Anna Monteiro Correia Lima-Ribeiro

Seroprevalence and risk factors for Leptospirosis in goats in Uberlândia, Minas Gerais, Brazil

The prevalence of Leptospirosis in goat herds of the State of Minas Gerais has seldom been studied. The present research had as its objectives: (1) investigate the seroprevalence of Leptospirosis in the county of Uberlândia, MG, (2) verify the Leptospirosis serovars, and (3) identify the risk factors associated with infection on the farms examined. Serum samples from 230 animals in 11 properties were tested using the microscopic agglutination test. An epidemiological examination furnished data for analysis regarding the risk factors. The prevalence of Leptospirosis was found to be 31.3% with variation from 1:100 to 1:800. The most frequent serovars were: Autumnalis (30.30%), Tarassovi (19.20%), Pyrogenes (13.13%), and Icterohaemorrhagiae (11.11%). The ages and races of the animals were among the risk factors found to be significantly correlated (P < 0.05) with infection. At the farm level, the intensity of production, use of salaried workers, and association of other animals were all found to be related with the frequency of Leptospirosis. The results demonstrated that inadequate management was a factor which favored the occurrence of infection in the region of the study.

Sorovares de Leptospira spp. predominantes em exames sorológicos de caninos e humanos no município de Uberlândia, Estado de Minas Gerais

INTRODUCTION:This study aimed to verify the occurrence of the principal Leptospira spp. serovars in domestic dogs and humans, notified in 2008, and the main risk factors in a geographic approach to the disease in the City of Uberlândia, State of Minas Gerais, Brazil. METHODS: Canine blood serum samples (n=268) from different districts, belonging to the Northern, Southern, Eastern, Western and Central Sanitary Districts of Uberlandia, were collected during an animal vaccination campaign against rabies, in August 2008. A geographic approach to the city was conducted, including evaluation of locations in peripheral areas, waste landfills, garbage collection, rodent notification, human leptospirosis cases and overflow flood areas, during 2008. Leptospirosis was diagnosed using the microscopic agglutination test (MAT), the gold standard for animal and human leptospirosis diagnosis. RESULTS: Dogs mainly reacted to Autumnalis (34.2%) and Tarassovi (23.7%) serovars, while in humans, predominance of Tarassovi serovars occurred in the cases registered. The occurrence of these serovars could be related to an infection source common to both species, or dogs could be the infection source for humans. The Eastern Sanitary District showed a greater number of reactive dogs. CONCLUSIONS: Leptospirosis occurred in dogs and humans of the City of Uberlandia in 2008. This often neglected disease must be prevented because represents a public health risk and resembles other endemic illness like dengue.

Prevalence of Neospora caninum antibodies in sheep flocks of Uberlândia county, MG

Neosporosis is a parasitic disease that occurs in sheep and is associated with reproductive failure. The aim of this study was to verify seroprevalence of Neospora caninum antibodies in 12 sheep flocks in Uberlândia county, Minas Gerais, Brazil, using Indirect Immunofluorescence Assay (IFA). A total of 334 sheep blood samples were analyzed and an epidemiologic questionnaire was applied for each farm in order to correlate with risk factors of neosporosis: gender, age, breed, abortion problems, contact with cattle and dogs, and presence of wild canids. The prevalence of Neospora caninum antibodies in sheep was 8.1%, with titers ranging from 50 to 3200 and 83.3% of farms detected at least one ovine reactive. There was statistically significant difference in flocks with abortion problems associated with the presence of Neospora caninum antibodies (p < 0.05).

Seroprevalence and risk factors of antibodies against Leptospira spp. in ovines from Uberlândia municipality, Minas Gerais state, Brazil

The objectives of the present study were to verify the seroprevalence of anti-Leptospira spp. antibodies, identify the most frequent serovars and the risk factors associated with the infection in Uberlândia, Minas Gerais, Brazil . A total of 334 ovines blood samples were collected in 12 farms from Uberlândia municipality to be evaluated by means the Microscopic Agglutination Test (MAT) against 22 serovars of Leptospira spp. and an epidemiologic questionnaire was applied for each farm in order to correlate with risk factors of leptospirosis: sex, age and breed as well as contact with cattle, contact with dogs and presence of rodents. The prevalence of seropositive to MAT was found in seventy four ovines (22.2%; CI 95% 17.6-26.4%), with titers ranging from 100 to 3200. The most frequent serovars identified were: Hardjo, Autumnalis, Hardjo and Wolffi association and Grippotyphosa. Statistically significant differences were found in males, pure breeds and presence of rodents (p<0.05). The prevalence of anti-Leptospira spp. antibodies found in the present study demonstrated that this bacterium occurs in ovines of Uberlândia municipality, MG, Brazil . The need for the adoption of efficient management for the control of rodents and infection in ovines in order to avoid leptospirosis in the local flocks and future transmission to humans.

Pesquisa de anticorpos anti-Brucella abortus e anti-Brucella ovis em ovinos no município de Uberlândia, MG

The first epidemiologic inquiry to Brucella abortus (B. abortus) and Brucella ovis (B. ovis) was carried out in sheep from Uberlândia county, MG. A total of 334 blood serum samples of sheep from both sexes and different ages and breeds were collected in 12 farms. An epidemiologic questionnaire was applied for each farm. Tests for B. abortus and B. ovis antibodies were Buffered Acidified Antigen and Complement Fixation, respectively. None of the sheep was reactive to B. abortus and B. ovis; however, the adoption of sanitary measures is important to avoid the introduction of infections caused by these bacteria.

Interference in diagnostic tests for brucellosis in cattle recently vaccinated against leptospirosis

The aim of the current study was to verify if cattle vaccinated against leptospirosis may react in diagnostic tests for brucellosis. Sixty cows were divided into 5 groups, each comprising 12 animals. Four groups were given different vaccines against leptospirosis, while the control group received only saline. Two doses of vaccine were given, as recommended by the manufacturers. Serum samples were collected on the first day of immunization (day 0) and on postvaccination days 7, 14, 21, 28, 35, 42, 49, 56, 96, and 126. All the serum samples were tested for brucellosis and leptospirosis. Twenty animals were reactive at least once to the Rose Bengal test, but by day 96, no further reactions were elicited by this test. Twenty-six samples were reactive to the Rose Bengal test, but only 7 remained positive in confirmatory tests: 1 to the 2-mercaptoethanol test, 2 to the fluorescence polarization assay, and 6 to indirect enzyme-linked immunosorbent assays. None of the samples was reactive in the complement fixation test. None of the animals in the control group was reactive. A significant difference was found between the control group and the groups vaccinated against leptospirosis, according to Fisher exact test. However, the groups were found to respond independently of the vaccine brand. The results indicate that cattle vaccinated against leptospirosis may show reactivity on screening tests for brucellosis.

Cinética da resposta imune humoral de cães jovens imunizados contra Leptospira interrogans

The objective was to analyze the humoral immune response against Leptospira interrogans using the microscopic agglutination test (MAT) in 26 young dogs, and 17 mixed breed (Group A) and nine mixed breed (Group B) of both sexes, pertaining to kennels and home environments in Uberlandia, Minas Gerais. Dogs were vaccinated with commercial inactivated polyvalent bacterin with Canicola, Grippotyphosa, Icterohaemorrhagiae and Pomona serovars. The immunization schedule was based on three immunizations. The first vaccination was performed at forty-five days of age, considered day zero, and after two boosters at intervals of thirty days each. Seven blood samples from each dog were made from time zero up to 180 days post-vaccination, at intervals of thirty days each. Titles have not been detected pre-vaccination against serovars Canicola, and Icterohaemorrhagiae Grippotyphosa on day zero. Only one dog in group A was reactive with a titer of 1:100 against Pomona in the first harvest. There was no statistical difference between the agglutinating titers between Groups A and B (p>0.05) induced by commercial vaccine used, except at harvest II (p<0.05), in which the group B presented evidence to serovar Autumnalis in all dogs evaluated, whereas in group A, 64.7% of dogs were not reactive to any serovar tested. There were on the 30th title to serovar Autumnalis that persisted until 180 days post-vaccination in both groups, varying only the intensity of immune response without significant statistical difference. To assess the efficiency of vaccine culture anti-Leptospira this research to warn the risks infection that dogs are vaccinated annually submitted.

Occurrence of antibodies against Leptospira spp. In free-ranging wild canids from the Brazilian savanna

The Brazilian savanna, also known as Cerrado, is one of the worlds richest and most ecologically invaluable tropical savanna regions. There are few studies in Brazil about the diseases that affect the wild canids of this biome, which may be harmful to wildlife populations and public health. The aim of this study was to evaluate the occurrence of antibodies against Leptospira spp. in three Cerrado wild canids species using the microscopic agglutination test (MAT). Serum samples were tested from 19 crab-eating foxes (Cerdocyon thous), 14 maned wolves (Chrysocyon brachyurus), and seven hoary foxes (Lycalopex vetulus), all free-ranging animals found in the municipalities of Araguari and Uberlândia, Minas Gerais State, and Cumari, Goias State, Brazil. Fourteen (35%) of these samples were seropositive. The most frequent serovars detected in the samples were Copenhageni and Hardjo, but reactions to the serovars Autumnalis, Grippotyphosa, Hebdomadis, Wolffi, and Icterohaemorrhagiae also occurred. Notwithstanding other reported results, this study is the first to report the presence of antibodies against Leptospira spp. in L. vetulus. The three species of wild canids examined may act as potential hosts for several serovars of leptospira in Brazils savanna environment.

Frequência de lesões macroscópicas em carcaças de bovinos reagentes ao teste tuberculínico

The aim of this study was to analyze the frequency of macroscopic lesions suggestive of tuberculosis in cattle reacting to the tuberculin test. Cattle of this study were from dairy herds located in the cities of Perdizes, Patos de Minas, Lagoa Formosa and Uberlândia, Minas Gerais, Brazil. We evaluated 140 cattle carcasses positive to the cervical comparative intradermal tuberculin test. During the slaughter a post-mortem inspection of carcasses was done, and the lesions suggestive of tuberculosis were recorded. We evaluated the mediastinal lymph nodes, liver, lung and carcass. Of the 140 cattle examined, 78 (55%) carcasses had some kind of macroscopic lesions suggestive of tuberculosis, 38 (49%) occurred only in the mediastinal lymph nodes, 22 (28%) in the liver and 11 (14%) in the lungs; 5 (6%) carcasses showed lesions in liver, lungs and lymph node, and 2 (4%) showed lesions in lung and lymph nodes. We concluded that lesions that were not visualized in bovine tuberculin skin test reagents may occur and are related mainly to the stage of the disease, insufficient time to detect the lesions, and nonspecific reactions to other mycobacteria.

Produção e purificação de imunoglobulinas Y policlonais anti-Leptospira spp.

The aim was to determine whether hens immunized with an inactivated suspension of Leptospira and a solution of outer membrane proteins extracted from the serovar Hardjo, could produce specific polyclonal antibodies to Leptospira, detected in ELISA assay. Eight hens White Leghorn race with 25-weeks-old were immunized, three with an inactivated suspension of Leptospira, three with a solution of outer membrane proteins (OMP) extracted from the serovar Hardjo and two controls immunized with saline. Blood samples were collected fortnightly and eggs daily. The IgY was purified from the egg yolk using the method for the delipidation of dilution with water acidic and ammonium sulfate precipitation. The ELISA assay was performed to verify the specificity of the IgY, these was possible to observe the production of specific antibody to Leptospira both in serum and purified egg yolk. The specific antibody titers peaked in the fifth week post immunization. The production of polyclonal IgY was effective for producing high titers of specific antibodies.