Sero Epidemiology Transmission Dynamics And Hematological Studies On Neospora Caninum In Dairy Buffaloes
By: Amir Nasir | Prof.Dr.Muhammad Ashraf.
Contributor(s): Prof. Dr. Muhammad Sarwar Khan.
Material type: BookPublisher: 2011Subject(s): Department of Clinical Medicine & Surgery | Phd. thesisDDC classification: 1366,T Dissertation note: The current study was carried out in two districts of the Punjab province (pakistan), viz. Lahore and Narowallocated;on the eastern part of the province bordering Indian Punjab ::. and the first study assessing the epidemiology of N caninum in dairy buffalo in Pakistan. Overall, the true sercprevalence of Neospora caninum in dairy buffalo (assessed by using cELISA validated for buffalo by using IFAT as reference test) of the two districts was 39.4 % - with no significant difference in the prevalence of N caninum antibodies between male (29.5%) and female (41.5%) dairy buffalo. However, in the Lahore district alone, the prevalence in the female (46.1 %) buffalo was significantly higher than in their male (23.8%) counterparts. In contrast, in Narowal district, the prevalence in male (42.4%) buffalo was higher than females (32.2%) but this difference was not statistically different. The other risk factors evaluated in regards to the prevalence of N caninum in buffalo were similar overall in both the districts; these included age-specific, season-specific, pregnancy-specific, parity- specific, abortion-specific and dog contact-specific prevalence. The difference in sero- prevalence was not significant amongst all the ages but was significant between the younger " 3yrs.) and adult (> 3yrs.) age buffalo. The adult buffalo showed a higher prevalence of N caninum antibodies compared with younger buffalo. Anyhow, the age group of buffalo >3-5 yrs. showed consistently the highest prevalence of N caninum antibodies overall and in both the districts in the current study. The summer season was the one in which buffalo of the two districts and overall showed the highest prevalence, followed by high prevalence in autumn; while the lowest prevalence of N caninum antibodies was observed in buffalo sampled during the winter. The prevalence in the higher parities buffalo was significantly higher than the lower parity and pregnant heifers. The prevalence in pregnant dams was significantly higher than in non- pregnant buffalo in the herds in different areas of the two districts. Similarly, aborting buffalo in regular contact with dogs- at the dairy properties showed significantly higher prevalence of N. caninum antibodies than non-aborting buffalo without the contact of dog. The serological analysis-of dogs (using cELIS A) present at some dairy buffalo '" properties generally showed high prevalence of N. caninum; antibodies at the dairy properties where the buffalo were in regular contact with dogs compared with farm premises and their buffalo without any contact with dogs at the farm. This signifies the roleof the dogs in the - . transmission of N. caninum oocysts and infection to buffalo (intermediate host) as the isolates of dog and bovine origin has been reported to be identical (Stenlund et al., 1997). The analysis of milk samples from the dairy buffalo. also tested for serum antibodies using iscom (immune stimulating complex) ELISA and showed a good level of agreement (Kappa ratio=O.567) between the performance of two tests (iscom ELISA versus cELISA). However, the cELIS A (VMRD, Pullman, W A) showed higher sero-positivity compared to iscom ELISA (SV ANOV A, Uppsala, Sweden). Therefore, the use of either ELISA used on milk for evaluating the prevalence of N. caninum antibodies in buffalo can give good results . for lactating buffalo, but cELIS A appeared to have superior sensitivity in our study. The use of iscom ELISA offers advantages regarding ease of sampling and repeated screening of lactating herds but with little lower sensitivity than serum antibody cELISA. The co-existence of N. caninum with Br. abortus, another important abortifacient pathogen in buffalo, is quite significant as the probability of such infectious abortions is increased in the susceptible herds resulting in more economic losses compared to those caused by single pathogen. The co-existence of Br. abortus in N. caninum seropositive buffalo in the current study was 13.2%, while the overall prevalence of Br. abortus antibodies in buffalo of two districts was 12.2%. The prevalence trend of Bt: abortus was related to age, ~ though not exclusively; as prevalence continued to increase with age except in the age groups of 6-7 yrs, and> 7 yrs. old buffalo. The higher prevalence in the adult age groups indicates the association of Br. abortus with development of the reproductive system of the host (buffalo). It also suggests the increase in the exposure of the buffalo to the pathogen with increase.in age to some good extent. However, this prevalence was statistically not signific~ "0. in all the age groups of buffalo. The prevalence of co-existence was highest (18.5%) in -, buffalo >3-5 yrs. old followed by 18.2% in buffalo >7 yrs. age. Howe er, statistically, the difference in the prevalence of co-existing antibodies against N caninum and Br. abortus in buffalo was not significant. Hematological analysis of the N caninum sere-positive and sero-negative dairy buffalo for different haematological determinants, such as total leukocytic counts (TLC), differential leukocytic counts (DLC), RBCs, haemoglobin, haematocrit, platelets and blood plasma glucose level showed no difference in sero-positive and sero-negative two groups particularly, regarding the effect of sero-positivity in buffalo. Albeit, some interactions such as season x N caninum seropositivity showed significantly lower monocyte counts and high blood glucose level in N caninum sere-positive buffalo compared with sero-negative buffalo. Overall, in both groups no significant changes were observed in the seropositive buffalo compare to sero-negative ones. Some interaction have independently affected certain haematological parameters although, the animals were not seropositive. This suggests the effect of some environmental factors and physiology states of the buffalo on its haematological dynamics. These effects included the effect of lactation on the lymphocyte count in the lactating and non-lactating buffalo, where lymphocyte counts were higher in non-lactating compared with lactating buffalo most possibly due to the recruitment of lymphocytes in the udder for excretion in milk. Similarly, blood haemoglobin was lower in the hot months and packed cell volume was higher in the cooler months of the year in the buffalo.Item type | Current location | Collection | Call number | Status | Date due | Barcode | Item holds |
---|---|---|---|---|---|---|---|
Thesis | UVAS Library Thesis Section | Veterinary Science | 1366,T (Browse shelf) | Available | 1366,T |
The current study was carried out in two districts of the Punjab province (pakistan),
viz. Lahore and Narowallocated;on the eastern part of the province bordering Indian Punjab
::.
and the first study assessing the epidemiology of N caninum in dairy buffalo in Pakistan.
Overall, the true sercprevalence of Neospora caninum in dairy buffalo (assessed by using
cELISA validated for buffalo by using IFAT as reference test) of the two districts was 39.4 %
-
with no significant difference in the prevalence of N caninum antibodies between male
(29.5%) and female (41.5%) dairy buffalo. However, in the Lahore district alone, the
prevalence in the female (46.1 %) buffalo was significantly higher than in their male (23.8%)
counterparts. In contrast, in Narowal district, the prevalence in male (42.4%) buffalo was
higher than females (32.2%) but this difference was not statistically different. The other risk
factors evaluated in regards to the prevalence of N caninum in buffalo were similar overall in
both the districts; these included age-specific, season-specific, pregnancy-specific, parity-
specific, abortion-specific and dog contact-specific prevalence. The difference in sero-
prevalence was not significant amongst all the ages but was significant between the younger
" 3yrs.) and adult (> 3yrs.) age buffalo. The adult buffalo showed a higher prevalence of N
caninum antibodies compared with younger buffalo. Anyhow, the age group of buffalo >3-5
yrs. showed consistently the highest prevalence of N caninum antibodies overall and in both
the districts in the current study. The summer season was the one in which buffalo of the two
districts and overall showed the highest prevalence, followed by high prevalence in autumn; while
the lowest prevalence of N caninum antibodies was observed in buffalo sampled during the
winter. The prevalence in the higher parities buffalo was significantly higher than the lower parity
and pregnant heifers. The prevalence in pregnant dams was significantly higher than in non-
pregnant buffalo in the herds in different areas of the two districts.
Similarly, aborting buffalo in regular contact with dogs- at the dairy properties showed significantly
higher prevalence of N. caninum antibodies than non-aborting buffalo without the contact of dog.
The serological analysis-of dogs (using cELIS A) present at some dairy buffalo
'"
properties generally showed high prevalence of N. caninum; antibodies at the dairy properties
where the buffalo were in regular contact with dogs compared with farm premises and their
buffalo without any contact with dogs at the farm. This signifies the roleof the dogs in the
-
. transmission of N. caninum oocysts and infection to buffalo (intermediate host) as the isolates
of dog and bovine origin has been reported to be identical (Stenlund et al., 1997).
The analysis of milk samples from the dairy buffalo. also tested for serum antibodies
using iscom (immune stimulating complex) ELISA and showed a good level of agreement
(Kappa ratio=O.567) between the performance of two tests (iscom ELISA versus cELISA).
However, the cELIS A (VMRD, Pullman, W A) showed higher sero-positivity compared to
iscom ELISA (SV ANOV A, Uppsala, Sweden). Therefore, the use of either ELISA used on
milk for evaluating the prevalence of N. caninum antibodies in buffalo can give good results
. for lactating buffalo, but cELIS A appeared to have superior sensitivity in our study. The use
of iscom ELISA offers advantages regarding ease of sampling and repeated screening of
lactating herds but with little lower sensitivity than serum antibody cELISA.
The co-existence of N. caninum with Br. abortus, another important abortifacient
pathogen in buffalo, is quite significant as the probability of such infectious abortions is
increased in the susceptible herds resulting in more economic losses compared to those
caused by single pathogen. The co-existence of Br. abortus in N. caninum seropositive
buffalo in the current study was 13.2%, while the overall prevalence of Br. abortus antibodies
in buffalo of two districts was 12.2%. The prevalence trend of Bt: abortus was related to age,
~
though not exclusively; as prevalence continued to increase with age except in the age groups
of 6-7 yrs, and> 7 yrs. old buffalo. The higher prevalence in the adult age groups indicates
the association of Br. abortus with development of the reproductive system of the host
(buffalo). It also suggests the increase in the exposure of the buffalo to the pathogen with
increase.in age to some good extent. However, this prevalence was statistically not signific~
"0.
in all the age groups of buffalo. The prevalence of co-existence was highest (18.5%) in -,
buffalo >3-5 yrs. old followed by 18.2% in buffalo >7 yrs. age. Howe er, statistically, the
difference in the prevalence of co-existing antibodies against N caninum and Br. abortus in
buffalo was not significant.
Hematological analysis of the N caninum sere-positive and sero-negative dairy
buffalo for different haematological determinants, such as total leukocytic counts (TLC),
differential leukocytic counts (DLC), RBCs, haemoglobin, haematocrit, platelets and blood
plasma glucose level showed no difference in sero-positive and sero-negative two groups
particularly, regarding the effect of sero-positivity in buffalo. Albeit, some interactions such
as season x N caninum seropositivity showed significantly lower monocyte counts and high
blood glucose level in N caninum sere-positive buffalo compared with sero-negative buffalo.
Overall, in both groups no significant changes were observed in the seropositive buffalo
compare to sero-negative ones. Some interaction have independently affected certain
haematological parameters although, the animals were not seropositive. This suggests the
effect of some environmental factors and physiology states of the buffalo on its haematological
dynamics. These effects included the effect of lactation on the lymphocyte count in the lactating
and non-lactating buffalo, where lymphocyte counts were higher in non-lactating compared with
lactating buffalo most possibly due to the recruitment of lymphocytes in the udder for excretion in
milk. Similarly, blood haemoglobin was lower in the hot months and packed cell volume was
higher in the cooler months of the year in the buffalo.
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