- : Ms Word, Ms Word Format
- : 100 Pages
- : ₦5000
- : 1-5 Chapters
- Click to DOWNLOAD Materials
SEROPREVALENCE AND RISK FACTORS OF BRUCELLA INFECTION IN DOGS IN ENUGU AND ANAMBRA STATES.
ABSTRACT
A cross-sectional survey was used to assess the seroprevalence of Brucella canis and Brucella abortus antibodies in dogs in Anambra and Enugu States, Nigeria. The objectives of the study were to determine the seroprevalence of B. canis and B. abortus in dogs presented to major vet clinics, dogs for slaughter in selected areas and apparently healthy owned dogs in visited households in Enugu and Anambra States; to determine the sex, age and breed distribution of B. canis and B. abortus antibodies in screened dogs in both states and the possible risk factors for brucella infections in the study area. Five major veterinary clinics, two each in Enugu and Onitsha metropolis, one in Nsukka Urban; 2 major slaughter points in each state; and households with dogs that have history of infertility or abortion were selected by purposive sampling method. The study population was made up of 3 groups: dogs presented at veterinary clinics, household dogs with history of infertility or abortion and, dogs slaughtered for meat at markets. Visits were made to the purposively selected veterinary clinics, households, and slaughter points, once every other week for six months. A total of 123 dogs made up of 65 clinic dogs, 34 slaughter dogs and 24 household dogs were screened. Profiles of the dogs presented at the clinics and household dogs were also collected. Blood was collected from each dog and processed for serology. For B. abortus antibody assay, the serum was subjected to Rose Bengal plate test (RBPT) and Serum agglutination test (SAT). With the SAT, a titer value of 40IU/ml and above was regarded as positive. For B. canis antibody identification, Solid Phase Immunoassay technique using Immunocomb® Canine Brucellosis Antibody Test Kit was used. Titer value of 1:200 (IFA titer) and above was regarded as positive. Chi-square statistic and odds ratio were used to analyze the data obtained. Out of the 123 dogs, screened, none was positive for Brucella abortus antibodies using both the Rose Bengal Plate Test (RBPT) and the Serum Agglutination Test (SAT). Thirty-four (27.7%) of the dogs screened were positive for B. canis antibodies using the Solid Phase Immunoassay Technique. Twenty-two out of 65 (18%) dogs presented to veterinary clinics, 8 out of 24 household dogs (6.5%), and 4 out of the 14 slaughter dogs (3.3%) were positive for B. canis antibodies. There was a strong association (p<0.05) between infection and sex with the infection being significantly higher (p<0.05) in female than in male dogs. Prevalence was significantly higher (p<0.05) in foreign breeds than in mixed and local breeds. There was no association (p>0.05) between the infection and the antibody titer levels of the different categories of dogs. Dogs presented at the clinics and household dogs with titer levels 1:600 and above had history of recent abortion or infertility. There was significant association (p<0.05) between the presence of Brucella canis antibodies and free roaming of dogs. This study provides the first serological evidence of B. canis infection but found no evidence of antibodies to B. abortus in dogs in Enugu and Anambra States. This shows that B. canis is endemic in both states and can be considered as a new emerging disease, underscoring the need for further studies including isolation of bacteria and DNA extraction . Female dogs, exotic breeds of dogs and free roaming of dogs are at a higher risk of brucella infection in the study area. Therefore, preventive and controlling measures are strongly recommended.
TABLE OF CONTENTS
Title Page
Declaration page — — — — — — — — — i
Certification page — — — — — — — — — ii
Dedication page — — — — — — — — — iii
Acknowledgement — — — — — — — — — iv
Table of contents — — — — — — — — — vi
List of Tables — — — — — — — — — — x
List of figures — — — — — — — — — — xi
Abstracts — — — — — — — — — — xii
CHAPTER ONE: INTRODUCTION — — — — — — 1
1.1 Background of the Study — — — — — — — 1
1.2 Statement of the Problem — — — — — — — 3
1.3 Research Questions — — — — — — — — 5
1.4 Aims and Objective of the Study — — — — — — 5
1.5 Significance of the Study — — — — — — — 6
CHAPTER TWO: LITREATURE REVIEW
2.1: Historical review — — — — — — — — 7
2.2 Aetiology — — — — — — — — — 8
2.3 Classification — — — — — — — — — 8
2.4 Epidemiology — — — — — — — — — 9
2.4.1 Distribution of Brucellosis — — — — — — — 9
2.4.2 Brucellosis in Nigeria — — — — — — — — 9
2.4.3 Canine Brucellosis — — — — — — — — 10
2.4.4 Bovine Brucellosis — — — — — — — — 10
2.4.5 Caprine Brucellosis — — — — — — — — 11
2.4.6 Brucellosis in Sheep — — — — — — — — 12
2.4.7 Brucellosis in Horses — — — — — — — — 12
2.4.8 Brucellosis in Camels — — — — — — — — 13
2.4.9 Brucellosis in Pigs — — — — — — — — 13
2.4.10 Brucellosis in Chickens — — — — — — — 14
2.4.11 Brucellosis in Marine Animals — — — — — — 14
2.4.12 Brucellosis in Humans — — — — — — — 15
2.5 Growth Media and Growth Characteristics of Brucella Organisms — — 16
2.6 Transmission of Brucellosis — — — — — — — 17
2.7 Reservoir of Brucella canis and Brucella abortus — — — — 19
2.8 Resistance and Survival of Brucella Organisms in the Environment — — 20
2.9 Zoonotic Potential — — — — — — — — 20
2.10 Pathogenesis — — — — — — — — — 21
2.11 Pathology — — — — — — — — — 23
2.12 Immunity — — — — — — — — — 24
2.12.1 Humoral Immunity and Globulin Production During Infection — — 24
2.12.2 Cell Mediated Immunity — — — — — — — 24
2.13 Diagnosis of Brucella Infections — — — — — — 25
2.13.1 Clinical Signs — — — — — — — — — 25
2.13.2 Direct Smear Examination — — — — — — — 26
2.13.3 Identification and typing — — — — — — — 26
2.13.4 Animal Innoculation — — — — — — — — 27
2.13.5 Serological Diagnosis — — — — — — — — 28
2.13.5.1 Rose Bengal Plate Test (RPBT) — — — — — — 28
2.13.5.2 Serum AgglutinationTest (SAT) — — — — — — 29
2.13.5.3 Rapid Slide Agglutination Test (RSAT) — — — — — 29
2.13.5.4 Agar Gel Immunodiffusion Test (AGID) — — — — — 30
2.13.5.5 Agglutination Tests — — — — — — — — 30
2.13.5.6 Other Serological Tests — — — — — — — 30
2.14 Treatment of Brucellosis in Animals and Humans — — — — 31
2.15 Public Health Importance — — — — — — — 32
2.16 Economic Importance of Brucellosis — — — — — — 33
2.17 Control, Prevention and Eradication of Brucellosis — — — — 34
2.17.1 Vaccines — — — — — — — — — 35
2.17.2 Control and Prevention of Brucellosis in Humans — — — — 35
CHAPTER THREE: MATERIALS AND METHODS — — — — 37
3.1. Study design — — — — — — — — — 37
3.2. Area of study — — — — — — — — — 37
3.3 Map of Enugu State — — — — — — — — 38
3.4 Map of Anambra State — — — — — — — 39
3.5 Study Duration — — — — — — — — 40
3.6 Study Population — — — — — — — — 40
3.7 ` Sample Size Determination — — — — — — — 40
3.8 Sampling Technique — — — — — — — — 40
3.9 Sample Collection — — — — — — — — 41
3.10 Sample Analysis — — — — — — — — 41
3.10.1 Serological Tests — — — — — — — — 41
3.10.2 `Test Procedure — — — — — — — — 42
3.10.2.1 Procedure for Rose Bengal plate test (RBPT) — — — 42
3.10.2.2 Procedure for Serum Agglutination Tests (SAT) — — — — 42
3.10.2.3 Procedurefor the ImmunoComb® Canine Brucellosis Antibody Test Kit Specific
for B. canis Antigen — — — — — — — — 43
3.11 Statistical Analysis — — — — — — — — 44
CHAPTER FOUR: RESULTS — — — — — — — 45
4.1 Distribution of Dogs Based on States and Sources where samples were collected 45
4.2 Prevalence of Brucella abortus Antibodies based on the Sources of Dogs — 47
4.3 Prevalence of Brucella canis Antibodies based on the Sources of the Dogs — 49
4.4 Antibody Titre Levels of B. canis Positive Dogs Screened in Anambra and Enugu
States — — — — — – — — — 51
4.5 Antibody titre Levels of Brucella canis Positive Dogs based on the Sources
of Dogs — — — — — — — — — — 53
4.6 Sex Distribution of Brucella canis Antibody Positive Dogs — — — 55
4.7 Antibody Titre Levels of B. canis Positive Dogs According to Sex — — 57
4.8 Age Distribution of Brucella canis Antibody Positive Dogs (Clinical and
Household dogs) — — — — — — — — 59
4.9 Breed distribution of Brucella canis Antibody Positive Dogs — — 61
CHAPTER FIVE: DISCUSSION — — — — — — — 63
Discussion — — — — — — — — — 63
CHAPTER SIX: CONCLUSION AND RECOMMENDATION — — 68
6.1 Conclusion — — — — — — — — — 68
6.2 Recommendation — — — — — — — — 69
REFERENCES — — — — — — — — — 70
CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
Brucellosis is considered by the Food and Agriculture Organization (FAO), the World Health Organization (WHO) and the Office of International des Epizootics (OIE) as one of the most wide spread zoonoses in the world (Schelling et al., 2003). According to OIE, it is the second most important zoonotic disease in the world after rabies. The disease affects cattle, swine, sheep, goats, camel and dogs. It may also infect other ruminants and marine mammals (Corbel, 1988; Radostits et al., 1995; Abubakar et al., 2012). Synonyms of brucellosis include: Undulant fever, Malta fever, Mediterranean fever, Enzootic abortion, Epizootic abortion, Contagious abortion, and Bang’s disease. It is an important Zoonotic disease and causes significant reproductive loss in sexually mature animals (Forbes and Tessaro, 1996; Wadood et al., 2009). The disease is manifested by late term abortions, weak calves, still births, infertility and characterized mainly by placentitis, epididymitis and orchitis, with excretion of the organisms in uterine discharges and milk (England et al., 2004). In females the most prominent sign is abortion after 45-55 days of gestation in about 75% of the cases; early embroyonic death and resorption, or abortion 10-20 days after mating may occur in some cases (Shin and Carmicheal, 1999). The organism occurs in the fetus, placenta, fetal fluids and vaginal discharges after an abortion or stillbirth. This organism can be found in vaginal discharges for 4 to 6 weeks after abortion; it is also shed in normal vaginal secretion; particularly, during estrus, as well as in milk (Iowa State University, 2012). In males, the main sign is epididymitis of one or both testes and infertility (Shin and Carmiceal, 1999). B. Canis infection are found in semen for up to two months after infection and also found in urine, saliva, nasal and occur in secretions, and feces.
Worldwide, nine species of the genus Brucella have been recognized and the genus Brucella contains a group of very closely related bacteria. The first member of the group, Brucella melitensis, affects primarily sheep and goats. The second member of the group, B. abortus, affects primarily cattle B. suis affects pigs, B. Ovis affects sheep, B. canis affects dogs while the other members include B. neotomae, B.microti, B. ceti and B. pinnipedialis (Corbel, 1988; Sati, 2002; Dauglas, 2006; Foster et al., 2007; Scholtz et al., 2008). Cross transmission of brucellosis can occur between cattle, swine, sheep and goats and other species including dogs, horses, bison, rein deer and camels (FAO, 2003). Dogs can be infected by four of the six species of Brucella (Brucella canis, Brucella abortus, Brucella melitenses and Brucella suis, excluding Brucella ovis and Brucella neotomae) (Hollet, 2006). Outbreaks of canine abortions had been reported in 1963, but it was not until 1966 -1967 that B. canis was isolated from tissues and vaginal discharges of dogs. (Carmicheal, 1966; Carmicheal et al., 1967, Taul et al., 1967).
Brucellosis was first recognized as a disease affecting human-beings on the Island of Malta in the 19th and early 20th centuries when Brucella melitensis was first isolated from the spleen of a resident of the Island of Malta who died from a disease locally known as Malta fever (Brunner and Gilespire, 1966). In Nigeria, an outbreak of brucellosis was first reported in a government cattle farm located in Zaria in 1934. Serum plate agglutination test showed positive reactors of about 15% of the total animals in the farm (Banerjee and Bhalty, 1970).
Brucellosis as a zoonoses poses serious human health hazards worldwide (Hamidy et al., 2002; Maloney and Fraser, 2004; Cadmus et al; 2006). Ruminants, pigs, horses, dogs and donkeys play an important role in the transmission of this disease to man (Cadmus et al., 2006). In human, the infection is acquired by consumption of contaminated food of animal origin, and through aerosol (Gul and Khan, 2007). Infection can also result through contact with infected aborted materials such as aborted fetuses, placenta membranes or fluids and other vaginal exudates (FAO/OIE/WHO, 2006).
Brucellosis has a considerable impact on animal and human health, as well as wide socio-economic impacts, especially in countries in which rural income relies largely on livestock breeding and dairy products (Maadi et al., 2011). It also causes morbidity and considerable loss of productivity (Pappas et al., 2006). The disease is important from economic point of view; it is one of the most devastating trans-boundary animal diseases and also a major barrier for trade (Gul and Khan, 2007). Occupationally, Brucella can gain entry into humans especially veterinarians, animal handlers, butchers, abattoir workers through abraded skins, mucous membranes, conjunctiva, respiratory and gastro intestinal tracts.
1.2 Statement of the Problem
Dogs are the closest domestic animals to humans in Nigeria thus its interactions with human the populace may lead to an increase in the risk of infection (Cadmus et al., 2012).
In dogs, the infection is insidious and many are asymptomatic (Ewalt and Bricker, 2000); with the infected dogs shedding the organisms via urine, vaginal secretions, ejaculates, fetuses and feces and carrier dogs can be a source of infection and transmission to households (Brooks, 2006).
The increase in dog ownership in Nigeria is associated with some risk factors that render them vulnerable to brucellosis. Firstly, many exotic breeds are imported and are not screened before entry into the country (Cadmus et al., 2011). Secondly, some household dogs are fed with fetuses from cows and ruminants from slaughtered cattle with a history of bovine brucellosis from abattoirs (Cadmus et. al, 2010). In addition to these factors, some household dogs roam around freely, placing them at greater risk of exposure to brucellosis. Also non-screening of mating dogs used for breeding predisposes to the high risk of infection among breeding kennels.
In both clinical and household dogs; as well as in Kennel dogs, abortion was recognized but not considered to be from infections with Brucella. Abortion due to trypanosomosis and other causes had also apparently been confused with Brucella abortion.
Increased consumption of dog meat has led to a spike in the slaughter of unscreened apparently healthy dogs for meat, hence an increase in risk of infection to the handlers, butchers, etc.
Symptoms in human brucellosis can be highly variable, ranging from non-specific, flu-like symptoms (acute form) to undulant fever which may progress to a more chronic form and can also produce serious complications affecting the musculoskeletal, cardiovascular, and central nervous systems, arthritis, orchitis and epidiymitis and may be confused with a wide range of other diseases (Baba et. al, 2001). The cost of treatment and work days lost to ill health, combined with the loss of productivity in the animal husbandry, leads to decreased availability of food that adversely affects the health and economic well being of the population (Chauhan et al., 2000; Baba et al, 2001).
Although brucellosis is a notifiable disease in Nigeria, the incidence, prevalence and distribution of the disease is difficult to determine as the system of disease surveillance and reporting is fragmentary and inefficient (Ocholi et al., 2004). Serological prevalence rate between 0.20% and 79.70% have been reported in animals and humans in various parts of the country (Esuroso, 1974; Chukwu, 1987b; Ocholi, 1993; Onunkwo et al., 2005; Junaidu et al; 2008); much emphasis is laid on cattle, sheep and goat; the same cannot be said of dogs.
It is also regarded as a disease of public health significance as it is zooonotic in nature, thereby making occupationally risk persons like butchers, abattoir workers, livestock owners and rearers, veterinarians as well as other humans susceptible (Yagupsky and Baron, 2005; Belizadi and Mogheiseh, 2011). Thus, there is need to know more about the disease.
- Research Questions
- Are canis and B. abortus present in dogs presented in major Veterinary clinics in Enugu and Anambra States?
- Are canis and B. abortus present in slaughter dogs in areas purposively selected for screening in Enugu and Anambra States?
- Are canis and B. abortus present in apparently healthy owned dogs not presented to clinics?
- What is the overall prevalence rate of Brucella infection in dogs in the study area?
- What is the age, sex and breed distribution of Brucella infection in dogs in the study
area?
- Are there possible risk factors that may influence infection rate in dogs in the study area?
- Aim and Objectives of the Study.
The aim of this study is to conduct a seroprevalence survey of Brucella canis and Brucella abortus infections in dogs in purposively selected areas of Enugu and Anambra States and to determine the possible risk factors that may influence infection.
The specific objectives are:
- To determine the seroprevalence of B. canis and B. abortus in dogs presented to major veterinary clinics in Enugu and Anambra States.
- To determine the seroprevalence of B. canis and B. abortus in dogs for slaughter in selected areas in both states.
- To determine the prevalence of B. canis and B. abortus in apparently healthy owned dogs in visited households in both states.
- To determine the overall prevalence rate of Brucella infections in the study area.
- To determine the sex, age and breed distribution of B.canis and B. abortus in screened dogs in Enugu and Anambra States.
- To determine the possible risk factors that may influence the infection rates in dogs in the study area.
- Significance of the Study
This work will provide information on the current seroprevalence of Brucella antibodies in dogs in these States as well as the prevalent species.
The study will also provide information on sex, breed, and age distribution as well as some risk factors that may influence Brucella infection in dogs therefore contributing to the epidemiology of Brucella infection in dogs in Anambra and Enugu States.
The result will also be used to provide an appropriate recommendation to dog owners, veterinarians, butchers, cooks, public health authorities and government to institute urgent measures towards the control of the disease.
SEROPREVALENCE AND RISK FACTORS OF BRUCELLA INFECTION IN DOGS IN ENUGU AND ANAMBRA STATES.
