboviral infections is best achieved by avoiding mosquitoes—using insect repellent, wearing long pants and sleeves, sleeping in well-screened rooms, using bed nets, etc.

Diagnosis of arboviral encephalitis is based on clinical symptoms and serologic testing of serum or CSF. There are no antiviral drugs to treat any of these arboviral diseases, so treatment consists of supportive care and management of symptoms.

Eastern equine encephalitis (EEE) is caused by eastern equine encephalitis virus (EEEV), which can cause severe disease in horses and humans. Birds are reservoirs for EEEV with accidental transmission to horses and humans by Aedes , Coquillettidia , and Culex species of mosquitoes. Neither horses nor humans serve as reservoirs. EEE is most common in US Gulf Coast and Atlantic states. EEE is one of the more severe mosquito-transmitted diseases in the United States, but fortunately, it is a very rare disease in the United States ( [link] ). US Centers for Disease Control and Prevention, “Eastern Equine Encephalitis Virus Disease Cases and Deaths Reported to CDC by Year and Clinical Presentation, 2004–2013,” 2014. http://www.cdc.gov/EasternEquineEncephalitis/resources/EEEV-Cases-by-Year_2004-2013.pdf. US Centers for Disease Control and Prevention, “Eastern Equine Encephalitis, Symptoms&Treatment, 2016,” Accessed June 29, 2016. https://www.cdc.gov/easternequineencephalitis/tech/symptoms.html.

Questions & Answers

What are antibodies?
Happy Reply
they are immune cells that are released by immune system to fight strangers like microbes
Ahmed
a blood protien produce in response to an counteracting a specific antigen
Pooja
Why salmonella typhi is harmful protozoan?
Saily Reply
because make typhoid that is considered as a food born illness
Ahmed
Name any five modes of transmission.
Happy
what are the scientific names and common names of some microbes
Rich Reply
Staphylococcus aureus - staph Streptococcus pyogenes - strep Botulism - Clostridium botulinum Rocky Mountain spotted fever - Rickettsia rickettsii Diphtheria - Corynebacterium diphtheriae Gonorrhea - Neisseria gonorrhoeae
Tammy
what are the limitations of the Koch's postulate
Naa
how a microorganism growth.
Zubair Reply
Is foetus a parasite to his or her mother? if yes and if no ho
Mashauri Reply
y
Yusri
yes
Yashkin
yes
Zubair
yes it a parasite to the mother because it feeds on the mother for survival
Beatrice
yes
Redwan
no
Elasha
definition of a parasite: an organism that lives in or on an organism of ANOTHER species (its host) and benefits by deriving nutrients at the other's expense
Elasha
no because an organism can inky be a parasite if it causes harm to its HOST. And the fetus does not cause harm to its mother under normal conditions
aliyu
yes
Naa
what is biosensor in microbiology
Raja Reply
What are biosensor
Raja
what's are biosensor
Raja
what is microbiology defination
Rinku Reply
microbiology is the study of small or manuit organisms which cannot be seen with our nacked eyes unless with the aid of the microscope
Brandina
is the study of living organisms which are not directly visible to a direct eye but can only be seen under a microscope
Ipa
ok
Ipa
microbiology is the study of living organisms of microscopic size it is also the study of micro organisms with their form structure reproduction psychology metabolism and classification
Priyanka
what are the importances of Microbiology?
Erick Reply
don't know
SINGLE
we obtained the insulin from the bacteria. and some microorganisms are decomposer in ecosystems.
Zubair
nitrogen in the air is fixed into the soil by microbes example is nitrobactor
Matilda
yes
Zubair
how a weak immune region where microorganisms attack easily?
Zubair Reply
with examples differentiate gram positive from gram negative bacteria
Mary Reply
Differentiate gram positive from gram negative
Mary
I have no idea
Zubair
hello
Kuonain
and example of gram negative is E. coli
Pooja
gram positive stain purple when subjected to gram stain whilst gram positive bacterial has thick wall composed of peptidoglycan
Matilda
ok
Zubair
what is a process of gene expression in eukaryotes ?
Nayyab Reply
pls help us with the answer
Abdussalam
spontaneous generation means
Siddhi Reply
hiii
Siddhi
Hello
eman
So, what's next 😂
eman
I have a problem with Micro
eman
I studying things and see question Some thing else
eman
Can u help me, please
eman
What i havta do
eman
firsfall when you studying understand things...
Siddhi
good afternoon dear Friends
yaya
Greeting to everyone in here.
Manka
There is a problem. I need a diagram of a virus with it functions.
Manka
structure of bacterial
Kuyiba
gghhhh
Zubair
group plz i need help in microbio
Kuonain
it really difficult fr me
Kuonain
kashur cha kah
suhail
sorry now I read in class 8th but I can help u
Zubair
Me too. It's very difficult for me
Angela
rod shape
Priyanka
helical
Priyanka
Hello
esike
spherical
Priyanka
peomorphic
Priyanka
I am ryt or not
Priyanka
hi
suhail
hello
DIPTI
Are we together pls what's the topic for the day?
esike
what is innate
Lizzy
innate means natural
Pooja
the genetic makeup of an individual
Matilda
pls i need the common names for the following parasites..ENTEROBIUS VERMICULARIS,NECATOR AMERICANUS,ASCARIES LUMBRICOIDES,TRICHURIS TRICHIURA,TRICHOMONAS VAGINALIS,GIARDIA LAMBLIA,ENTAMOEBA HISTOLYTICA,SCHISTOSOMA MANSONI,SCHISTOSOMAHEMATOBIUM,STROGYLOIDES STERCORALIS,AND TRAPANOSOMA BRUCI GAMBIENSE
timothy
ENTEROBIUS VERMICULARIS and STROGYLOIDES STERCORALIS have the same common name which is pin worm and thread worm
Chinedu
I didn't find the common names for TRICHOMONAS VAGINALIS, GIARDIA LAMBLIA, ENTAMOEBA HISTOLYTICA, TRYPANOSOMA BRUCEI GAMBIENSE
Chinedu
NECATOR AMERICANUS - New world hookworm ASCARIS LUMBRICOIDES- Ascarid TRICHURIS TRICHIURA- Whip worm
Chinedu
Hi guys
Chinedu
Why are myeloblasts not present in the bloodstream?
Chinedu
thank u
Dasaah
is blood from capillary puncture suitable for hormonal assays
NANCY Reply
Direct this question to a hematologist for a better answer please.
LAFIA
In most cases the blood is necessary but it's limited from my own Analysis
Lee
u can do but it depends on your sampling blood its enev or not
Ali
Control indications of cipro, doxicyclin, setracyclin, cloxacyclin, erythromycin
Oslen Reply
oo
babinthe
what is sims position
babinthe Reply

Get the best Microbiology course in your pocket!





Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Microbiology' conversation and receive update notifications?

Ask