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Investigating Transplacental Transmission of Equine Piroplasmosis in Thoroughbred Foals in Trinidad
Journal of Equine Veterinary Science 39 (2016) S98eS107
Contents lists available at ScienceDirect
Journal of Equine Veterinary Science journal homepage: www.j-evs.com
10th IEIDC Abstracts-Working Equids 074 Unraveling the causes of respiratory disease in the working equids of Ethiopia: A cross sectional survey G. Laing*1, R. Christley 1, A. Stringer 1, A. Radford 1, N. Aklilu 2, R. Newton 3, G. Pinchbeck 1 1 Institute of Infection and Global Health, University of Liverpool, UK; 2 Society for the Protection of Animals Abroad (SPANA), Ethiopia; 3 Animal Health Trust, Newmarket, UK Previous research has demonstrated that respiratory disease, particularly coughing and nasal discharge are consistently ranked in the top-three health concerns for working equid owners. However, there is little existing literature on the possible aetiology and these syndromes are poorly defined. This study aimed to better understand respiratory disease, including frequency of signs, in working equids and assess exposure to the major respiratory pathogens. A cross-sectional study was conducted across 19 sites in Central Ethiopia. Owners and horses were sampled using systematic random sampling from a selected focal point in the town. A brief questionnaire was administered to drivers/owners to ascertain horse details and history of respiratory signs or disease. A clinical examination was performed and a jugular blood sample was taken. Heat-treated serum was transported to the UK for testing. Serology for antibody titres to equine influenza virus (EIV) used a multispecies Influenza A competitive Enzyme-linked Immunosorbant Assay (ELISA). Samples showing a borderline negative result (<100% colour change) on ELISA were subsequently tested using haemagglutinin inhibition for EIV H7N7 (Prague) and H3N8 (Miami and Newmarket 2) strains. Detection of antibodies to equine arteritis virus (EAV) and Streptococcus equi subsp. equi were by ELISA. Positive samples on EAV ELISA were subject to virus neutralisation test. S equi samples were deemed positive if optical density (OD) >0.3 on ELISA. Complement fixation was used to determine serum antibody titres to equine herpes viruses (EHV-1/4) and equine rhinitis viruses (ERAV/ERBV). Over 19 sites, 350 participants were selected. Owners reported 38% animals examined had recent history of coughing (last 30 days), 8% had a history of nasal discharge and 3% had suffered other breathing problems. In addition 11% horses examined had a clinically significant nasal discharge. Serology results for 350 horses suggested recent exposure to S equi in 23%, EAV 3.4%, but exposure to influenza virus was very rare. Low antibody titres to EHV-1/4 and ERAV/ERBV were also detected. Clinical signs of respiratory disease were relatively uncommon on examination of these working horses; however owners reported higher levels of respiratory signs in the previous 30 days, particularly coughing, consistent with results from the previous participatory studies. It appears S equi is endemic in the population and is likely to be a
0737-0806/$ e see front matter
significant contributor to respiratory disease in Ethiopian working equids. The low prevalence of EHV-1/4, ERAV/ERBV and EAV suggest the presence of these pathogens in the population but they are unlikely to be causing the majority of respiratory signs reported. Equine influenza did not appear to be present in the population in this region of Ethiopia. Other causes of respiratory signs such as inflammatory or allergic airway disease, or other pathogens should be further investigated.
086 Investigating Transplacental Transmission of Equine Piroplasmosis in Thoroughbred Foals in Trinidad C. Sant*1, I. Pargass 1, A. Basu 1, Z. Asgarali 1, K. Georges 1 1 School of Veterinary Medicine, Faculty of Medical Sciences, The University of the West Indies, Trinidad, West Indies Equine piroplasmosis caused by Theileria equi and Babesia caballi is endemic in Trinidad, West Indies. Transmission occurs mainly by ticks of the genus Ixodidae. T. equi can also be transmitted transplacentally, however transplacental transmission of Babesia caballi is unknown. Carrier mares may transmit T. equi across the placenta to infect the offspring which can result in abortions, stillbirths neonatal piroplasmosis or healthy carrier foals. Neonatal foals can show signs at birth or clinical signs can manifest at 2 to 3 days of age. Some of the clinical signs include icteric mucous membranes (Figure 1) and haemoglobinuria (Figure 2). This study aims to investigate the incidence of transplacental transmission of Theileria equi and Babesia caballi from thoroughbred mares naturally infected via the tick vector. EDTA blood and serum samples were collected from 118 mares in the fifth month of pregnancy. Samples were also collected from each of their foals within the first 36 hours of birth. All samples were analyzed microscopically for piroplasms. Serum ELISA, conventional and real time PCR amplification of the 18S rRNA gene from DNA extracted from whole blood for B. caballi were conducted. Serum ELISA, conventional PCR amplification of the 18S rRNA gene and real time PCR analysis based on ema -1 gene for T. equi were also performed on DNA extracted samples obtained from whole blood. Eighty three (74.7%) mares and 40 (44.9%) of their foals were seropositive for B. caballi. Four (3.4%) mares were positive for B. caballi by conventional PCR. Six (6.7%) of the foals were positive for B. caballi by real time PCR. Thirty-four (30.6%) mares and 15 (16.8%) of their foals were seropositive for T. equi. Twenty-seven (24.3%) mares and four (4.5%) foals were positive for T. equi by conventional PCR. Real time PCR analysis based on the ema e 1 gene revealed that seven (7.9%) of the foals were positive for T. equi. Transplacental transmission due to T. equi or B. caballi is a more common occurrence than previously suspected. Newborn foals should be screened for equine piroplasmosis at
10th IEIDC Abstracts / Journal of Equine Veterinary Science 39 (2016) S98eS107
one day old so treatment of positive foals can be started earlier for a better prognosis.
S99
trypanocide treatment was administered and the animals were observed for adverse reactions. Follow up evaluation was performed at one and two weeks to assess treatment effect. Blood samples for each animal collected at weeks 1, 2 and 3 underwent PCR analysis with validated specific primers1 for T. vivax west (TVW), T. congolense savannah (TCS) and T. brucei (TBR).
Figure 1. Bar charts illustrating the PCR status of animals in each treatment group at the three time points
Figure 1. Icteric mucous membranes observed on a 10 hours post-partum thoroughbred foal.
Figure 2. Blood tinged urine observed from a 10 hours post-partum thoroughbred foal.
113 Treatment efficacy in Equine Trypanosomosis: A prospective comparative study of three trypanocides in over 250 clinical cases in working equidae A.G. Raftery*1, J. Rodgers 2, D.G.M. Sutton 1 1 Weipers Centre Equine Hospital; 2 Institute of Infection, Inflammation and Immunity, University of Glasgow, Glasgow G61 1QH Trypanocides are essential in trypanosomosis management, but evidence regarding treatment efficacy in equids is scarce. The objective of this study was to establish the relative efficacy of three trypanocides (Diminasan® 3.5 mg/kg IM, Cymelarsan® 0.25 mg/kg IV and Samorin® 0.5 mg/kg IV) with respect to improvement of clinical parameters and parasitic burden and to evaluate adverse drug reactions. A prospective randomised clinical efficacy study was performed in ten villages in The Gambia. Owners were invited to present horses and donkeys for free examination (history, clinical examination and jugular blood sample for packed cell volume (PCV) and total serum protein). Horses and donkeys were enrolled if they fulfilled at least 2/5 inclusion criteria for trypanosomosis (anaemia (PCV<24%), poor body condition (1.5), limb or ventral oedema, abortion or pyrexia). Randomised
254/710 animals examined fulfilled study inclusion criteria with follow up data obtained for 243. Age, gender, species, median PCV (22%; range 8-26) and body condition score (median 1.5/5; range 0.5-2.5) were comparable between treatment groups (p>0.1). No immediate adverse reactions occurred following Cymelarsan® or Diminasan®. Immediate reactions occurred in 12/45 (27%) of donkeys treated with Samorin® ranging from neck scratching, lip smacking to tachycardia, cold extremities, sweating and hypothermia. Demeanour classifications improved following treatment with Samorin® or Diminasan® (p¼0.002). PCV increased at 1 and 2 weeks post treatment for all treatment groups (p<0.001). On preliminary analysis of PCR results (n¼65), animals representing four villages were positive before treatment (week 1) for TVW (55/65; 85%), TCS (44/65; 67%) and TBR (17/65; 26%) with mixed infection common (45/65; 69%). Trypanosome species profile varied between villages (p<0.05). Post treatment positives occurred in all groups for all Trypanosoma sp but with a marked decrease in prevalence (Fig 1). Positives were most common in the Cymelarsan® group, particularly for TCS (7/13; 54%). Two weeks post treatment Diminasan® (15/19; 79%) and Samorin® (19/23; 83%) had reduced parasitaemia below the threshold of detection in most cases. The data support the continuation of treatment with Diminasan® and Samorin® (with careful titration of dosing in donkeys). Further investigation to quantify parasitaemia in post treatment positives will aid differentiation between treatment failure, reduced parasitaemia, new infections and residual non-viable parasite DNA.
Acknowledgements This work was funded by The Donkey Sanctuary.
Reference 1 Masiga DK, Smyth AJ, Hayes P, Bromidge TJ, Gibson WC Sensitive detection of trypanosomes in tsetse flies by DNA amplification 1992 International Journal for Parasitology 22: 7; 909-918.
114 Analysis of Theileria equi and Babesia caballi in equine populations of the West Indies L.N. Wise*1, C.M. Butler 1, I.E. Karasek 1, G. Gemmell 1, A.H. Werners 1, L.S. Kappmeyer 2, D.P. Knowles 2, 3 1 St.George’s University School of Veterinary Medicine, True Blue, Grenada, West Indies; 2 Washington State University College of Veterinary Medicine &; 3 USDA ARS, Pullman, WA 99163 Theileria equi and Babesia caballi are tick-borne globally distributed apicomplexan parasites of equids. Infection with either of these parasites can result in a variety of disease symptoms ranging from fatal hemolytic anemia, nonspecific mild signs of
Contents lists available at ScienceDirect
Journal of Equine Veterinary Science journal homepage: www.j-evs.com
10th IEIDC Abstracts-Working Equids 074 Unraveling the causes of respiratory disease in the working equids of Ethiopia: A cross sectional survey G. Laing*1, R. Christley 1, A. Stringer 1, A. Radford 1, N. Aklilu 2, R. Newton 3, G. Pinchbeck 1 1 Institute of Infection and Global Health, University of Liverpool, UK; 2 Society for the Protection of Animals Abroad (SPANA), Ethiopia; 3 Animal Health Trust, Newmarket, UK Previous research has demonstrated that respiratory disease, particularly coughing and nasal discharge are consistently ranked in the top-three health concerns for working equid owners. However, there is little existing literature on the possible aetiology and these syndromes are poorly defined. This study aimed to better understand respiratory disease, including frequency of signs, in working equids and assess exposure to the major respiratory pathogens. A cross-sectional study was conducted across 19 sites in Central Ethiopia. Owners and horses were sampled using systematic random sampling from a selected focal point in the town. A brief questionnaire was administered to drivers/owners to ascertain horse details and history of respiratory signs or disease. A clinical examination was performed and a jugular blood sample was taken. Heat-treated serum was transported to the UK for testing. Serology for antibody titres to equine influenza virus (EIV) used a multispecies Influenza A competitive Enzyme-linked Immunosorbant Assay (ELISA). Samples showing a borderline negative result (<100% colour change) on ELISA were subsequently tested using haemagglutinin inhibition for EIV H7N7 (Prague) and H3N8 (Miami and Newmarket 2) strains. Detection of antibodies to equine arteritis virus (EAV) and Streptococcus equi subsp. equi were by ELISA. Positive samples on EAV ELISA were subject to virus neutralisation test. S equi samples were deemed positive if optical density (OD) >0.3 on ELISA. Complement fixation was used to determine serum antibody titres to equine herpes viruses (EHV-1/4) and equine rhinitis viruses (ERAV/ERBV). Over 19 sites, 350 participants were selected. Owners reported 38% animals examined had recent history of coughing (last 30 days), 8% had a history of nasal discharge and 3% had suffered other breathing problems. In addition 11% horses examined had a clinically significant nasal discharge. Serology results for 350 horses suggested recent exposure to S equi in 23%, EAV 3.4%, but exposure to influenza virus was very rare. Low antibody titres to EHV-1/4 and ERAV/ERBV were also detected. Clinical signs of respiratory disease were relatively uncommon on examination of these working horses; however owners reported higher levels of respiratory signs in the previous 30 days, particularly coughing, consistent with results from the previous participatory studies. It appears S equi is endemic in the population and is likely to be a
0737-0806/$ e see front matter
significant contributor to respiratory disease in Ethiopian working equids. The low prevalence of EHV-1/4, ERAV/ERBV and EAV suggest the presence of these pathogens in the population but they are unlikely to be causing the majority of respiratory signs reported. Equine influenza did not appear to be present in the population in this region of Ethiopia. Other causes of respiratory signs such as inflammatory or allergic airway disease, or other pathogens should be further investigated.
086 Investigating Transplacental Transmission of Equine Piroplasmosis in Thoroughbred Foals in Trinidad C. Sant*1, I. Pargass 1, A. Basu 1, Z. Asgarali 1, K. Georges 1 1 School of Veterinary Medicine, Faculty of Medical Sciences, The University of the West Indies, Trinidad, West Indies Equine piroplasmosis caused by Theileria equi and Babesia caballi is endemic in Trinidad, West Indies. Transmission occurs mainly by ticks of the genus Ixodidae. T. equi can also be transmitted transplacentally, however transplacental transmission of Babesia caballi is unknown. Carrier mares may transmit T. equi across the placenta to infect the offspring which can result in abortions, stillbirths neonatal piroplasmosis or healthy carrier foals. Neonatal foals can show signs at birth or clinical signs can manifest at 2 to 3 days of age. Some of the clinical signs include icteric mucous membranes (Figure 1) and haemoglobinuria (Figure 2). This study aims to investigate the incidence of transplacental transmission of Theileria equi and Babesia caballi from thoroughbred mares naturally infected via the tick vector. EDTA blood and serum samples were collected from 118 mares in the fifth month of pregnancy. Samples were also collected from each of their foals within the first 36 hours of birth. All samples were analyzed microscopically for piroplasms. Serum ELISA, conventional and real time PCR amplification of the 18S rRNA gene from DNA extracted from whole blood for B. caballi were conducted. Serum ELISA, conventional PCR amplification of the 18S rRNA gene and real time PCR analysis based on ema -1 gene for T. equi were also performed on DNA extracted samples obtained from whole blood. Eighty three (74.7%) mares and 40 (44.9%) of their foals were seropositive for B. caballi. Four (3.4%) mares were positive for B. caballi by conventional PCR. Six (6.7%) of the foals were positive for B. caballi by real time PCR. Thirty-four (30.6%) mares and 15 (16.8%) of their foals were seropositive for T. equi. Twenty-seven (24.3%) mares and four (4.5%) foals were positive for T. equi by conventional PCR. Real time PCR analysis based on the ema e 1 gene revealed that seven (7.9%) of the foals were positive for T. equi. Transplacental transmission due to T. equi or B. caballi is a more common occurrence than previously suspected. Newborn foals should be screened for equine piroplasmosis at
10th IEIDC Abstracts / Journal of Equine Veterinary Science 39 (2016) S98eS107
one day old so treatment of positive foals can be started earlier for a better prognosis.
S99
trypanocide treatment was administered and the animals were observed for adverse reactions. Follow up evaluation was performed at one and two weeks to assess treatment effect. Blood samples for each animal collected at weeks 1, 2 and 3 underwent PCR analysis with validated specific primers1 for T. vivax west (TVW), T. congolense savannah (TCS) and T. brucei (TBR).
Figure 1. Bar charts illustrating the PCR status of animals in each treatment group at the three time points
Figure 1. Icteric mucous membranes observed on a 10 hours post-partum thoroughbred foal.
Figure 2. Blood tinged urine observed from a 10 hours post-partum thoroughbred foal.
113 Treatment efficacy in Equine Trypanosomosis: A prospective comparative study of three trypanocides in over 250 clinical cases in working equidae A.G. Raftery*1, J. Rodgers 2, D.G.M. Sutton 1 1 Weipers Centre Equine Hospital; 2 Institute of Infection, Inflammation and Immunity, University of Glasgow, Glasgow G61 1QH Trypanocides are essential in trypanosomosis management, but evidence regarding treatment efficacy in equids is scarce. The objective of this study was to establish the relative efficacy of three trypanocides (Diminasan® 3.5 mg/kg IM, Cymelarsan® 0.25 mg/kg IV and Samorin® 0.5 mg/kg IV) with respect to improvement of clinical parameters and parasitic burden and to evaluate adverse drug reactions. A prospective randomised clinical efficacy study was performed in ten villages in The Gambia. Owners were invited to present horses and donkeys for free examination (history, clinical examination and jugular blood sample for packed cell volume (PCV) and total serum protein). Horses and donkeys were enrolled if they fulfilled at least 2/5 inclusion criteria for trypanosomosis (anaemia (PCV<24%), poor body condition (1.5), limb or ventral oedema, abortion or pyrexia). Randomised
254/710 animals examined fulfilled study inclusion criteria with follow up data obtained for 243. Age, gender, species, median PCV (22%; range 8-26) and body condition score (median 1.5/5; range 0.5-2.5) were comparable between treatment groups (p>0.1). No immediate adverse reactions occurred following Cymelarsan® or Diminasan®. Immediate reactions occurred in 12/45 (27%) of donkeys treated with Samorin® ranging from neck scratching, lip smacking to tachycardia, cold extremities, sweating and hypothermia. Demeanour classifications improved following treatment with Samorin® or Diminasan® (p¼0.002). PCV increased at 1 and 2 weeks post treatment for all treatment groups (p<0.001). On preliminary analysis of PCR results (n¼65), animals representing four villages were positive before treatment (week 1) for TVW (55/65; 85%), TCS (44/65; 67%) and TBR (17/65; 26%) with mixed infection common (45/65; 69%). Trypanosome species profile varied between villages (p<0.05). Post treatment positives occurred in all groups for all Trypanosoma sp but with a marked decrease in prevalence (Fig 1). Positives were most common in the Cymelarsan® group, particularly for TCS (7/13; 54%). Two weeks post treatment Diminasan® (15/19; 79%) and Samorin® (19/23; 83%) had reduced parasitaemia below the threshold of detection in most cases. The data support the continuation of treatment with Diminasan® and Samorin® (with careful titration of dosing in donkeys). Further investigation to quantify parasitaemia in post treatment positives will aid differentiation between treatment failure, reduced parasitaemia, new infections and residual non-viable parasite DNA.
Acknowledgements This work was funded by The Donkey Sanctuary.
Reference 1 Masiga DK, Smyth AJ, Hayes P, Bromidge TJ, Gibson WC Sensitive detection of trypanosomes in tsetse flies by DNA amplification 1992 International Journal for Parasitology 22: 7; 909-918.
114 Analysis of Theileria equi and Babesia caballi in equine populations of the West Indies L.N. Wise*1, C.M. Butler 1, I.E. Karasek 1, G. Gemmell 1, A.H. Werners 1, L.S. Kappmeyer 2, D.P. Knowles 2, 3 1 St.George’s University School of Veterinary Medicine, True Blue, Grenada, West Indies; 2 Washington State University College of Veterinary Medicine &; 3 USDA ARS, Pullman, WA 99163 Theileria equi and Babesia caballi are tick-borne globally distributed apicomplexan parasites of equids. Infection with either of these parasites can result in a variety of disease symptoms ranging from fatal hemolytic anemia, nonspecific mild signs of