Survey of vector-borne agents in feral cats and first report of Babesia gibsoni in cats on St Kitts, West Indies

Background: As there is little data on vector-borne diseases of cats in the Caribbean region and even around the world, we tested feral cats from St Kitts by PCR to detect infections with Babesia, Ehrlichia and spotted fever group Rickettsia (SFGR) and surveyed them for antibodies to Rickettsia rickettsii and Ehrlichia canis. Results: Whole blood was collected from apparently healthy feral cats during spay/ neuter campaigns on St Kitts in 2011 (N = 68) and 2014 (N = 52). Sera from the 52 cats from 2014 were used to detect antibodies to Ehrlichia canis and Rickettsia rickettsii using indirect fluorescent antibody tests and DNA extracted from whole blood of a total of 119 cats (68 from 2011, and 51 from 2014) was used for PCRs for Babesia, Ehrlichia and Rickettsia. We could not amplify DNA of SFG Rickettsia in any of the samples but found DNA of E. canis in 5% (6/119), Babesia vogeli in 13% (15/119), Babesia gibsoni in 4% (5/119), mixed infections with B. gibsoni and B. vogeli in 3% (3/119), and a poorly characterized Babesia sp. in 1% (1/119). Overall, 10% of the 52 cats we tested by IFA for E. canis were positive while 42% we tested by indirect fluorescent antibody (IFA) for R. rickettsii antigens were positive. Conclusions: Our study provides the first evidence that cats can be infected with B. gibsoni and also indicates that cats in the Caribbean may be commonly exposed to other vector-borne agents including SFGR, E. canis and B. vogeli. Animal health workers should be alerted to the possibility of clinical infections in their patients while public health workers should be alerted to the possibility that zoonotic SFGR are likely circulating in the region

Detection of antibodies to Cowdria ruminantium in the serum of domestic ruminants by indirect ELISA

Un test ELISA a été mis au point pour la détection d'anticorps contre Cowdria ruminantium dans le sérum de ruminants domestiques. Les micro-organismes cultivés dans des cellules bovines endothéliales ombilicales ont été utilisés comme antigène. Lorsque la culture a montré une lyse à 90 p. 100, le surnageant a été centrifugé, soniqué et appliqué sur des plaques microtitres en polystyrène. Des anticorps ont été détectés à partir de 9 jours après immunisation expérimentale de chèvres. La sensibilité de l'ELISA, calculée sur 73 sérums de ruminants, se trouvait entre 97,3 et 98,6 p. 100. La spécificité globale du test était de 97 p. 100 (N = 2925). Néanmoins, la spécificité était beaucoup plus basse pour les ovins (94,4 p. 100, N = 881) que pour les caprins (98,6 p. 100, N = 651) et les bovins (97,8 p. 100, N = 1393). Des réactions croisées, qui peuvent expliquer certaines des réactions faussement positives, ont été trouvées entre l'antigène de Cowdria et des sérums contre Ehrlichia bovis (1 bovin positif sur 2 infectés expérimentalement) et E. ovina (2 moutons positifs sur 2 infectés), mais non pas contre E. phagocytophila. Les variabilités intra- et inter-test étaient respectivement de 7,5 et de 7,8 p. 100, ce qui montre une bonne reproductibilité de l'ELIS

Association between canine leishmaniosis and Ehrlichia canis co-infection: a prospective case-control study

Abstract Background In the Mediterranean basin, Leishmania infantum is a major cause of disease in dogs, which are frequently co-infected with other vector-borne pathogens (VBP). However, the associations between dogs with clinical leishmaniosis (ClinL) and VBP co-infections have not been studied. We assessed the risk of VBP infections in dogs with ClinL and healthy controls. Methods We conducted a prospective case-control study of dogs with ClinL (positive qPCR and ELISA antibody for L. infantum on peripheral blood) and clinically healthy, ideally breed-, sex- and age-matched, control dogs (negative qPCR and ELISA antibody for L. infantum on peripheral blood) from Paphos, Cyprus. We obtained demographic data and all dogs underwent PCR on EDTA-blood extracted DNA for haemoplasma species, Ehrlichia/Anaplasma spp., Babesia spp., and Hepatozoon spp., with DNA sequencing to identify infecting species. We used logistic regression analysis and structural equation modelling (SEM) to evaluate the risk of VBP infections between ClinL cases and controls. Results From the 50 enrolled dogs with ClinL, DNA was detected in 24 (48%) for Hepatozoon spp., 14 (28%) for Mycoplasma haemocanis, 6 (12%) for Ehrlichia canis and 2 (4%) for Anaplasma platys. In the 92 enrolled control dogs, DNA was detected in 41 (45%) for Hepatozoon spp., 18 (20%) for M. haemocanis, 1 (1%) for E. canis and 3 (3%) for A. platys. No Babesia spp. or “Candidatus Mycoplasma haematoparvum” DNA was detected in any dog. No statistical differences were found between the ClinL and controls regarding age, sex, breed, lifestyle and use of ectoparasitic prevention. A significant association between ClinL and E. canis infection (OR = 12.4, 95% CI: 1.5–106.0, P = 0.022) was found compared to controls by multivariate logistic regression. This association was confirmed using SEM, which further identified that younger dogs were more likely to be infected with each of Hepatozoon spp. and M. haemocanis, and dogs with Hepatozoon spp. were more likely to be co-infected with M. haemocanis. Conclusions Dogs with ClinL are at a higher risk of co-infection with E. canis than clinically healthy dogs. We recommend that dogs diagnosed with ClinL should be tested for E. canis co-infection using PCR

Target genes for strain-specific diagnostic of Ehrlichia ruminantium and use thereof

The invention provides a combination of target genes that are useful as genetic markers for the strain-specific detection of Ehrlichia ruminantium. The invention also provides diagnostic methods using said combination of markers.(Résumé d'auteur

The sero-diagnosis of heartwater : a comparison of 5 tests

Cinq tests sérologiques, l'ELISA indirect, l'ELISA de compétition, deux tests par immunofluorescence indirecte utilisant des antigènes différents, et la technique de Western blotting, ont été comparés sur des sérums de contrôle négatifs ou positifs pour Cowdria ruminantium et des sérums d'animaux de régions indemnes de cowdriose. Aucun des tests ne donnait de réaction positive sur les sérums de contrôle négatifs. En dehors de variations peu importantes dans la sensibilité, il y avait une bonne corrélation entre les 5 tests. Leur spécificité reste contestée, car dans tous les 5 tests, des réactions croisées considérables ont été enregistrées avec des anticorps contre un agent non encore identifié, probablement Ehrlichi

Differences in clinicopathologic variables between Borrelia C6 antigen seroreactive and Borrelia C6 seronegative glomerulopathy in dogs.

BackgroundRapidly progressive glomerulonephritis has been described in dogs that seroreact to Borrelia burgdorferi, but no studies have compared clinicopathologic differences in Lyme-seroreactive dogs with protein-losing nephropathy (PLN) versus dogs with Borrelia-seronegative PLN.Hypothesis/objectivesDogs with Borrelia C6 antigen-seroreactive PLN have distinct clinicopathologic findings when compared to dogs with Borrelia seronegative PLN.AnimalsForty dogs with PLN and Borrelia C6 antigen seroreactivity and 78 C6-seronegative temporally matched dogs with PLN.MethodsRetrospective prevalence case-control study. Clinical information was retrieved from records of dogs examined at the University of California, Davis, Veterinary Medical Teaching Hospital. Histopathologic findings in renal tissue procured by biopsy or necropsy of dogs with PLN were reviewed.ResultsRetrievers and retriever mixes were overrepresented in seroreactive dogs (P < .001). Seroreactive dogs were more likely to have thrombocytopenia (P < .001), azotemia (P = .002), hyperphosphatemia (P < .001), anemia (P < .001), and neutrophilia (P = .003). Hematuria, glucosuria, and pyuria despite negative urine culture were more likely in seroreactive dogs (all P ≤ .002). Histopathologic findings were consistent with immune-complex glomerulonephritis in 16 of 16 case dogs and 7 of 23 control dogs (P = 006). Prevalence of polyarthritis was not different between groups (P = .17).Conclusions and clinical importanceC6 seroreactivity in dogs with PLN is associated with a clinicopathologically distinct syndrome when compared with other types of PLN. Early recognition of this syndrome has the potential to improve outcomes through specific aggressive and early treatment

Prevalence of Anaplasma phagocytophilum infection and effect on lamb growth

Background: A major challenge in sheep farming during the grazing season along the coast of south-western Norway is tick-borne fever (TBF) caused by the bacteria Anaplasma phagocytophilum that is transmitted by the tick Ixodes ricinus. Methods: A study was carried out in 2007 and 2008 to examine the prevalence of A. phagocytophilum infection and effect on weaning weight in lambs. The study included 1208 lambs from farms in Sunndal Ram Circle in Møre and Romsdal County in Mid-Norway, where ticks are frequently observed. All lambs were blood sampled and serum was analyzed by an indirect fluorescent antibody assay (IFA) to determine an antibody status (positive or negative) to A. phagocytophilum infection. Weight and weight gain and possible effect of infection were analyzed using ANOVA and the MIXED procedure in SAS. Results: The overall prevalence of infection with A. phagocytophilum was 55%. A lower weaning weight of 3% (1.34 kg, p < 0.01) was estimated in lambs seropositive to an A. phagocytophilum infection compared to seronegative lambs at an average age of 137 days. Conclusions: The results show that A. phagocytophilum infection has an effect on lamb weight gain. The study also support previous findings that A. phagocytophilum infection is widespread in areas where ticks are prevalent, even in flocks treated prophylactic with acaricides

Bartonella infections in fleas (Siphonaptera : Pulicidae) and lack of Bartonellae in ticks (Acari : Ixodidae) from Hungary

Fleas (95 Pulex irritans, 50 Ctenocephalides felis, 45 Ctenocephalides canis) and ixodid ticks (223 Ixodes ricinus, 231 Dermacentor reticulatus, 204 Haemaphysalis concinna) were collected in Hungary and tested, in assays based on PCR, for Bartonella infection. Low percentages of P. irritans (4.2%) and C. felis (4.0%) were found to be infected. The groEL sequences of the four isolates from P. irritans were different from all the homologous sequences for bartonellae previously stored in GenBank but closest to those of Bartonella sp. SE-Bart-B (sharing 96% identities). The groEL sequences of the two isolates from C. felis were identical with those of the causative agents of cat scratch disease, Bartonella henselae and Bartonella clarridgeiae, respectively. The pap31 sequences of B. henselae amplified from Hungarian fleas were identical with that of Marseille strain. No Bartonella-specific amplification products were detected in C. canis, L ricinus, D. reticulatus and H. concinna pools

Acute febrile illness is associated with Rickettsia spp infection in dogs

BACKGROUND: Rickettsia conorii is transmitted by Rhipicephalus sanguineus ticks and causes Mediterranean Spotted Fever (MSF) in humans. Although dogs are considered the natural host of the vector, the clinical and epidemiological significance of R. conorii infection in dogs remains unclear. The aim of this prospective study was to investigate whether Rickettsia infection causes febrile illness in dogs living in areas endemic for human MSF. METHODS: Dogs from southern Italy with acute fever (n = 99) were compared with case–control dogs with normal body temperatures (n = 72). Serology and real-time PCR were performed for Rickettsia spp., Ehrlichia canis, Anaplasma phagocytophilum/A. platys and Leishmania infantum. Conventional PCR was performed for Babesia spp. and Hepatozoon spp. Acute and convalescent antibodies to R. conorii, E. canis and A. phagocytophilum were determined. RESULTS: The seroprevalence rates at first visit for R. conorii, E. canis, A. phagocytophilum and L. infantum were 44.8%, 48.5%, 37.8% and 17.6%, respectively. The seroconversion rates for R. conorii, E. canis and A. phagocytophilum were 20.7%, 14.3% and 8.8%, respectively. The molecular positive rates at first visit for Rickettsia spp., E. canis, A. phagocytophilum, A. platys, L. infantum, Babesia spp. and Hepatozoon spp. were 1.8%, 4.1%, 0%, 2.3%, 11.1%, 2.3% and 0.6%, respectively. Positive PCR for E. canis (7%), Rickettsia spp. (3%), Babesia spp. (4.0%) and Hepatozoon spp. (1.0%) were found only in febrile dogs. The DNA sequences obtained from Rickettsia and Babesia PCRs positive samples were 100% identical to the R. conorii and Babesia vogeli sequences in GenBank®, respectively. Febrile illness was statistically associated with acute and convalescent positive R. conorii antibodies, seroconversion to R. conorii, E. canis positive PCR, and positivity to any tick pathogen PCRs. Fourteen febrile dogs (31.8%) were diagnosed with Rickettsia spp. infection based on seroconversion and/or PCR while only six afebrile dogs (12.5%) seroconverted (P = 0.0248). The most common clinical findings of dogs with Rickettsia infection diagnosed by seroconversion and/or PCR were fever, myalgia, lameness, elevation of C-reactive protein, thrombocytopenia and hypoalbuminemia. CONCLUSIONS: This study demonstrates acute febrile illness associated with Rickettsia infection in dogs living in endemic areas of human MSF based on seroconversion alone or in combination with PCR