Surveillance , Disease Control and Prevention for Chikungunya Fever Thailand, 20082009

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Surveillance , Disease Control and Prevention for
Chikungunya FeverThailand, 2008-2009
BUREAU OF EPIDEMIOLOGY-Ministry of Public Health
(MOPH), THAILAND
Rome Buathong, MD., FETP. Central Epidemiological
Investigation and Surveillance Bureau of
Epidemiology Thailand-Ministry of Public Health
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Chikungunya Infection

• Arthropod-borne viral arthritis and rash syndrome
  consist of
• Chikungunya virus disease
• Mayaro virus disease
• Sindibis virus disease
• Onyong-nyong Fever less arthritis
• Chikungunya virus disease ???? RNA virus
  ????????? Alphavirus gunus, Togaviridae family

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Chikungunya Infection

• Three strains were distinguished
• East/Central African Strain
• West African Strain
• Asian Strain
• Aedes aegypti (??????????), Aedes albopictus
  (?????????) are main vector

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West African Strain
East/Central African Strain
Asian Strain
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India, 1,500,000 cases
Malaysia (Sep 08) 2,000
Singapore (Jan 08) 200
Report 200 death cases
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BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND
History of Chikungunya Fever in Thailand
1958, First identified in Bangkok
1976 Prachinburi
1988 Surin
1991 Khon Khean
Chikv strain identified in 1962-1995 was all
Asian strain (AFRIMS)
1993 Loei, Phrayao
1995 Nongkhai(94), Nakhon
Si Thammarat(576)
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In October, 2008 Cluster of fever , rash and
severe arthralgia was detected in one village at
Laharn health center and then chikungunya was
suspected After investigation among 82 suspected
case revealed positive Chikungunya by RT-PCR and
seroconversion by HI (60)
Yi-ngo ?.?????
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Background
BUREAU OF EPIDEMIOLOGY- MOPH, THAILAND

• Since Chikungunya fever was not a notifiable
  disease in Thailand, thus the Bureau of
  Epidemiology included Chikungunya fever is the
  latest notifiable disease and launched in
  November 2008 (passive surveillance nationwide
  all gov. hospitals and some private)
• Three case definitions were described as
  suspected, probable and confirmed
• All suspected cases required to retrospective
  report to the national surveillance system

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Case Definitions
BUREAU OF EPIDEMIOLOGY- MOPH, THAILAND

• Suspected Case
• Fever with at least two of the following symptoms
• Arthralgia/Arthritis/Joint swelling
• Rash
• Myalgia
• Headache
• Retro-orbital pain
• Probable Case suspected case with
• 1) PLT normal and WBC lt 5000 or
• 2) Epi-linkage with confirmed case
• Confirmed Case suspected case with CHIKV
  laboratory confirmed by PCR, HI a/o IgM

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Protocol for Lab Testing
BUREAU OF EPIDEMIOLOGY- MOPH, THAILAND
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Surveillance Results
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• By March 10th, 2009, totally 12,115 suspected
  cases were reported to the passive surveillance
  system with no death case
• Male female ratio was 11.5
• Adult cases was 86
• Median age was 38 years (IQR 23, 50)
• The main occupation was agricultural (47)
• The OPDIPDActive cases ratio was 1511

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Number of Cases by Date of Onset, Chikungunya
Fever, Thailand August 2008-March 2009
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• X-sectional serosurvey was conducted in one
  village (n521)
• 26 seropositive by IgM (40 units) HI (140),
  
• 10 Asymptomatic infection,
• Adult spec. AR 29 vs Children spec. AR7
  (plt0.001)

N12,115
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Songkhla, 3629 cases 272/100,000 pop.
Pattani, 1612 cases 251/100,000
pop.
Sep 10th ,08
Yala, 488 cases 103/100,000 pop.
Nov 1st ,08
Narathiwat, 6371 cases 890/100,000 pop.
Oct 12th ,08
Aug 11th ,08
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Laboratory Results
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• Totally 1,009 cases were sent for laboratory
  testing for CHIKV (Jan 31st, 09)
• 492 cases were laboratory confirmed (48.8)
  either RT-PCR or sero-conversion for HI
  (four-fold rising)
• The yield of RT-PCR for CHIKV was 58.0(457/788)
  and sero-conversion HI was 47.9 (114/238)
• Dengue was positive 4.3 (43/1009)

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BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND
Dengue 4
Chikungunya Suspected
Measles lt1
Rubella lt1
Confirmed Chikungunya Fever 50
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Entomology
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• Aedes albopictus and Ae. aegypti were identified
  in epidemic setting of deep southern part of
  Thailand
• CHIKV was isolated by PCR in both species of
  Aedes spp.
• Molecular sequencing is pending

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BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND
Within 24 hr, Early control and containment
PCR/IgM
SRRT, 1030 nation wide
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Prevention Control Strategies
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• Early detection clinical criteria and
  laboratory testing especially in new area
• Early investigation and control immediately
• National campaign for mosquito larva eradication
  (as much as possible)
• Health education
• Nationwide TV, internet, printing media
• Local community radio

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BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• Contagious spreading as a majority
• Sporadic cases were detected in non-epidemic area
• All cases associated with southern epidemic area
• Imported by travelers students, military
  recruits
• No sustainable local transmission
• Active surveillance in nursing colleges,
  military units, transportation terminals in BKK

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East/Central African Strain Islands in Indian
Ocean, India, Srilangka, Malaysia, Thailand
2008-2009
Mutation of E1 gene at Position 226 change
from Alanine to Valine ( 226 A ? 226V)
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Molecular Sequencing of Chikungunya virus in human
E1 226V
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Update Laboratory Diagnosis

• NIH
• HI titer 4-fold rising in paired
• Rapid test IgM no longer interpretation
• IgM will be available in OD cut point
• PCR ( only RT) is the best
• Viral isolation ? Sequencing
• AFRIM
• PCR ( RT, Nested and real time) ? sequencing
• IgM by ELISA ( unit) gt 40 units
• HI titer
• Virus isolation

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Significant Finding in Serosurvey Study at
Village no 8, Laharn Sub-district, Yi-Ngor
District, Narathiwat 2008

• Pisittawoot Ayood, MD. FETP.
• Bureau of Epidemiology
• Department of Disease Control
• Ministry of Public Health

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Results

• Overall survey 698 people ( 750 pop)
• Totally 480 people were blood drawn
• Blood testing for IgM and HI at AFRIM and NIH
• IgM 40 units gt Acute infection
• HI titer 140 gt Recent infection
• Totally 117 cases was met seropositive criteria
  (24.4)
• Median age 53 years, Range (4-87), IQR (43-65)
• Number of children case was only 6 (5)
• Male female ratio was 11 (5859)

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Symptom Vs. Asymptom in Confirmed Chikungunya
Infection
N117
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Clinical Presentation of Symptomatic Confirmed
Chikungunya Infection
N 78
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Clinical Case Definition compare to Laboratory
Confirmed Chikungunya Infection as a Gold Standard
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Clinical Presentation of Symptomatic Confirmed
Chikungunya Infection

• Among 78 symptomatic confirmed cases
• Fever joint symptom (pain or swelling)79.5
• Fever joint pain 78.2
• Fever rash 57.7
• Fever joint symptom rash 52.6

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Conclusion
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• The re-emerging Chikungunya fever is confirmed
  after the 13-year absence with new strain
• The outbreak tends to spread out in the adjacent
  provinces (one month apart)
• Few confirmed cases were reported from other
  parts of the country (with related to southern
  area)
• The vector control measures were limited in this
  complicated situation area with high density of
  both species of Aedes mosquito circulation
• The major interventions include early case
  detection by clinical criteria and then
  laboratory testing with PCR, rapid investigation
  and implementation of control measures

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Contributions
BUREAU OF EPIDEMIOLOGY-MOPH, THAILAND

• Department of Disease Control
• Department of Medical Sciences
• Department of Medical Services
• Offices of Permanent Secretary
• Medical Schools/Universities
• Royal College of Physician and Pediatrics of
  Thailand
• Ministry of Defense
• AFRIMS

MOPH
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BUREAU OF EPIDEMIOLOGY- MOPH, THAILAND
Thank you for your attention
SAWASDEE THAILAND