Transcript Review of Tick Distributions, Surveillance, and Disease in

Distribution of Ticks and the
Potential Impact of Tick-Borne
Disease on United States Forces
in Korea
LTC William J. Sames IV
Entomology Consultant 18th MEDCOM
&
Dr. Terry A. Klein
Regional Infectious Disease Coordinator (Contractor)
&
Dr. Hung-Chol Kim
5th Medical Detachment (Ento)
&
Dr. Joon-Seok Chae
Seoul University
Korea
Tick-Borne Disease and Military
Importance in ROK
• Taxonomic knowledge gap identified
– 1971 - Last published collective taxonomic work; US Army and
associates out of Cp Zama, Japan; Yamaguti, Tipton, Keegan,
Toshioka
– 1980s – Additional work by Kang and associates
– No published distribution maps; out-of-date checklists
• Disease knowledge gap identified
– Individual articles on particular diseases, but no published list or
discussion of importance
– Tick-borne diseases are not reportable by medical authorities
• Threat to military forces is currently best guess based
upon diseases present, tick population, exposure rates,
mitigation actions, season, etc.
Knowledge Correction Activities
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Conduct literature search and review
Compile tick collection data
Determine tick distributions
Create tick-borne disease list for Korea
Estimate prevalence of tick-borne disease
in Korea
• Conduct surveillance activities for
additional data to complement the above
actions
Results of Tick Literature Review
• Bibliography of tick literature regarding Korean
ticks created in MS EXCEL worksheet
– Expanded to include literature regarding ticks from
Japan, NE China, and SE Russia
• PDF files are being acquired for listed citations
• As of 1 Feb 2007:
– 222 citations have been listed
– 151 or 68% of listed files are in PDF
• Intent is to incorporate bibliography and PDF
files into DPMIAC for future DOD access
Tick Collection Database
• Created in MS EXCEL worksheet
• Multiple column format to capture as much
information as possible and to facilitate sorting
and searches
• Data from literature, non-published military
collection records, other sources as found
• Potential benefits
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Distribution data by species
Host association data
Tick-Disease association
Seasonality and population estimates
Ticks of Korea – Checklist*
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Argas boueti
Argas japonicus
Argas vespertilionis
Boophilus microplus
Dermacentor coreus
Dermacentor reticulatus
Haemaphysalis campanulata
Haemaphysalis concinna
Haemaphysalis cornigera
Haemaphysalis flava**
Haemaphysalis japonica**
Haemaphysalis kutchensis
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Haemaphysalis longicornis**
Ixodes angustus
Ixodes granulatus
Ixodes nipponensis**
Ixodes ovatus
Ixodes persulcatus**
Ixodes ricinus
Ixodes signatus
Ixodes turdus
Ixodes verpertilionis
Rhipicephalus sanguineus
*Checklist from literature sources – list has not been validated; work in progress
**Species collected during 2006 US Army surveillance.
Known Tick Distributions
• Under development – more confidence as
additional collection records are acquired
• Adding tick collection data to spreadsheet
• Plot locations of above data to assist in
determining distributions
• Limited data available from NK – can
speculate based upon NE China and SE
Russia collections and limited NK data
Known Tick-Borne Disease in ROK*
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Anaplasma equi
Anaplasma phagocytophila
Borrelia burgdorferi
Ehrlichia bovis
Ehrlichia canis
Ehrlichia chaffeensis
Spotted Fever Group Rickettsia
Theileria sergenti
Tick-borne encephalitis
*Disease list created from literature sources primarily individual articles about
each disease. List to eventually associate vectors with each disease.
Prevalence of Tick-Borne Disease
in ROK
• No medical reporting requirements – best
guess as to prevalence
• Most Korean tick-borne diseases treatable
with antibiotics
– Antibiotics
• Used to be available without prescription
• 2004 – law changed requiring prescription
– Some tick-borne diseases are self limiting
Surveillance Activities
• Sparse surveillance activities in literature sources
• Few Army tick surveys reported since 1960s
• Air Force documents: no ticks found on military
working dogs on AFB in Korea (in DPMIAC)
• In 2004-2006, 18th MEDCOM Entomology
Consultant conducted annual drag/flag tick
surveys
• Some tick data from rodent surveys
• Need surveillance which targets host species
• Need peninsula wide collections
• Need entire season collections to show species
seasonal activity
Surveillance Activities
• Spring/Summer 2007
– Using degree days to estimate “best’ surveillance
dates
• Gets warmer in the south, hence earlier season
• Degree day estimates based upon average daily
temperatures above 32oF beginning on 1 Jan
• Used 7 years of data (1 Jan-30 Jun, 2000-2006) for
degree day estimates.
– Known that ticks present in good numbers north of
Seoul around 1 April
• Degree days suggest late-Feb/early-Mar for Jeju Island
• Degree days suggest last week of March for Mokpo
(southern mainland Korea)
Summary
• Gaps in Korean tick-borne disease
knowledge identified and being corrected
– Bibliography of literature on Korea ticks
– Spreadsheet of tick collection data
– Checklists for ticks and tick-borne disease
– Distribution and disease prevalence
information being compiled
– Surveillance activities for additional data
Questions?