11

Outbreak of Fatal Cardiopulmonary Outbreak of Fatal Cardiopulmonary Failure among ChildrenFailure among Children

Caused by an Emerging Strain of Caused by an Emerging Strain of Enterovirus 71 - NakhornEnterovirus 71 - Nakhorn

Ratchasima Province, Thailand, 2006Ratchasima Province, Thailand, 2006

Rome Buathong, MD., MIH., FETP.Rome Buathong, MD., MIH., FETP.Wanna Hanshoaworakul, MD. MSc.Wanna Hanshoaworakul, MD. MSc.

Michael O’Reilly, MD., MPH.Michael O’Reilly, MD., MPH.Kumnuan Ungchusak, MD., MPH.Kumnuan Ungchusak, MD., MPH.

Bureau of Epidemiology Bureau of Epidemiology Ministry of Public HealthMinistry of Public Health

22

EnterovirusesFamily PicornaviridaeSmall particle size (20-30 nm) & stableResistant to pH & temperature change, lipid Solvents & detergentsSingle-stranded RNA GenomeTransmission: mainly fecal-oral route and respiratory droplets

33

Classification of Human Enteroviruses

Poliovirus Types 1, 2, 3Poliovirus Types 1, 2, 3Coxsackievirus A Types 1- 24Coxsackievirus A Types 1- 24Coxsackievirus B Types 1- 6Coxsackievirus B Types 1- 6Echovirus Types 1-3 4Echovirus Types 1-3 4Enterovirus Types 68 - 71Enterovirus Types 68 - 71

44

Clinical Manifestations of EV71Clinical Manifestations of EV71Asymptomatic Febrile illness URI

HFMD, Herpangina

Meningitis/Encephalitis/AFP

Myocarditis/Pericarditis

Pneumonia

Diarrhea/Gastroenteritis

Myopathy Pulmonary edema/ hemorrhage

Enterovirus 71

55

Etiological Agent of HFMDEtiological Agent of HFMD

HFMD

CoX A(24 spp)

CoX B(6 spp)

Echo(34 spp)

EV68-71(4 spp)

Total 68 spp.

66

BackgroundBackground

July 4th, 2006: Nakhorn Rachasima health officer reported 4 unexplained sudden deaths among young children in 3 days. An attending clinician primarily suspected myocarditis as the cause of deathThe BoE promptly started an investigation

77

ObjectivesObjectivesTo identify the cause of death for these 4 To identify the cause of death for these 4 children children To define the scope of the epidemic by To define the scope of the epidemic by active case findingactive case findingTo describe clinical characteristics of the To describe clinical characteristics of the fatal casesfatal casesTo rapidly implement control and To rapidly implement control and prevention measure prevention measure

88

Descriptive StudyDescriptive Study

Fatal cases: Fatal cases: – Reviewed medical recordsReviewed medical records– Interviewed parents of fatal casesInterviewed parents of fatal cases– Interviewed medical staffInterviewed medical staff

Non fatal cases: Non fatal cases: – Active case finding (screening) in affected Active case finding (screening) in affected

communities: Districts A and Bcommunities: Districts A and B

99

Laboratory InvestigationLaboratory Investigation

• Viral isolation Viral isolation

• Paired sera for micro-nuetralization Paired sera for micro-nuetralization antibody of EV71antibody of EV71

• Nucleotide sequencing Nucleotide sequencing

• Electron Microscopy Electron Microscopy

1010

Case DefinitionsCase DefinitionsSuspect CaseSuspect Case:: Any child < 15 years old, living in the Any child < 15 years old, living in the

same village where a fatal case occurred, who had same village where a fatal case occurred, who had one or both of the following: one or both of the following:

Fever (history or T > 37.8 C) Fever (history or T > 37.8 C) or or

Any lesion on buccal mucosa, hands or feetAny lesion on buccal mucosa, hands or feet Period: June – August 2006Period: June – August 2006

Probable CaseProbable Case:: Met suspect case criteria and died Met suspect case criteria and died without confirmatory testingwithout confirmatory testing

Confirmed CaseConfirmed Case:: Met the inclusion criteria with Met the inclusion criteria with laboratory confirmation for any Enterovirus specieslaboratory confirmation for any Enterovirus species

1111

Results

1212

CharacteristicsCharacteristics Case 1Case 1 Case 2Case 2 Case 3Case 3 Case 4Case 4GenderGender FemaleFemale MaleMale MaleMale MaleMale

Age (months)Age (months) 44 2424 1717 3939

VillageVillageDistrictDistrict

XXAA

XXAA

YYBB

ZZBB

Epidemiological Epidemiological linkage linkage Close contactClose contact NoneNone NoneNone

Onset DateOnset Date June June 2525thth

June June 2323rdrd

June June 2222ndnd

June June 2424thth

Duration of illness Duration of illness until death (days)until death (days) 44 33 33 44

Demographic Characteristics of Four Fatal Cases, Thailand , 2006

1313

Clinical Clinical Case 1Case 1 Case 2Case 2 Case 3Case 3 Case 4Case 4 FFeverever > 39 > 39 ooCC PresentPresent PresentPresent PresentPresent PresentPresent Fever duration Fever duration (days)(days) 33 33 22 33

URI symptomsURI symptoms GI symptomsGI symptoms

NoNoNoNo

NoNoNoNo

NoNoNoNo

YesYesYesYes

Acute DyspneaAcute Dyspnea PresentPresent PresentPresent PresentPresent PresentPresent Hand, foot, oral Hand, foot, oral lesionslesions

NoNo NoNo No No NoNo

TachycardiaTachycardia (HR > 200)(HR > 200)

PresentPresent PresentPresent PresentPresent PresentPresent

Clinical Manifestations among Four fatal Cases, Thailand 2006

1414

Lab/ImagingLab/Imaging Case 1Case 1 Case 2Case 2 Case 3Case 3 Case 4Case 4

EKG EKG Sinus Sinus TachycardiaTachycardia

Atrial Atrial TachycardiaTachycardia

Sinus Sinus TachycardiaTachycardia

Supravent. Supravent. TachycardiaTachycardia

WBCWBC 16,00016,000 15,30015,300 33,20033,200 22,50022,500

NeutrophilsNeutrophils 68%68% 60%60% 82%82% 72%72%

Serum glucoseSerum glucose(mg/dL)(mg/dL) > 500> 500 200-578200-578 153-408153-408 166-354166-354

Cardiac Cardiac EnzymesEnzymes ElevatedElevated Not DoneNot Done ElevatedElevated ElevatedElevated

Ejection FractionEjection Fraction 20 %20 % Not DoneNot Done 68 %68 % 10 %10 %

CXRCXR Pulmonary Pulmonary EdemaEdema

Pulmonary Pulmonary EdemaEdema

Pulmonary Pulmonary EdemaEdema

Pulmonary Pulmonary EdemaEdema

Laboratory and Imaging Results among Four Fatal Cases, Thailand 2006

1515

Chest X-Ray, Case 2Chest X-Ray, Case 2Bilateral Pulmonary Edema

No Cardiomegaly

Non - Cardiogenic Pulmonary Edema

1616

Autopsy Findings: Case 1Autopsy Findings: Case 1• Brain: diffuse brain edema; small numbers of

lymphocytes and histiocytes in the subarachnoid space; scattered foci of necrosis in the thalamus, pons and medullathalamus, pons and medulla

• Heart: diffuse congestion; no pericarditis, myocarditis or endocarditis; no infarct

• Lungs: diffuse pulmonary edema & hemorrhage; small numbers of neutrophiles and lymphocytess present in the interstitium of alveolar septa

1717

Formalin-fixed Brain Tissue

Viral-like particles, 20 nm in average diameter, non-enveloped, cytoplasm

1818

Nucleotide SequencingNucleotide Sequencing

EV71 in Case 2 identified into EV71 in Case 2 identified into Genogroup C4 Genogroup C4 Nearest strain to the isolate was Nearest strain to the isolate was Shzh01-8 (nucleotide homology: 95.8%)Shzh01-8 (nucleotide homology: 95.8%) This strain had not previously been This strain had not previously been identified in Thailand identified in Thailand

19

N5202-TW-98

2286-TX-97

6F/AUS/6/99

2641-AUS-95

S11051/SAR/98 S18191/SAR/02

1117-MA

A-98

S40221/SAR/00

0948-MAA-00

SB9564-SAR-03

5026-SIN-02

03784-MAA-97 1M/AUS/12/00

shzh03-105

shzh01-8

shzh04-J41

SHH02-6

shzh03-58

TW-0

0

SB2864

/SAR/00

2027/SIN/01

CN04104/SAR/00

5511/SIN/00

18/Sin/97

N7008-TW-99 N5101-TW-98

MY104/9/SAR/97

3799/SIN/98 7673-CT-87 2222-IA-88 2258-CA-79

2609-AUS-74

AB204852 AB204853

U22521

0.01

100100

100

99.9

TH_SI 01/06

KOR-00KOR-00

KOR-00

73.6

98.5

100

100100

91.8

78.6

100

73.3

TW-0

0

TH_SI 08/01 TH_SI 06/01

A

B1

B2B3

B4

C4

C1

C2

C3

Case 2

Courtesy of Puthawathana P.

Previously

Previously

200.01

shzh02-40

shzh03-106

AFP9811134

shzh01-8

shzh04-J39

H26-CHN-00

SHH02-17

Seksan-THAI VP197-56-CHN-

F2-CHN-00

shzh04-3

shzh03-58

shzh04-12

E20051733-

E2004104-T

ZJ-CHN-3-0

shzh04-38

EV71-CQ03-

SHH02-6

638-Yamaga

2779-Yamag

1530-Yamag

C4 Subgenogroup

Courtesy of Puthawathana P.

2121

Active Case FindingActive Case Finding• 38 non-fatal cases detected.38 non-fatal cases detected.• Age: all cases < 10 years; median age Age: all cases < 10 years; median age

24 months (3 – 120 months).24 months (3 – 120 months).• Male : Female Ratio = 1:1 (19:19)Male : Female Ratio = 1:1 (19:19)• Clinical manifestationsClinical manifestations

HFMD: 12

Herpangina:1

Febrile: 25

2222

Viral Isolation ResultsViral Isolation ResultsClinicalClinical Number Number

of Caseof Case EV71EV71 COX B & COX B & Other EVOther EV

HFMDHFMD 1212 33 11

HerpanginaHerpangina 11 00 11

Febrile Febrile IllnessIllness 2525 55 22

FatalFatal 44 22 00

TotalTotal 4242 1010 44

2323

Number of Cases by Onset of Cases Number of Cases by Onset of Cases in District A and B, Jun – Aug, 2007in District A and B, Jun – Aug, 2007

0

1

2

3

4

5

6

6/1/

2006

6/8/

2006

6/15

/200

6

6/22

/200

6

6/29

/200

6

7/6/

2006

7/13

/200

6

7/20

/200

6

7/27

/200

6

8/3/

2006

Onset

Num

ber

SuspectedConfirmrd non EV71Confirmed EV71

/-------------------Jun------------------------/ -------------------------Jul---------------------/--Aug-->

N = 42Fatal cases = 4Non-fatal cases = 38

2424

ConclusionConclusion

• EtiologyEtiology: Enterovirus 71 (Genogroup C4): Enterovirus 71 (Genogroup C4)• Cause of DeathCause of Death: Brain stem encephalitis, : Brain stem encephalitis,

+/- Myocarditis, pulmonay edema and +/- Myocarditis, pulmonay edema and hemorrhage, respiratory failurehemorrhage, respiratory failure

• StrainStrain: Emerging strain: Emerging strain• High Case Fatality ProportionHigh Case Fatality Proportion: 9.5%: 9.5%

2525

DiscussionDiscussion• Previous reports of fatalities associated with EV Previous reports of fatalities associated with EV

71 outbreaks in East Asia have occurred in the 71 outbreaks in East Asia have occurred in the context of large (thousands, tens of thousands) context of large (thousands, tens of thousands) HFMD outbreaks and low CFRs. HFMD outbreaks and low CFRs.

• In this outbreak, CFR was high (9.5%) and fatal In this outbreak, CFR was high (9.5%) and fatal cases did not manifest classic HFM signs.cases did not manifest classic HFM signs.

• This is a new epidemiologic pattern for EV 71 in This is a new epidemiologic pattern for EV 71 in Thailand. Careful monitoring of HFMD and Thailand. Careful monitoring of HFMD and pediatric cardiopulmonary failure cases is pediatric cardiopulmonary failure cases is needed.needed.

2626

Chronological Change of EV71 Chronological Change of EV71 Subgenogroups in West Pacific RegionSubgenogroups in West Pacific Region

((K.H. Lin et. al. K.H. Lin et. al. J. Med. Virol. 78J. Med. Virol. 78))CountriesCountries 8080 8686 9797 9898 9999 0000 0101 0202 0303 0404 0505

SingaporeSingapore -- -- B3,B3,B4B4

B3B3C1C1 B3B3 B4B4 B4B4 C1 C1

B4B4 -- -- --

MalaysiaMalaysia -- -- B3B3 C1C1 NoNo B4B4 C1C1 NoNo C1C1 C1 C1

B5B5 NoNo --

ThailandThailand -- -- -- -- -- -- -- C1C1 -- -- --

TaiwanTaiwan B1B1 B1B1 -- C2C2 B4B4 B4B4 B4B4 B4B4 B4B4 B4B4 C4C4 C4C4

JapanJapan-- --

B3 B3 B4 B4 C2C2

-- -- B4 B4 C2C2 C4C4 C4C4 --

ChinaChina -- -- C3C3 C4C4 -- C4C4 C4C4 C4C4 C4C4 C4C4 --

Australia, PerthAustralia, Perth -- -- -- -- B3 B3 C2C2 C1C1 NoNo NoNo

Pathogenesis of Enterovirus InfectionPathogenesis of Enterovirus Infection

Clinical Stage of Enterovirus 71Clinical Stage of Enterovirus 71 Stage I : Symptom onset stage Stage I : Symptom onset stage

(24-72 hrs)(24-72 hrs)– Fever , loss of appetite, oro-pharyngeal Fever , loss of appetite, oro-pharyngeal

symptoms, skin manifestation and coughsymptoms, skin manifestation and cough

Stage II : Symptom generalized Stage Stage II : Symptom generalized Stage (12-24 hrs )(12-24 hrs )

– Irritable, restlessness, unable to get into Irritable, restlessness, unable to get into sleep, abdominal distension, paralytic ileus, sleep, abdominal distension, paralytic ileus, vomiting, headache, photophobia, startle vomiting, headache, photophobia, startle responseresponse

Clinical Stage of Enterovirus 71Clinical Stage of Enterovirus 71 Stage III : Brainstem dysfunction Stage Stage III : Brainstem dysfunction Stage

( 12-24 hrs )( 12-24 hrs )– Generalized brainstem symptomsGeneralized brainstem symptoms– Apathic, dullness, myoclonic jerks, sleepy, Apathic, dullness, myoclonic jerks, sleepy,

drowsy, visual or auditory or vestibular drowsy, visual or auditory or vestibular hallucinationshallucinations

– Localized brainstem symptomsLocalized brainstem symptoms– Mono-/Hemi-/or General weakness, ataxia, Mono-/Hemi-/or General weakness, ataxia,

tension tremor, panic of unknown reason, tension tremor, panic of unknown reason, conjugated ocular disturbance, CN palsy conjugated ocular disturbance, CN palsy ( VI,VII,IX,X,XII)( VI,VII,IX,X,XII)

– Autonomic dysfunction symptomsAutonomic dysfunction symptoms– Tachycardia, cold sweating, poor peripheral Tachycardia, cold sweating, poor peripheral

circulation, HR > 160 bpmcirculation, HR > 160 bpm

Clinical Stage of Enterovirus 71Clinical Stage of Enterovirus 71

Stage IV : Deteriorating Stage Stage IV : Deteriorating Stage ( 6 – 12 hrs )( 6 – 12 hrs )

– Hypothermia, hemorrhagic cystitisHypothermia, hemorrhagic cystitis– Tachycardia > 200 bpmTachycardia > 200 bpm– Apnea, respiratory disturbance, Apnea, respiratory disturbance,

opsocloniaopsoclonia– Neurogenic shock, conscious Neurogenic shock, conscious

disturbancedisturbance

Clinical Stage of Enterovirus 71Clinical Stage of Enterovirus 71

Stage V : Terminal Stage Stage V : Terminal Stage ( 6-12 hrs )( 6-12 hrs )

– Cardiopulmonary failureCardiopulmonary failure– ARDSARDS– ComatoseComatose– ExpiredExpired

Timeline of Clinical Stage Timeline of Clinical Stage (Involved Brain Stem) (Involved Brain Stem)

3-5 days 1-3 days ½ - 1day ½ - 1 day ¼ - ½ day ½ day

Incubation period

Stage I Stage II Stage III Stage IV Stage V

Onset

The longest length of clinical course – 6 days

The shortest length of clinical course – < 3 days

3 4 5 5.5 6

1 1.5 2 2.25 2.75Infect

3333

Public Health ActionsPublic Health Actions• Established a working group of epidemiologists Established a working group of epidemiologists

and pediatricians aimed at studying clinical and and pediatricians aimed at studying clinical and epidemiological aspects of fatal EV71 infectionsepidemiological aspects of fatal EV71 infections

• Strengthened lab capacity for identifying Strengthened lab capacity for identifying enteroviral infections (12 new labs w/ PCR)enteroviral infections (12 new labs w/ PCR)

• Created new national surveillance system for Created new national surveillance system for pediatric cardiopulmonary failure and fatal pediatric cardiopulmonary failure and fatal HFMD cases in ThailandHFMD cases in Thailand

• Media campaign for educating public about Media campaign for educating public about HFMD and non-HFMD EV71 infection by TV, HFMD and non-HFMD EV71 infection by TV, newspaper and internetnewspaper and internet

3434

LimitationsLimitations

• No specimens available to confirm etiology No specimens available to confirm etiology in most cases, including most fatal casesin most cases, including most fatal cases

• Etiology determined in only 14/42 cases Etiology determined in only 14/42 cases (2/4 fatalities)(2/4 fatalities)

• Investigation delayed for almost 2 weeks Investigation delayed for almost 2 weeks after fatalities occurred; may have missed after fatalities occurred; may have missed non-fatal cases and overestimated CFRnon-fatal cases and overestimated CFR

3535

AcknowledgementAcknowledgementssNakhorn Ratchasima Health OfficeNakhorn Ratchasima Health OfficeMaharaj Nakhorn Ratchasima Regional Hospital Maharaj Nakhorn Ratchasima Regional Hospital Srikue Community HospitalSrikue Community HospitalNational Institute of Health, Department of Medical National Institute of Health, Department of Medical

Science, MOPHScience, MOPHDepartment of Microbiology, Siriraj Hospital and Department of Microbiology, Siriraj Hospital and

Faculty of Medicine, Mahidol University Faculty of Medicine, Mahidol University Thailand MoPH – US CDC Collaboration (TUC)Thailand MoPH – US CDC Collaboration (TUC)

** Travel Budget supported by IEIP, TUC** Travel Budget supported by IEIP, TUC

3636

Thank You for Your Kind Attention

3737

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3838

Viral Study Result among Viral Study Result among Fatal CasesFatal Cases

Viral StudyViral Study Case 1Case 1 Case 2Case 2 Case 3Case 3 Case 4Case 4

Enterovirus Enterovirus IsolationIsolation

No No specimen specimen EV71 EV71 No No

specimenspecimenNoNospecimenspecimen

Autopsy Autopsy Brainstem Brainstem InfectionInfection

Not Not DoneDone

NotNot Done Done

NotNot DoneDone

ElectronElectron MicroscopyMicroscopy

EV identified EV identified in Brainstemin Brainstem

Not Not DoneDone

NotNot Done Done

NotNot DoneDone

SummarySummary ConfirmConfirm ConfirmConfirm ProbableProbable ProbableProbable

3939

Seroprevalence of Anti-EV71 among Singaporean Child, 2005

Highly Susceptible

Age: 1 mo – 5 yr

4040

Reticular formation involvement autonomic dysfunctionDamage of some area of brain stem esp. medullary vasomotor center

Sympathetic over-stimulation

Excessive release hormonal of Cathecolamine & Cortisol

HT, Tachycardia, Sweating, Hyperglycemia

Pulmonary veins constriction

Inc. pulmonary capillary hydrostatic pressure

Pulmonary edema

Pathogenesis: “unclear”

4141

EV71EV71• In Taiwanese outbreak, cause of death was In Taiwanese outbreak, cause of death was

brainstem EV71 infection resulting in brainstem EV71 infection resulting in cardiopulmonary failurecardiopulmonary failure

• All 6 cases of fatal confirmed EV71 infection All 6 cases of fatal confirmed EV71 infection occurring in Thailand since 2006 have shown occurring in Thailand since 2006 have shown evidence of multiple indicators of brainstem evidence of multiple indicators of brainstem infection includinginfection including• Pulmonary edema/hemorrhagePulmonary edema/hemorrhage• HyperglycemiaHyperglycemia• TachycardiaTachycardia• Leukocytosis Leukocytosis

4242

Case 3 and Case 4Case 3 and Case 4

They had the indicators of brainstem They had the indicators of brainstem infection or damage resulting to infection or damage resulting to cardiopulmonary malfunction which cardiopulmonary malfunction which includingincluding1. Non-cardiogenic pulmonary edema1. Non-cardiogenic pulmonary edema2. Increased sympathetic activity2. Increased sympathetic activity

HyperglycemiaHyperglycemiaExtreme tachycardia with irregular patternExtreme tachycardia with irregular pattern

3. Leukocytosis3. Leukocytosis

4343

Situation of Fatal EV71 Infection in Situation of Fatal EV71 Infection in Thailand 2006Thailand 2006

In 2006, we found 15 cases of EV71 infection In 2006, we found 15 cases of EV71 infection with deathwith death– 8 cases8 cases presented with fever and acute pulmonary presented with fever and acute pulmonary

edema (non-cardiogenic) edema (non-cardiogenic) without HFMDwithout HFMD Of these 8 cases the laboratory confirmed for EV71 in 3 Of these 8 cases the laboratory confirmed for EV71 in 3 cases ( all other 2 cases specimen unavailable, 3 cases cases ( all other 2 cases specimen unavailable, 3 cases negative for any EV ) negative for any EV )

– 7 cases7 cases presented with fever and acute pulmonary presented with fever and acute pulmonary edema edema with HFMDwith HFMD

Of these 7 cases the laboratory confirmed for EV71 in 3 Of these 7 cases the laboratory confirmed for EV71 in 3 cases ( all other were no specimen available)cases ( all other were no specimen available)

4444

Viral Pathogen’s Structures Viral Pathogen’s Structures causing Brain Stem Infectioncausing Brain Stem Infection

PathogenPathogen StructuresStructuresEnterovirusesEnteroviruses ss-RNA, ss-RNA, non-envelopednon-enveloped, , 20-30 20-30 nm, nm,

IcosahedralIcosahedral, , mature in cytoplasmmature in cytoplasm FlavivirusesFlaviviruses ss-RNA, enveloped, 37-50 nm, ss-RNA, enveloped, 37-50 nm,

Icosahedral Icosahedral HerpesvirusesHerpesviruses ds-DNA, enveloped, 150-200 nm, ds-DNA, enveloped, 150-200 nm,

IcosahedralIcosahedralAdenovirusesAdenoviruses ds-DNA, enveloped, 60-90 nm, ds-DNA, enveloped, 60-90 nm,

IcosahedralIcosahedralRhabdovirusesRhabdoviruses RNA, enveloped, 180 nm, cylindricalRNA, enveloped, 180 nm, cylindrical