Introduction: The spread and prevalence of the HIV epidemic has resulted in extensive social, cultural and economic consequences in sub-Saharan Africa. It is estimated that about 60% of adults living with HIV in sub-Saharan Africa are women. South Africa, with 5.2 million HIV infected people, is estimated to have the largest number of people living with HIV/AIDS in the world. HIV among older women is not well documented, despite high prevalence rates amongst women 45 years and older. Moreover, few HIV-related interventions are directed to the elderly in South Africa. HIV risk factors among older women have also not been well documented. It is important to determine the factors associated with older women, and how they affect their HIV infection rates. Understanding these factors may lead to better HIV prevention strategies. This study aimed to determine the HIV prevalence in older South African women and to determine the factors associated with HIV infection in older South African women living in Soweto, Johannesburg. Materials and Methods: We did an analytical cross-sectional study on a convenience sample of 500 women (45 years and older) recruited from various venues in Soweto, a large urban African setting in Johannesburg, South Africa, and who accepted to be tested for HIV. Private face-to-face interviews were conducted and included an assessment of socio-demographic characteristics and behavioural factors thought to be associated with HIV. Results: 449 women were included in the study and 52 (11.6%) women were found to be HIV positive. Increased odds of HIV infection was associated with condom use (OR=3.75, 95%CI: 1.71–8.19), transactional sex (OR=2.44, 95%CI: 1.04–5.69) and marital status. Compared to a married woman, a woman was more likely to be HIV positive if she was single, widowed or “cohabiting”. Decreased odds of HIV infection was associated with age (OR=0.90, 95%CI: 0.85–0.96) and education. With respect to a woman with less than 5 years of education, a woman was less likely to be HIV infected if she had more than 5 years of education. Conclusion: Further research needs to be done to determine the exact HIV prevalence amongst older women, as well as risk factors associated with HIV infection. It is also important that older women be encouraged to use condoms, as they are known to be an effective barrier to HIV infection. There is need for HIV-related interventions targeted to older women.

A total of 4,778 cows from 179 herds were tested for antibodies to N. caninum using a commercially availableELISA. Neospora caninum herd-level seroprevalence ranged from 25.0% to 75.9% (a herd was considered positive with ¡Ý 2 cows testing positive). The true cow prevalence was estimated as 5.2% (95% CI= 4.6 ¨C 5.8). ¡°Pre-calving use of dry lots¡±, ¡°separation of cow-calf pair from other cows after calving¡±, ¡°use of standing water in summer¡±, ¡°use of running water in winter¡±, ¡°feeding heifers with manure handling equipment¡±, ¡°abortion and stillbirths left for canids¡± and ¡°number of sightings of wild canids per year¡± (categorized into three categories: less than 10 times per year, 11¨C 25 times per year, and greater than 26 times per year) were positivelyassociated with herd serological status. However, ¡°washing boots between visits to livestock farms¡± was negatively associated with serological status. These 8 variables were included in a multivariable logistic regression model. Province and herd size were considered potential confounders and kept in the model regardless of significance. Only 4 variables remained significant in the final model.Risk factors associated with prevalence included the use of dry lots/corrals as pre-calving area (OR=2.8; 95% CI =1.3 ¨C 6.2), the use of natural standing water in summer (OR=3.2; 95%CI=1.31 ¨C 8.0), and leaving abortions/stillbirths for dogs or wild canids (OR=2.5; 95%CI=1.0 ¨C 5.9). As the frequency of sighting coyotes and foxes increased so did herd seroprevalence to N. caninum. Risk factors suggested the likely role of horizontal transmission in the transmission of N. caninum in these beef cow-calf herds. Beef herd managers might consider biosecurity practices such as preventing the access of wild canids to fetuses and stillbirths thereby preventing pasture contamination and controlling contamination of water source with oocyst of N. caninum thereby reducing chances of infection. Aherd was considered positive for Bovine leukemia virus (BLV) if ¡Ý 1 animal tested positive.Estimates of cow-level seroprevalence was 1.01% (95% CI= 0.73% ¨C 1.29%) while herd seroprevalence was 12.4% (95% CI= 7.57 ¨C 17.23). Potential risk factors examined for BLV transmission included the use of blade or surgical castration without disinfection between animals, using gouger and saw dehorning methods, multi-use of common rectal sleeve between cows without disinfection and the use of communal pasture where mating occurred. No associations existed between potential risk factors and seropositivity to BLV because the number of herds testing positive to BLV were too few to find any association. However, management practices observed in this study may have the potential to transmit infections. Lapses in biosecurity practices identified were addition of new animals to the herds(73.7%, 132/179), the use of communal grazing (24.0% (43/179) of herds using with 28% (12/43) using more than one communal pasture where mating occurred(93%, 40/43) with bulls from other herds. During communal grazing, contact herds ranged between 1 and 25 (mean = 7.4). Large herds (¡Ý111) animals were more likely to use communal pasture compared to medium sized or small herds (¡Ü46) (P<0.01). Domestic and wild canids had access to stored grain in 19% (34/179) of herds. The odds of wildlife gaining access to stored gain is twice as high (OR=2.37, P<0.02) in western Canada compared to eastern Canada. Purebred herds were less likely to be fed on the ground compared to cross-bred herds (P<0.03). Herds from western Canada administered more feedstuffs on the ground compared to herds from eastern Canada (P<0.01). Large herds were more likely to store feedstuffs outdoors compared to small herds (P<0.01). Herds from western Canada were more likely to store their feedstuffs outside compared to herds from eastern Canada (P<0.01). The odds of not removing surface manure from maternity pens was almost three times (OR=2.98, P<0.01) in herds from western Canada compared to eastern Canada. 78.7% (140/179) of herds disposed ofmanure by spreading on surface ground. 52% (93/179) of herds borrowed manure contaminated equipment from other producers for use on their farms. Thirty three percent (53/179) of herds performed breeding soundness examinations in breeding bulls and 9.5% (17/179) of herds performed trichomonas testing on breeding bulls. Large herds were more likely to co-mingle cows and heifers during the breeding season (P<0.01) compared to small herds. Cow-calf pair separation from other cows after calving occurred more in large herds compared to medium sized or small herds (P<0.01). The odds of using maternity pen as hospital pen was twice in western compared to the eastern Canada (OR=2, P=0.04). Sixty percent (107/179) of herds used the same area for calving and winter-feeding. Herds from western Canada were more likely to use the same area for calving and winter feeding compared to herds from eastern Canada (P<0.01). Forty-one percent (73/179) of herds used hospital pens as maternity pens during calving season. 35.8% (64/179) of herds transported animals to veterinary clinic for treatment. In nine percent (16/179) of herds visitors or outside employees changed their boots, and in18% (32/179) visitors washed their boots. Eighty two percent (146/179) of herds dehorned cattle, of which 74% (109/148) used non-bloodless methods. Of herds using non-bloodless dehorning methods, 28.4% (31/109) disinfected dehorning equipment between animals. 73.7% (132/179) of herds reported castrating animals, of which 32.6% (43/132) used surgical castration method. Of herds using surgical castration method, 81.4% (35/43) disinfected surgical equipment between animals. 12.2% (22/179) of herds disinfected or used new needles between animals when injecting drugs or vaccines. Thirty five percent (63/179) of herds changed sleeves between animals when performing rectal examinations.Over twenty nine percent (29.6%, 53/179) of herds left abortions for dogs and coyotes while 27.4% (49/179) of herds left stillbirths for dogs and coyotes.The risk of adding calves persistently infected (PI) with Bovine Viral Diarrhea (BVD) virus exists with 13% (23/179) of herds adding unweaned beef calves and 18.4% (33/179) adding weaned beef calves without pre-purchase testing.PI calves are known for shedding large amounts of BVD virus and spreading BVD virus infection in beef herds. BVD virus vaccination may compensate for exposure to the virus in a cowherd by mitigating the risk of fetalinfection; however, the timing of vaccination is essential to offer protective immunity. BVD virus vaccine administered during pregnancy check may not protect the fetus against BVDV infection.There is likelihood of infection in-utero resulting in immunotolerant fetus persistently infected (PI) with BVDV and carried to term. This may occur if calf was infected in-utero before 125 days of gestation. Herds in this study administered BVD virus vaccination to breeding cows prior to breeding (60%, 118/179), during pregnancy check (28%, 50/179), and at other times (6%, 11/179). In replacement heifers, BVD vaccination was administered prior to breeding (79%, 142/179), during pregnancy check (13.4%, 24/179), and at other times (7.3%, 13/179).Herds vaccinating breeding cows for BVD virus were 63.1% (113/179), of which 29.1% (52/179) used modified live vaccine and 34.1% (61/179) used killed vaccine. Herds vaccinating replacement heifers for BVD were sixty percent (107/179), of which 25.1% (45/179) used modified live virus vaccine and 34.6% (62/179) used killed vaccine. The role ofthe veterinarianis essential in educating producers on what constitute risky practices and how to mitigate such risks. Approach to mitigating risks may not necessarily be the same for all cow-calf herds; it must be tailored to each production unit. Initial risk assessment will identify what constitutes risky management practices, after which sound mitigation measure are designed to address such risks. On-farm biosecurity practices needs approach within the framework of risk assessment and periodic review for effectiveness.

A total of 4,778 cows from 179 herds were tested for antibodies to N. caninum using a commercially availableELISA. Neospora caninum herd-level seroprevalence ranged from 25.0% to 75.9% (a herd was considered positive with ¡Ý 2 cows testing positive). The true cow prevalence was estimated as 5.2% (95% CI= 4.6 ¨C 5.8). ¡°Pre-calving use of dry lots¡±, ¡°separation of cow-calf pair from other cows after calving¡±, ¡°use of standing water in summer¡±, ¡°use of running water in winter¡±, ¡°feeding heifers with manure handling equipment¡±, ¡°abortion and stillbirths left for canids¡± and ¡°number of sightings of wild canids per year¡± (categorized into three categories: less than 10 times per year, 11¨C 25 times per year, and greater than 26 times per year) were positivelyassociated with herd serological status. However, ¡°washing boots between visits to livestock farms¡± was negatively associated with serological status. These 8 variables were included in a multivariable logistic regression model. Province and herd size were considered potential confounders and kept in the model regardless of significance. Only 4 variables remained significant in the final model.Risk factors associated with prevalence included the use of dry lots/corrals as pre-calving area (OR=2.8; 95% CI =1.3 ¨C 6.2), the use of natural standing water in summer (OR=3.2; 95%CI=1.31 ¨C 8.0), and leaving abortions/stillbirths for dogs or wild canids (OR=2.5; 95%CI=1.0 ¨C 5.9). As the frequency of sighting coyotes and foxes increased so did herd seroprevalence to N. caninum. Risk factors suggested the likely role of horizontal transmission in the transmission of N. caninum in these beef cow-calf herds. Beef herd managers might consider biosecurity practices such as preventing the access of wild canids to fetuses and stillbirths thereby preventing pasture contamination and controlling contamination of water source with oocyst of N. caninum thereby reducing chances of infection. Aherd was considered positive for Bovine leukemia virus (BLV) if ¡Ý 1 animal tested positive.Estimates of cow-level seroprevalence was 1.01% (95% CI= 0.73% ¨C 1.29%) while herd seroprevalence was 12.4% (95% CI= 7.57 ¨C 17.23). Potential risk factors examined for BLV transmission included the use of blade or surgical castration without disinfection between animals, using gouger and saw dehorning methods, multi-use of common rectal sleeve between cows without disinfection and the use of communal pasture where mating occurred. No associations existed between potential risk factors and seropositivity to BLV because the number of herds testing positive to BLV were too few to find any association. However, management practices observed in this study may have the potential to transmit infections. Lapses in biosecurity practices identified were addition of new animals to the herds(73.7%, 132/179), the use of communal grazing (24.0% (43/179) of herds using with 28% (12/43) using more than one communal pasture where mating occurred(93%, 40/43) with bulls from other herds. During communal grazing, contact herds ranged between 1 and 25 (mean = 7.4). Large herds (¡Ý111) animals were more likely to use communal pasture compared to medium sized or small herds (¡Ü46) (P<0.01). Domestic and wild canids had access to stored grain in 19% (34/179) of herds. The odds of wildlife gaining access to stored gain is twice as high (OR=2.37, P<0.02) in western Canada compared to eastern Canada. Purebred herds were less likely to be fed on the ground compared to cross-bred herds (P<0.03). Herds from western Canada administered more feedstuffs on the ground compared to herds from eastern Canada (P<0.01). Large herds were more likely to store feedstuffs outdoors compared to small herds (P<0.01). Herds from western Canada were more likely to store their feedstuffs outside compared to herds from eastern Canada (P<0.01). The odds of not removing surface manure from maternity pens was almost three times (OR=2.98, P<0.01) in herds from western Canada compared to eastern Canada. 78.7% (140/179) of herds disposed ofmanure by spreading on surface ground. 52% (93/179) of herds borrowed manure contaminated equipment from other producers for use on their farms. Thirty three percent (53/179) of herds performed breeding soundness examinations in breeding bulls and 9.5% (17/179) of herds performed trichomonas testing on breeding bulls. Large herds were more likely to co-mingle cows and heifers during the breeding season (P<0.01) compared to small herds. Cow-calf pair separation from other cows after calving occurred more in large herds compared to medium sized or small herds (P<0.01). The odds of using maternity pen as hospital pen was twice in western compared to the eastern Canada (OR=2, P=0.04). Sixty percent (107/179) of herds used the same area for calving and winter-feeding. Herds from western Canada were more likely to use the same area for calving and winter feeding compared to herds from eastern Canada (P<0.01). Forty-one percent (73/179) of herds used hospital pens as maternity pens during calving season. 35.8% (64/179) of herds transported animals to veterinary clinic for treatment. In nine percent (16/179) of herds visitors or outside employees changed their boots, and in18% (32/179) visitors washed their boots. Eighty two percent (146/179) of herds dehorned cattle, of which 74% (109/148) used non-bloodless methods. Of herds using non-bloodless dehorning methods, 28.4% (31/109) disinfected dehorning equipment between animals. 73.7% (132/179) of herds reported castrating animals, of which 32.6% (43/132) used surgical castration method. Of herds using surgical castration method, 81.4% (35/43) disinfected surgical equipment between animals. 12.2% (22/179) of herds disinfected or used new needles between animals when injecting drugs or vaccines. Thirty five percent (63/179) of herds changed sleeves between animals when performing rectal examinations.Over twenty nine percent (29.6%, 53/179) of herds left abortions for dogs and coyotes while 27.4% (49/179) of herds left stillbirths for dogs and coyotes.The risk of adding calves persistently infected (PI) with Bovine Viral Diarrhea (BVD) virus exists with 13% (23/179) of herds adding unweaned beef calves and 18.4% (33/179) adding weaned beef calves without pre-purchase testing.PI calves are known for shedding large amounts of BVD virus and spreading BVD virus infection in beef herds. BVD virus vaccination may compensate for exposure to the virus in a cowherd by mitigating the risk of fetalinfection; however, the timing of vaccination is essential to offer protective immunity. BVD virus vaccine administered during pregnancy check may not protect the fetus against BVDV infection.There is likelihood of infection in-utero resulting in immunotolerant fetus persistently infected (PI) with BVDV and carried to term. This may occur if calf was infected in-utero before 125 days of gestation. Herds in this study administered BVD virus vaccination to breeding cows prior to breeding (60%, 118/179), during pregnancy check (28%, 50/179), and at other times (6%, 11/179). In replacement heifers, BVD vaccination was administered prior to breeding (79%, 142/179), during pregnancy check (13.4%, 24/179), and at other times (7.3%, 13/179).Herds vaccinating breeding cows for BVD virus were 63.1% (113/179), of which 29.1% (52/179) used modified live vaccine and 34.1% (61/179) used killed vaccine. Herds vaccinating replacement heifers for BVD were sixty percent (107/179), of which 25.1% (45/179) used modified live virus vaccine and 34.6% (62/179) used killed vaccine. The role ofthe veterinarianis essential in educating producers on what constitute risky practices and how to mitigate such risks. Approach to mitigating risks may not necessarily be the same for all cow-calf herds; it must be tailored to each production unit. Initial risk assessment will identify what constitutes risky management practices, after which sound mitigation measure are designed to address such risks. On-farm biosecurity practices needs approach within the framework of risk assessment and periodic review for effectiveness.

Hepatitis E virus (HEV) is the main cause of acute viral hepatitis worldwide, predominantly in developing areas where it is endemic. Recently, HEV has gained more attention in the developed world, prompting several industrialized countries to assess seroprevalence rates using blood donor samples. The seroprevalence among Canadian blood donor samples collected from July 2013 - December 2015 was 5.84% (240/4,107). None of the 14,053 samples tested were positive for HEV RNA. There was no significant increase in the high-risk groups we tested. HIV was determined to be a significant risk-factor for HEV infection in a retrospective study of Kenya-based sex-worker cohorts, but not so in a Canadian cohort of HIV-positive intravenous drug users. Overall, HEV seroprevalence in Canada is lower than that published in other countries. This together with failing to detect HEV RNA in Canadian blood donations indicates that HEV currently poses low risk to the Canadian blood supply. / February 2017

Comparison of HIV seroprevalence between males and females at clinic and community level in Mpumalanga South Africa. Background: Two cross-sectional surveys were conducted in Embalenhle community (February 2002) and Dunusa community mobile clinics (November 2001), to establish prevalence of HIV and STIs (Chlamydia trachomatis and Neisseria gonorrhea). Methods: Multiple logistic regression models were fitted to the combined data from the two sites, to identify factors associated with HIV prevalence and also to check whether the effects were consistent over the two sites. Results: HIV Prevalence was 33.5% (30.2%vs.35.9% in males and females respectively, p=0.124) at community site and 34.8% at clinic site (22.8%vs.47.4% in males and females respectively, p=0.001). The models show a significant site by sex interaction i.e. the effect of sex differs in the 2 sites (p=0.036). After adjusting for agegroup and Neisseria gonorrhea, predicted probabilities from the logistic regression model shows that the sex difference is much greater in community mobile clinics (23%vs.44.1% in males and females respectively) than at the community site (29.9%vs.34.9% in males and females respectively). After adjusting for site and Neisseria gonorrhea, the model showed an agegroup by sex interaction (p<0.001). Predicted probabilities show a difference, where HIV in males is higher than in females; in males in the 25-34 year age group from 18-24 years (36.3 vs 18.2 % respectively), while in females the prevalence is very similar in the 18-24 year and 25-34 year age groups. There were no interactions between Neisseria gonorrhea and other variables. Conclusions: The different HIV–age distribution for males and females are consistent with the results of previous studies. We found that the sex difference in prevalence was much smaller at the community level than at the clinic level. The traditional interpretation of national antenatal surveillance data assumes a fairly large difference in male and female seroprevalence (a ratio of 7:10 is used in extrapolating results of the South African National antenatal seroprevalence survey to males). These results suggest that more work is needed in checking that assumption.

No description available.

Cytomegalovirus (CMV) is an important antenatal infection that is prevalent in the developing world. The disabling and potentially fatal effects of CMV acquisition or reactivation during pregnancy on the developing foetus and or neonate are known but, factors predisposing pregnant women to CMV are not well studied. CMV has a wide host cell tropism that includes gut epithelial cells. CMV infection in the gut epithelial cells results in a leaky gut and potential gut microbial dysbiosis. In this study, we set out to determine the prevalence of CMV infection as well as factors associated with CMV reactivation in a cohort of pregnant Zimbabwean women. We also aimed to determine the role of CMV infection and CMV susceptibility host genetics on gut bacterial profiles. Seroprevalence of CMV was determined using the enzyme-linked immunosorbent assay. A high prevalence of previous exposure to CMV, as denoted by the presence of anti-CMV IgG antibodies in participants' sera, was observed. Anti-CMV IgM antibodies that denote active CMV infection were detected in the sera of 4.6% (n=35/524) study participants. Prevalence of CMV was also determined using real time PCR, CMV reactivation was higher (6.7%) when using PCR than when using immunological assays (4.6%). The presence of CMV DNA was significantly associated with HIV positivity (p=0.04). PCR is the gold standard for CMV diagnosis, thus, CMV DNA positivity was used to denote CMV infection status in this thesis. The second objective was to determine if the differential effect of CMV acquisition or reactivation among HIV infected participants was due to variability in plasma efavirenz containing antiretroviral therapy (ART) exposure. Efavirenz (EFV) plasma concentrations were determined using high performance liquid chromatography (HPLC). Single nucleotide polymorphisms (SNPs) in the CYP2B6 gene, which encodes the main EFV metabolizing enzyme were genotyped. Carriers of CYP2B6 poor metaboliser (PM) genotypes (c.516T/T and c.983T/C) had significantly higher mean plasma EFV concentration compared to carriers of CYP2B6 fast metabolizer genotypes (i.e., c.516G/G and c.983T/T). CYP2B6 PM genotype carriers were significantly less likely to be positive for CMV DNA when compared with fast metabolizer genotype carriers (pC (p=0.002), TLR7 rs179008A>C (pC (p=0.003). In contrast, presence of the IL6 rs10499563T>C polymorphism was inversely correlated with CMV infection (p=0.002). The reported genetic variants are reported to modulate proteins involved in immune responses against viral infections, thus, their association with susceptibility to CMV infection. Such findings may assist in the designing of a muchneeded candidate CMV vaccine. Lastly, we set out to determine the possible role of CMV infection in shaping gut microbiota profiles. We report on a significant difference (p=0.001) in the beta diversity of gut bacterial profiles between HIV- and age-matched CMV-infected (cases) and CMVuninfected (controls) participants. Using linear discriminant analysis (LDA) effect size (LefSe), significant differences in the relative abundance of specific bacterial taxa were observed between cases and controls (p2). Significantly lower abundance of Lactobacillus reuteri and Roseburia, genera associated with lower microbial translocation was observed in cases than controls. Lower relative abundance of Lactobacillus and Roseburia, is consistent with microbial translocation and heightened inflammation, respectively, hence higher likelihood of microbial translocation and inflammation occurring in cases than controls. Furthermore, Prevotella copri, a species that has been association with cytokine release and chronic inflammation was significantly more abundant in cases than controls. CMV is a known chronic inflammatory condition, and this study provides further confirmation through the higher relative abundance of P.copri in cases than controls. Biomarker identification has proven to be a successful means of translating molecular data into clinical practice, such as vaccine development in the case of CMV infection. Overall, this study reports the possible interaction of various host factors in facilitating CMV acquisition or reactivation during pregnancy. In the setting of HIV-CMV coinfection, our findings emphasise on the need for genotype guided drug dosage to achieve therapeutic EFV so as to maintain the balance between host and coinfecting microbes in HIV management. Comprehensive genotype guided drug dosage, if taken as a once-off test should be affordable especially in resource-limited settings. This is particularly important in pregnant women who are at a risk of vertically transmitting infection to the immunologically immature foetus and or neonate. Data from this study may assist in curbing the host associated challenges in designing an effective CMV vaccine. Moreover, the biomarkers reported may assist in diagnosis and management of potential CMV acquisition or reactivation during pregnancy. However, bigger prospective, functional studies would be needed to confirm the exact roles of the biomarkers identified in this study in the diagnosis, prognosis and therapeutics of CMV infection.

Brucellosis is a zoonotic disease caused by a Gram-negative coccobacillus. There are four Brucella strains of zoonotic importance in our domestic species, subdivided by their culture phenotypes: Brucella abortus (B. abortus, B. melitensis, B. suis (smooth strains) and B. canis (rough strain). Dogs can serve as hosts for all four of the zoonotic strains; however, routine serologic testing in dogs has been limited to the identification of antibodies to B. canis. The aim of our study was to identify a serologic test that can be utilized to identify smooth Brucella strain antibodies in canines. We hypothesize that the Brucella abortus Fluorescence Polarization Assay would be successful in identifying antibodies to smooth Brucella strain in canines. Ninety-five dogs, including forty-five hog hunting dogs were screened for circulating antibodies to any of the four zoonotic strains of the bacteria utilizing a combination of Canine Brucella Slide Agglutination Test (CBSA), Brucella canis Agar Gel Immunodiffusion II test (AGID), Brucella abortus Card Agglutination Test (BCA), and the Brucella abortus Fluorescence Polarization Assay (FPA). Test interpretation results yielded a 0% (0/95) smooth Brucella strain seropositivity rate, with 2% (2/95) of dogs yielding inconclusive rough Brucella strain serology results (0-2% rough strain seropositivity rate). Additionally, a retrospective portion of the study was performed to identify sera containing circulating antibodies to any of the smooth strains of Brucella by testing previously banked canine serum samples stored at Cornell's Veterinary Diagnostic Laboratory from 2018-2019 via Brucella abortus FPA. Of the 769 serum samples tested, 13/769 (1.7%) yielded an inconclusive result, 725/769 (94.2%) were negative, 30/769 (4%) yielded a positive FPA test result, and 1/769 (0.1%) had to be excluded due to insufficient sample remaining to perform the diagnostic test. Of the 30 FPA positive canine serum samples, 97% (29/30) also tested positive on the CBSA test. Additionally, there was a statistically significant (p <0.0001) likelihood of altered (spayed/neutered) and mixed breed dogs to be FPA positive when compared to intact, purebred dogs. / Master of Science / Brucellosis is a bacterial disease that can cause severe reproductive, orthopedic and general illness in both dogs and humans. There are four different species of Brucella that can be transmitted between animals and people: Brucella canis, abortus, suis, and melitensis. Although Brucella canis is the species that is widely recognized and breeding dogs are routinely tested for this strain, we have vastly under recognized the ability for dogs to contract and transmit the other three (smooth) Brucella species. Of added concern is the fact that the test currently used to screen dogs for brucellosis only identifies Brucella canis infection. Thus, veterinarians may be missing cases where dogs are infected with other Brucella species. This study revealed promising evidence in identification of smooth Brucella strain antibodies in canines, particularly altered and mixed breed canines, via the Brucella abortus Fluorescent Polarization Assay. The contributions of this study are threefold. First, to heighten awareness that both smooth and rough strains of brucellosis infection in dogs are infectious diseases of zoonotic concern. Second, it demonstrates that smooth Brucella strain infection along with the traditional strategy of selectively screening dogs breeding dogs may be underestimating the prevalence of brucellosis among the canine population in the United States thus, supporting the need for broadened screening recommendations. Third, it reveals the need for a commercially-available, validated test for the smooth strains of brucellosis in dogs and offers direction for future research efforts to likely focus on the validation of the Brucella abortus Fluorescent Polarization Assay.

No description available.

Contagious bovine pleuropneumonia (CBPP) is a bovine bacterial disease of major economic importance in sub-Saharan Africa. Vaccination has been recommended to control the disease in endemic areas such as the Maasai ecosystems of Kenya and Tanzania; however, the currently used live attenuated vaccine has been reported to have poor vaccine safety and efficacy. To compare standard (current) and an improved (buffered) version of the live CBPP-vaccine, several epidemiological studies were carried out in Maasai cattle in Kenya between 2006 and 2008. Specifically, the aims were to estimate CBPP seroprevalence at herd and animal level; to identify risk factors for seroprevalence at both levels; to investigate the spatial distribution of seroprevalence; to compare post vaccination adverse events in cattle vaccinated with a standard and a buffered vaccine, and finally to compare efficacy of the two vaccines to induce seroconversion and to prevent development of clinical signs suggestive of CBPP. A cross-sectional study was carried out in 6872 cattle in 175 randomly selected herds from Loita and Mara divisions. A competitive ELISA revealed that 85% of the herds in the area had at least one seropositive animal and that seropositive herds were harbouring 11% seropositive cattle. A complement fixation test revealed that 46% of the herds had at least one seropositive animal and that seropositive herds were harbouring 4% seropositive cattle. A multivariable logistic regression analysis of the seroprevalence indicated that previous vaccination against CBPP, a history of CBPP outbreaks in the herd, animal age and the location of the herd in the division of Mara were positively correlated to seroprevalence. To investigate the observed difference in herd seroprevalence between the two divisions further, a spatial analysis was conducted. A SatScan test revealed clusters in Mara in areas identified by veterinary personnel as CBPP ‘hot spots’. A logistic regression using spatial information identified that location in the midland agro-ecological zone or close to a river and vaccination were positively associated with seroprevalence. To compare safety and efficacy of a standard and a buffered vaccine, two cohorts of approximately 40,000 cattle were used. The study showed that within 100 days post vaccination, 6.2 cattle per 1000 vaccinates developed adverse events, 4.1 of which were specifically attributable to vaccination and ranging from swelling of the tail to the tail sloughing off. This study revealed a slightly higher incidence of adverse events in cattle vaccinated with the buffered vaccine compared to the standard vaccine. A comparison of the efficacy of the two vaccines revealed that cattle vaccinated with the buffered vaccine had higher odds of seroconversion and lower odds of developing symptoms of CBPP, three and twelve months post vaccination respectively. The epidemiological studies conducted clearly show wide spread seroprevalence in the Maasai cattle. Given the (spatial) heterogeneity observed, control measures should probably be targeted in areas of increased risk (clusters). However, positive association of vaccination and seropositivity call for better diagnostics tests that can differentiate vaccinated from infected animals. Vaccination with buffered vaccine resulted in increased seroconversion, decreased clinical signs indicative of CBPP post vaccination and low seroprevalence post ‘outbreak’. Nevertheless, the increase in adverse events related to the buffered vaccine calls for further research into safer CBPP vaccines.