Eduardo Bento Faria

Prevalence and risk factors associated to infection by Toxoplasma gondii in ovine in the State of Alagoas, Brazil

The aim of this study was to evaluate the prevalence of anti-Toxoplasma gondii antibodies and to identify risk factors associated to the infection in the three meso-regions of the State of Alagoas, Brazil. A total count of 23 towns and 27 meat sheep farms were visited where blood samples were collected in order to perform the indirect immunofluorescence test to evaluate the antibodies presence. Questionnaires exploring the production system and nutritional, sanitary, and reproduction handling were handed out. The prevalence rate was 32.9% and the number of foci was 100%. In the multivariate statistical analysis, there was a significant association for the following variables: age (OR = 4.01; C.I. 2.03–7.94), size of the property (or the farm; OR = 0.48; C.I. 0.26–0.90), semi-intensive rearing system (OR = 3.17; C.I. 1.24–8.13), running water source (OR = 3.13; C.I.–1.66–5.87), and presence of cats (OR = 1.72; C.I. 1.08–2.75). It is concluded that sheep of the three meso-regions of the State of Alagoas are exposed to the infection caused by T. gondii with high prevalence. Control and prophylactic measures must be adopted seeking the improvement of the rearing system and the implantation of health promoting programs in cooperation with sheep farmers in order to elucidate the transmission means of this disease.

Experimental infection by Toxoplasma gondii using contaminated semen containing different doses of tachyzoites in sheep

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii that affects reproductive performance in small ruminants. Although the T. gondii life cycle is well understood since 1960s, several aspects related to its infection remain unclear. In the present study we hypothesized that sheep inseminated with T. gondii-contaminated semen would develop toxoplasmosis. In order to test that hypothesis, 41 sheep were experimentally infected with semen spiked with the organism. Females were divided in three groups (G1-G3): (a) females in G1 group were inseminated with semen containing 6.5 x 10(4) tachyzoites; (b) females in G2 group with semen containing 4 x 10(7) tachyzoites; and (c) females in G3 group with tachyzoite-free semen (control group). To confirm T. gondii infection via semen, serological tests were performed using indirect immunofluorescence reaction and the detection of parasite DNA in the blood stream using the nested PCR test. While in G1 group only 5/15 (33.3%) of the females presented seroconversion, all sheep in G2 15/15 (100%) seroconverted. The nested PCR test showed that 14/15 (93.3%) of the females in the G1 and 14/15 (93.3%) in the G2 group were positive for T. gondii while in the G3 group all samples were negative. In addition, ultra-sound test evidenced that in sheep presented embryonic reabsorption in animals from the infected groups. In conclusion, insemination using fresh semen experimentally contaminated with different infectant doses of T. gondii tachyzoites was able to infect sheep, leading to the possibility of toxoplasmosis transmission via semen.

Occurrence of antibodies to Neospora caninum and Toxoplasma gondii in dogs from Pernambuco, Northeast Brazil

A serological survey was carried out to assess the occurrence of anti-Neospora caninum antibodies in dogs from the State of Pernambuco. A total of 625 serum samples of dogs (289 from Paulista, 168 from Amaraji and 168 from Garanhuns) were tested by an immunofluorescence antibody assay for the detection of anti-N. caninum antibodies. A total of 177 (28.3%; IC 95%, 24.9-32.1) samples were positive. The seropositivity rates found in Paulista, Amaraji and Garanhuns were 26% (IC 95%, 21-31.4), 26.2% (IC 95%, 19.7-33.5) and 34.5% (IC 95%, 27.4-42.2), respectively. Of the 177 serum samples positive to anti-N. caninum antibodies, 170 were additionally tested for the presence of anti-Toxoplasma gondii antibodies and out of these 57.6% (IC 95%, 49.8-65.2) were positive. The results indicate that dogs from Amaraji, Paulista and Garanhuns are exposed to both N. caninum and T. gondii infections. The presence of dogs infected by N. caninum in Pernambuco represents a potential risk factor for the occurrence of outbreaks of abortion in cattle and small ruminants in this state. This study is the largest serological survey on the presence of anti-N. caninum antibodies in dogs carried out in Brazil and reports for the first time the exposure to N. caninum and T. gondii in dogs from Pernambuco.

Risk Factors Associated with Neospora caninum Seropositivity in Sheep From the State of Alagoas, in the Northeast Region of Brazil

Abstract The aim of this study was to identify risk factors associated with Neospora caninum seropositivity in sheep from the State of Alagoas, in the northeast region of Brazil. Twenty-six herds were selected, and blood samples were collected from 343 animals > 6-mo-old. The indirect fluorescent antibody test (IFAT) was used for serological diagnosis of N. caninum infection. Epidemiological questionnaires were applied for each herd to identify the risk factors associated with infection. Thirty-three (9.6%) animals tested positive for anti–N. caninum IgG antibodies, with titers ranging from 1∶50 to 1∶1,600. Fourteen herds (53.8%) presented at least 1 seropositive animal. Risk factors identified were property size ≤ 30 ha (odds ratio  =  7.23; 95% CI  =  1.99–26.49) and source of water (wells + municipal + water courses) (odds ratio  =  4.76; 95% CI  =  1.23–18.47). This is the first ezootiological study of N. caninum infection in sheep to be carried out in the State of Alagoas. Preventive measures focusing primarily on water treatment should be taken to reduce the risk of infection by N. caninum.

Occurrence of antibodies to Toxoplasma gondii in mules and donkeys in the northeast of Brazil.

Abstract: The aim of the present study was to investigate antibodies to Toxoplasma gondii in the serum of mules and donkeys bred in the northeast of Brazil. In total, 483 samples were used (395 mules and 88 donkeys) from 4 states (Pernambuco, Rio Grande do Norte, Paraíba, and Sergipe). The indirect immunofluorescence reaction (IFI) technique was used to investigate antibodies to T. gondii with a cut-off point of 64. Positive frequencies of 23.8% and 43.2% were recorded for mules and donkeys, respectively. The state of Pernambuco had the highest prevalence of positive samples (29%) with statistically significant differences for species (P < 0.001) and state (P = 0.048). This is the first study of antibodies to T. gondii in mules and donkeys in these 4 states of the northeastern region of Brazil and serves as a warning to health authorities regarding the risks of ingesting equine meat.

Occurrence and risk factors associated with infection by Toxoplasma gondii in goats in the State of Alagoas, Brazil.

INTRODUCTION Goats are considered very susceptible to infection by Toxoplasma gondii and when this occurs during pregnancy, it may cause fetal death with subsequent fetal resorption, abortion, mummification, stillborn or the birth of weak goats. The objective of this work was to determine the occurrence of and identify risk factors for T. gondii infection in goats in different mesoregions in the State of Alagoas. METHODS The research was conducted on 24 goat breeding farms in 10 municipalities. A total of 454 blood samples were examined for anti-T. gondii antibodies by indirect immunofluorescence antibody test. To evaluate the risk factors of toxoplasmosis in goats, questionnaires were applied analyzing the farms production system and nutritional, reproductive and sanitary management. RESULTS Disease occurrence was 39% with 95.8% of farms presenting seropositive animals. Significant associations were observed for mesoregion (OR = 0.23; 95%CI = 0.09 - 0.57), age (OR = 0.36; 95%CI = 0.20 - 0.64), semi-intensive herd management (OR = 8.70; 95%CI = 1.87 - 40.43), access of cats to water provided for goats (OR = 3.38; 95%CI = 1.89-6.02) and cats feeding on placental remnants (OR = 2.73; 95%CI = 1.38 - 5.40). CONCLUSIONS Toxoplasma gondii infection is disseminated in the State of Alagoas and the adoption of a program that monitors infection foci is required to reduce the risk factors identified in the present study.

Anticorpos IgG anti-Neospora caninum e Toxoplasma gondii em búfalas (Bubalus bubalis) criadas no estado do Pará

To investigate the occurrence of antibodies IgG anti-Neospora caninum and Toxoplasma gondii, blood samples were collected from 374 adult female water buffaloes originated from 14 production units located in 13 counties of the state of Para. The sera were subjected to indirect fluorescent antibody (IFA), using titers of 200 and 64 as IFA cut off points for N. caninum and T. gondii, respectively. Hundred and fifty three (40.9%) buffaloes were sero-positive for N. caninum, with 100% of the properties being sources of infection. Four buffaloes (1.1%) in four farms were seropositive for T. gondii, and one buffalo cow (0.27%) was seropositive for the two parasites. The presence of antibodies indicates that these protozoan parasites are circulating among buffaloes from the properties studied, representing a source of infection to other animals, as well as a possible cause of reproductive disorders in this species.

Seroprevalence and risk factors associated with infection by Neospora caninum of dairy cattle in the state of Alagoas, Brazil

The objective of this study was to investigate the prevalence of anti-Neospora caninum antibodies in cattle from milk producing farms of the microregion of Batalha, state of Alagoas, Brazil, as well as to identify the risk factors associated with the infection. Blood samples were collected from 1,004 cattle of 17 farms for the serological investigation regarding the presence of anti-N. caninum antibodies by the Indirect Immunofluorescence Reaction Technique (IMRT). From the total amount of samples analyzed, 77/1,004 (7.67%) were positive and 927/1,004 (92.33%) were negative. The logistical regression identified that cattle from farms without consortium breeding have an infection risk 6.33 (p<0.001; C.I. 2.89-13.10) times higher than cattle from farms with that type of breeding. Cattle from farms where the aborted fetuses are not adequately buried have an infection risk 3.04 (p<0.001; C.I. 1.64-5.63) times higher than cattle from farms with adequate destination of these fetuses. Infection by N. caninum occurs in cattle of the investigated region. The factors identified in our study can be used as risk indicators, so that control measures could be implemented to avoid infection by N. caninum in the herds of this region.

Prevalência e fatores de risco associados à infecção por Toxoplasma gondii em granjas suinícolas tecnificadas no Estado de Alagoas

This study was aimed to determine the prevalence and to identify risk factors associated with infection by Toxoplasma gondii in pigs from commercial swine farms in the state of Alagoas, Brazil. To compose the sample size of prevalence 342 pigs were used, with 312 sows and 30 boars, from of seven swine farms and distributed in five districts of the state of Alagoas. The serological examination for the detection of anti-Toxoplasma gondii antibodies was achieved by Indirect Immunofluorescence (IFAT), using anti-pig IgG-conjugated to fluorescein isothiocyanate. The analysis of risk factors were performed by the application of questionnaires consisting of objective questions relating to the designer, the general characteristics of the property, the production, reproductive and health management. The prevalence was of 26,9% (92/342) of seropositive pigs. The associated factor was the boars introduction on farms in the last five years (p=0,014; OR=1,83; CI=1,13-2,96). It is concluded that infection with Toxoplasma gondii is widespread in commercial pig farms in the state of Alagoas, Brazil. The results suggest the control of cat population, the performance of cleaning and sanitation practices and laboratory testing to detect of infection by T. gondii in animals to be placed on the farms as measures to reduce the infection rates on region studied.

Comparação das técnicas de ELISA indireto e Imunofluorescência indireta na detecção de anticorpos anti-Neospora caninum em búfalas (Bubalus bubalis)

Para comparar dois testes sorologicos na deteccao de anticorpos anti-Neospora caninum em soros sanguineos de bufalas, foram coletados amostras de 288 bufalas entre dois a dez anos de idade. Para identificar a presenca de imunoglobulina G anti-N. caninum utilizou-se a reacao de imunofluorescencia indireta (RIFI), tendo o titulo 200 como ponto de corte, e o Ensaio Imunoenzimatico indireto (ELISA-indireto), considerando-se positiva as amostras que obtiveram razao S/P>0,5. Observaram-se 153 (53,12%) animais soropositivos para N. caninum, atraves da RIFI, enquanto que 50 (17,36%) animais foram reagentes no ELISA. A ocorrencia de anticorpos anti-N. caninum demonstram que o parasito esta circulando entre bufalas criadas no estado do Para, sendo que ambos os teste de RIFI e ELISA podem ser utilizados para diagnosticar imunoglobulinas contra este agente. No entanto observou-se uma fraca correlacao (Kappa=0,36) entre ambos os testes, considerando a RIFI como padrao ouro.