1.
Detection Of Influenza A Virus Contamination In Newcastle Disease Live Virus Vaccines And Their Pathological Effects On Visceral Organs
by Munir Hussain (2004-VA-64) | Mr. Muhammad Saeed Imran | Prof. Dr. Asim Aslam | Dr. Shafqat Fatima Rehmani.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Poultry is one of the most vibrant commercial sector which is playing a vital role to
bridge the gap between supply and demand of animal protein foods to cater for its ever
increasing human population 2.1 per cent annually in Pakistan (Sahota et al. 2003).
Vaccination is one of the most effective way to prevent the poultry birds from the
specific diseases. Disease producing microorganisms can be classified smallest to largest as
viruses, bacteria, fungi, protozoa and parasites. All, except the viruses are sensitive to drugs
when outbreaks occur. Vaccination is basically the introduction of a specific biological substance
(antigen) into the bird to stimulate the antibodies formation or immunity to a particular disease.
Usually the biological substance is avirulent the live disease organisms, which are capable to
protect the bird against the particular disease by producing an immune response. Presence of
these organisms (antigen) in the blood stimulates the body's defense mechanism to produce
antibodies that neutralize the disease causing organisms when the bird is exposed to them
(Kamboh et al. 2009).
A danger of such type of live vaccines is that the live microbes can back mutate to a
virulent form. While, dead vaccines that contain whole killed (usually by formalin or phenol)
microbes are safe. They may contain little or no extraneous material and therefore tend to
produce fewer adverse effects (Palombo and Semple 2001). The vaccines that contain dead
organisms are safe with respect to residual virulence and are easy to store, since organisms are
already dead. While live vaccines may possess residual virulence for the animal by reversion of
avirulent organisms to fully virulent type or spread to nonvaccinated animals. Dead vaccines
have very little risk of ‘alive’ contamination, while live vaccines always run the risk of
contamination with unwanted organisms; for instance, outbreaks of reticuloendotheliosis in
Introduction
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2
chickens in Japan and Australia have been traced to contaminated Marek’s disease vaccine
(Tizard 1995).
Avian Influenza viruses typically produce Syndromes ranging from asymptomatic
infection to respiratory disease and drops in egg production to severe, systemic disease with near
100% mortality (Olsen et al. 2002). Avian influenza initially was recognized as a highly lethal,
systemic disease (i.e., highly pathogenic). HPAI was known by various name including fowl
plague, fowl pest etc. Avian Influenza viruses are classified in the family orthomyxoviridae,
genus influenza virus A (Garten et al. 2009). Avian influenza viruses can be categorized into
four clinical groups:1) highly virulent, 2) moderately virulent, 3) mildly virulent, and 4)
Avirulent (Swayne and Suarez 2000). Avian Influenza further sub type based on serologic
reaction of HA and NA surface glycoproteins. Fifteen sub types of HA and nine sub types of
NA are recognized (Swayne and Suarez 2000). MP AI viruses in domestic poultry produce
clinical sign reflect abnormalities in the respiratory, digestive, urinary and reproductive organs
(Allwright et al. 1993). To date, naturally occurring highly virulent influenza A viruses that
produce acute clinical disease in chickens, turkeys and other birds of economic importance have
been associated only with the H5, H7 and H9 subtypes. Influenza A viruses of subtype H9 are
now considered to be wide spread in poultry and have demonstrated the ability to infect humans
(Fedorko et al. 2006).
To date, all outbreaks of the highly pathogenic form have been caused by influenza A viruses
of the subtypes H5 and H7. The disease is transmitted horizontally by direct contact through
contamination. There is little or no evidence of vertical transmission (egg-borne infection).
However, eggshell surfaces can be contaminated with the virus (Potima 2007). Wild and
domesticated water fowl is the major natural reservoir of influenza A viruses. Representatives of
Introduction
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3
all of the different subtypes of avian influenza A virus have been isolated from birds, particularly
from aquatic species such as ducks, geese, and gulls (Karasin et al. 2000). Wild birds such as
geese, ducks and game birds; they can be carriers of even highly pathogenic strain H5N1
shedding the virus in their feces without clinical signs of disease.
Thus, the present study was carried out to examine the viral contamination (Influenza A
virus) in poultry vaccines manufactured locally and imported from different countries of the
world in Pakistan. The findings of the study have helped us to see the Avian Influenza A virus
contamination in vaccines which are used in field conditions and also help to evaluate the purity
of vaccines. The RT-PCR based technology has been described for the detection of different
RNA viruses such as Newcastle disease virus etc. (Payne et al. 1981) revealed contamination of
vaccines with ALVs, specifically in two Marek´s vaccines, which confirms that these agents are
potential contaminants of viral vaccines applied in poultry. This assay has meant a considerable
advance due to a higher sensitivity and specificity upon differentiating the subgroups compared
with ELISA. It is quicker test for detection of RNA viruses than the viral isolation, which
requires until 10 days and it needs detection by ELISA for the identification result. Availability: Items available for loan: UVAS Library [Call number: 2212,T] (1).
2.
A Study On Point Prevalence, Etiological And Biochemical Investigations Of Post Parturient Haemoglobinuria In Buffaloes In Tehsil Bhalwal
by Muhammad Azeem (2015-VA-430) | Dr. Muti-ur-Rehman Khan | Prof. Dr. Asim Aslam | Prof. Dr. Shafqat Fatima Rehmani.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: Post-parturient haemoglobinuria is a disease of great economic importance of sub-continent affecting a large number of buffaloes. It is characterized by intravascular hemolysis, haemoglobinemia, haemoglobinuria ultimately leading to anemia. The exact pathogenesis is yet unknown as there are many diversified etiological factors have been associated with this disease. All the relevant information is relatively scanty. Consequently present study has been aimed to study all possible risk factors associated with this disease in tehsil Bhalwal of district Sargodha where a large number of increasing cases were reported by the local governmental body. Etiological, hematological and biochemical risk factors were quantified to facilitate control measures and upcoming research priorities.
This study was conducted from the period of about 4 months from November 2016 to February 2017. Cross-sectional epidemiological observations were documented on hemoglobinuric and healthy buffaloes for hematological and biochemical study related to parturient haemoglobinuria. The sample size was determined to three hundred and eighty four animals.Present study was observed during the period of four months (November 2016 to February 2017). Out of 384, forty animals (n=40) were confirmed with post parturient hemoglobinuria. The point prevalence observed during the period of four months was 10.4%.
Buffaloes showing signs of hemoglobinuria along with parturition history, pale mucous membranes, mild tachycardia and dyspnoea was assumed as affected with post-parturient haemoglobinuria while animals suffering from other problems like babesiosis causing red urine were omitted from the study after verification of diagnosis through giemsa staining. The blood samples were processed for haematological analysis for the final confirmation of positive
haemoglobinuric buffaloes. Blood sample collected and placed in EDTA vacutainerswas processed for hematology to study hemoglobin (Hgb) values, total erythrocytes count (TEC), erythrocytes sedimentation rate (ESR) and hematocrit (Hct), total leukocyte count (TLC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) in addition to mean corpuscular hemoglobin concentration (MCHC) by using haematological analyzer. Haematological analysis of all the samples was made from Department of Pathology, UVAS, Lahore.Serum samples of all buffaloes were analyzed for biochemical analysis asalkaline phosphatase (ALP), serum urea, glucose,bilirubin, creatinine, calcium, phosphorus, copper, and molybdenum. Moreover, urinalysis was done for gross and biochemical analysis.
Results of the study revealed significant difference among complete blood count (CBC) includingHgb, TEC, Hct and TLC, ESR, MCV and MCH. However, there was no significant variation among MCHC values in affected buffaloes. Serum biochemistry also revealed significant difference of various parameters including ALP, creatinine,BUN, total bilirubin, phosphorus, copper and molybdenum. However, no significant difference was detected among the healthy and affected groups regarding blood glucose and serum calcium levels. There was significant elevation in pulse and respiration rates in buffaloes affected with hemoglobinuria.
The results regarding mineral analysis of the soil shows significant difference in phosphorus and copper. Moreover, mineral levels of soil and serum of animals showed significant relation of phosphorus levels, followed by the levels of molybdenum. Calcium and copper levels also showed moderate relationship.
Observations regarding parity/lactation number reveal the highest incidence rate of 35% among buffaloes at 3rd lactation, followed by buffaloes at 4th, 2nd, 5th, 1st and 6th lactation, respectively. Milk production showed direct relationship with buffaloes affected with post parturient hemoglobinuria.
From the present study, it is concluded thathemoglobinuria was observed in buffaloes of tehsil Bhalwal may be due to variation of soil composition particularly the deficiency of Phosphorus which may lead to the lysis of erythrocytes and hemoglobinuria through various pathways. However, efficient replenishment of minerals content in fodder producing soil is necessary to overcome the disease in buffaloes affecting from parturient hemoglobinuria in the aforementioned area.
Availability: Items available for loan: UVAS Library [Call number: 2847-T] (1).
