IV. RESULTS AND DISCUSSION
4.1 Study of Cattle Population
South Kalimantan province is one of the regions with the number of beef cattle is quite high in the Kalimantan Island. The population of cattle in this area
was 218,065 animals in 2009 with the density of cattle were 5.83 animals per kilometer square. The highest cattle population is Tanah Laut that is equal to
80,533 animals or approximately 36.93 of total population, followed by Tanah Bumbu district with a population of 30,556 14.01 and Banjar district with a
population of 18,413 8.44. There are 13 sub districts with a cattle density more than 30 heads per kilometer square, 9 sub districts with a cattle density between
20 – 30 headskm
2
, 17 sub districts with a cattle density between 10 – 20 headskm
2
, 9 sub districts with a cattle density between 5 – 10 headskm
2
, and 93 sub districts with cattle density less than 5 headskm
2
Figure 6.
Figure 6. Cattle Population in South Kalimantan Province
4.2 Spatial Distribution of Jembrana Disease
During 2008 to 2010, 1714 samples were collected from 46 villages, covered 31 sub districts and 10 districts in South Kalimantan province. JD sample
were not collected in 120 sub districts. Sample collection focused on the endemic area and in the area with higher of Bali cattle population. The distribution of JD
sample location during this period is shown in Figure 7. The sample collection mainly conducted at district of Barito Kuala, Tanah Bumbu, Tabalong, Kotabaru,
and Tanah Laut. There were no any sample collection in district of Hulu Sungai Tengah, Hulu Sungai Utara, and Banjarmasin.
Figure 7. The Distribution of JD Sample Location during 2008 – 2010
There are 571 samples 33.31 were screened by ELISA, 122 samples 7.12 were screened by PCR, and 1021 samples 59.57 were screened by
ELISA followed by PCR. Among the total of 1143 samples which were screened by PCR or ELISA and followed by PCR, 57 samples 4.99 were positive to JD
based on the PCR assay. The results of the sample testing are shown in Table 2. The JD prevalence in South Kalimantan province tends to decrease in this period.
Table 2. The Number of JD Seropositive and Seroprevalence based on the PCR in South Kalimantan Province during 2008 – 2010
Year Sample
Positive Negative
Prevalence 2008
54 11
43 20.37
2009 293
15 278
5.12 2010
796 31
765 3.89
There are eight districts had been reported at least one positive serological result to JD. The highest JD seropositive was in Barito Kuala, followed by Tanah
Laut and Tabalong, while the lowest JD seropositive was in Tapin and Kotabaru. There are five districts that are no samples tested by PCR or ELISA followed by
PCR, i.e. Hulu Sungai Selatan, Hulu Sungai Tengah, Hulu Sungai Utara, Balangan, and Banjarmasin.
Table 3. The Number of JD Seropositive and Seroprevalence at District Level in South Kalimantan Province during 2008 – 2010.
District Sample
Positive Negative Prevalence
Tanah Laut 149
14 135
9.40 Barito Kuala
492 17
475 3.46
Tapin 4 2
2 50.0
Tanah Bumbu 263
3 260
1.14 Kotabaru 6
1 5
16.67 Banjar 22
3 19
13.64 Tabalong 193
12 181
6.22 Banjarbaru 14
4 10
28.57 Kalimantan Selatan
1143 57
1086 4.99
The seroprevalence of JD at district level ranged from 1.14 to 50.00 Table 3. However, due to the limitation of sample, the JD seroprevalence in
Tapin and Kotabaru was excluded in this analysis. The number of samples in this area was not representative. The highest JD seroprevalence was located at
Banjarbaru, followed by Banjar and Tanah Laut, while the lowest JD
seroprevalence was Tanah Bumbu. The overall prevalence of JD in South Kalimantan was 4.99.
Figure 8. The Jembrana Disease Seropositive in South Kalimantan Province
Among the total 13 districts in South Kalimantan Province, 8 districts 61.54 had at least one positive serological result to JD Figure 8. There are 5
districts that were not classified as endemic area occupied by 16.12 of the total cattle population, 5 districts were low endemic area occupied by 36.72 of the
total cattle population, and 3 districts were medium endemic area occupied by 47.15 of the total cattle population. Sample testing positive to JD mostly
located in the southern, western, and northern parts of the province Figure 8. Based on the risk area, there are 5 districts were not classified occupied
by 16.12 of the total cattle population, 6 districts were low risk area occupied by 73.87 of the total cattle population, 1 district was medium risk area
occupied by 8.45 of the total cattle population, and 1 district were high risk area occupied by 1.57 of the total cattle population Figure 9. District of
Tapin and Kotabaru were assumed to be classified as low risk area due to limited sample.
Figure 9. The Jembrana Disease Seroprevalence in South Kalimantan Province
JD is endemic in several districts in South Kalimantan province since the first outbreak. Based on the clinical, pathologic, and virologic, JD was found in
district of Tanah Laut and Tanah Bumbu. The results of this study showed that JD serologically found throughout the district which have taken samples both blood
and tissue sample. It is allow that JD seropositive was also found in all districts in South Kalimantan province. During this period, JD has spread to other districts
especially Barito Kuala, Banjarbaru, Banjar, Tapin, and Tabalong Figure 9. Uncontrolled movement of cattle was probably a factor in the spread of
JD. Ditjennak 2005 explained that regional autonomy and cattle trading played a role in the spread of JD in South Kalimantan province. There are several livestock
check-points on the border that was not functioning properly. The suspected cattle allow entering new area that free from JD due to the infected cattle was not
usually show the clinical signs of JD. The JD virus was transmitted by suspected or carrier cattle to healthy cattle in non endemic area.
ELISA is a common diagnostic method for JD serological test but can lead to false positive results of vaccination. Vaccination activities that have not been
implemented uniformly in all areas make it difficult to distinguish JD cases. Confirmation by PCR test must be implemented to test the causative agent of JD
with better accuracy. PCR can be used to confirm both field and laboratory diagnosis of JD in Bali cattle with good accuracy Tenaya and Hartaningsih
2005. Therefore, the analysis of JD spatial distribution in this study used PCR technique to determine JD seropositive.
This spatial analysis was limited to the described endemic area based on the active and passive surveillance. From a total of 1714 samples, 64 samples
3.73 come from active surveillance. However, the understanding of the spatial distribution of JD would be enhanced if the non endemic area were also included
in the active and passive surveillance. It is also important to consider the sample size is proportional to its cattle population in the next investigation.
4.3 Jembrana Disease Mapping
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