CNS VIRUSES

4 CNS viruses

• enterovirus

• echovirus

• arbovirus

• rabies virus

non-enveloped, icosahedral, + SS RNA virus

PICORNAVIRIDAE

PICORNAVIRIDAE, italian word piccolo, meaning

small

PICORNAVIRIDAE, family of viruses includes:

• enteroviruses

• rhinoviruses

• parechovirus

• cardioviruses

• HAV

non-enveloped, single stranded, + SS RNA virus

ENTEROVIRUSES

among the most common human viral infections, though may still cause serious disease.

ENTEROVIRUSES

ENTEROVIRUSES, can cause:

• aseptic meningitis

• Polio

polio is caused by

poliomyelitis

aseptic meningitis, most common cause

inflammation of brain parenchyma

Polio cause of poliomyelitis, divided into

• poliovirus

• coxsackie virus

• echovirus 

number of serogroups of Enterovirus

67

Enterovirus new and improve reclassification

Enterovirus A to D and RVs A to C

t low ph; are stable at what pH

low pH

ENTEROVIRUSES replicates in the

GI tract

ENTEROVIRUSES are excreted in the

stool

ENTEROVIRUSES, Transmitted through

oral-fecal route

POLIOVIRUSES are inactivated when heated at

55°C for 30 minutes

prevents inactivation of polioviruses

Mg2+, 1 mol/L

is inactivated by a chlorine concentration of 0.1 ppm.

purified poliovirus

purified poliovirus is inactivated by

chlorine concentration of 0.1 ppm

Polioviruses are not affected by

• ether

• sodium deoxycholate 

poliovirus are grown in

Primary or continuous cell line cultures derived from human tissues, monkey's kidney, testis or muscle

Poliovirus requires a _________ for infection

primate-specific membrane receptor

antigen in poliovirus found on the native, infectious virus particle. protective antigen that triggers the immune system to produce neutralizing antibodies

D or N antigen

poliovirus antigen that is found on noninfectious, empty virus particle that lacks RNA.

C or H antigen

poliovirus portal of entry

mouth

poliovirus primary multiplication takes place in the

oropharynx or intestine

poliovirus can cause

nonparalytic poliomyelitis

detailed multiplication of poliovirus

multiplies in the tonsils, the lymph nodes of the neck, Peyer's patches, and the small intestine.

T or F: Poliovirus multiply in muscle in vivo

FALSE

Incubation period of poliovirus

7-14 days but may range from 3 to 35 days.

most common form of poliovirus

Mild Disease

form of poliovirus that causes stiffness and pain in back and neck and lasts 2-10 days

Nonparalytic Poliomyelitis (Aseptic Meningitis)

form of poliovirus, predominating complaint is flaccid paralysis resulting from lower motor neuron damage. Recovery can last 6 months 

Paralytic Poliomyelitis

form of poliovirus with recrudescence of paralysis and muscle wasting, decades after paralytic poliomyelitis

Progressive Postpoliomyelitis Muscle Atrophy

poliovirus laboratory diagnosis after onset of illness

throat swabs

poliovirus laboratory diagnosis for over long periods

rectal swab or stool

Cytopathogenic effects of poliovirus appear

3-6 days

T OR F: poliovirus Immunity is Permanent.

TRUE

two types of immunization for poliovirus

• Live attenuated virus vaccine

• killed-virus vaccine

two Live attenuated virus vaccine for poliovirus 

• Formalin-inactivated vaccine (salk)

• sabin

T OR F: treatment is available for poliovirus

FALSE

ECHOvirus stand for

Enteric Cytopathogenic Human Orphan Viruses

ECHOVIRUS has how many serotypes

30

ECHOVIRUS Infect the human

enteric tract

ECHOVIRUS SUSCEPTIBLE POPULATIONS

• young children and pregnant women

• immunocompromised individuals

TRANSMISSION for ECHOVIRUS

Oral-fecal Route

CLINICAL MANIFESTATIONS of ECHOVIRUS

• Viral Meningitis

• Encephalitis

• Myocarditis

• Neonatal infections

Inflammation of membranes surr brain and spinal cord

Viral Meningitis

Brain inflammation

Encephalitis

Heart inflammation; chest pain irregular heartbeat

Myocarditis

severe, fatal sepsis in newborns

Neonatal infections

specimens for echovirus

Throat, swab, stool or rectal swabs and CSF

shares several characteristics with rhinovirus

Enterovirus 68

Enterovirus 68 was known as

rhinovirus 87

chief cause of acute hemorrhagic conjunctivitis. Incubtaion period 1 day and duration of 8- 10 days.

Enterovirus 70

one of the main causes of CNS disease; fatal

Enterovirus 71

small, roughly spherical, enveloped, SS RNA

ARBOVIRUSES

are a group of viruses that are transmitted by mosquitoes, ticks, or other arthropods

ARBOVIRUSES

ARBOVIRUSES Primary Families includes

• bunyaviridae

• flaviviridae 

• togaviridae 

vector aquires a lifelong infection through ingestion of blood from it.

Viremic Vertebrae

virus multiply in the tissues of the arthropod without evidence of disease or damage.

Specific type of Biting Arthropod

Major Arbovirus diseases

• yellow fever

• dengue

• japanese B encephalitis

• st.louise encephalitis

• tick-borne encephalitis

• west nile fever

• chikungunya fever

• zika virus

• sandfly fever

positive SS RNA; nonsegmented enveloped

TOGAVIRIDAE FAMILY

TOGAVIRIDAE FAMILY replciates

cytoplasm

TOGAVIRIDAE, mosquito borne that causes encephalitis

Alphavirus

disease in horses and humans.

• Birds (Natural reservoirs); spread to humans and horses.

• Vector: MOSQUITO

(EEE) Eastern Equine Encephalitis

disease in human and horses

• milder compared to EEE.

• asymptomatic to mild infection (fever, headache, nausea)

(WEE) Western Equine Encephalitis

• causes large outbreaks of human an equine encephalitis.

• Death less common in patients with VEE than WEE and EEE.

• 4-14% develop neurologic diseae.

(VEE) Venezuelan Equin Encephalitis

positive SS RNA; nonsegmented enveloped

FLAVIVIRIDAE FAMILY

Includes: Japanese Encephalitis Virus, Dengue Virus, Yellow Fever Virus, St. Louis Encephalitis (SLE) Virus, Zika Virus, Murray Valley Encephalitis Virus, Omsk Hemorrhagle Fever Virus, Powassan Virus, Tick-Borne Encephalitis Virus, Wesselsbron Virus And WN.

FLAVIVIRIDAE FAMILY

FLAVIVIRIDAE FAMILY replicates where

cytoplasm

Major cause of encephalitis in Asia; most common cause of Arboviral Encephalitis in the World.

JAPANESE ENCEPHALITIS

Vectors: Mosquito (Aa and Aa), has 4 serotypes

DENGUE VIRUS

bone pain from dengue

break-bone fever

Patient develops Jaundice, bleeding from mouth eyes, nose, stomach and other areas.

YELLOW FEVER

YELLOW FEVER vector

Aedes aegypti

Px develop fever some develop meningoencephalitis. Transmitted to humans via bird biting culex mosquitoes

St. louis encephalitis

• 80% PX asymptomatic

• neuroinvasive disease (meningitis or encephalitis); (50 years old above; primary risk).

WEST NILE VIRUS

insect vectore-borne disease that is most commonly transmitted through (A. aegypti and A. albopictus

ZIKA VIRUS

negative SS RNA; spherical, segmented, enveloped. contains more than300 viruses 

BUNYAVIRIDAE FAMILY

BUNYAVIRIDAE FAMILY is mostly transmitted by

arthropods

BUNYAVIRIDAE FAMILY envelope has

2 glycoproteins.

Bunyaviruses are sensitive to inactivation by

heat, detergents, formaldehyde, and low pH

• transmitted by various woodland mosquitoes, primarily the Aedes triseriatus. 

• viral infection is abrupt

• half develop seizures

• illness last from 10-14 days

CALIFORNIA ENCEPHALITIS VIRUS

• mild, insect-borne disease

• caused by a bunyavirus in the Phlebovirus genus

SANDFLY FEVER VIRUS

SANDFLY FEVER VIRUS AKA

Phlebotomus feve

The agent of disease, a bunyavirus of the Phlebovirus genus, is a mosquito borne zoonotic virus pathogenic primarily for domestic livestock

RIFT VALLEY FEVER VIRUS

RIFT VALLEY FEVER VIRUS, mosquito cell lines that is most widely used

C6/36

bullet shaped; enveloped, linear, (-) SS RNA; helical nucleocapsid

RABIES VIRUS

99% or rabies deaths in humans are implicated b

dogs

2 FORMS of rabies

• FURIOUS RABIES

• DUMB RABIES

FORM of rabies - lymbic or nervous system

FURIOUS RABIES

FORM of rabies - neocortex

DUMB RABIES

• Extreme agitation, restlesness and aggressive behavior, including attacking stationary objects or other animals.

• Excessive salivation, leading to foam around the mouth due to the inability to swallow; hydrophobia; fear of air.

FURIOUS RABIES

Progressive paralysis, starting in the hind limbs which is the dominant feature. Paralysis progresses throughout the body, leading to coma and death.

DUMB RABIES

animals with dumb rabies may appear

dull

DUMB RABIES Can be mistaken for

Gulliane-Barrane Syndrome

rabies incubation period

1-3 months

T OR F: once rabies symptoms appear px can still be treated

FALSE