Download 74. Status of foot-and-mouth disease in Pakistan

The Global control of FMD - Tools, ideas and ideals – Erice, Italy 14-17 October 2008
Appendix 74
STATUS OF FOOT-AND-MOUTH DISEASE IN PAKISTAN
S.M. Jamal1, 2, *, S. Ahmed2, M. Hussain3 and Q. Ali1
1
2
National Veterinary Laboratory (NVL), Park Road, 44500, Islamabad, Pakistan.
Department of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
3
FAO project (GTFS/INT/907/ITA) for Central Asian Countries, NVL, Islamabad
Pakistan.
ABSTRACT
Foot-and-mouth disease is a world-wide known disease of economic significance. The disease is
endemic in south Asian region. The present study reports observations and spatial distribution of
153 laboratory confirmed field outbreaks taken place during 2002 to 2007 and serotypes of the
virus involved. Distribution of different serotypes from outbreaks in Pakistan and samples tested
either in Pakistan or sent to WRL-FMD for virus typing during 1952 to 2007 has been shown.
Serotype O was found to be the most prevalent serotypes followed by serotype Asia-1 and A. No
sample was found positive for serotype C during the period 1996-2007. Mixed infection of either
serotypes O and Asia-1 or A and Asia-1 was also detected in some samples. The disease was found
to be more prevalent in cattle than buffaloes. Moreover, higher number of outbreaks of the disease
was noted between the months of January to March during the period of 2002-07, which may be
attributed to the livestock movement in the country due to religious festival, Eidul Azha, in which
the animals are slaughtered.
1. INTRODUCTION
Foot-and-mouth disease (FMD) is an infectious and highly contagious viral disease of cloven-hoofed
animals that causes heavy economic losses to the livestock industry in term of high morbidity in
adult animals and mortality in young stock, reduced milk production, loss of work efficiency in
draught animals and sanctions on export of animals and animal products due to sanitary measures.
The disease is endemic in south Asian region. Historically, the disease was well-known in the IndoPakistan subcontinent but it is not known as to what part/place was first affected. However,
occurrence of the disease in pre-partition Punjab from 1900 onward is mentioned in the literature.
Only limited and isolated studies, mainly on farm/district level, have been conducted on FMD in
Pakistan (Rauf et al. 1981; Riaz et al. 1992; Ahmad et al. 2002; Klein et al. 207; 2008), which do
not reflect the true status of the disease in the country. Country-wide systematic study on FMD and
serotype involved in disease outbreaks has not been conducted in Pakistan. Therefore, exact
situation of the disease in the country is unknown.
Aim of the present study is to identify the virus serotypes from FMD field outbreaks taken place
during 1952 to 2007, spatial distribution of serotypes responsible for 153 laboratory confirmed
cases of the outbreaks between 2002 to 2007, species of the animals affected and seasonal
prevalence of the disease.
2. MATERIALS AND METHODS
Epithelial samples received from suspected cases of FMD from various parts of the country during
2002-2007 were tested for diagnosis of FMD and virus typing using indirect sandwich ELISA at
National Veterinary Laboratory (NVL), Islamabad, Pakistan following Roeder and La Blanc Smith
(1987). Some samples were also sent to the World Reference Laboratory for FMD, Pirbright, UK for
virus typing. Historical data on FMD between 1952 to 2002 were collected from different sources.
The data were analyzed for distribution of serotypes of the virus among positive samples, species
affected and to determine association between serotypes and species of animals. Chi square test
was applied to know the comparative incidence of serotypes involved in disease outbreaks. Fisher’s
exact test was used to know the association between species and serotypes of the virus involved in
disease outbreaks. All the analyses were carried out analyzed using statistical software, R (www.rproject.org).
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The Global control of FMD- Tools, ideas and ideals – Erice, Italy 14-17 October 2008
3. RESULTS
Distribution of virus types among the positive samples collected during 1952 to 2007 are shown in
Figure 1. Serotype O was detected in 61% of the total samples tested positive. Mixed infection of
serotypes O and Asia1 or A and Asia-1 were also detected in some samples. A significant difference
in incidence of disease outbreaks due to different FMD virus serotypes was observed in 153 field
outbreaks taken place during 2002-2007. Serotype O was found responsible for significantly higher
(p<0.0001) number of outbreaks, followed by serotypes Asia-1 and A. However, no significant
difference (p>0.05) in disease outbreaks due to serotypes Asia-1 and A was observed. Significantly
higher numbers (p<.0001) of cattle were affected in FMD outbreaks compared to buffaloes.
However, serotype of the virus was found to be independent of the species of large ruminants.
Exotic breeds of cattle and their crosses were found to be more susceptible to FMD than local
cattle. Higher number of outbreaks of the disease was noted between the months of January to
March during the period of 2002-2007 (Figure 2). Spatial distribution of different serotypes
responsible for FMD outbreaks in the country during 2002-2007 is shown in Figure 3.
4. DISCUSSION
The study shows that FMD is endemic and widely spread throughout Pakistan. The study reveals
that major FMD outbreaks are caused by serotype O virus compared to serotype A or Asia-1. This
finding is in agreement with Rweyemamu et al (2008), who reported that serotype O was the most
widely prevalent serotype in the world. Asia-1 was first detected by WRL-FMD in 1954 from an
epithelial sample collected from Pakistan. Asia-1 is still responsible for disease outbreaks in the
country. Serotype C was for the first time detected in Pakistan in 1954. Last outbreak of FMD in the
neighboring country, India, was reported in 1995 (Hemadri et al. 2003). Serotype C is probably no
longer present is Asia (Rweyemamu et al. 2008) and appears to have disappeared from the world
as a whole with last outbreak in Kenya in 2004. Historically, this is the rarest of the FMD serotypes
to have occurred in the world.
In the present study, cattle were found to be the most affected species followed by buffaloes with
only few reports of FMD in small ruminant. This finding may be due to a high likelihood that cattle
are affected compared with buffaloes or clinical signs/severity of the disease are les pronounced in
buffaloes than cattle, which would result in differential under-reporting of buffaloes cases of FMD.
Higher number of FMD outbreaks noted between the months of January to March during the period
of 2002-2007 may be due to livestock movement in the country due to religious festival, Eidul
Azha, falling from December to February during the reported period.
Progressive control of FMD is the most pragmatic approach for Pakistan. The critical components of
such an approach should include a national FMD control initiative, continuous surveillance and
monitoring of the FMD situation, facility for FMD virus isolation and sub-typing, and availability of
an effective vaccine. Some studies on the antigenic characterization of Pakistani isolates originating
from Landhi cattle colony, Karachi have been done (Jamal et al. 2007) and such studies on
country-wide basis has already been planned as a collaborative project between Government of
Pakistan and Danish Government with financial support of an FAO funded project,
GTFS/INT/907/ITA.
5. REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
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Ahmad et al (2002). Pak Vet J. 22: 201-203.
Hemadri et al. (2003). Vet Microbiol. 92: 25-35.
Jamal et al (2007). Report submitted to the EU-FMD, Rome.
Klein et al. (2007). Virol J. 4:122.
Klein et al. (2008). Virol J. 5:53.
Rauf et al. (1981). Pak Vet J. 1: 13-14.
Riaz et al (1992). Pak Vet J. 12: 86-88.
The Global control of FMD - Tools, ideas and ideals – Erice, Italy 14-17 October 2008
1000
900
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Serotypes
700
600
500
400
300
200
100
0
O
A
Asia-1
C
Number
Figure 1. Frequency distribution of different serotypes from suspected cases of FMD
submitted to the laboratory during 1952 to 2007
40
35
Number of outbreaks
30
25
20
15
10
5
0
Jan
Feb
March
April
May
June
July
Aug
Sept
Oct
Nov
Dec
Month
Figure 2. Seasonal distribution of laboratory confirmed FMD outbre aks taken place during 2002-2007
(n=153)
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The Global control of FMD- Tools, ideas and ideals – Erice, Italy 14-17 October 2008
Figure 3: Spatial distribution of serotypes from laboratory confirmed cases of FMD during 20022007
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