Little House on the Prairie author wrote that her sister Mary was - - PDF document

Carol Glaser, DVM, MPVM, MD

Encephalitis and Special Investigations Section Division of Communicable Disease Control California Department of Public Health & Department of Pediatrics Division of Pediatric Infectious Diseases University of California, San Francisco

• Background
• Encephalitis
• California Encephalitis Project (CEP)
• Case vignettes
• Highlights of agent-specific findings with focus on

diagnostics (rather than Rx)

• CEP experience and lessons learned, particularly as

it relates to diagnostic testing

• Present variety of cases-
• some relatively common where diagnostic problems

arose and

• other rare, but important, causes
• Handout slightly different > lecture
• “Little House on the Prairie” author wrote that

her sister Mary was robbed of her sight by scarlet fever

• The journal Pediatrics asserts that it wasn’t

scarlet fever, it was viral meningoencephalitis Mary’s meningoencephalitis likely caused optic neuritis, inflammation of her optic nerves, which resulted in her vision loss

• Wide range of incidence rates depending
• n country, age-group etc.,
• 0.7-13.8/100,000
• Generally higher pediatric population >

adults

• Higher in tropical areas > “Western”

countries

• Comparable to ‘purulent meningitis’

Jmor F et al., Jour Virol 2008 Granerod J et al., Lancet Infect Dis 2010 Michael BD et al., Epilepsia, 2010

One of the most challenging syndromes for clinicians to diagnose and manage:

• Severity of syndrome with high morbidity/

mortality

• Vast number of infectious agents
• Large number of non-infectious mimickers
• Specific pathogen/underlying cause is

identified < 50% of cases

• Not a single disease entity
• Often an uncommon presentation of a

common infection

• But sometimes a rare infection
• Lots of misconceptions about diagnostic

testing

• Togavirus: EEE, VEE, WEE
• Flavivirus: SLE, WN, JV, Dengue
• Bunyaviruses: LaCrosse,
• Paramyxoviridae: mumps, measles
• Arenaviruses: LCM, Machupo, etc
• Enteroviruses: Polio, coxsacki, etc
• Reoviruses: CTF
• Rhabdovirus: rabies
• Filoviridae: Ebola, Marburg
• Retroviridae: HIV
• Herpes: HSV1/2,VZV,EBV,CMV,HHV6
• Adenovirus
• Rickettsial
• Bacterial
• Fungal
• Parasites
• Prion
• Non-infectious “mimickers”

• 1998 – 2011
• Viral and Rickettsial Disease Laboratory,

State of CA

• Funding from CDC Emerging Infections

Program

• Cases referred from MDs throughout CA
• Not population-based (e.g., large sampling

throughout CA)

• Biased toward more severe and diagnostically

difficult cases

• TN and NY had similar programs
• Hospitalized w/ encephalopathy (depressed or ALOC >

24 hours) AND

• 1 or more of the following:
• fever (38o C)
• seizure(s)
• focal neurological findings
• CSF pleocytosis
• EEG findings c/w encephalitis
• abnormal neuroimaging
• Exclusions: <6 months old or immunocompromised
• CSF
• Acute serum
• Respiratory sample

(NP/throat swab)

• Convalescent serum

(10-14 days > acute serum)

• Brain tissue if available
• Molecular, serologic, isolation
• Multiple specimen types (CSF, sera,

respiratory, brain if available)

• Core testing:
• Arboviruses (WNV, SLE, WEE)
• Herpesviruses (HSV1, HSV2, VZ, EBV, HHV6)
• Enteroviruses
• Respiratory viruses (Flu A/B, Paraflu 1-3, adenovirus, HMPV)
• Mycoplasma pneumoniae
• Expanded testing - exposures, clinical

symptomatology, laboratory

• 10 year old, previously healthy,

white female

• Admitted with 2 day history fever and

upper respiratory illness, increasing lethargy and somnolence

• Admission exam - inattentive, drooling,

and “difficulty finding words”

• Exposure history:
• Owns dog and cat
• Residence in rural area
• No sick contacts
• No recent travel
• Admit labs/Neuroimaging
• LP: WBC = 90 cells/mm3 (75%L, 14%M),

Protein = 26 mg/ml, Glucose = 59 mg/ml

• CT Scan: Left frontal lobe enhancement,

mass effect

CEP results

• CSF PCR
• HSV-1, HSV-2: Negative (HSV-1 PCR also negative
• utside hospital)
• VZ: Negative
• Mycoplasma: Negative
• Enterovirus: Negative
• Serology:
• Arboviruses/Mycoplasma/Chlamydia/

Adenovirus/EBV: Not significant

• Respiratory PCR
• Influenza A/B, Adenovirus, Mycoplasma,

Enterovirus: Negative

• On HD#3 developed seizures
• EEG: slowing L>R, sharp wave in left parietal
• MRI: multifocal T2 prolongation with patchy

enhancement, most pronounced in left temporal lobe

• HD#4 LP repeated:
• CSF WBC=113 WBC cells/mm3(83%L)
• Protein=107 mg/dl, Glucose=57 mg/dl
• 1. Rabies
• 2. Bacterial meningitis
• 3. Herpes simplex

encephalitis

• 4. Balamuthia mandrillis
• 5. Non-infectious, anti-

NMDAR

• 6. Enterovirus
• CSF PCR HSV-1 repeated on 2nd CSF:
• Hospital lab: Positive HSV-1
• VRDL: Positive HSV-1
• Diagnosis: Herpes Simplex

Encephalitis (HSE)

• HSV-1 considered to be leading

cause of encephalitis

• Acute necrotizing encephalitis
• PCR: considered sensitive and

specific

• Tunkel AR et al., Clin Inf Dis, 2008
• CEP: 80 cases --~ 20% had initial PCR

negative (biased toward more difficult cases)

• Of those with false negative 1st CSF, CSFs

were relatively bland:

• Initial CSF lab values:

 Median CSF WBC=17 WBCs/mm3

(range: 0-330)

 Median CSF Protein=34 mg/dL

(range: 22-87)

• False negative PCRs tend to occur early in course
• f illness (e.g., w/in 72 hours of onset) or CSF

fluid relatively “bland’’

• 3/11 (27%) patients tested within 72 hours:

negative-repeat LP 5-11 day later positive

• Weil AA et al, CID, 2002
• 8/33 (24%) negative first 3 days5 cases repeat LP

and 4 were positive

• De Tiege X et al, CID, 2003
• 2/15 (13%) of HSE cases were initially negative

HSV CSF PCR but results became positive in repeat CSF analyses

• Elbers JM et al, Pediatrics, 2007

• 10 year old male

— 3 days prior to admission with fever, right sided weakness, and slurred speech

• On admission

 febrile  lethargy  change in behavior  confusion  somnolence

• Exposure history

— Owns dog, cat and lizard — Raccoons in yard — Plays football — No international travel, traveled to Central Valley

• Admit labs, neuroimaging

— LP: WBC = 27 WBCs/mm3 (100% Mo) — Protein = 23 mg/dL, Glucose = 54 mg/ml — 1st MRI: bilateral thalamic enhancement, L>R

• CSF PCR
• HSV1, HSV2: Negative
• VZ: Negative
• Mycoplasma: Negative
• Enterovirus: Negative

Respiratory — Enterovirus: Negative — Other viruses: Negative

• Serology:
• Arboviruses (SLE, WEE, WNV), Mycoplasma,

Chlamydia, adenovirus, EBV: Not significant

• Quickly deteriorated within first few

days of hospitalization

— Intubated — Comatose — Non-interactive — Occasional — Repeat MRI: area of enhancement involvement with more extensive involvement of brainstem region

• A. Rabies
• B. Bacterial meningitis
• C. Herpes simplex encephalitis
• D. Balamuthia mandrillis
• E. Non-infectious, anti-NMDAR
• F. Enterovirus
• 1. Rabies
• 2. Bacterial meningitis
• 3. Herpes simplex

encephalitis

• 4. Balamuthia mandrillis
• 5. Non-infectious, anti-

NMDAR

• 6. Enterovirus
• Brain biopsy

— “necrotizing encephalitis”, no intranuclear cells, no organism

• Multiple studies done on biopsy

— All negative — EXCEPT for weakly positive Entero PCR — Prelim sequence data suggestive EV 71

Most common infection identified:

• 26% of all confirmed etiologies:
• 98 patients confirmed by positive PCR in CSF
• Median age = 14.0 years (mean=20.5 years)
• 63% pediatric, 37% adult
• CSF: median WBC = 58 cells (0-2655), Protein=40 mg/dl

(20-473), glucose=64 mg/dl (20-122)

• Relatively short length of stay, median= 6 days
• Most with good outcomes, however 5+ fatalities (e.g. Enterovirus

71)

Fowlkes AL et al., JID, 2008

• 57 additional cases considered probable or

possible –CSF EV PCR negative but positive in respiratory and/or stool

• CSF EV PCR good, but…not perfect
• Important to examine for enterovirus in

multiple specimens:

• Brain biopsy if possible
• Throat/Nasopharyngeal
• Stool
• Suspect we are missing EV cases due to

unsuitable or incomplete specimens

Outbreak of Neurologic EV 71 Disease: A Diagnostic Challenge

• EV-PCR CSF ‘frequently negative’
• EV-PCR from resp and gi tract

have higher yields > EV-PCR CSF

• Perez-Velez C, CID, 2007

CSF Blood Throat Rectal

• ther

# specimens

submitted

16 3 6 8 9+

# PCR positive

5 6 7 8 % positive 32% 100% 88% ~80%

Perez-Velez C, CID, 2007

• 12 year old previously healthy

Hispanic male

• Presented with one week of

progressively worsening headache, vomiting, decreased appetite, poor sleep, lethargy, and hallucinations

• CT concerning for brain tumor
• Intubated for increased ICP and ALOC
• Exposure history
• Bird at home
• Motorcycling – dusty conditions
• Admission laboratory results
• LP: WBC = 78 cells/mm3 (78%L, 20%M),

Protein = 42 mg/ml, Glucose = 74 mg/ml

• MRI suggestive of ADEM
• Negative bacterial, fungal, & AFB stains & cultures
• Negative Coccidioides, Blasto, Histo, Cocci, &

Cysticercosis

• Treatment
• Decadron, Vancomycin,

Cefotaxime, Flagyl

• Discharged one week later
• At baseline on 1 week oral

prednisone taper with dx of ADEM

• Symptoms returned
• 2 weeks after stopping oral prednisone
• Headache, nausea, vomiting, and

lethargy

• Repeat CT
• Worsening enhancement and edema
• Recurrent ADEM?
• Initial plan was for longer course of

steroids

• Changed after repeat MRI- concerning

for lymphoma

• Laboratory results
• LP: WBC = 298 cells/mm3 (89%L, 5%M),

Protein = 69 mg/ml, Glucose = 40 mg/ml

• Repeat infectious studies-bacterial, fungal, and

TB studies negative

• Biopsy #1- angiocentric lymphoid and plasma

cell infiltrates

• Full body CT, PET, & bone scans normal
• Treatment
• Prednisone
• 1. Rabies
• 2. Bacterial meningitis
• 3. Herpes simplex

encephalitis

• 4. Balamuthia mandrillis
• 5. Non-infectious, anti-

NMDAR

• 6. Enterovirus
• A. Rabies
• B. Bacterial meningitis
• C. Herpes simplex encephalitis
• D. Balamuthia mandrillis
• E. Non-infectious, anti-NMDAR
• F. Enterovirus

• Symptoms returned - California

Encephalitis Project contacted

• Balamuthia mandrillaris

testing positive

• Rx with ‘cocktail’ of different Rx

with initial improvement but died a few weeks later

• Type of free-living amoeba (living single-celled
• rganisms)
• Dozen of types of free-living amoeba, few are pathogenic
• Two distinct CNS presentations of free-living

amoeba:

• Fulminant, rapid progressive, fatal encephalitis —

Naegleria fowlerii (diving in brackish water)

• Granulomatous amoebic encephalitis

– Acanthoemba sp., – Balamuthia mandrillis

• Considered to be a rare cause of encephalitis

• Subacute to chronic presentation
• Imaging: ring-enhancing, hydrocephalus, or

parenchymal mass

• Often lymphocytic CSF pleocytosis
• Insidious onset -- headache, nausea, low-grade

fever, lethargy, & confusion

• Can mimic
• Brain tumor
• ADEM
• Mycobacterium tuberculosis
• Neurocysticercosis
• Viral encephalitis
• Found in soil and water
• Worldwide distribution
• Inhalation or direct contamination of skin lesion
• 15 confirmed cases identified by CEP since 1990:

(probably additional cases but no brain tissue)

• Positive serology often the ‘tip-off’ but brain biopsy

needed for confirmation

• Demographics
• Median age = 19 years (1-84 years)
• 82% Hispanic

 Is this because of exposure vs. genetic susceptibility vs. ?

• 91% male
• Most immunocompetent

• CSF: lymphocytic or neutrophilic

predominance, normal-high protein, normal-low glucose

• All had abnormal neuroimaging: ring-

enhancing, mass lesions, hydrocephalus

• Exposure/risk factor:
• Not clear but most with soil exposure such as

gardener, construction worker, jeeping/motorcycling in dusty area

• Most died but 2 still living (one lost-to-

follow-up)

Consult with CDC National Center for Emerging and Zoonotic Infectious Diseases Waterborne Disease Prevention Branch, CDC

(or if in California, consult with California State Health Dept)

• Testing

Brain material for IHC and molecular (serology can be helpful as well)

• Treatment recommendations
• Combination of Sulfadiazine, Flucytosine, Azole,

Azithromycin and Pentamidine

• CEP cases survivors

Case 4

• 72 y/o male with possible encephalitis,

referred to CEP

• Onset of headache/fever
• 5 days later hospitalized with lethargy,

somnolence and ascending paralysis

• Clinician thought it was probably a

stroke but wanted to rule out encephalitis

• Exposure history:
• Born and raised in the Philippines and had

been there 10 months prior to onset of illness

• US resident for 10 years
• No known mosquito bites
• No known animal exposures
• Admit labs/Neuroimaging:
• LP: WBC = 10 WBCs/mm3, Protein =

172 mg/dL, Glucose = 60 mg/dL

• MRI: mild atrophy (appropriate for age),
• therwise normal
• Died 11 days after hospitalization
• No autopsy, cause of death:

“cerebral vascular accident”

CEP results

• CSF PCR
• Herpes consensus: NEG
• Mycoplasma: NEG
• Enterovirus: NEG
• Serology
• Arboviruses/Mycoplasma/Chlamydia/Adenovirus/

EBV: Negative

• Respiratory PCR
• Influenza A/B, Adenovirus, Mycoplasma,

enterovirus: Negative

• 1. Rabies
• 2. Bacterial meningitis
• 3. Herpes simplex

encephalitis

• 4. Balamuthia mandrillis
• 5. Non-infectious, anti-

NMDAR

• 6. Enterovirus
• A. Rabies
• B. Bacterial meningitis
• C. Herpes simplex encephalitis
• D. Balamuthia mandrillis
• E. Non-infectious, anti-NMDAR
• F. Enterovirus
• CEP deceased “core testing” includes

rabies testing:

• Rabies antibody positive and rabies PCR

positive from “throat swab” (contaminated with saliva)

• Sequenced strain: canine strain/

Philippines

• Patient originally from Philippines,

was there 10 months prior to onset of illness

Etiology

• Family: Rhabdoviridae
• Negative-stranded RNA genome
• Genus: Lyssavirus
• Envelope virus, bullet-shaped

Epidemiology

• Only 1-2 recognized cases/year in the

United States…so why is it so important?

• “uniformly fatal” without vaccine [until

recently]

• Tremendous ‘angst’ : ~40,000 persons

receive post-exposure prophylaxis (PEP) in the US

• Many encephalitis cases are ‘rule out’

rabies …on the other hand, cases are missed

• World: 50,000-100,000 cases/year

Rabies Reservoirs

• All mammals are susceptible
• However some species much

more important > others, e.g., canine rabies, raccoon rabies, bat rabies, skunk, etc.

• Humans generally “dead-

end” hosts

Bats (non-terrestrial) and Rabies

• Most common source of human

infection in US

• Since 1990, > 90% of

endemically acquired rabies in the US

• Exposure to bat not always

recognized, especially bites

Bites from bats may be

• verlooked
• Jackson A, Lancet, 2001
• Most cases of rabies in India, China, SE Asia,

Iran, Africa and South America

• Most are canine rabies
• Estimated 50,000 cases/year

Clinical

• Incubation period ranges from few days to

>1 year

• Most cases present between 2 and 16

weeks

• Pleomorphic manifestations, often mistaken

for other CNS diseases [e.g., case 2]

• Initial symptoms are nonspecific:
• Fever, malaise, fatigue, anxiety,

headache

• Half of patients have pain, itching or

paresthesias at site of the bite

• Lasts 2-10 days

Clinical

After prodrome:

• Furious form (aka “mad dog”) Increasing

agitation, hyperactivity, seizures, hallucinations, aggressive behavior, hydrophobia (spasm of respiratory muscles when attempting to drink)

• Coma develops, then death
• Paralytic form (aka dumb rabies) Progressive

lethargy, incoordination and ascending paralysis

• Respiratory muscle paralysis may occur
• Coma, then death

Diagnosis of Rabies

• Always consider in case of acute onset, rapidly

progressive encephalitis

• Diagnosis before death is ‘tricky’, testing includes:
• Testing for viral antigen by DFA in nuchal skin or corneal

cells

• Testing for viral RNA by PCR of saliva, neural tissue, or

CSF

• Serology for antibodies in the blood
• Growing virus isolated from saliva or CSF in cell culture
• Testing after death includes:
• Testing for viral antigen by DFA in brain tissue

Prevention and Treatment issues

these issues often confused…note the differences

• Rabies Pre-exposure prophylaxis
• Given to ‘high risk’ individuals such as veterinarians,

animal control workers, spleunkers before exposure

• 3 doses vaccine
• Rabies Post-exposure prophylaxis (PEP)
• Given following a bite from rabid (or suspected rabid)

animal

• Rabies Immune globulin (RIG) and 4 doses vaccine (day

0,3,7,14)

• Highly effective for prevention
• Rabies “Treatment”
• No known effective Rx; once symptoms develop;

vaccine and RIG of no benefit

• Experimental treatment

PEP - Yes or No?

• Type of exposure (bite, non-bite)
• If bite: provoked vs. unprovoked
• Assess other circumstances of exposure,

e.g., behavior of animal

• Severity of wound
• Animal species involved
• Animal health and vaccination history
• Local animal rabies epidemiology
• Animal available for observation / testing
• Urgent but not “emergency”, consult local public

health

c

22 y/o Asian female,

• Admitted to psychiatric unit for odd behavior,

“completely out of her mind”

• Abnormal movements
• High heart rate, hypotension
• California Encephalitis Project contacted

because clinicians were concerned about rabies

• CSF PCR
• HSV 1&2 (-)
• VZV (-)
• HHV6 (-)
• Enterovirus (-)
• Parvo B19 DNA (-)
• IgG 5.3 IgM <0.1
• West Nile (-)
• HIV-1 PCR <50
• CMV IgG (+), IgM (-)
• EBV IgM <0.90, IgG

3.27

• VRDL NR
• Strongyloides Ab 0.29
• Schistosoma Ab 0.0
• G. lamblia Ag (-)
• Tropheryma whipplei (-)
• Bartonella panel (-)
• Cryptococus (-)
• C. immitis (-)
• RPR NR
• HBc IgM NR
• HBV DNA <40
• HBc Ab (+)
• HCV Ab NR
• HAV IgG (+)
• Mumps Ab (+)
• Rickettsia panel IFA
• Typhus IgG (-)
• RMS IgG (-)
• E. chaffeensis IgG (-)
• A. phagocytophilla IgG (-)
• Q fever phase I and II IgG (-)
• Arbo Panel pending
• M. pneumo IgM 307, IgG 1.24
• H. capsulatum Ab <8
• pANCA (-)
• cANCA (-)
• Heavy metal screen (WNL)
• β-HCG (-)
• α-fetoprotein 1.5
• VGCC Ab
• Pemphigus Ab Screen
• ANNA titers
• GAD 65 Ab <0.5
• Neuroimm
• Thyroid Peroxidase Ab

<10

• TSH 2.93 T4 1.65
• DS DNA Ab (-)
• ANA (-)
• 1. Rabies
• 2. Bacterial meningitis
• 3. Herpes simplex

encephalitis

• 4. Balamuthia mandrillis
• 5. Non-infectious, anti-

NMDAR

• 6. Enterovirus

• A. Rabies
• B. Bacterial meningitis
• C. Herpes simplex encephalitis
• D. Balamuthia mandrillis
• E. Non-infectious, anti-NMDAR
• F. Enterovirus
• Suggested:
• Anti-N-methyl-D-aspartate receptor

(anti-NMDAR) testing

• Abdominal/pelvic ultrasound
• Results:
• U/S – teratoma
• Antibody positive for anti-NMDAR

antibody

• Initially recognized ~ 7 years

ago in young Asian females,

• ften with teratoma
• Initially considered a

‘paraneoplastic syndrome’

• Immune form of encephalitis
• Some have teratomas, but the

young children and males generally do not Comparison to Viral Agents

CEP data (2007-2011)

5 10 15 20 25 30 35 EV WNV HSV-1 VZV NMDAR

< 30 years of age

• Gable M et al, CID, 2012

• Herpes simplex:
• Limitations of CSF PCR testing, consider

re-tap if temporal lobe involvement

• Enterovirus
• Another leading cause of encephalitis
• More often in pediatrics but still important

in adults

• Multiple specimen types needed to
• ptimize yield
• Balamuthia mandrillis
• Although not common, probably not so rare
• Consider testing in patients with parenchymal

lesions especially if CSF profile “MTB/fungal-ish”

• Rabies
• Should be considered in any rapidly progressive

encephalitis

• Probably also being missed
• Changing paradigm-not all fatal
• Bacterial meningitis

— Prior antibiotics influence culture, role for PCR in these cases

• Anti-NMDAR encephalitis
• THE leading entity in CEP, consider

in patients with movement disorders, seizures and/or autonomic instability

11 year old female

— Fever — Upper respiratory illness for a few days — Seen by PMD, Rx Amoxicillin

• A few days later presented to ER

— Lethargy and confusion — Aphasia — Stiff neck

Laboratory: CSF: 1700 WBCs (70P/30Mo) Protein=120 mg/dl G= 50 mg/dl

• Routine bacterial & Blood

cultures: negative

• Referred to CEP
• Because of ‘bacterial’-looking

CSF profile

— PCRs for Strep pneumo and Neisseria meningitis peformed

• Postive Strep pneumo

Organism Incidence (cases per 100,000) 1986 1995 2006-2007

• H. influenzae

2.9 0.2 0.08

• S. pneumoniae

1.1 1.1 0.81

• N. meningitidis

0.9 0.6 0.19 Group B streptococcus 0.4 0.3 0.25

• L. monocytogenes

0.2 0.2 0.05

1986: Wenger et al. J Infect Dis 1990;162:1316-23 1995: Schuchat A, et al. NEJM 1997;337:970-7 2006-7: Thigpen M, et al. NEJM 2011; 364:2016-25.

• Estimated 3,000–6,000 cases

per year in U.S.

• #1 cause of bacterial meningitis

in US

• Case-fatality rate ~30%, up to

80% in the elderly

• Neurologic sequelae common

among survivors

• Gram-positive bacteria
• At >90 known serotypes
• Polysaccharide capsule important

virulence factor

• Type-specific antibody is

protective

“Treatment”

Human Rabies Survivors - Prior Experiences in US

• Recovery without rabies PEP
• 15 year old female, Wisconsin, 2004Milwaukee protocol
• 17 year old female, Texas, 2009 (“Abortive Case”)
• Both met case definition for human rabies based on

clinical manifestations and rabies virus specific antibodies in serum and CSF

• Rabies virus, antigen, nucleic acid not detected from

these patients

• Antibody identified “early”
• Willoughby et al., New Eng J Med, 2005
• CDC, MMWR, 2010

Controversial whether this was really a case or not…