ZoonosesDiseaseUnitTalk

Report
Philip M. Kitala1 and Stella Kiambi2
1University
of Nairobi
Dept Public Health, Pharm and Toxi
Email: [email protected]
2Ministry of Livestock Development
Zoonoses Disease Unit (ZDU)
Email: [email protected]
History of rabies
 Rabies, an ancient disease, is well known in Kenya
 1st confirmed rabies case was in 1912 in a dog in the
outskirts of Nairobi
 1st documented human rabies case was in 1928 in a
woman from South Nyanza
 Records kept by the Vet Dept shows that Kenya
experienced rabies epidemics in early 1930s, late
1940s, and early 1950s



Widespread deployment of an egg-adapted life virus
vaccine in the 1950s and 1960s, effectively controlled
rabies so that by 1973, the disease was virtually
eliminated from the country
However, following an outbreak in late 1974 in
Taita/Taveta, the rabies situation changed dramatically
By 1979,the disease had spread along the densely
populated coastal strip and along the Tanzania border to
Trans Mara, South Nyanza, and Western Kenya



By end of 1982, rabies had spread throughout Nyanza,
Western Province, Central Rift Valley, Nairobi and
adjacent areas
To date rabies is more widespread and prevalent in
Kenya than at any time in its history
By 1992, only 4 districts of the then 41 (10%), had no
confirmed rabies cases
Epidemiology of rabies in Kenya…
Figure 1: Distribution of confirmed animal rabies
cases in Kenya, 2002 – March, 2013
Year
2012
2010
2008
2006
2004
2002
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
1958
Number of rabies cases
Canine rabies cases in Kenya, 1958-2012
200
180
160
140
120
100
80
60
40
20
0
Distribution of rabies cases by species
 The domestic dog remains the principal reservoir and
transmitter of rabies to both man and his other domestic
animals in Kenya
 From 1912 to end of May 1991, a total of 2931 animal
specimens were confirmed positive with dogs
accounting for 64.2% (1881)
 Between 1983-1990, domestic dogs accounted for 63%
of the 2149 animal rabies cases confirmed


By contrast, of the 1034 animal specimens confirmed
positive for rabies in the last ten years (2002-March
2013), dogs accounted for 46% of the positives and
cattle 37%.
We believe this apparent decline in dog rabies
prevalence is a reflection of weaknesses of the
surveillance of rabies in recent years – suspected rabies
in the more economically important dairy cattle are
more likely to be reported by their owners relative to
suspected dog rabies cases.

Due to defective surveillance of rabies in the country
these figures should only be taken as an indication of
the rabies trend in the country and not a reflection of
the true incidence of the disease and therefore rabies
burden
Confirmed rabies cases by species in Kenya, 2002-March
2013
The distribution of rabies cases by species and province of
origin in Kenya during the period 2000 - 2010
Number of rabies cases
250
200
150
100
50
0
Central
No. Dogs
Eastern
No. Cattle
Nairobi N.Eastern Nyanza
No. Cats
Province
No goats
R.Valley Western
No. Donkeys
No. Others
Rabies trend in Kenya, 2002-March 2013



Role of wildlife in the epidemiology of rabies in Kenya
remains unclear
The disease has been confirmed in the following wildlife
species:
Jackals
Fox
Mongoose (white-tailed)
Hyena
Genet cat
Leopard
Squirrel
Monkey
Honey badger
Bat (Lagos bat virus, Shimoni bat virus)
The few wildlife rabies virus isolates so far typed have been
found to be of the canid type (Africa 1b) – indicating
transmission from dogs to wildlife
Human cases of animal bites



Over the last three years, a total of 318 456 cases of animal-bites were
documented countrywide:
2010 ---------------- 38 944
2011 ---------------- 133 150
2012 ---------------- 146 362
Assuming a human population of 40 million people, the crude estimate of
animal-bite incidence for the three years:
2010 ---------------- 97 bites /100 000 population
2011 ----------------- 333 bites /100 000 population (3.4 times)
2013 ----------------- 366 bites /100 000 population (1.1 times)
Compare with incidence estimated for Machakos 1992/1993 of 234/100 000
population (97% by dogs) and for Tanzania in 2010 of 140/100 000 population
Human rabies cases
 Information on numbers of confirmed human rabies cases in
Kenya is scanty
 True incidence of human rabies deaths in Kenya is grossly
underestimated
 Reasons for this are many in Africa:
1)
Rabies victims are often too ill to travel to hospital or die
before arrival;
2) Families recognize the futility of medical treatment for
rabies
3) Patients are considered to be the victims of
bewitchment rather disease;
4) Clinically recognized cases at hospitals may go
unreported to central authorities
5) Misdiagnosis is not uncommon
Spatial distribution of human rabies cases in Kenya, 2002-March 2013
Conclusions
 The rabies burden in Kenya is likely to be substantial
but its size and extent remains unknown
 The domestic dog remains the principal reservoir and
vector of rabies in the country
 Past rabies control efforts have been ineffective
 Rabies occurs over large parts of the country mainly
due to a large, poorly supervised, and inadequately
protected dog population by vaccination
What is lacking?
 Better reporting of both rabies cases and dog bites in
the country
 Better communication between the veterinary and
medical communities in terms of:
 Outbreak reporting
 Information flow
 Joint vaccination programs
 Budgets
Scaled-up approach across wide regions rather than a
one-off exercise
• Big scale interventions over long periods of time,
with annual vaccination of dogs
• Centralized management
 Commitment to a sustained budget


CAN IT BE DONE?
Vaccinated dogs
(Millions)
Cases of rabies in humans
18
70
15.9
16
14.9
60
14
12.6
12
45
10
8
10.6
9.3
9.1
7.1
16.2
7.5
10.9
13.3
14.5
13.7
50
11.1
9.7
40
30
29
6
60
20
20
22
20
19
4
15
10
7
2
3
0
1
0
0
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
1
2003
0 0
2004

THANK YOU!

similar documents