Marion Koopmans | November 2008

Preparing for emerging infectious diseases: the public health response to West Nile virus

Gubler, 2002

Main arbovirus problems

1999: Emergence of West Nile virus in North America

MacKenzie et al, 2004

Emergence of WNV in North AmericaPossible sources of WNV in New York, 1999

Migratory birdsImportation of birdsPerson incubation stage Transport mosquitoes by airplane

0

10

20

30

0-910-19

20-2930-39

40-4950-59

60-6970-79

80-8990-99

Age group (yr)

Prop

ortio

n of

dis

ease

cas

es (%

) WNME WNF

Human WNV Disease Cases, by Age Group and Clinical Category, United States, 2003

fever

Meningo-encephalitis

Fever (+)

~80%Asymptomatic

<1%serious

Koopmans et al., 2008

Improved surveillance

Fever (+)

~80%Asymptomatic

<1%serious

Drastic change in epidemiology resulting from a single mutation

Brault et al., 2007

www.efsa.eu.int risk assessment Rift Valley fever, 2005

Assessing risk of emergence is virtually impossible

Would WNV introduction be detected?

0

10

20

30

40

50

60

WNNI WNF D

20032004

Nr cases, State of NY

Case 1 Case 2 Case 3 Case 4

37 yr, male 53 yr, male 68 yr male 38 yr male

Fever Fever Fever FeverHeadache cough joint pain coughChest pain balance history of gout chillsCough history TIA headache

nauseavomiting

Spott-Whitney et al., 2006

People are not horses

Rockx et al., 2006

ICD9-CM codes

Description 1999 2000 2001 2002 2003 Total

3229 Meningitis NOS* 263 312 284 314 286 14593230 Encephalitis in viral

disease 0 1 3 1 1 63234 Encephalitis other, due

to infection1 0 1 1 1 4

3239 Encephalitis NOS 205 200 241 264 241 11510479 Menigitis viral NOS 335 749 404 402 453 2343

0499 Encephalitis viral NOS 70 89 62 80 59 360Total

874 1351 995 1062 1041 5323

Nr of unexplained cases of neurological illness, based on hospital discharge diagnoses, The Netherlands

•Almost 90 % of meningitis and encephalitis of suspected viral etiology remainswithout diagnosis

•of the ones that test positive, 53% herpes, 44% enterovirus positive

•substantial differences between laboratories

Test result Properties Lab A Lab Bpos

N (%) 14 (1,3) 106 (4)% herpes 86 1% entero 14 99avg age 32 9range 0-60 0-42

neg N (%) 997 (98,7) 2543 (96)avg age 44 31range 0-84 0-93

Entero virus notifications and

Hospital meningitis/encephalitis (unexpl.+ unspec.vir.)

0

10

20

30

40

50

60

0 50 100 150 200 250 300

weeknumbers 1999-2003

# ca

ses

(mov

.avg

5w

ks)

meningitis andencephalitis

entero notifications

Summer 2000

Summer 2003

0

10

20

30

40

50

60

m j j a s o n d j f m a m j j a s o n d j f m a m j j a s o n

50 or more

Rockx et al., 2006

0

50

100

150

200

250

300

350

2002 2003 2004 2005 2006 2007 2008

Nr of CSF samples submitted for WNF exclusion

*

Tick-borne virusesTBE

Mosquito borne virusesDengue group

Japanese encephalitis groupJapanese encephalitis

Murray Valley EncephalitisSaint Louis Encephalitis

UsutuWest Nile virus

Yellow fever virus groupViruses with no known arthropod vector

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 2 4 6 8 10

Number of WNV-meningitis/encephalitis cases*

Prob

abili

ty o

f det

ectio

n

59% of unexplained mengitis orencephalitis cases tested in 2003

If 90% of unexplained cases had beentested

Probability of detection of WNV in 2003 by hypothetical outbreak size

Dauphin and Zientera, 2006

ongoing

Scholte et al., 2007

0

20

40

60

80

100

120

140

160

180

200

27-30

31-34

35-38

39-42

43-46

47- 5

0 51

-2 3-6

7-10

11-14

15-18

19-22

23-26

time (w eek nrs)

cum

ulat

ive

num

ber o

f col

lect

ed A

e. a

lbop

ictu

s of

all

com

pani

es (b

lack

bar

s)

0

2

4

6

8

10

12

num

ber o

f Luc

ky b

ambo

o-im

port

ing

com

pani

es

posi

tive

for

Ae.

alb

opic

tus

(gre

y ba

rs)# Ae. albopictus

# infested companies

Presence of Ae. Albopictus in Europe, January 2007

Chikungunyaoutbreak, Aug 2007

West Nile outbreakSept 2008

Serosurvey on six of the 14 companies Blood samples for serology

Questionnaire: - exposure to mosquitoes- history of possible exposure to

Flaviviridae by traveling or vaccination.

1 person flavivirus positive > TBE from Poland

Freedman et al., 2006; 30 sites, 6 continents, n=17.353, 1996-2004

Diarrhoea

Diarrhoea

Diarrhoea

Diarrhoea

fever

Diarrhoea

Resp

Resp Resp

RespResp

Malaria

MalariaMalariaMalariaMalaria

Malaria

DengueDengue

Dengue Dengue Dengue

Dengue

Diarree

fever

feverfever

fever

fever

fever

Development of serological micro arrays forsyndrome detection

Use of serological arrays for syndrome-based evaluation of patient groups with minimal amounts of specimen

Mumps measles rubella Polio 1, 2, 3

TABLE 1

Most important infectious causes of CNS diseases*

viral (aseptic meningitis) viralEnteroviruses Herpes simplex viruses

Tick-borne encephalitis- Varicella-zoster virus& other Arboviruses† Epstein-Barr virus

Mumps MumpsHerpesviruses Measles

HIV EnterovirusesInfluenzaviruses Japanese encephalitis virus

Parainfluenza West Nile encephalitis virusMeasles Tick-borne encephalitis virus

Rotavirus Other ArbovirusesLymphocytic choriomeningitis Rabies

bacterial (septic meningitis) bacterialHaemophilus influenzae b Listeria monocytogenes

Neisseria meningitidis Mycobacterium tuberculosisStreptococcus pneumoniae Mycoplasma pneumoniae

Staphylococcus spp. Borrelia spp.Streptococcus spp.

Leptospira spp.Treponema pallidum

Mycobacterium tuberculosisBorrelia spp.

fungal fungalCryptococcus neoformans Cryptococcus neoformans

parasital parasitalAcanthamoeba spp. Acanthomoeba spp.Toxoplasma gondii

* adapted from: www.meduniwien.ac.at/hygiene www.enivd.de/ENCDISEASES/fs_encdiseases.htm† Arbovirus= arthropod-borne virus

Meninigitis Encephalitis/ Meningo-encephalitis

Conclusions

• ARBO virus diseases continue to pose a health threat• Sudden changes in epidemiology possible, difficult to predict• Requires alertness in travel clinics• Preparedness program for arboviral diseases

• CIb themes- Entomological component - Vector-pathogen surveillance and competence- Signalling unexplained disease outbreaks- Rapid detection and control of EID- Interdisciplinary collaboration and data sharing for risk assessment

and early warning

Early warning committee• Since 1999, on request of Health Care Inspectorate

• Weekly meeting

• Main task: Recognize timely and completely threats to public health caused byinfectious diseases

• Participants:- Microbiologists, epidemiologists from various departments of the RIVM- Food Safety Authority

• Cooperation with other relevant organisations or experts - Blood supply, organ donation and transplantation, etc

• Before the meeting: assess information from various sources to be discussedduring the meeting

Centre for Infectious Disease Control, RIVMAnnette de Boer, Chantal Reusken, Kees van de WijngaardeJohan Reimerink, Gert-Jan Godeke, Hilly Blok, Catja van Haren

Plantenziektenkundige DienstErnst-Jan Scholte, Harry Ruijs, PD-inspecteurs

Wageningen UniversityWillem Takken, Frans Jacobs

Marion.koopmans@rivm.nl