Conjunctival habronemiasis in a square‐lipped rhinoceros (Ceratotherium simum)

A captive female square‐lipped rhinoceros born in 1993 had been showing intermittent signs of bilateral conjunctivitis and conjunctival proliferation since 1998. Periodic improvement was noted, especially in winter, but overall the condition had deteriorated over the years. Treatment with various topical, intralesional, and systemic antibiotics and glucocorticosteroids was largely ineffective, as were repeated dewormings. No primary cause for these lesions was found in biopsies taken in 2000 and 2006, although a severe infiltrate of numerous eosinophils was observed in the latter. As the condition worsened, secondary corneal changes were noted, and eventually vision was lost due to proliferative conjunctival tissue. Aggressive resection of the proliferating tissue in 2013 restored vision and submitted biopsies yielded a diagnosis of severe allergic conjunctivitis, eosinophilic granuloma, and habronematid (Habronema or Draschia) larval infection. As no other rhinoceros in the herd was affected, including two calves born to the patient who were in close contact with their mother, it was concluded the presentation was most likely due to a hypersensitivity reaction to the dead or dying larvae. Fly repellent is now regularly applied around the eye of this rhinoceros, and a protective face mask has been fitted. Ongoing periodic relapses are treated with oral ivermectin, topical antibiotics, and steroids.     

Pharmacokinetics of an intravenous and oral dose of enrofloxacin in white rhinoceros (Ceratotherium simum)

South Africa currently loses over 1000 white rhinoceros (Ceratotherium simum) each year to poaching incidents, and numbers of severely injured victims found alive have increased dramatically. However, little is known about the antimicrobial treatment of wounds in rhinoceros. This study explores the applicability of enrofloxacin for rhinoceros through the use of pharmacokinetic‐pharmacodynamic modelling. The pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin were evaluated in five white rhinoceros after intravenous (i.v.) and after successive i.v. and oral administration of 12.5 mg/kg enrofloxacin. After i.v. administration, the half‐life, area under the curve (AUC_tot), clearance and the volume of distribution were 12.41 ± 2.62 hr, 64.5 ± 14.44 μg ml^?1 hr^?1, 0.19 ± 0.04 L h^?1 kg^?1, and 2.09 ± 0.48 L/kg, respectively. Ciprofloxacin reached 26.42 ± 0.05% of the enrofloxacin plasma concentration. After combined i.v. and oral enrofloxacin administration oral bioavailability was 33.30 ± 38.33%. After i.v. enrofloxacin administration, the efficacy marker AUC₂₄: MIC exceeded the recommended ratio of 125 against bacteria with an MIC of 0.5 μg/mL. Subsequent intravenous and oral enrofloxacin administration resulted in a low Cmax: MIC ratio of 3.1. The results suggest that intravenous administration of injectable enrofloxacin could be a useful drug with bactericidal properties in rhinoceros. However, the maintenance of the drug plasma concentration at a bactericidal level through additional per os administration of 10% oral solution of enrofloxacin indicated for the use in chickens, turkeys and rabbits does not seem feasible.     

The devil is in the details—Host disease and co‐infections are associated with zoonotic pathogen carriage in Norway rats (Rattus norvegicus)

Traditionally, zoonotic pathogen ecology studies in wildlife have focused on the interplay among hosts, their demographic characteristics and their pathogens. But pathogen ecology is also influenced by factors that traverse the hierarchical scale of biological organization, ranging from within‐host factors at the molecular, cellular and organ levels, all the way to the host population within a larger environment. The influence of host disease and co‐infections on zoonotic pathogen carriage in hosts is important because these factors may be key to a more holistic understanding of pathogen ecology in wildlife hosts, which are a major source of emerging infectious diseases in humans. Using wild Norway rats (Rattus norvegicus) as a model species, the purpose of this study was to investigate how host disease and co‐infections impact the carriage of zoonotic pathogens. Following a systematic trap and removal study, we tested the rats for the presence of two potentially zoonotic bacterial pathogens (Bartonella tribocorum and Leptospira interrogans) and assessed them for host disease not attributable to these bacteria (i.e., nematode parasites, and macroscopic and microscopic lesions). We fitted multilevel multivariable logistic regression models with pathogen status as the outcome, lesions and parasites as predictor variables and city block as a random effect. Rats had significantly increased odds of being infected with B. tribocorum if they had a concurrent nematode infection in one or more organ systems. Rats with bite wounds, any macroscopic lesion, cardiomyopathy or tracheitis had significantly increased odds of being infected with L. interrogans. These results suggest that host disease may have an important role in the ecology and epidemiology of rat‐associated zoonotic pathogens. Our multiscale approach to assessing complex intrahost factors in relation to zoonotic pathogen carriage may be applicable to future studies in rats and other wildlife hosts.     

White‐Tailed Deer (Odocoileus virginianus) as a Potential Sentinel for Human Lyme Disease in Indiana

We assessed the potential of white‐tailed deer (WTD) (Odocoileus virginianus) to be a sentinel for human cases of Lyme disease (LD) in Indiana using location data from a 3‐year survey of approximately 3400 hunted deer with associated tick Ixodes scapularis and Borrelia burgdorferi (Bb) data. Data on human LD cases at the county level were obtained from the Indiana Department of Health. All data were assigned to county centroids to match the resolution of the LD data before creating optimized trend surfaces for LD incidence, hunted deer count, Ixodes scapularis and Bb prevalence. To determine whether LD was spatially associated with the areas of high densities of deer, deer with Ixodes scapularis and deer with ticks infected with Bb, we used spatial analysis with distance indices (SADIE). The SADIE analysis found significant spatial association between LD and the distribution of three organismal predictor variables, that is, WTD, Ixodes ticks and Bb. Lyme disease incident rate varied between 0.08 cases per 10 000 habitants (Johnson county) and 5.9 cases per 10 000 habitants (Warren county). In conclusion, WTD can be used as an accurate and cost‐effective sentinel for human LD. This method will permit public health workers to identify potentially endemic areas independently of human case reports.     

Changes in the prevalence of Salmonella serovars associated swine production and correlations of avian,bovine and swine‐associated serovars with human‐associated serovars in the United States (1997–2015)

As Salmonella enterica is an important pathogen of food animals, surveillance programmes for S. enterica serovars have existed for many years in the United States. Surveillance programmes serve many purposes, one of which is to evaluate alterations in the prevalence of serovars that may signal changes in the ecology of the target organism. The primary aim of this study was to evaluate changes in the proportion of S. enterica serovars isolated from swine over a near 20‐year observation period (1997–2015) using four longitudinal data sets from different food animal species. The secondary aim was to evaluate correlations between changes in S. enterica serovars frequently recovered from food animals and changes in S. enterica serovars associated with disease in humans. We found decreasing proportions of S. enterica serovar Typhimurium, serovar Derby and serovar Heidelberg and increasing proportions of S. enterica serovar 4,[5],12:i:‐, serovar Infantis and serovar Johannesburg in swine over time. We also found positive correlations for the yearly changes in S. enterica serovar 4,[5],12:i:‐, serovar Anatum and serovar Johannesburg between swine and human data; in S. enterica Worthington between avian and human data; and in S. enterica serovar 4,[5],12:i:‐ between bovine and human data. We found negative correlations for the yearly changes in S. enterica serovar 4,[5],12:i:‐ and serovar Johannesburg between avian and human data.     

Adult‐onset,chronic, cyclic thrombocytopenia in a Rhesus macaque (Macaca mulatta) after dengue virus vaccination and viral challenge

An 8‐year‐old, male Rhesus macaque (Macaca mulatta), previously used for dengue virus (DENV) vaccine research with viral challenge, was presented with adult‐onset, chronic, cyclic thrombocytopenia. Platelet number, morphology, and function were evaluated by automated hematology, peripheral blood smears, electron microscopy, flow cytometry, and impedance aggregometry. Bone marrow was evaluated by cytology. Both serum anti‐dengue nonstructural protein 1 (NS1) antibodies and anti‐platelet antibodies were detected by ELISA. Platelet characterization showed a lack of aggregation to all agonists (ADP, ASP, and collagen), increased activation with increased expression of surface marker (HLA‐ABC), and an absence of surface receptor GPIX during clinical episodes of petechiae and ecchymoses, even in the presence of normal platelet counts. Bone marrow aspirates identified potential mild megakaryocytic hypoplasia. All platelet functions and morphologic attributes were within normal limits during clinically normal phases. Presence of anti‐dengue NS1 serum antibodies confirmed a positive DENV titer 8 years postvaccination. Based on the history and clinical findings, a primary differential diagnosis for this chronic, cyclic platelet pathology was autoimmune platelet destruction with potential bone marrow involvement.     

Knowledge,perceptions and attitude of a community living around a colony of straw‐coloured fruit bats (Eidolon helvum) in Ghana after Ebola virus disease outbreak in West Africa

A large population of straw‐coloured fruit bats (Eidolon helvum) colonizes a prime area in the city of Accra where several public amenities are located. Although the colony is positive to several zoonotic viruses including the Ebola virus, there is limited information on the social dimensions of the existence of the bats. As a step towards effective response to health risk and conservation of the bats, this study assessed the knowledge and attitude of the community living around the bats and determined their level of environmental and public health consciousness. The community generally lacks interest in bat bushmeat consumption but had low knowledge and disease risk perception of the bats. Despite major campaigns during the recent Ebola outbreak in West Africa, elements of risky behaviour including disbelief and disregard for some preventive measures and lack of interest in post‐bat exposure prophylaxis were recorded among a limited proportion of the community. There was the need to focus public health education on the community and possibly others that may have E. helvum colonies in West Africa.     

Attribution of human infections with Shiga toxin‐producing Escherichia coli (STEC) to livestock sources and identification of source‐specific risk factors,The Netherlands (2010–2014)

Shiga toxin‐producing Escherichia coli (STEC) is a zoonotic pathogen of public health concern whose sources and transmission routes are difficult to trace. Using a combined source attribution and case–control analysis, we determined the relative contributions of four putative livestock sources (cattle, small ruminants, pigs, poultry) to human STEC infections and their associated dietary, animal contact, temporal and socio‐econo‐demographic risk factors in the Netherlands in 2010/2011–2014. Dutch source data were supplemented with those from other European countries with similar STEC epidemiology. Human STEC infections were attributed to sources using both the modified Dutch model (mDM) and the modified Hald model (mHM) supplied with the same O‐serotyping data. Cattle accounted for 48.6% (mDM) and 53.1% (mHM) of the 1,183 human cases attributed, followed by small ruminants (mDM: 23.5%; mHM: 25.4%), pigs (mDM: 12.5%; mHM: 5.7%) and poultry (mDM: 2.7%; mHM: 3.1%), whereas the sources of the remaining 12.8% of cases could not be attributed. Of the top five O‐serotypes infecting humans, O157, O26, O91 and O103 were mainly attributed to cattle (61%–75%) and O146 to small ruminants (71%–77%). Significant risk factors for human STEC infection as a whole were the consumption of beef, raw/undercooked meat or cured meat/cold cuts. For cattle‐attributed STEC infections, specific risk factors were consuming raw meat spreads and beef. Consuming raw/undercooked or minced meat were risk factors for STEC infections attributed to small ruminants. For STEC infections attributed to pigs, only consuming raw/undercooked meat was significant. Consuming minced meat, raw/undercooked meat or cured meat/cold cuts were associated with poultry‐attributed STEC infections. Consuming raw vegetables was protective for all STEC infections. We concluded that domestic ruminants account for approximately three‐quarters of reported human STEC infections, whereas pigs and poultry play a minor role and that risk factors for human STEC infection vary according to the attributed source.     

Conversion of α‐linolenic acid to long‐chain omega‐3 fatty acid derivatives and alterations of HDL density subfractions and plasma lipids with dietary polyunsaturated fatty acids in Monk parrots (Myiopsitta monachus)

The effect of α‐linolenic acid from a flaxseed (FLX)‐enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty‐four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at ?5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n‐3 (α‐linolenic acid), 20:5n‐3 (eicosapentaenoic acid) and 22:6n‐3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n‐6 (arachidonic acid). By day 70, the high‐density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α‐linolenic acid to the long‐chain omega‐3 derivatives including docosahexaenoic acid and reduce 20:4n‐6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time.     

Tumour necrosis factor‐alpha‐induced protein 8 (TNFAIP8) expression associated with cell survival and death in cancer cell lines infected with canine distemper virus

Oncolytic virotherapy is a novel strategy for treatment of cancer in humans and companion animals as well. Canine distemper virus (CDV), a paramyxovirus, has proven to be oncolytic through induction of apoptosis in canine‐derived tumour cells, yet the mechanism behind this inhibitory action is poorly understood. In this study, three human mammary tumour cell lines and one canine‐derived adenofibrosarcoma cell line were tested regarding to their susceptibility to CDV infection, cell proliferation, apoptosis, mitochondrial membrane potential and expression of tumour necrosis factor‐alpha‐induced protein 8 (TNFAIP8). CDV replication‐induced cytopathic effect, decrease of cell proliferation rates, and >45% of infected cells were considered death and/or under late apoptosis/necrosis. TNFAIP8 and CDVM gene expression were positively correlated in all cell lines. In addition, mitochondrial membrane depolarization was associated with increase in virus titres (p < 0.005). Thus, these results strongly suggest that both human and canine mammary tumour cells are potential candidates for studies concerning CDV‐induced cancer therapy.