Public Health Quiz: Rabies and West Nile Virus

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Questions and Answers

What is the recommended timing for post-exposure prophylaxis following a rabies exposure?

Within 5 days of exposure

Within 10 days of exposure (correct)

Within 14 days of exposure

Within 24 hours of exposure

Which of the following is NOT a recommended preventive measure for rabies?

Vaccination of infected humans (correct)

Oral vaccination of wild animals

Vaccination of cats and dogs

Prompt washing of wounds

What is the primary method of transmission for West Nile Virus?

Bite from an infected mosquito (correct)

Consumption of contaminated water

Direct contact with infected animals

Airborne particles from infected humans

What percentage of individuals infected with West Nile Virus remain asymptomatic?

80% Signup and view all the answers

In which climatic conditions is West Nile Virus transmission more likely to occur?

Year-round in tropical climates Signup and view all the answers

Which virus is associated with post-infectious complications like Subacute sclerosing panencephalitis (SSPE)?

Measles Signup and view all the answers

What is the usual route for enteroviruses to reach the CNS?

Via the bloodstream Signup and view all the answers

Which of the following viruses is primarily associated with flaccid paralysis?

Zika virus Signup and view all the answers

Which virus is NOT typically associated with viral meningitis?

Cytomegalovirus Signup and view all the answers

Which type of viruses are associated with congenital infection and CNS damage?

Zika virus Signup and view all the answers

What is a common characteristic of viral meningitis compared to bacterial causes?

More common occurrence Signup and view all the answers

Which virus is associated with causing both encephalitis and meningitis?

Mumps virus Signup and view all the answers

Which route of infection does NOT contribute to CNS damage?

Through direct contact with air Signup and view all the answers

What is the main clinical presentation difference between meningitis and encephalitis?

Neck stiffness in meningitis versus motor deficits in encephalitis Signup and view all the answers

Which of the following is not a typical cause of viral encephalitis?

Streptococcus pneumoniae Signup and view all the answers

What is a prominent feature of meningoencephalitis?

Presence of both meningitis and encephalitis symptoms Signup and view all the answers

Which virus is specifically noted for being the cause of viral meningitis?

Enterovirus Signup and view all the answers

What type of infection can viral infections of the CNS be part of?

Generalized infection affecting multiple body systems Signup and view all the answers

In which condition is there a risk of altered personality and behavior changes?

Viral encephalitis Signup and view all the answers

What does the presence of the meningism triad indicate?

Symptoms of meningitis Signup and view all the answers

Which of the following viruses is associated with Transmissible Spongiform Encephalopathy (TSE)?

Prion proteins Signup and view all the answers

What is a classic symptom of viral meningitis?

Neck stiffness Signup and view all the answers

Which pathogen is the most common cause of viral meningitis?

Echovirus Signup and view all the answers

What is the typical progression of symptoms in viral meningitis compared to bacterial meningitis?

Symptoms evolve more slowly over several days Signup and view all the answers

What route is primarily responsible for the transmission of non-polio enteroviruses?

Faecal-oral route Signup and view all the answers

Which enterovirus is specifically associated with encephalitis in Eastern and Southeast Asia?

Enterovirus 71 Signup and view all the answers

What is a notable characteristic of enteroviral infections regarding their symptoms?

They often present with fever and rash Signup and view all the answers

In diagnosing rabies, which test remains a standard diagnostic tool?

Direct immunofluorescent antibody staining of a skin biopsy Signup and view all the answers

Which symptom is NOT typically associated with the prodrome of rabies?

Muscle weakness Signup and view all the answers

What is a common preventive veterinary measure against rabies?

Vaccination of wild animal populations Signup and view all the answers

Which aspect of West Nile Virus epidemiology is correct?

Transmission can occur year-round in tropical climates. Signup and view all the answers

In the context of rabies treatment, which statement is NOT accurate?

Post-exposure prophylaxis can begin up to 30 days after exposure. Signup and view all the answers

What is a significant characteristic of the clinical presentation of West Nile Virus?

Approximately 80% of infected individuals are asymptomatic Signup and view all the answers

Which statement about rabies vaccination is true?

The rabies vaccine must be administered in combination with rabies immunoglobulin. Signup and view all the answers

Which of the following correctly describes the clinical presentation of encephalitis?

Altered mental status, motor or sensory deficits, and seizures Signup and view all the answers

What distinguishes meningoencephalitis from meningitis and encephalitis?

It is characterized by inflammation of both the meninges and brain parenchyma. Signup and view all the answers

Which of the following viral pathogens is primarily associated with viral meningitis?

Poliovirus Signup and view all the answers

Which of the following symptoms is specifically indicative of encephalitis rather than meningitis?

Altered mental status Signup and view all the answers

Which viral infection could lead to the manifestation of progressive neurological deficits and personality changes?

HIV Signup and view all the answers

Which statement about the causative pathogens of viral encephalitis is false?

Enteroviruses are the primary etiological agents of encephalitis. Signup and view all the answers

What is a critical step in the diagnosis of viral infections affecting the CNS?

CSF analysis through lumbar puncture Signup and view all the answers

What differentiates sporadic Creutzfeldt-Jakob Disease (CJD) from variant CJD?

Variant CJD has a longer incubation period. Signup and view all the answers

Which of the following viruses is most commonly associated with post-infectious complications such as Subacute sclerosing panencephalitis (SSPE)?

Measles Signup and view all the answers

Which route of entry is primarily utilized by enteroviruses to infect the central nervous system (CNS)?

Via the bloodstream Signup and view all the answers

Which type of viral infection is more prevalent than bacterial causes when referring to meningitis?

Viral meningitis Signup and view all the answers

Which of the following viral infections is NOT typically associated with encephalitis?

Rubella Virus Signup and view all the answers

What common characteristic is shared by both enteroviruses and arboviruses in relation to CNS infections?

They both can lead to viral meningitis. Signup and view all the answers

Which of the following viruses is NOT commonly associated with congenital CNS damage?

Mumps Virus Signup and view all the answers

What neurological symptom is primarily associated with post-infectious complications following a viral infection?

Seizures Signup and view all the answers

Which condition is primarily characterized by the presence of neurological symptoms after an initial measles infection?

Subacute sclerosing panencephalitis Signup and view all the answers

What distinguishes the clinical progression of viral meningitis from bacterial meningitis?

Symptoms evolve more slowly over several days. Signup and view all the answers

Which of the following enteroviruses is primarily known for causing serious illness in neonates?

Enterovirus 71 Signup and view all the answers

What is the predominant route of transmission for non-polio enteroviruses?

Faecal-oral route Signup and view all the answers

Which clinical symptom is least likely associated with viral meningitis?

Severe abdominal pain Signup and view all the answers

How does the immune response contribute to CNS pathology during viral infections?

It can lead to additional cellular damage via cytokines. Signup and view all the answers

Which of the following clinical presentations is most indicative of rabies?

Restlessness and irritability Signup and view all the answers

Among non-polio enteroviruses, which is particularly associated with acute flaccid paralysis?

Enterovirus D68 Signup and view all the answers

What is a common characteristic of the seasonality of non-polio enterovirus infections?

Peak activity is observed in late spring to autumn. Signup and view all the answers

Study Notes

Viral Pathogens of the CNS/Encephalitis

This presentation covers viral causes of CNS infections, including meningitis and encephalitis
Meningitis: inflammation of the meninges
Encephalitis: inflammation of the brain parenchyma
Viral meningitis is typically caused by enteroviruses, often self-limiting
Viral encephalitis: HSV, WNV, Tick-borne, Japanese, Polio, Rabies, and other viruses can cause CNS manifestations
Other important viruses with CNS manifestations include polio, Zika, measles, JC virus, and HIV.
Transmissible spongiform encephalopathies (TSEs) are also discussed, including their aetiology and the differences between sporadic and variant CJD.

Key Differences Between Meningitis and Encephalitis

Meningitis is inflammation of the meninges (membranes surrounding the brain and spinal cord)
Encephalitis is inflammation of the brain tissue itself.
Meningoencephalitis occurs when both the meninges and brain tissue are inflamed.

Viral Infections of the CNS

Viral infections of the CNS can be part of a generalized infection (e.g., polio) or can solely affect the CNS.
They can present some time after the initial infection (e.g., measles- associated Subacute sclerosing panencephalitis (SSPE))

Viruses Causing CNS Infection

Meningitis: Enteroviruses, Herpes viruses (HSV, VZV, HHV6), Mumps
Encephalitis: Herpes viruses (HSV, VZV, HHV6), Enteroviruses, Mosquito-borne viruses (WNV, JE), Tick-borne flaviviruses, Rabies
Paralysis: Enteroviruses (esp. poliovirus), WNV, JE, Zika
Post-infectious complications: Measles (post-infectious encephalitis-including SSPE), VZV (vasculitis, arteritis, stroke).

Viral Meningitis in Ireland

Provides a visual representation through a graph of the frequency of cases from 1988-2019 in Ireland.
The data shows which virus subtype was the most frequent cause of viral meningitis in Ireland.

Viral Encephalitis in Ireland

Provides a visual representation through a graph of the frequency of cases by type from 1992-2019 in Ireland.

Infectious Disease Notifications in Ireland, 2019-2023

Presents data on the number of reported cases of viral encephalitis, viral hemorrhagic fevers, and viral meningitis in Ireland from 2019-2023
Categorized by year.

Congenital Infection and CNS Damage

Rubella, Cytomegalovirus, and Zika virus are associated with congenital damage to the CNS.

Viral Meningitis

More common than bacterial meningitis
Viral causes include Enteroviruses (Echoviruses, Coxsackie B, Enterovirus 71), Herpes viruses (Herpes simplex, VZV), Mumps, and Arboviruses (e.g., West Nile virus, Japanese encephalitis virus)
Route of infection: After primary multiplication in other sites (e.g., GI tract for enteroviruses), the virus can reach the CNS via the bloodstream, along nerve pathways, or through the olfactory mucosa.

How Do Viruses Cause Damage in the CNS?

The pathology of viral infection in the CNS is multifactorial, including virus multiplication and resultant cellular damage and host immune response (cellular response + cytokines)
Symptoms typically include fever, headache, stiff neck, vomiting and photophobia

Non-Polio Enteroviruses

Common pathogens causing viral meningitis, particularly in infants and young children
Subtypes include Echoviruses, Coxsackie B, and Enterovirus 71.
Often self-limiting, but can be severe in neonates
Peak activity is in late spring to autumn.
Transmission usually through the faecal-oral route, multiplying in the GI tract and occasionally causing GI symptoms leading to the bloodstream and seeding multiple organs including the CNS. .
Other CNS manifestations like encephalitis (esp. in the East & SE Asia) and acute flaccid paralysis are also listed

CSF Findings in Viral Meningitis

Provides a schematic table of CSF findings in bacterial, viral, and TB meningitis, including protein levels, glucose levels, and cell types.

CJD- Creutzfeldt-Jakob Disease

A fatal degenerative brain disease
Acquired through BSE, contaminated products, and contaminated blood.
Genetic mutation of a prion protein, or contamination through medical procedures

Herpes Simplex Encephalitis

HSV-1 is the most frequent cause in Northern Europe
Commonly affects the temporal lobe in adults and children older than 3 months
It has a high mortality rate without treatment.
Diagnosis: MRI, EEG, and CSF with HSV PCR
Treatment if suspected: IV aciclovir (acyclovir).
Neonatal HSV encephalitis: typically acquired during delivery via maternal secretions, significantly high mortality rate and diagnosed by IgM presence, treated with IV aciclovir.

Varicella-Zoster Encephalitis (VZV)

Can be a complication of chicken pox or shingles reactivation
Presents similarly to HSV encephalitis
Diagnosis: Detection of VZV DNA by PCR in CSF
Treatment: high dose aciclovir IV

Rabies

Viral, zoonotic disease causing acute encephalitis.
A high number of human deaths annually
95% of cases in Africa and Asia.
Main reservoir: wild and domestic dogs, wolves, foxes, coyotes, dingoes, bats.
Incubation period: depends on distance virus has to travel to reach CNS (3- >1=2 weeks)
Diagnosis: clinical, PCR, immunofluorescence, serology and CSF testing (if no prior rabies vaccination)
Treatment: immediate wound washing, post-exposure prophylaxis (within 10 days of exposure), rabies immunoglobulin, and rabies vaccine.

West Nile Virus

Arbovirus transmitted via mosquito bites
Common in temperate countries (late summer/early autumn) and tropical climates.
Often asymptomatic or has mild flu-like symptoms
More serious cases can include encephalitis or meningoencephalitis (risk increased with age and immunosuppression)
Diagnosis: West Nile Virus IgM (blood or CSF), presence of viral RNA early, serology.
Treatment: supportive, including hydration, fever reduction.

Japanese Encephalitis

Major cause of encephalitis in Asia; related to WNV
Transmitted by infected Culex mosquitoes; human= incidental host
Reservoir: primarily pigs and wading birds
Endemic in rural agricultural areas (rice paddy fields, flood irrigation)
Primarily affects children; adults build immunity.
Symptoms range from asymptomatic to severe neurological disease, including encephalitis and meningoencephalitis.
Diagnosis: JE virus specific IgM detection on blood & CSF
Treatment: No antiviral; supportive care

Tick-Borne Encephalitis Virus

RNA flavivirus, member of arboviruses
Transmitted by infected Ixodes ticks, occasionally from unpasteurized milk.
10-12,000 cases per year
Incubation period: 6-28 days
Clinical features: 60-70% asymptomatic; biphasic illness with initial febrile phase, followed by interval and then second phase when CNS involvement occurs, mortality 0.5-1%
Diagnosis: Travel/exposure hx, viral RNA PCR in blood, TBE IgM and IgG in blood & CSF, convalescent serology
Prevention: Minimize exposure (avoid tick areas, use repellents), Immunization (part of childhood immunization schedules in some endemic countries).

Other Causes of Viral Encephalitis

Other enteroviruses (including polio), and various arboviruses can also lead to encephalitis

Poliovirus

Important cause of paralysis prior to vaccination
Human-only reservoir; transmitted faecal-orally
High success with global eradication program, with extremely low incidence in 2020.
Prevention: live oral or inactivated IM or intradermal vaccines.
Clinical presentation: most cases are asymptomatic or mild; some cases include meningitis, bulbar or bulbospinal polio.

Paralysis Syndrome

Different types, including spinal polio (80%), and bulbar/bulbospinal conditions
Typically causes asymmetric paralysis of muscles innervated by infected anterior horn cells

Polio Re-Emergence

Waning vaccine uptake and disruptions to vaccine programs have led to re-emergence in areas where polio was previously considered eradicated.
Critical for public health campaigns.

Zika Virus

RNA virus of the Flaviviridae family; mainly transmitted via Aedes mosquitos
Infection of the CNS and peripheral nervous system
Congenital Zika Syndrome, including severe microcephaly and decreased brain tissue.
Associated with Guillain-Barre Syndrome, a post-infectious paralysis.

Chronic CNS Viral Infections

Subacute sclerosing panencephalitis (SSPE) : persistent measles infection in CNS, years after the initial infection, rare, behavioral/intellectual deterioration, seizures.
HIV Encephalopathy : HIV associated; convulsion, dementia, and progressive multifocal leukoencephalopathy (PML)- opportunistic infections.

Additional notes:

The slides also include diagrams and graphs illustrating the various aspects of these diseases. The presentation format for these topics is a slide presentation, hence the information is presented in a condensed and detailed way.
This document summarizes the main points from the slides and is intended for study notes.

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Description

Test your knowledge on the recommended protocols for rabies post-exposure prophylaxis and the transmission dynamics of West Nile Virus. This quiz covers key preventive measures and statistics related to these infectious diseases. Challenge yourself and enhance your understanding of public health measures.