Clebert José Alves

Soroprevalência e fatores de risco para a leptospirose em cães de Campina Grande, Paraíba

The prevalence of leptospirosis was investigated in dogs from Campina Grande city, State of Paraiba, Brazil, and the risk factors for infection were analyzed. Two hundred and eighty five blood samples were collected from dogs during the rabies vaccination campaign, in September 2003. The diagnostic method run for leptospirosis was the microscopic agglutination test, using a batch of 22 leptospiral serovars. The most prevalent serovar was found crossing the results of frequency and titer of agglutinins. The prevalence was 21.4% (95% CI = 16.8%-26.6%) and most frequent reactant serovars were autumnalis (7.4%), copenhageni (6%) and canicola (2.1%). The multivariate logistic regression analysis showed that the risk factors for leptospirosis were: age older than one year (odds ratio = 3.00; P = 0.006), mixed breed (odds ratio = 4.02; P = 0.011) and occurrence of floods in the area (odds ratio = 2.32; P = 0.039).

Prevalence and risk factors for anti-Toxoplasma gondii antibodies in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil

The prevalence and risk factors for anti-Toxoplasma gondii antibodies were investigated in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil. Three hundred and sixty-six blood samples from goats collected by jugular venopuncture were used. For the serologic diagnosis of Toxoplasma gondii infection, the indirect fluorescent-antibody test (IFAT) with cut-off value 1:64 was carried out. The prevalence of anti-T. gondii antibodies was 30.6% [95% CI=25.9-35.6%] with titers ranging from 1:64 to 1:16,384. The multivariate logistic regression analysis showed that the risk factors associated to anti-T. gondii antibodies were presence of cats in the herd, extensive/semi-intensive management systems and lack of mineral supplementation.

Soroprevalência de leptospirose em cães errantes da cidade de Patos, Estado da Paraíba, Brasil

This work aimed to survey the prevalence of leptospirosis in stray dogs from Patos city, state of Paraiba, Brazil. This study was held during the period of February to April of 2003, when 130 serum samples were collected. The diagnostic method run for leptospirosis was the microscopic agglutination test, using a batch of 22 leptospiral serovars. The most prevalent serovars were found crossing the results of frequency and titer of agglutinins. The results obtained indicated a prevalence of 20% and most frequent reactant serovars were autumnalis (20%), pomona (17,5%), grippotyphosa (10%) e patoc (10%).

Inquérito soro-epidemiológico e fatores de risco associados à infecção por Brucella ovis em carneiros deslanados do semi-árido da Paraíba

A sero-epidemiological survey was conducted to determine the prevalence and distribution of Brucella ovis infection in rams in the state of Paraiba, northeastern Brazil. The risk factors for the infection were also verified. Serum samples from 498 rams, 8 months of age or older, of 283 sheep herds in the Sertao Paraibano and Borborema mesoregions were investigated. All sera were examined by AGID test (screening test) and CFT (confirmatory test). From the total of examined herds, 8.59% (95% CI = 5.83%-12.48%) were seropositive for Brucella ovis. The prevalence of seropositive rams was 5.57% (95% CI = 3.86%-7.97%). The seropositivity was lower in herds where cleanliness was frequently made (p< 0.05).

Inquérito sorológico e fatores de risco para a brucelose por Brucella canis em cães do município de Santana de Parnaíba, Estado de São Paulo

The prevalence of brucellosis due to Brucella canis was investigated in dogs of the Santana de Parnaiba county, State of Sao Paulo, southeastern Brazil, and the risk factors for infection were analyzed. For this purpose, 410 blood samples were collected from dogs during the rabies vaccination campaign, in August 1999. The agar gel immunodiffusion test (AGID), using lipopolysaccharides and protein antigens from Brucella ovis, strain Reo 198, was applied first as a screening test on normal sera, and secondly, for confirmation. The same AGID test was applied to sera treated previously with 2-mercaptoethanol (ME-AGID). The complement fixation test (CFT), using B. ovis antigen, strain 63/290, was applied also as a confirmatory test. For the prevalence analysis, animals presenting positive results in both ME-AGID and CFT were considered positive. The prevalence of brucellosis due to B. canis was 2.2% (95% C.I.=1.01-4.13%). Dogs that were allowed by their owners to stay free outside their home had a higher risk for contracting B. canis infection, with an odds ratio value of 8.73 (95% C.I.=1.48-51.55) and p=0.04.

Flock-level risk factors associated with leptospirosis in dairy goats in a semiarid region of Northeastern Brazil.

A cross-sectional study based on a planned sampling was carried out to determine flock-level risk factors associated to Leptospira spp. infection in dairy goat flocks in a semiarid region of Northeastern Brazil. Serum samples from 975 adult dairy goats from 110 flocks were examined for Leptospira spp. antibodies by MAT using 24 serovars. A structured questionnaire focusing on risk factors for leptospirosis was completed for each flock. Of the 110 flocks 48 (43.6%; 95% CI: 34.2-53.4%) presented at least one seropositive animal, and most frequent serovar was Autumnalis (10.9%). Ninety-eight (8.7%; 95% CI: 5.7-12.9%; design effect=4.23) of the 975 goats tested seropositive at MAT, and serovar Autumnalis was also the most frequent (1.74%). Presence of rodents (OR=2.78; P=0.015) was identified as a risk factor. There was also association between history of infertility (OR=14.74; P=0.015) and prevalence of positive flocks. We suggest that a program of rodent control should be included in the flock management practices aiming to reduce transmission of the agent and then to reduce prevalence of positive flocks and occurrence of reproductive disorders such as impaired fertility.

Influência da via de inoculação sobre o estabelecimento e a evolução da leptospirose em hamsters (Mesocricetus auratus) experimentalmente infectados com Leptospira interrogans sorovar pomona

Foi investigada a influencia da via de inoculacao sobre o estabelecimento e a evolucao da leptospirose em hamsters (Mesocricetus auratus) experimentalmente infectados com Leptospira interrogans sorovar pomona. As vias de inoculacao ensaiadas foram: intraperitoneal, subcutânea, oral, conjuntival e escarificacao cutânea. O inoculo infeccioso foi constituido por uma cultura em meio de Fletcher, com 20 a 30 leptospiras por campo microscopio no aumento de 200 vezes. Os animais controle foram inoculados apenas com meio de Fletcher. Foram colhidas amostras de soro sanguineo e fragmentos de rins na fase agonica da doenca ou no 21o dia pos-infeccao, quando todos os animais foram sacrificados. Para a pesquisa de leptospiras, foi feito o exame direto com microscopia optica em campo escuro e cultivo em meio de Fletcher, pela tecnica das diluicoes seriadas. A deteccao de aglutininas anti-leptospiras foi realizada pela tecnica de soroaglutinacao microscopica. A instalacao e evolucao da leptospirose foram afetadas pela via de inoculacao. A via oral foi a menos efetiva em estabelecer a infeccao. Nao foi observada associacao estatistica entre a frequencia de portadores e a via de inoculacao.

Herd-level prevalence and associated risk factors for Mycobacterium avium subsp. paratuberculosis in cattle in the State of Paraíba, Northeastern Brazil

A cross-sectional study based on a planned sampling was carried out to determine herd-level and animal-level prevalences, and to identify risk factors associated with herd-level prevalence for bovine paratuberculosis in the State of Paraíba, Northeastern Brazil. The state was divided into three sampling groups: sampling stratum 1 (mesoregion of Sertão), sampling stratum 2 (mesoregion of Borborema), and sampling stratum 3 (mesoregions of Zona da Mata and Agreste). For each sampling stratum, herd-level and animal-level prevalences were estimated by a two-stage sampling survey. In the first stage, a pre-established number of herds (primary sampling units) were randomly selected; in the second stage, a pre-established number of cows aged ≥24 months were randomly selected (secondary sampling units). Ten animals were sampled in herds with up to 99 cows aged over 24 months; 15 animals were sampled in herds with 100 or more cows aged over 24 months; and all animals were sampled in those with up to 10 cows aged over 24 months. In total, 2504 animals were sampled from 480 herds. Enzyme-linked immunosorbant assay (ELISA) test kits were used for Mycobacterium avium subsp. paratuberculosis (MAP) antibody detection. A herd was deemed positive for the presence of MAP if it included at least one positive animal in herds of up to 24 females, and two positive animals in herds with more than 24 females. The herd-level prevalence in the State of Paraíba was 34.5% (95% CI=30.2-39.1%), 26.6% (95% CI=20.2-34.2%) in the region of Borborema, 30.5% (95% CI=23.9-38.0%) in Agreste/Mata, and 41.4% (95% CI=34.0-49.1%) in Sertão. The animal-level prevalence was 10.7% (95% CI=7.3-15.4%) in the State of Paraíba, 7.9% (95% CI=5.2-11.7%) in the region of Borborema, 9.4% (95% CI=7.3-12.1%) in Sertão, and 13.9% (95% CI=6.2--28.3%) in Agreste/Mata. The frequency of seropositive animals per herd ranged from 6.7% to 100% (median of 20%). The risk factors identified were as follows: Sertão region (OR=1.9), more than 12 adult animals in the herd (OR=1.9), and not using maternity pens (OR=1.7). Our findings suggest that MAP herd-level seroprevalence in the State of Paraíba, Northeastern Brazil, is high, and support the idea that the use of maternity pens will be important for preventing transmission of MAP in the herds.

Isolation of rabies virus from the parotid salivary glands of foxes (Pseudalopex vetulus) from Paraíba State, Northeastern Brazil.

To determine the presence of rabies virus in the parotid salivary glands, 12 road-killed rabies-positive hoary foxes (Pseudoalopex vetulus) were tested by using the fluorescent antibody test (FAT) and mouse inoculation test (MIT). All 12 parotid salivary glands were positive for both tests, although in some cases several passages were required. The findings of this study support the importance of the hoary fox as rabies reservoir in the sem-iarid region of Paraíba State, Northeastern Brazil.

Ehrlichia canis in dogs in a semiarid region of Northeastern Brazil: Serology, molecular detection and associated factors

This study investigated infection by Ehrlichia spp. agents by PCR, immunofluorescence assay test (IFAT), and by Giemsa-stained blood smears in 108 dogs from a semiarid region of the state of Paraíba, Northeastern Brazil. Seventy-five (69.4%) of the 108 dogs were found to be seropositive to Ehrlichia canis, while only four dogs (3.7%) were positive in real-time PCR for E. canis. In six dogs (5.6%) E. canis-like morulae were observed in monocytes. Animals that stayed in environment whose floor was dried dirt, and dogs whose owners reported low frequency of cleaning the dog environment had higher (P<0.05) PCR positivity for E. canis. Increasing seropositivity was found in older dogs (P=0.012). This study provides the first molecular detection of E. canis in the semiarid region of Northeastern Brazil.