Case report in Republic of Korea

Dong-Kun Yang

Senior researcher

Lab. of rabies in viral disease division of QIA

Contents

1. Epidemiological situation of rabies

2. Current control program in wildlife

3. Recent research project related to

rabies

Epidemiological classification of animal rabies

case in Korea

Since the first rabies occurred in 1907,

in total, 16,129 rabies cases have been recorded in Korea.

0

100

200

300

400

500

600

700

800

90007

12

17

22

27

32

37

42

47

52

57

62

67

72

77

82

87

92

97

02

07

Case o

f ra

bie

s

Year

Epidemic stage Elimination stage Recurrence

stage

- 1939 ~ 1945: No outbreak (7 years)

- 1985 ~ 1992: No outbreak (8 years)

No outbreak of animal rabies cases

two times up to now

0

100

200

300

400

500

600

700

800

900

07

12

17

22

27

32

37

42

47

52

57

62

67

72

77

82

87

92

97

02

07

Case o

f ra

bie

s

Year

(8 years)

Korea’s policy to control rabies in 1960’s

- Implement mass vaccination program to dogs.

- Slay stray dogs.

- Perform the education for people.

As the result, urban rabies was eradicated in 1985. Since 1993, sylvatic rabies

has been reported in northern border area of Korea.

Distribution of rabies cases in Korea

from 1993 to 2011

1993 - 2003 2004 - 2011

Most of rabies were detected in two provinces near the border of demilitarized zone.

Korean raccoon dogs have played a important role in transmission of rabies since 1993.

DMZ

Change of rabies cases in Korea

according to provinces

Since 2007, rabies cases have not been reported in Gyeonggi province

but continued to occur and move to north-eastward in Gangwon province.

This result may be obtained from application of bait vaccine to two provinces.

Numbers of human rabies and biting

cases in rabies risk regions of Korea

No human rabies occurred between 2005 and 2011.

Even though incidence of patients bitten by animals in rabies risk regions has been

increased, the patients have been treated with postexposure prophylaxis(PEP)

properly.

0

100

200

300

400

500

600

700

2005 2006 2007 2008 2009

Bitin

g c

ases

Year

No. of patients bitten by animals

0

20

40

60

80

100

120

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

Rabie

s c

ase

Year

Human rabies cases

Incidence rate of rabies

according to animal species

Rabies cases have been diminished in dog.

But, since rabies was first confirmed in a Korean raccoon dog in 1994,

The cases have been increase.

0

10

20

30

40

50

60

70

80

90

100

Cattle Dog Raccoon dog Others

Case rate

(%)

1930-1938 1993-2003 2004-2011

Monthly distribution of animal rabies cases

from 1993 to 2011

Season (month) Number of

cases(%)

Spring (March-May) 133 (28.9.)

Summer (June-August) 64 (13.9)

Autumn (September-November) 97 (21.0)

Winter (December-February) 167 (36.2)

Total 461 (100)0

20

40

60

80

100

120

140

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

No. of ra

bie

s c

ases

1993-2003 2004-2011 1993-2011

The monthly distribution of animal rabies during 18 years period peaked in Jan.

The incidence rate was the highest during winter. That is because raccoon dogs

did not accumulate enough fat in their body for hibernation and came down to

villages to seek food.

Identification of Korean rabies isolates using IFA

test and electronic microscopy

The confirmative diagnostic method is fluoresent antibody test(FAT) .

And an asset of virus isolation (VI) is availability for further characterization.

Most of rabies isolates are propagated well in neuroblastoma cells (NG-108-15 ).

11

Application of RT-PCR and rapid kit

to rabid brain samples

M 1 2 3 4 5 6 7 8 9 10 11 NC PC M

M 12 13 14 15 16 17 18 19 20 NC PC M

RT-PCR and rapid immunodiagnostic kit can also be used for the detection

of rabies in brain or saliva samples of infected animals to make a rapid decision.

These kinds of methods could be used as supplementary diagnostic tools.

KRVB1002

KRVB0907

KRVB0902

KRVC0802

KRVB0905

KRVB1003

KRVR0901KRVR0803

KRVB0904

KRVB1004

KRVB0910KRVB1005

KRVB0908

KRVB0909

KRVR0906

KRVB1006

KRVR0801

KRVB1001

KRVB0903

KRVR0804

SKRDG0204HC

SKRRD0205HC

SKRBV0403CW

SKRRD0406CC

SKRBV0404HC

SKRDG0204CW

SKRRD9903YG

SKRRD9901PJ

SKRRD9902PJ

SKRDG9901GY

SKRDG9902GY

SKRDG0203CW

SKRBV9801YC

NeiMeng1025C

NNV-RAB-HSerotype1

RV-97

NishigaharaNi-CE

PVERA

SAD

CVS-11

Flury-LEP

F02

D02

FJ009

RRVON99-298

9583

95

72

85

94

100

10099

100

100

Gangwon II

10091

81

89

100

100

99

100

99

Gyeonggi

Gangwon I

6262

64

Korean rabies isolates belong to serotype I, genotype I.

Based on the phylogenetic tree, Korean rabies isolates classified into 3 subclades.

and were most closely related to the eastern Chinese and Russian strains.

Korean isolates originated from a rabid animal in northeastern Asia.

Multiple alignments of amino acid sequences of

glycoprotein from the 14 Korean isolates

Isolates 26 37 310 319 333 346

★ ★KRVR0801 PNNLVVEDEGCTNLSGF.....GFGKAYTIFNKTLMEADAHYKSVRTWNEIIPSKGCLR

KRVC0802 -----------------.....-------------------------D-----------

KRVR0803 -----------------.....-------------------------------------

KRVR0804 -----------------.....-------------------------------------

KRVR0901 -----------------.....-------------------------------------

KRVB0902 -----------------.....------------------H------------------

KRVB0903 -----------------.....-------------------------------------

KRVB0904 -----------------.....-------------------------------------

KRVB0905 -----------------.....-------------------------------------

KRVR0906 -----------------.....-------------------------------------

KRVB0907 -----------------.....-------------------------------------

KRVB0908 -----------------.....-------------------------------------

KRVB0909 -----------------.....-------------------------------------

KRVB0910 -----------------.....-------------------------------------

The arginin(R) at position 333 of the residue within the ectodomain of glycoprotein

is essential for virulence. There were no changes of arginin among isolates.

Therefore, rabies isolates circulating in Korea may pathogenic in several hosts.

Rabies case report occurred in March 2011

Species: cattle (Hanwoo), about 5 years old.

Date: 21 April 2011.

Location: Bukmyeon Inje Gangwon province

Latitude: 38.06,43 Longitude: 128.11.23.

Symptom: severe salivation, extreme tremors

ataxia, paralysis.

Diagnosis: rabies.

Indication: All cattle of farm must be vaccinated.

According to statement from farmer, wild

animal, raccoon dogs were seen wandering

Around farm frequently.

Like this, recent rabies cases were related to

attacks by raccoon dogs. Indications are transferred to farmer

associated with rabies

Current control program of rabies

in Korea

Current Korea’s policy to control rabies

National animal rabies eradication program

1. Annual vaccination of dogs all around of Korea

2. Obligatory vaccination of cattle in rabies risk area

3. Distribution of bait vaccines for wild animals, raccoon dogs

4. Carry out serosurveillance of rabies in two provinces

5. Education for people

Amount of bait vaccine to be distributed

into two provinces and intake rate

About 500 thousand doses were distributed in 2010.

The amount of bait vaccine has been regulated according to the incidence of region.

The points distributing bait vaccine are various ranging from 20,734 to 39,280.

The time of distribution is spring and autumn twice a year.

0

10

20

30

40

50

60

2005 2006 2007 2008 2009 2010

Am

ount of

dis

trib

ution(X

10,0

00)

Year

70

75

80

85

90

95

100

2005 2006 2007 2008 2009 2010

Rate

of

inta

ke(%

)

Year

Korean raccoon dog involved in rabies

Korean raccoon dogs do not bark and live near farm.

Population density of raccoon dogs is higher in Ganwon than in Gyeonggi.

American raccoon dogFamily: Canidae, Nycteeutesprocyonoides koreensis

48%

26%

18%

4% 4%

Mount Hill0

1

2

3

4

5

6

7

8

2002 2003 2004 2005 2006 2007 2008 2009

Density(

head/1

00ha)

Gangwon Gyeonggi

A process of distributing bait vaccine to field

Before distribution of bait vaccine, conduct education (wear gum glove), the

vaccines were distributed near farm and small stream. Check locations and the

vaccine three times each week. If no trace of taking bait vaccine, change the

location of distribution. After 2 month collect them and check the remaining

vaccine and report them.

Seroprevalence of rabies virus

in domestic animals of Ganwon province

We need continuous surveillance to check national eradication program .

From the result, about 70% of dogs demonstrated sero-positive against rabies.

It is well known that the rabies is not popular if the antibody ratio of positivity

is 70% or greater.

0

10

20

30

40

50

60

70

80

90

100

1999 2002 2003 2004 2005 2006 2007 2008 2009 2010

Positiv

e r

ate

(%)

Year

Canine Bovine

Recent research project related to

rabies

Prepare the ingredients of bait

Poultry meal

SugarFeather mealCorn

Fish meal Soybean cake Tetracycline

premix

Poultry oil+

Beta dextrin

bait

v

v

v

rERAG333Glu

N P M G(mutate) L

ERA genome plasmid

BHK/T7-9 cell

N P L

RC-HL helper

plasmids

・・・ T7 promoter

T7

The minimal infection unit of negative sense

RNA genome is ribonucleoprotein and N, P, L

genes are needed to recover recombinant virus

Strategy for developing candidate for bait vaccine

using reverse genetics system

Result of construction of recombinant

rabies virus and propagation in cells

M G1 G2 N1 N2

rERAG333 strain

Control cells

0

2

4

6

8

10

3 7

Viral tite

r(10FAID

50/m

l)Days after inoculation

rERAG333(BHK) rERAG333(NG108)

The recombinant vaccine candidate is propagated well in both BHK and NG108

cells. After checking immunogenicity and efficacy of candidate, this strain will be

Used for oral bait vaccine seed.

Trap-vaccination-release (TVR) program had been performed for 7 years. The

Ontario state was declared with rabies free region at October 2008. Concentric

rings around the location of a rabid animal represent vector population reduction

(PR), TVR and ORV zones. It is important to get national model to control rabies.

New strategy for the point infection

control (PIC) program

ORV

(oral vaccine)

TVR

PR

(population reduction)

Location of outbreak

Conclusion

National eradication program including massive

vaccination and distribution of bait vaccine for the

control of rabies in wild animals was lead to a

substantial decrease in number of rabies in Korea.

When the new reinforced program is prepared and

applied to the rabies risk areas, sylvatic rabies will be

eradicated in Korea in the near future.

These kinds of skills will be transferred to Asian

countries.