Abortion outbreak caused by Campylobacter fetus subspecies venerealis and Neospora caninum in a bovine dairy herd

In November 2015, an abortion outbreak occurred in a commercial dairy herd of 650 Holstein cows in Florida department, Uruguay. Forty-five (45) cows aborted within 3 wk. Five fetuses were subjected to gross and microscopic pathologic examination, and microbiological testing. One fetus had fibrinous epicarditis and peritonitis, and neutrophilic bronchopneumonia. Campylobacter fetus subsp. venerealis was detected by direct immunofluorescence, isolated and identified by PCR and sequencing of the 16S rDNA in the abomasal fluid and/or lung. Histologic examination of two other fetuses revealed nonsuppurative necrotizing encephalitis, lymphohistiocytic myositis and myocarditis, and lymphocytic interstitial nephritis. In these fetuses, N. caninum antigen was detected intralesionally by immunohistochemistry, and N. caninum DNA was amplified by PCR on formalin-fixed paraffin-embedded brain. Antibodies against N. caninum were detected by indirect immunofluorescence in 10 of 27 cows, with titers ranging from 1/200 to 1/3200. The results indicate that two abortigenic microorganisms may coexist and cause contemporaneous abortion in a herd. It is relevant to highlight the importance of performing multiple diagnostic tests in various aborted dams and fetuses from the same herd for the etiologic confirmation of bovine abortion syndromeEn noviembre de 2015 ocurrió un brote de abortos en un hato lechero comercial de 650 vacas Holstein en el departamento de Florida, Uruguay. Cuarenta y cinco (45) vacas abortaron en un lapso de 3 semanas. Cinco fetos fueron sometidos a un examen patológico macro y microscópico y a pruebas microbiológicas. Un feto tenía epicarditis fibrinosa y peritonitis, así como bronconeumonía neutrofílica. Se detectó Campylobacter fetus subesp. venerealis utilizando inmunofluorescencia directa; se lo aisló e identificó mediante PCR y secuenciación del 16S rDNA en el líquido abomasal y en el pulmón. El examen histológico de otros dos fetos reveló encefalitis necrotizante no supurativa, miositis linfohistiocítica y miocarditis, y nefritis linfocítica intersticial. En estos fetos se detectó intralesionalmente el antígeno de N. caninum mediante análisis inmunohistoquímico, y se amplificó el ADN de N. caninum mediante PCR en tejido cerebral fijado con formalina y embebido en parafina. Se detectaron anticuerpos contra N. caninum mediante inmunofluorescencia indirecta en 10 de 27 vacas, con títulos de entre 1/200 y 1/3200. Los resultados indican que dos microorganismos abortígenos pueden coexistir y provocar abortos contemporáneos en un hato. Subrayamos la importancia de realizar pruebas diagnósticas múltiples en diversas madres abortadas y fetos del mismo hato para obtener una confirmación etiológica del síndrome de aborto bovino.EEA BalcarceFil: Macías-Rioseco, Melissa. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Caffarena, Rubén D. Instituto Nacional de Investigación Agropecuaria; Uruguay. Universidad de la República, Facultad de Veterinaria; UruguayFil: Fraga, Martín. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Silveira, Caroline. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria; Uruguay. University of Minnesota, Veterinary Population Medicine Departament; UsaFil: Cantón, Germán. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Hecker, Yanina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Suanes, Alejandra. Ministerio de Ganadería Agricultura y Pesca. Montevideo. Dirección de Laboratorios Veterinarios; Uruguay.Fil: Riet-Correa, Franklin. Instituto Nacional de Investigación Agropecuaria; Urugua

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