Protection of Cattle against Epizootic Bovine Abortion (EBA) Using a Live Pajaroellobacter abortibovis Vaccine.

Epizootic bovine abortion (EBA) is an arthropod-borne bacterial disease that causes significant economic loss for cattle producers in the western United States. The etiologic agent, Pajaroellobacter abortibovis, is an intracellular pathogen that has yet to be cultivated in vitro, thereby requiring novel methodologies for vaccine development. A vaccine candidate, using live P. abortibovis-infected cells (P.a-LIC) harvested from mouse spleens, was tested in beef cattle. Over the course of two safety studies and four efficacy trials, safety risks were evaluated, and dosage and potencies refined. No incidence of anaphylaxis, recognized health issues or significant impact upon conception rates were noted. Vaccination did result in subclinical skin reactions. Early fetal losses were noted in two trials and were significant when the vaccine was administered within 21 days prior to conception. Administration of the EBA agent (EBAA) vaccine as a single dose, at a potency of 500 P.a-LIC, 56 days prior to breeding, provided 100% protection with no early fetal losses. Seroconversion occurred in all animals following EBAA vaccination and corresponded well with protection of the fetus from epizootic bovine abortion.

Serological Evidence of Human Infection with Coxiella burnetii after Occupational Exposure to Aborting Cattle.

Cattle are broadly deemed a source of Coxiella burnetii; however, evidence reinforcing their role in human infection is scarce. Most published human Q fever outbreaks relate to exposure to small ruminants, notably goats. Anti-phase II C. burnetii IgG and IgM were measured by indirect fluorescent antibody tests in 27 farm and veterinary diagnostic laboratory workers to ascertain whether occupational exposure to cattle aborting due to C. burnetii was the probable source of exposure. Four serological profiles were identified on the basis of anti-phase II IgG and IgM titres. Profile 1, characterised by high IgM levels and concurrent, lower IgG titres (3/27; 11.1%); Profile 2, with both isotypes with IgG titres higher than IgM (2/27; 7.4%); Profile 3 with only IgG phase II (5/27; 18.5%); and Profile 4, in which neither IgM nor IgG were detected (17/27; 63.0%). Profiles 1 and 2 are suggestive of recent C. burnetii exposure, most likely 2.5-4.5 months before testing and, hence, during the window of exposure to the bovine abortions. Profile 3 suggested C. burnetii exposure that most likely predated the window of exposure to aborting cattle, while Profile 4 represented seronegative individuals and, hence, likely uninfected. This study formally linked human Q fever to exposure to C. burnetii infected cattle as a specific occupational hazard for farm and laboratory workers handling bovine aborted material.

Molecular and Serological Study of Neospora caninum Infection among Dogs and Foxes in Sanandaj, Kurdistan Province, Iran.

Neospora caninum, a protozoan parasite, causes abortions in cattle, as well as neurological disorders and reproductive problems in dogs. This study aimed to investigate the serological and the molecular prevalence of N.caninum among foxes and dogs using indirect fluorescent antibody test (IFAT) and nested-polymerase chain reaction (PCR). For this purpose, 288 and 95 both fecal and serum samples of dogs and foxes were collected, respectively, from around industrial and traditional dairy flocks in different parts of Sanandaj, Kurdistan Province, Iran, from 2013 to 2015. The sera were examined using IFAT, and fecal samples were microscopically assessed for detecting Neospora oocyst and by nested-PCR. The findings revealed that N.caninum seroprevalence were 4.86% and 4.21% in dogs and foxes, respectively. In addition, no Neospora oocysts were found microscopically and by PCR. Since this study is the first serological and molecular investigation of N.caninum among both dogs and foxes in Sanandaj, the findings of indicated that stray dogs is a main source of N.caninum infection in dairy farms in Sanandaj, Iran.

Molecular and serological detection of Babesia bovis- and Babesia bigemina-infection in bovines and water buffaloes raised jointly in an endemic field.

Babesia bovis and Babesia bigemina are causative agents of bovine babesiosis, a tick-borne disease of cattle in tropical and subtropical regions. Babesia spp. infection adversely affects cattle health and can be fatal resulting in considerable economic loss worldwide. Under endemic stability conditions, herds contain high numbers of chronically infected, asymptomatic carrier animals, in which no parasitemia is detected by microscopic blood smear examination. In addition to bovines, also water buffaloes are infected by both Babesia spp. commonly leading to a subclinical infection. The infection rate (by nPCR) and herd exposure (by IFAT) of bovines and water buffaloes reared under similar field conditions in an area of endemic stability were determined and compared. In order to optimize direct parasite detection, highly sensitive nPCR assays were developed and applied, allowing the detection of as little as 0.1 fg DNA of each Babesia pathogen. Significantly lower percentages (p<0.001) of seropositive water buffaloes compared to bovines were observed for B. bovis (71.4% vs. 98%) and B. bigemina (85% vs. 100%). Interestingly, in comparison, differences noticed between water buffaloes and bovines were considerably larger with direct parasite detection by nPCR (16.2% vs. 82.3% and 24% vs. 94.1% for B. bovis and B. bigemina, respectively). As expected, bovines subjected to monthly acaricide applications exhibited a significant lower infection rate as determined by nPCR than bovines not subjected to these measures (B. bovis 33.3% vs. 90.7%, p<0.001; B. bigemina 80% vs. 96.5%, p<0.001, for treated vs. untreated animals). Interestingly no differences between these groups were observed with respect to seropositivity, suggesting similar rates of parasite exposure (B. bovis 100% vs. 97.7%, p<0.001; B. bigemina 100% vs. 100%, p<0.001). Importantly, a significantly higher number of water buffaloes as determined by nPCR were infected when reared jointly with bovines not subjected to tick control than when reared jointly with bovines subjected to tick control (B. bovis 31.6% vs. 9.5%, p<0.01; B. bigemina 42.1% vs. 9.5%, p<0.01, for water buffaloes reared with untreated vs. treated bovines) and/or when reared without bovines (B. bovis 31.6% vs. 11.6%, p<0.01; B. bigemina 42.1% vs. 20%, p<0.01). An accumulation of seropositivity and a decline of infection rates were observed in older animals, while differences observed with regard to gender may warrant further investigation. In summary, our findings suggest that water buffaloes are much more capable to limit or eliminate Babesia infection, possibly due to a more capable immune defense. Furthermore, an increased Babesia spp. parasite reservoir of bovines seems to increase the infection rate of water buffaloes when both are reared on the same pasture.

Seroepidemiological aspects of Leishmania spp in dogs in the Itaguai micro-region, Rio de Janeiro, Brazil / Aspectos soroepidemiológicos de Leishmania spp em cães na microrregião de Itaguaí, Rio de Janeiro, Brasil

This study evaluated factors associated with the frequency ofLeishmania spp. antibodies in dogs residing in the Itaguai micro-region, State of Rio de Janeiro, Brazil. Blood samples were collected from 524 dogs. The serum samples were submitted to indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) forLeishmania spp. The frequency of seropositive dogs was 28.24% (n = 148) in the micro-region, and among the three municipalities within that region, the highest frequency (p < 0.05) was observed in Seropedica (59.46%), followed by Itaguai (29.05%) and Mangaratiba (11.49%). Regarding factors associated with the host, mongrel dogs and those over the age of two presented higher frequency of antibodies to Leishmaniaspp. (p < 0.05). Concerning factors related to the environment and habits of the animal, dogs residing in rural areas (FR = 1.67, p = 0.0002), living outside the residence (FR = 1.42, p = 0.0197), with access to forest, streams and pastures (FR = 2.81, p = 0.0007), remaining loose (FR = 1.66, p = 0.0073), and those that had no shelter (FR = 2.16, p < 0.0001) were more likely to be seropositive. Canine leishmaniasis is a disease with high occurrence in the Itaguai micro-region, and aspects such as the definition of breed, age, habits and care by owners showed significant association in this micro-region.

Este estudo avaliou os fatores associados à frequência de anticorpos específicos para Leishmania spp. em cães domiciliados na microrregião de Itaguaí, Rio de Janeiro. Foram colhidas amostras de sangue de 524 cães. As amostras de soro foram submetidas a reação de imunofluorescência indireta (RIFI) e ensaio imunoenzimático indireto (ELISA-teste) para Leishmania spp. A frequência de cães soropositivos foi de 28,24% (n = 148) na microrregião e, entre os três municípios avaliados, a maior frequência (p < 0,05) foi observada em Seropédica (59,46%), seguida de Itaguaí (29,05%) e Mangaratiba (11,49%). Em relação aos fatores associados ao hospedeiro, observou-se que cães sem raça definida e aqueles com idade acima de dois anos apresentaram maior frequência de anticorpos para Leishmania spp. (p < 0,05). Em relação aos fatores relacionados ao ambiente e ao hábito do animal, os cães residentes em áreas rurais (RF = 1,67, p = 0,0002), animais que vivem fora da residência (RF = 1,42, p = 0,0197), com acesso à mata, córregos e pastagens (FR = 2,81, p = 0,0007), que permanecem soltos (RF = 1,66, p = 0,0073), e aqueles que não possuem abrigo (RF = 2,16, p < 0,0001) apresentaram maior chance de serem soropositivos. A leishmaniose canina é uma enfermidade com elevada ocorrência na microrregião de Itaguai, e aspectos como definição racial, idade, hábitos e cuidados estabelecidos pelo proprietário mostraram associação significativa nessa microrregião.

Soroprevalência e fatores de risco para Babesia bovis em rebanhos leiteiros na região sul de minas gerais / Seroprevalence and risk factors for Babesia bovis in dairy cattle from region southern Minas Gerais state, Brazil

Conduziu-se este trabalho, com o objetivo de determinar a prevalência e os fatores de risco associados à soropositividade para Babesia bovis em 556 bovinos leiteiros procedentes de dez propriedades localizadas no sul de Minas Gerais, as quais foram divididas em dois grupos de acordo com a produção média diária de leite: Alta Produção (AP) >2.000 l de leite/dia, e Baixa Produção (BP) 500 l de leite/dia. Os soros foram submetidos à reação de imunofluorescência indireta (RIFI) para pesquisa de anticorpos anti-B. bovis e considerados positivos na diluição de 1:320. A análise estatística foi realizada no programa SPSS 12.0 for Windows e se buscou determinar a associação entre níveis de positividade para B. bovis nos rebanhos e os fatores de risco por meio do Teste Exato de Fischer. Para testar a diferença das médias de soropositividade, foi utilizado o teste T Student e em todos os cálculos considerou-se o grau de significância de 95 por cento. A prevalência média global de bovinos infectados por B. bovis foi de 94,1 por cento (523/556). Não houve diferença significativa na frequência média de anticorpos anti-B. bovis entre as propriedades leiteiras dos grupos de AP (95,97 por cento) e BP (92,22 por cento); e o mesmo resultado foi observado entre os animais jovens e adultos de ambos os grupos. Não foi observada associação significativa entre os fatores de risco avaliados e a taxa de bovinos positivos para B. bovis. A alta prevalência de rebanhos leiteiros soropositivos permite caracterizar, epidemiologicamente, a microrregião de Lavras, sul de Minas Gerais, como área de elevada estabilidade endêmica para B. bovis.

The objective of this study was to determine the prevalence and risk factors associated with Babesia bovis infection in 556 dairy cattle from ten properties located in southern Minas Gerais State, Brazil. The herds were divided into two groups according to average daily milk production (liters): I- High Production (HP), >2,000 L milk/day; and II- Low Production (LP), d"500 L milk/day. The serum samples were submitted to the indirect fluorescent antibody test (IFAT) for antibodies anti-B. bovis and they were considered positive at a dilution of 1:320. The statistical analysis was performed using SPSS 12.0 for Windows. It was stated the association between positivity levels for B. bovis in dairy herds and the risk factors (farm size, production system, breed and feeding system) by Fisher exact test. The average prevalence of cattle with B. bovis infection was 94.06 percent (523/556). There was no significant difference (p>0.05) in the average frequency of antibodies anti-B. bovis between the groups of HP (95.97 percent) and LP (92.22 percent), and similar results were observed between young or adult cattle for both groups. The association between risk factors and seroprevalence of B. bovis has not been previously reported (p>0.05). The high prevalence of seropositive dairy herds allows to characterize epidemiologically the microregion of Lavras, south of Minas Gerais State, an area of enzootic stability to B. bovis.

Malaria Situation and Evaluation on the Control Effect in Henan Province during 1990-2005 / 中国寄生虫学与寄生虫病杂志

Objective To analyze malaria situation and evaluate the effect of control program in Henan Province during 1990-2005. Methods Data were collected and analyzed on the measures and effects of malaria control, vector surveillance, blood examination for cases with fever and serological surveillance in the province during 1990-2005. Results In the 16 years, a total of 802 700 people were given pre-transmission season treatment with chloroquine and primaquine for a radical cure of vivax malaria, chemoprophylaxis was given to 764 300 people at high risk during the transmission season, treatment or presumptive treatment was given to 43 891 cases. 11 216 100 cases with fever were tested and 11 213 (0.10%) were found positive accounting for 29.01% (11 213/338 654) of all malaria cases. A total of 1 332 800 bed nets were treated with insecticide and 1 999 300 people were protected in 1990-1992 and 1996-1999. 34 846 residents including pupils were tested with IFAT in 1990-2000 and 1149 (3.30%) were positive. The parasite rate amongst 71 234 local residents including pupils was 0.40% (286/71 234). The principal transmitting vectors were Anopheles sinensis and An.anthropophagus. The man-biting habit for An. sinensis and An.anthropophagus was 0.060 8 and 0.314 3 respectively, and the vectorial capacity of An.anthropophagus was 22.4 times higher than that of An.sinensis. In this period, 38 654 malaria cases were reported in the province and the annual malaria incidence was 2.62 per hundred thousand, the lowest annual incidence was in 1992 (0.37 per hundred thousand). 70.05% (27 076/38 654) of these malaria cases were from areas where An. anthropophagus was present. Conclusions In general, the malaria control activities have been effective and the epidemiological situation kept stable in Henan Province, although in some areas the situation is unstable and outbreak spots or focal epidemics occur.