Presented by Joseph M. Macharia, Jane W.K. Githinji and Jacqueline L. Kasiiti at the African Swine Fever Diagnostics, Surveillance, Epidemiology and Control Workshop, Nairobi, Kenya, 20-21 July 2011

1. ‘Overview of ASF
Impact and
Surveillance in Kenya’
By: Joseph M. Macharia
Jane W.K. Githinji
Jacqueline L. Kasiiti
Central Veterinary Laboratories, Kabete

2. African Swine Fever (ASF)
 First described from Kenya in 1910
(Montgomery, 1921)
 Defined as a highly contagious viral disease
with high mortality
 Natural hosts are pigs, warthogs, bush pigs,
and giant forest hogs.
 The argasid tick (ornithodorous moubata
porcinus) can serve both as vectors &
reservoirs
 It is a notifiable disease in Kenya – suspect
cases must be reported to the DVS.
 Montgomery R.E. (1921) A Form of Swine Fever occurring in British East Africa (Kenya
Colony) J. Comp. Pathol. 34: 159 - 191.

3. Reported ASF Outbreaks
SUDAN
ETHIOPIA
TURK ANA
Laikipia
MANDERA
MARSABIT
1954
UGANDA
WES PO KOT
T
WAJIR
MT. EL GO N
TRANS- NZOIA E MAR AKWET
.
S MBURU
A
ISIOL O
SOMALIA
BARING O
BUNGO MA
Kiambu
UASIN GI SHU
BUSIA
KAKAMEG A LAIKI PIA
NYAMBENE
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU NYE I
R
1958
HOMA_BAY KIRINYAG A
NYAMIR A E BU
M
M RAN GA
U MWI NGI GARISSA
KISII BOMET
MIG ORI
TRANS- MARA THIK A
KIAMB U
KURIA NAIROB I
NAROK
MACHAK OS
TANA R IVER
KITU I
MAKUENI
KAJIADO LAMU
TANZANIA
N
Trans-Nzoia
KILIFI
TAITA TAV TA
E
MO MBASA
KWALE
1964

4. ASF Outbreaks - 1994
SUDAN
ETHIOPIA
 30 farms
comprising a
total of 1442
TURK ANA
MANDERA pigs with a
MARSABIT
mean
stocking
UGANDA
WES PO KOT
T
WAJIR
density of 48
MT. EL GO N
TRANS- NZOIA E MAR AKWET
.
S MBURU
A
ISIOL O
SOMALIA 102, min
(sd
BARING O
BUSIA
BUNGO MA
KAKAMEG A
UASIN GI SHU 2, max 550).
LAIKI PIA
NYAMBENE
Kiambu
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU NYE I
R
ASF
KIRINYAG A

HOMA_BAY
NYAMIR A E BU
M
M RAN GA
U MWI NGI GARISSA
KISII BOMET
Thika
MIG ORI
THIK A
confirmed in
TRANS- MARA
KIAMB U
KURIA NAIROB I
NAROK
MACHAK OS
July 1994 but
TANA R IVER
KITU I
MAKUENI
Kajiado KAJIADO LAMU
few farmers
TANZANIA and some
Nairobi TAITA TAV TA
E
KILIFI N
vets. noticed
it as early as
1994
MO MBASA
KWALE
April.

5. ASF Outbreaks - 2001
SUDAN
ETHIOPIA
TURK ANA
MANDERA
MARSABIT
UGANDA
WES PO KOT
T
WAJIR
MT. EL GO N
TRANS- NZOIA E MAR AKWET
.
S MBURU
A
ISIOL O
SOMALIA
BARING O
BUNGO MA
UASIN GI SHU
BUSIA
KAKAMEG A LAIKI PIA
NYAMBENE
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU
Kiambu
NYE I
R
HOMA_BAY
NYAMIR A
KISII BOMET
M RAN GA
U
KIRINYAG A
E BU
M
MWI NGI GARISSA  From August
MIG ORI
2001, 11
TRANS- MARA THIK A
KIAMB U
KURIA NAIROB I
NAROK
MACHAK OS
Thika KAJIADO
MAKUENI
KITU I
TANA R IVER
LAMU
farms
comprising a
Nairobi TANZANIA
KILIFI N total of 9000
TAITA TAV TA
E
2001 KWALE
MO MBASA
pigs.

6. ASF Outbreaks – 2006/07
SUDAN
ETHIOPIA Kiambu
TURK ANA
MANDERA
Thika
MARSABIT Nairobi
UGANDA
WES PO KOT
T
WAJIR
Eldoret
S MBURU
A
SOMALIA
Nakuru
TRANS- NZOIA E MAR AKWET
.
MT. EL GO N ISIOL O
BARING O
BUNGO MA
UASIN GI SHU
BUSIA
KAKAMEG A LAIKI PIA
NYAMBENE
Kisumu
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU NYE I
R
HOMA_BAY KIRINYAG A
NYAMIR A E BU
M
M RAN GA
U MWI NGI GARISSA
KISII BOMET
MIG ORI
KURIA
TRANS- MARA
NAROK
KIAMB U
THIK A
NAIROB I
MACHAK OS
KITU I
TANA R IVER
Busia.
2006/07
MAKUENI
KAJIADO LAMU
TANZANIA
TAITA TAV TA
E
KILIFI N  From
KWALE
MO MBASA November
2006.

7. ASF Outbreaks – 2010/11
SUDAN
ETHIOPIA Kiambu
TURK ANA
MANDERA
Thika
MARSABIT Nairobi
UGANDA
WES PO KOT
T
WAJIR
Kajiado
S MBURU
A
SOMALIA
Kakamega
TRANS- NZOIA E MAR AKWET
.
MT. EL GO N ISIOL O
BARING O
BUNGO MA
UASIN GI SHU
BUSIA
KAKAMEG A LAIKI PIA
NYAMBENE
Kisumu
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU NYE I
R
HOMA_BAY KIRINYAG A
NYAMIR A E BU
M
M RAN GA
U MWI NGI GARISSA
KISII BOMET
MIG ORI
KURIA
TRANS- MARA
NAROK
KIAMB U
THIK A
NAIROB I
MACHAK OS
KITU I
TANA R IVER
Busia.
Kakamega 2010/11
MAKUENI
KAJIADO LAMU
TANZANIA
2010 TAITA TAV TA
E
KILIFI N
 From
KWALE
MO MBASA
September
2010.

8. ASF Outbreaks – Total Districts Confirmed
SUDAN
ETHIOPIA
TURK ANA
MANDERA
MARSABIT
UGANDA
WES PO KOT
T
WAJIR
MT. EL GO N
TRANS- NZOIA E MAR AKWET
.
S MBURU
A
ISIOL O
SOMALIA
BARING O
BUNGO MA
UASIN GI SHU
BUSIA
KAKAMEG A LAIKI PIA
NYAMBENE
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU NYE I
R
HOMA_BAY KIRINYAG A
NYAMIR A E BU
M
M RAN GA
U MWI NGI GARISSA
KISII BOMET
MIG ORI
TRANS- MARA THIK A
KIAMB U
KURIA NAIROB I
NAROK
MACHAK OS
TANA R IVER
KITU I
MAKUENI
KAJIADO LAMU
TANZANIA
KILIFI N
TAITA TAV TA
E
MO MBASA
KWALE

9. Laboratory Testing prior to 2006
 Testing Laboratories:
 Institute for Animal Health, Pirbright, UK
 Onderstepoort Veterinary Institute, Exotic
Diseases Division, South Africa
 Tests performed were:
 Virus isolation in bone marrow
macrophage cell cultures
 Polymerase Chain Reaction (PCR)
 ELISA for serum samples

10. From 2006: CISA-INIA, ILRI
 Tests used:
 Detection of ASFV genomic DNA by PCR and sequencing
 Virus isolation in primary culture cells.
 indirect ELISA – OIE Manual of diagnosis (OIE, 2004)
 INGENASA ELISA commercial kit for comparison.

11. ELISA vs PCR/Virus Isolation
Results from CVL Kabete & CISA-INIA, March 07
CVL Lab. Sample Source Serology PCR Virus
No district Isolation
P2 Liver, heart, lung Kiambu Negative Positive Positive
P3 Spleen, LN gastric, Kidney Eldoret Negative Positive Positive
P4 Spleen Nakuru Negative Positive Positive
P49 Serum (1) Kisumu Negative Positive Positive
P7 Sera (1-5) Nakuru Negative Positive Positive
P8 Sera (1-8) Eldoret Negative Positive Positive
P9 Liver, Lung, Spleen, Intestine Busia Negative Positive Positive

12. Capacity for Surveillance
 Limited - FAO TCP/KEN/6612 provided
some assistance in Strengthening of
Laboratory Diagnosis of African Swine
Fever (ASF) – ended 2000 – in
collaboration with Dr. Mary Louise-Penrith
of OVI.
 Need for capacity at CVL Kabete to
confirm ASF using PCR
 Need for a surveillance program for ASF –
And Contingency Plan

13. Kenya: Laboratory Network
SUDAN
ETHIOPIA
TURK ANA
MANDERA
MARSABIT
UGANDA
WES PO KOT
T
WAJIR
MT. EL GO N
TRANS- NZOIA E MAR AKWET
.
S MBURU
A
ISIOL O
SOMALIA
BARING O
BUNGO MA
UASIN GI SHU
BUSIA
KAKAMEG A LAIKI PIA
NYAMBENE
NANDI
V HIGA
I
MERU
KISUMU THARAKA
S AY
I A NYANDARUA
KERICHO NITH I
NAKURU NYE I
R
HOMA_BAY KIRINYAG A
NYAMIR A E BU
M
M RAN GA
U MWI NGI GARISSA
KISII BOMET
MIG ORI
TRANS- MARA THIK A
KIAMB U
KURIA NAIROB I
NAROK
MACHAK OS
TANA R IVER
KITU I
MAKUENI
KAJIADO LAMU
TANZANIA
KILIFI N
TAITA TAV TA
E
MO MBASA
KWALE

14. Clinical Signs
 Major Clinical Signs observed:
 Cyanosis of the ears, perineum and ventrum
 Fever – Approx. 410C for those in the initial stages
 Hypothermia & difficult breathing – advanced stages
 Innappetance/Anorexia
 Lethargy
 Recumbency/Moribund followed by death.
 Less commonly observed clinical signs:
 Frothy salivation
 Blood tinged diarrhoea
 Coughing and emaciation

15. Other Observations
 All age groups are affected
 The general body condition on most farms – fair
to poor
 Mean morbidity – 43% (sd 28%, min 5%, max
83%)
 Mean mortality – 33% (sd 26%, min 2%, max
77%) – may be due to intervention measures – subclinical?

16. Gross Pathology
 Purple coloration of the skin
 Haemorrhages throughout most of the
internal organs
 Lymph nodes markedly swollen,
reddened, haemorrhagic and look like
blood clots
 Massive clotting in the urinary bladder;
 Excessive oedema in body cavities, lungs
and the pericardium
 Spleen markedly enlarged and congested.

17. Control and Eradication
 Implementation procedure in accordance with the
Animal Diseases Act CAP 364 and the Pig Industry
Act CAP 361 of the Laws of Kenya
 Affected farms placed under immediate provisional
quarantine, pending laboratory confirmation.
 Affected farms and administrative divisions
consequently placed under full quarantines.
 DVS issues press release to alert public on social
economic importance of ASF and the eradication
measures put in place.
 Quarantine announcements by the concerned
District Veterinary Officers.

18. Control and Eradication contd.
 DVS appoints a team to coordinate surveillance,
control and eradication of the disease.
 Team meets pig owners, butchers & department
extension staff of affected areas.
 Team administers questionnaire to get ASF-related
information covering broad areas like:
 general management and housing, movement of pigs from
within & outside Kenya, health care & time of disease onset.
 DVS sends a circular detailing control measures to
VOs.
 VOs instructed to develop inventories of pig keepers, to
determine the population of pigs, to identify all infected
farms and to institute strict pig movement controls to stop
spread of the disease.

19. Control and Eradication contd.
 Instructions to pig farmers:
 Not to allow visitors in their piggeries. Persons/vehicles go
thru’ Magadi soda placed at entrance.
 Avoid feeding pigs with swill.
 To house all roaming pigs.
 Isolate and kill clinically sick and in-contact pigs and
incinerate or deep bury them under veterinary supervision.
 Clean well and disinfect depopulated premises. Re-stock
after six months if sentinel pigs fail to become infected.
 Slaughter ‘Healthy’ pigs from infected farms at premises
designated to slaughter only pigs from infected farms.
 Pigs from clean farms must be accompanied by a no
objection letter, a health certificate and a movement permit
to the other slaughter houses.
 Bury offal six feet deep & cover with Magadi soda or
incinerate.

20. Main Features of Kenyan Outbreaks –
Questionnaire
 All farms fed their pigs on un-boiled hotel left-overs (swill),
with a few of them supplementing with commercial feeds.
 Uncontrolled and sometimes illegal movement of pigs and
pig products within the country and into the country
 No spreading into other districts due to strict quarantine
procedures
 Freely roaming pigs, bush pigs and warthogs. Wild pigs are
prevalent in Thika, Ngong, Karen & around Kikuyu township.
 Permits for importation of pork products obtained from
Ministry of Health and Customs clearance when Legal
Notice No. 28 of 2000 allows only the DVS to issue import
permits for animals, animal products and by-products.
 The disease is noticed long before it is confirmed.

21. Main Features of Kenyan
Outbreaks – contd.
 The swine production units on these farms can be described as a loose
function of farrow-to-finish, farrow-to-wean and feeder operations; with the
latter dominating. No farm practices all-in, all-out production system.
 Majority of the farmers buy their replacement stock from Kiambu district.
Nonetheless, most of them were unwilling to name the farms of origin.
 Only 10% of the farms have double fencing for their piggeries.
 Only 2 slaughter houses kept some records of source (owner, district of
origin, permit number and date of issue, and number of pigs transported)
and meat inspection (identity of animal with respect to owner, reasons for
condemnation and date).
 Apart from Ndumboini slaughter house in Kiambu district not keeping any
records, they often procure pigs from as far as Busia district, probably
from across the border.
 The average pig keeping experience of farmers is 6 years, and none of
them is licensed. The health care services offered on these farms are
through private veterinarian (46%), government staff (15%), farm manager
(15%) and none (24%).

22. Challenges of Eradication
 Some farms have quite a big pig stock;
 Low prices offered by the butchers;
 Lack of compensation by the government;
 Lack of cooperation and plain stubbornness.
 Farmers unwilling to name sources of replacement stock
 Lack of knowledge as to the actual population at risk
 Failure to license piggeries
 Inadequate communication between DVS & private sector
 The Pig Industry Control Board is not operational

23. References
 Montgomery R.E. (1921) A Form of Swine Fever occurring in British
East Africa (Kenya Colony) J. Comp. Pathol. 34: 159 - 191.
 Kenya Department of Veterinary Services Reports
 OVI, South Africa Laboratory Results
 CISA-INIA Laboratory Results
Acknowledgements
 Kenya Agricultural Research Institute (KARI),
 International Livestock Research Institute (ILRI)
 CISA - INIA Spain
 Institute for Animal Health, Pirbright, U.K.
 Onderstepoort Institute for Exotic Diseases, Republic of South Africa
 Food an Agriculture Organisation of the United Nations (FAO)
THANKS