Parasitological, serological and molecular diagnosis of Dirofilaria immitis in dogs in Northeastern Brazil.

Dirofilaria immitis is a zoonotic filarid that mainly affects the domestic dog, causing a generally fatal chronic disease, known as heart worm disease. In addition to dogs, the parasite can affect wild canids, cats, and humans. Due to its importance to One Health, detection of parasitism by D. immitis in dogs can help the adoption of control measures that aim to reduce the occurrence of parasitosis in animals and humans. The detection of D. immitis is based on the use of parasitological, serological, and molecular methods, which vary in sensitivity and specificity. Therefore, the objective was to evaluate and compare the efficiency and performance of parasitological, serological, and molecular tests in the detection of D. immitis in dogs in Northeastern Brazil. Whole blood and serum from 140 dogs from the municipality of Sousa were used, varying between males and females; aged one to 17 years; pure and mixed breeds; domiciled and stray. Three microscopic parasitological techniques (MPT) were used: capillary blood smear (CBS), peripheral (PBS) and modified Knott test (MK) associated with the morphometric diagnosis of the microfilariae. For the detection of D. immitis antigens, a rapid immunochromatographic test (RIT) (ALERE Dirofilariose AG Teste kit®, Seogu-dong, Korea) was used, and polymerase chain reaction (PCR) as a molecular method. To evaluate the tests, PCR was considered the gold standard, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) values were calculated. To verify the agreement of the tests, the Kappa test was performed (p ≤ 0.05). From the 140 analyzed samples, 33.6% (48/140) presented microfilariae, antigen and/or parasitic DNA. 23.6% (33/140) were positive in the CBS; 25.7% (36/140) in the PBS; 29.3% (41/140) in the MK; 30% (42/140) in the RIT and 28.6% (40/140) in the PCR. All methods showed almost perfect agreement with PCR, high sensitivity (0.8-0.95), specificity (0.94-0.99), and values established with VPP (0.8571-0.9722) and VPN (0.9519-0.9797). The CBS and PBS showed less sensitivity and greater specificity. MK presented the highest sensitivity and RIT was the choice for hidden infections. Considering the occurrence of D. immitis in dogs in a non-coastal region of Northeastern Brazil, an epidemiological approach is recommended to identify risk factors for this zoonotic parasitosis.

High rate of feline immunodeficiency virus infection in cats in the Brazilian semiarid region: Occurrence, associated factors and coinfection with Toxoplasma gondii and feline leukemia virus.

To evaluate the occurrence of feline immunodeficiency virus (FIV) and factors associated with this and to demonstrate occurrences of coinfection with Toxoplasma gondii and feline leukemia virus (FeLV) in cats, a total of 103 blood samples were collected from owned cats, during home visits. To diagnose FIV and FeLV, immunochromatographic kit was used and serological diagnoses of T. gondii, the indirect immunofluorescence test was performed. The occurrence of FIV-seropositive cats was 23.3% (24/103) and the factor associated with infection was male sex. T. gondii seropositivity of 53.4% (55/103) was observed and 75% of FIV cases (18/24) were positive for T. gondii coinfection. Only 0.9% (1/103) was positive for FeLV. It can be concluded that the seroprevalence of FIV in cats in the Brazilian semiarid region is high and that FIV positive cats were also likely to be T. gondii seropositive, while FeLV had very low occurrence in the study region.

Vertical transmission of Toxoplasma gondii in naturally infected ewes in the semiarid region of Brazil.

To evaluate transplacental transmission of Toxoplasma gondii in naturally infected ewes, blood samples were collected from 55 pregnant ewes and their offspring, before ingestion of colostrum. From 16 offspring of positive ewes and nine offspring from negative ewes, blood samples were obtained after 48 h and 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. T. gondii antibodies were detected in serum samples using the indirect fluorescence antibody test (IFAT ≥ 64). Four of the 30 positive ewes (13.3 %) had offspring positive for T. gondii before ingesting colostrum (vertical transmission). The colostrum antibody titers decreased every week, and only 20 % (2/10) of the lambs in continued to present detectable antibody titers until day 56 after birth. Therefore, vertical transmission of T. gondii in lambs was indication of occur and is an important route for transferring and maintaining the agent in sheep herds in the Brazilian semiarid region.

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.

Leptospirose bovina no Estado da Paraíba: prevalência e fatores de risco associados à ocorrência de propriedades positivas / Bovine leptospirosis in Paraíba State: prevalence and risk factors associated with the occurrence of positive herds

Foram determinadas as prevalências de propriedades positivas e de animais positivos e identificados fatores de risco associados à leptospirose em vacas no Estado da Paraíba, Nordeste do Brasil. Foram aleatoriamente selecionadas 2.317vacas com idade ≥ 24 meses, procedentes de 450propriedades. Para o diagnóstico sorológico da infecção por Leptospira spp. foi empregado o teste de soroaglutinação microscópica (SAM), utilizando-se 24 sorovares como antígenos. Uma propriedade foi considerada positiva quando apresentou pelo menos um animal soropositivo. Das 450 propriedades investigadas 398 (89,7 por cento; IC 95 por cento = 86,6-92,2 por cento) apresentaram pelo menos um animal reagente na SAM para qualquer sorovar, e 1.349 (61,1 por cento; IC por cento = 56,6-65,4 por cento) animais foram soropositivos. O sorovar Hardjo foi o mais prevalente nas propriedades e nos animais, com frequências de 58,17 por cento e 54,69 por cento, respectivamente. Propriedade ser localizada no Sertão (odds ratio = 3,20; p = 0,003), presença de animais silvestres (odds ratio =2,89; p=0,005), não resfriar o leite (odds ratio =3,83; p=0,034) e presença de pastos alagados (odds ratio =2,36; p<0,001) foram identificados como fatores de riscos associados à prevalência de propriedades positivas. Conclui-se que a leptospirose encontra-se amplamente difundida em bovinos do Estado da Paraíba, o que reforça a necessidade de intensificação de medidas de prevenção e controle, como a vacinação dos rebanhos. De acordo com os resultados da análise de fatores de risco, sugere-se que o controle sanitário antes da introdução de animais, drenagem de áreas alagadas e melhora nas condições de manejo são importantes medidas para a prevenção da infecção.

Herd-level and animal-level prevalences were determined and risk factors associated with leptospirosis were identified in cows in the State of Paraíba, Northeastern Brazil. A total of 2,317 cows with ≥ 24 months of age from 450 herds were randomly sampled. For the serological diagnosis of Leptospira spp. infection, the microscopic agglutination test (MAT) was carried out using 24 serovars as antigens. A herd was considered positive when presented at least one seropositive animal. Of the 450 investigated herds, 398 (89.7 percent; 95 percent CI = 86.6-92.2 percent) presented at least one reactant animal at MAT to any serovar, and 1,349 (61.1 percent; 95 percent CI = 56.6-65.4 percent) animals were seropositive. Serovar Hardjo was the most prevalent in herds and animals, with frequencies of 58.17 percent and 54.69 percent respectively. Location of the herd in the Sertão (odds ratio = 3.20; p=0.003), presence of wildlife (odds ratio =2.89; p=0.005), not cooling milk (odds ratio =3.83; p=0.034) and presence of flooded pastures (odds ratio =2.36; p<0.001) were identified as risk factors for herd-level prevalence. It is concluded that leptospirosis is widely spread in cattle in State of Paraíba, which reinforces the need for increased prevention and control measures, such as vaccination of herds. According to the results of risk factors analysis it is suggested that the sanitary control before the introduction of animals, drainage of wetlands and improvement in management conditions are important measures to preventing the infection.

Seroprevalence and risk factors associated with Chlamydophila abortus infection in dairy goats in the Northeast of Brazil / Soroprevalência e fatores de risco associados com a infecção por Chlamydophila abortus em caprinos leiteiros do Nordeste brasileiro

Few data are available on the prevalence and risk factors of Chlamydophila abortus infection in goats in Brazil. A cross-sectional study was carried out to determine the flock-level prevalence of C. abortus infection in goats from the semiarid region of the Paraíba State, Northeast region of Brazil, as well as to identify risk factors associated with the infection. Flocks were randomly selected and a pre-established number of female goats > 12 mo old were sampled in each of these flocks. A total of 975 serum samples from 110 flocks were collected, and structured questionnaire focusing on risk factors for C. abortus infection was given to each farmer at the time of blood collection. For the serological diagnosis the complement fixation test (CFT) using C. abortus S26/3 strain as antigen was performed. The flock-level factors for C. abortus prevalence were tested using multivariate logistic regression model. Fifty-five flocks out of 110 presented at least one seropositive animal with an overall prevalence of 50.0% (95%; CI: 40.3%, 59.7%). Ninety-one out of 975 dairy goats examined were seropositive with titers >32, resulting in a frequency of 9.3%. Lend buck for breeding (odds ratio = 2.35; 95% CI: 1.04-5.33) and history of abortions (odds ratio = 3.06; 95% CI: 1.37-6.80) were associated with increased flock prevalence.

São escassos os trabalhos publicados sobre a prevalência e fatores de risco associados à infecção por Chlamydophila abortus em caprinos no Brasil. Foi conduzido um estudo transversal para determinar a prevalência de rebanhos positivos para a infecção por C. abortus em caprinos do semiárido do Estado da Paraíba, Nordeste do Brasil, bem como identificar os fatores de risco associados com a infecção. Os rebanhos foram selecionados aleatoriamente e um número pré-estabelecido de cabras com idade >12 meses foi amostrado por rebanho. No total, foi colhido sangue de 975 animais procedentes de 110 rebanhos, e no momento da colheita foi aplicado um questionário epidemiológico a cada proprietário. Para o diagnóstico sorológico foi utilizado o teste de fixação de complemento (FC) usando a estirpe de C. abortus S26/3 como antígeno. Os fatores de risco para a prevalência de C. abortus em nível de rebanho foram testados com o uso de modelo de regressão logística multivariada. Cinquenta e cinco rebanhos dos 110 analisados apresentaram pelo menos um animal soropositivo, com uma prevalência de 50,0% (IC 95%: 40,3-59,7%). Noventa e um animais entre os 975 examinados foram soropositivos com título >32, resultando em uma frequência de 9,3%. Compartilhar reprodutores (odds ratio = 2,35; IC 95%: 1,04-5,33) e histórico de abortamentos (odds ratio = 3,06; IC 95%: 1,37-6,80) foram associados com o aumento da prevalência de rebanhos.

Prevalência de leptospirose em caprinos leiteiros do semiárido paraibano / Prevalence of leptospirosis in dairy goats in the semiarid region of Paraíba state

Este trabalho teve como objetivos determinar a prevalência de propriedades de caprinos leiteiros positivas e de animais soropositivos para leptospirose no semiárido paraibano. A amostragem foi delineada para a determinação da prevalência de propriedades positivas (focos) e de animais soropositivos para a infecção por Leptospira spp. No total, foram colhidas amostras de sangue de 975 animais procedentes de 110 propriedades leiteiras localizadas no Munícipio de Monteiro, microrregião do Cariri Ocidental, Estado da Paraíba. Para o diagnóstico da infecção por Leptospira spp., foi utilizado o teste de soroaglutinação microscópica (SAM), utilizando como antígenos 24 sorovares. Uma propriedade foi considerada foco quando apresentou pelo menos um animal soropositivo. As prevalências de propriedades positivas e de animais soropositivos foram de 43,6% (IC 95% = 34,2-53,4%) e de 8,7% (IC 95% = 5,7-12,9%), respectivamente. Nos animais, os sorovares mais frequentes foram Autumnalis (1,74%; IC 95% = 0,97-3,09%), Sentot (1,71%; IC 95% = 0,82-3,52%) e Whitcomb (1,39%; IC 95% = 0,65-2,93%), e nas propriedades, os sorovares Autumnalis (10,9%; IC 95% = 5,8-18,3%), Whitcomb (8,2%; IC 95% = 3,8-15,0%) e Sentot e Patoc (7,3%; IC 95% = 3,2-13,8%) foram os mais frequentes. Sugere-se que a infecção está distribuída em caprinos da região, e que há necessidade de implantação de medidas de controle e prevenção, com o intuito de reduzir a ocorrência da infecção e, consequentemente, diminuir perdas econômicas ocasionadas e bloquear a possível transmissão do agente aos seres humanos.

This study aimed to determine the prevalence of positive dairy goat herds and seropositive animals for leptospirosis in the semiarid region of Paraíba state, Brazil. Sampling was designed to determine the prevalence of positive herds (foci) and seropositive animals for leptospirosis. A total of 975 serum samples were collected from goats of 110 dairy herds in the Monteiro municipality, Western Cariri microregion of Paraiba. For the serological diagnosis of leptospirosis the microscopic agglutination test (MAT) was carried out using 24 Leptospira spp. serovars as antigens. A herd was considered positive when existed at least one seropositive animal. The prevalence of positive herds and seropositive animals were 43.6% (95% CI = 34.2-53.4%) and 8.7% (95% CI = 58.7-12.9%) respectively. The most frequent serovars in goats were Autumnalis (1.74%; 95% CI = 0.97-3.09%), Sentot (1.71%; 95% CI = 0.82-3.52%) and Whitcomb (1.39%; 95% CI = 0.65-2.93%), and by herd, serovars Autumnalis (10.9%; 95% CI = 5.8-18.3%), Whitcomb (8.2%; 95% CI = 3.8-15.0%) and Sentot and Patoc (7.3%; 95% CI = 3.2-13.8%) were the most frequent. It is suggested that leptospirosis is spread in goats in the region, and that there is need to implement control and preventive measures in order to reduce infection and economic losses, and to avoid possible transmission of infection to humans.