Dendritic cell vaccination plus low-dose doxorubicin for the treatment of spontaneous canine hemangiosarcoma.

Angiosarcoma is a deadly neoplasm of the vascular endothelium. Metastatic disease is often present at diagnosis, and 5-year survival is only 10-35%. Although there exist no immunocompetent mouse models of angiosarcoma with which to study immune-based approaches to therapy, angiosarcoma is a major killer of companion dogs, responsible for up to 2% of all canine deaths in some susceptible breeds or an estimated 120,000 per year in the US. The canine disease (HSA) often presents in the spleen as acute hemoabdomen secondary to splenic rupture. Even if life-saving splenectomy is performed, median overall survival (OS) is only 48 days, and 1-year survival is negligible. Here we report the analysis of a pilot phase I open-label trial of chemo-immunotherapy performed on consecutively presenting splenectomized canines with histologically verified HSA. Subjects received an abbreviated course of low-dose doxorubicin plus alpha interferon and an autologous dendritic cell-therapy reported to enhance durable CD8+ memory. Disease was monitored monthly by abdominal ultrasound, chest X-ray, and echocardiogram. Median OS in the per protocol population was 109 days including one of five animals that died cancer-free at 16 months after documented resolution of relapsed disease. These results indicate that therapeutic administration of chemo-immunotherapy is both feasible and safe, substantiating the rationale for additional veterinary and human clinical studies.

Insertion-responsive microneedles for rapid intradermal delivery of canine influenza vaccine.

In this study, we present transcutaneous influenza vaccination using a novel tip-separable microneedle system called insertion-responsive microneedles (IRMNs). IRMNs are composed of dissolvable hyaluronic acid (HA) tips and biocompatible polycaprolactone (PCL) bases, the tip of which is instantly separated from the base during microneedle insertion and retraction. Vaccine antigens derived from canine influenza virus (A/canine/VC378/2012; H3N2) were successfully coated on HA tips by rapidly freezing the tips prior to coating. An ex vivo porcine skin insertion test showed that IRMNs were capable of penetrating the skin without tip breakage and releasing the coated materials within the skin. The thermal stability of the vaccine as determined by hemagglutination assay revealed that the coated vaccine partially maintained its activity when stored at 50 °C for 3 weeks, whereas the liquid form completely lost the activity. Immunization in guinea pigs showed that hemagglutination inhibition (HI) antibodies induced by IRMNs were two times higher than those induced by intramuscular (IM) injections. When challenged with influenza A/canine/Korea/01/2007 (H3N2) wild-type virus 2 weeks after the second vaccination, viral shedding was completely eliminated at 8 days post infection in both IRMNs and IM injection groups. Our results suggest that IRMNs have great potential for rapid and convenient vaccination, which will be particularly attractive for animal vaccinations.

Assessment of Lymphoid Molecular Clonality in Canine Thymoma.

The aim of this study was to document the molecular clonality of lymphoid cells in canine thymoma using polymerase chain reaction for antigen receptor rearrangement (PARR). Fifteen formalin-fixed and paraffin wax-embedded samples of canine thymoma were analyzed for T- and B-cell receptor clonality. Two of these 15 cases were excluded from the study due to insufficient DNA concentration. Twelve of the 13 remaining samples (92.3%) showed a polyclonal lymphoid component and in one case the lymphoid component was monoclonal (T-cell clonality). PARR could therefore be a useful tool for differentiating canine thymoma from canine mediastinal lymphoma.

Tool for Eliminating Dog-Mediated Human Rabies through Mass Dog Vaccination Campaigns.

The World Health Organization and collaborating agencies have set the goal of eliminating dog-mediated human rabies by 2030. Building on experience with rabies endemic countries, we constructed a user-friendly tool to help public health officials plan the resources needed to achieve this goal through mass vaccination of dogs.

A flow cytometric assessment of the lymphocyte immunophenotypes in dogs naturally infected with Babesia rossi.

Immunity to Babesia infection requires both innate and acquired responses, including cell mediated- and humoral responses. The aims of this study were to investigate the variation in selected peripheral blood lymphocyte phenotypes in dogs with virulent babesiosis at presentation and over time after treatment, and to determine whether these were correlated with the severity of clinical signs. Forty-four dogs naturally infected with B. rossi were studied and 5 healthy dogs were included as controls. Blood samples were collected from the jugular vein at admission, prior to any treatment, and at 24h and 48-72h. Leukocytes were incubated with canine specific, fluorochrome conjugated anti-CD3, anti-CD4, anti-CD8, and anti-B cell markers. Babesia-infected dogs were divided into complicated or uncomplicated groups on clinical grounds and in-house laboratory assays. The percentage CD3+ lymphocytes in the complicated group was lower compared to the controls (P=0.014) and uncomplicated group (P=0.007). The percentage CD4+ T lymphocytes in the complicated group was lower compared to the controls (P=0.027) and uncomplicated group (P=0.014). Both the complicated as well as the uncomplicated groups expressed a lower percentage CD8+ T lymphocytes compared to the control group (P<0.001 and P=0.005, respectively). The percentage B lymphocytes was higher in the complicated group at 48-72h. These findings could indicate the presence of a functional immune suppression secondary to increased apoptosis or redistribution of effector lymphocytes and/or a combination of other immune modulatory mechanisms induced by B. rossi infection.

Treatment of presumptive primary immune-mediated thrombocytopenia with mycophenolate mofetil versus cyclosporine in dogs.

OBJECTIVES: The objective of this study was to compare hospitalisation duration, survival times, adverse events and cost of therapy in dogs with presumptive primary immune-mediated thrombocytopenia undergoing therapy with mycophenolate mofetil and corticosteroids versus cyclosporine and corticosteroids. METHODS: A retrospective study of medical case records of dogs with presumed primary immune-mediated thrombocytopenia was conducted. Data collected included signalment, presenting complaints, haematologic and biochemical profiles, vector-borne disease testing, thoracic and abdominal radiographs, abdominal ultrasound, medications administered, duration of hospitalisation, 30- and 60-day survival, adverse events and cost of therapy. Variables were compared between dogs treated solely with mycophenolate mofetil and corticosteroids or cyclosporine and corticosteroids. RESULTS: A total of 55 dogs with primary immune-mediated thrombocytopenia were identified. Eighteen were excluded because multiple immunosuppressive medications were used during treatment. Hospitalisation times, 30-day survival and 60-day survival times were similar between both groups. Dogs in the mycophenolate mofetil/corticosteroid group experienced fewer adverse events than the cyclosporine/corticosteroid group. Therapy with mycophenolate mofetil was less expensive than that with cyclosporine. CLINICAL SIGNIFICANCE: These results suggest that using the combination of mycophenolate mofetil and corticosteroids appears to be as effective as cyclosporine and corticosteroids in the treatment of presumed primary immune-mediated thrombocytopenia in dogs. Adverse events were less common and cost of therapy was lower in the mycophenolate mofetil group. Additional larger prospective, controlled, double-masked, outcome-based, multi-institutional studies are required to substantiate these preliminary findings.

Review on dog rabies vaccination coverage in Africa: a question of dog accessibility or cost recovery?

BACKGROUND: Rabies still poses a significant human health problem throughout most of Africa, where the majority of the human cases results from dog bites. Mass dog vaccination is considered to be the most effective method to prevent rabies in humans. Our objective was to systematically review research articles on dog rabies parenteral vaccination coverage in Africa in relation to dog accessibility and vaccination cost recovery arrangement (i.e.free of charge or owner charged). METHODOLOGY/PRINCIPAL FINDINGS: A systematic literature search was made in the databases of CAB abstracts (EBSCOhost and OvidSP), Scopus, Web of Science, PubMed, Medline (EBSCOhost and OvidSP) and AJOL (African Journal Online) for peer reviewed articles on 1) rabies control, 2) dog rabies vaccination coverage and 3) dog demography in Africa. Identified articles were subsequently screened and selected using predefined selection criteria like year of publication (viz. ≥ 1990), type of study (cross sectional), objective(s) of the study (i.e. vaccination coverage rates, dog demographics and financial arrangements of vaccination costs), language of publication (English) and geographical focus (Africa). The selection process resulted in sixteen peer reviewed articles which were used to review dog demography and dog ownership status, and dog rabies vaccination coverage throughout Africa. The main review findings indicate that 1) the majority (up to 98.1%) of dogs in African countries are owned (and as such accessible), 2) puppies younger than 3 months of age constitute a considerable proportion (up to 30%) of the dog population and 3) male dogs are dominating in numbers (up to 3.6 times the female dog population). Dog rabies parenteral vaccination coverage was compared between "free of charge" and "owner charged" vaccination schemes by the technique of Meta-analysis. Results indicate that the rabies vaccination coverage following a free of charge vaccination scheme (68%) is closer to the World Health Organization recommended coverage rate (70%) than the achieved coverage rate in owner-charged dog rabies vaccination schemes (18%). CONCLUSIONS/SIGNIFICANCE: Most dogs in Africa are owned and accessible for parenteral vaccination against rabies if the campaign is performed "free of charge".

Longitudinal assessment of T-lymphocyte subpopulations during generalized demodicosis in dogs and their relationship with remission.

BACKGROUND: The pathogenesis of canine generalized demodicosis is poorly understood but is thought to involve dysfunction of the immune system. Previous studies showed diminished CD4+ T lymphocyte counts in affected dogs, but none has evaluated this subpopulation through resolution of the disease. HYPOTHESIS/OBJECTIVES: In this longitudinal study, we tested whether quantification of CD4+ cells, CD8+ cells and the ratio of CD4+ to CD8+ cells are good indicators of immunological status and could be used as biomarkers of treatment efficacy and prognosis. ANIMALS: Sixteen dogs of several breeds with diagnoses of generalized demodicosis, plus 30 age/breedmatched healthy dogs. METHODS: Total lymphocytes, CD4+, CD8+ and CD4+:CD8+ ratio were quantified at four time points: at diagnosis, 30 days after diagnosis (during treatment), at first negative parasitological examination and at clinical cure. RESULTS: Absolute numbers of CD4+ cells were significantly lower in affected dogs at the time of diagnosis. Absolute numbers of CD4+ and CD8+ cells were significantly augmented in affected animals compared with control dogs after treatment was established, and this persisted until the first negative parasitological examination, at which time the CD4+ counts equalled those of the control group. CONCLUSIONS AND CLINICAL IMPORTANCE: Our findings suggest that longitudinal quantification of CD4+ and CD8+ T lymphocytes is a useful indicator of the efficacy of demodicosis treatment.

Assessment of the cytokine profile in peripheral blood mononuclear cells of naturally Sarcoptes scabiei var. canis infested dogs.

The mechanism of cytokine secretion from T lymphocytes plays an important role in the immune response of dogs and parasitic skin infestations. Assessment of the cytokine profile of naturally S. scabiei var. canis infested dogs could augment understanding of the pathobiology of canine sarcoptic mange. Therefore, the present study examined the cytokines in peripheral blood mononuclear cells of dogs suffering from sarcoptic mange. Thirteen dogs naturally infected with sarcoptic mange participated in the study. The dogs were found positive for S. scabiei var. canis mites in skin scraping examinations and revealed at least three clinical inclusion criteria. Another five clinically healthy dogs were kept as healthy controls. Peripheral blood mononuclear cells were isolated from heparinized blood samples and used for extraction of mRNA. Further, cDNA was synthesized by using 1 mg of mRNA by reverse transcription using oligonucleotide primers. Relative levels of cytokine expression were compared with normalized glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcripts. The levels of interleukin-4, interleukin-5 and transforming growth factor beta (TGF-ß) mRNA expression in dogs with sarcoptic mange were significantly higher (P ≤ 0.01), whereas the level of tumor necrosis factor alpha (TNF-α) was significantly lower (P ≤ 0.01) in comparison with the healthy dogs. No remarkable difference was seen for interleukin-2 mRNA expression between these animals. An overproduction IL-4 and IL-5 might be involved in immuno-pathogenesis of canine sarcoptic mange. S. scabiei var. canis mites possibly induce an overproduction of TGF-ß and reduced expression of TNF-α and thus could be conferring the immune suppression of infested dogs.

Use of activity monitors for assessment of pruritus in an acute model of canine atopic dermatitis.

BACKGROUND: We developed a canine model of acute atopic dermatitis to evaluate the potential of compounds to treat pruritus and skin lesions induced in Dermatophagoides farinae (Df)-sensitized dogs. HYPOTHESIS/OBJECTIVES: The aim was to investigate the effectiveness of long-term recording activity monitors to assess pruritus induced by allergen challenges. ANIMALS: Thirty-two Df-sensitized laboratory dogs. METHODS: In two blinded crossover studies, 28 Df-sensitized dogs were challenged on 3 days with a Df slurry applied to clipped abdominal skin. Dogs were treated with a positive control (prednisolone 1 mg/kg once daily for 5 days, starting 1 day before challenge) or left untreated; all were fitted with activity monitors. To confirm pruritus, a parallel study with four dogs was conducted, filming the dogs before and during challenge and assessing the film for pruritic behaviour. RESULTS: The activity of dogs treated with prednisolone was significantly lower between 00.00 and 03.00 h and between 03.00 and 06.00 h compared with untreated dogs (repeated-measures ANCOVA; P < 0.0001). To determine whether the recorded night-time activity corresponded to pruritic manifestations, we compared activity monitor and video recordings of four dogs for two periods (16.30-20.30 and 24.00-03.00 h) before and during a Df challenge. The correlation between night-time activity monitor activity and observed pruritic behaviour was highly significant (test of correlation coefficient versus zero: r = 0.57, P < 0.0001). CONCLUSIONS AND CLINICAL IMPORTANCE: Determination of night-time activity with activity monitors after allergen challenge appears to be an objective and practical way to assess pruritus in this experimental model of canine atopic dermatitis.

Development and evaluation of a recombinant-glycoprotein-based latex agglutination test for rabies virus antibody assessment.

The measurement of neutralizing antibodies induced by the glycoprotein of rabies virus is indispensable for assessing the level of neutralizing antibodies in animals or humans. A rapid fluorescent focus inhibition test (RFFIT) has been approved by WHO and is the most widely used method to measure the virus-neutralizing antibody content in serum, but a rapid test system would be of great value to screen large numbers of serum samples. To develop and evaluate a latex agglutination test (LAT) for measuring rabies virus antibodies, a recombinant glycoprotein was expressed in an insect cell system and purified, and the protein was coated onto latex beads at concentrations of 0.1, 0.25, 0.5, 0.75, and 1 mg/ml to find out the optimal concentration for coating latex beads. It was found that 0.5 mg/ml of recombinant protein was optimal for coating latex beads, and this concentration was used to sensitize the latex beads for screening of dog serum samples. Grading of LAT results was done with standard reference serum with known antibody titers. A total of 228 serum samples were tested, out of which 145 samples were positive by both RFFIT and LAT, and the specificity was found to be 100 %. In RFFIT, 151 samples were positive, the sensitivity was found to be 96.03 %, and the accuracy/concordance was found to be 97.39 %. A rapid field test-a latex agglutination test (LAT)-was developed and evaluated for rabies virus antibody assessment using recombinant glycoprotein of rabies virus expressed in an insect cell system.

Assessment of circulating concentrations of proinflammatory and anti-inflammatory cytokines and nitric oxide in dogs with brachycephalic airway obstruction syndrome.

OBJECTIVE: To evaluate plasma concentrations of inflammatory mediators in dogs with brachycephalic airway obstruction syndrome, identify a possible role for these mediators in the syndrome, and investigate the relationship between plasma concentrations of inflammatory mediators and severity of clinical signs. ANIMALS: 17 dogs with brachycephalic airway obstruction syndrome and 10 mesocephalic (control) dogs. PROCEDURES: A blood sample was collected once from each dog. Plasma concentrations of interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, IL-6, IL-17A, IL-10, and IL-13 were measured with ELISAs. Nitric oxide (NO) concentrations were determined with a Griess test. For analysis, brachycephalic dogs were categorized into groups depending on weight (small [< 16 kg]) and large [≥ 16 kg]) or on whether they required medical or surgical treatment. RESULTS: Compared with control dog values, plasma concentrations of TNF-α, IL-10, IL-13, and IL-17A were significantly higher in brachycephalic dogs and markedly so for brachycephalic dogs that required surgery; findings for small and large brachycephalic dogs did not differ. A similar pattern of differences between control and brachycephalic dogs was identified for plasma NO concentration. Plasma IL-1ß and IL-6 concentrations in control and brachycephalic dogs did not differ. CONCLUSIONS AND CLINICAL RELEVANCE: In brachycephalic dogs, plasma TNF-α, IL-10, IL-13, L-17A, and NO concentrations were higher than values in control dogs and appeared to be associated with disease severity. These variables may be useful as indicators of inflammatory processes associated with brachycephalic airway obstruction syndrome in dogs.

Serological detection of circulating Angiostrongylus vasorum antigen and specific antibodies in dogs from central and northern Italy.

The most frequently employed method for the diagnosis of Angiostrongylus vasorum in dogs is the detection of first stage larvae (L1) in faeces. The sensitivity of coproscopy, however, is limited in case of low parasite load, intermittent larval excretion, and during pre-patency. An epidemiological survey on dogs was conducted applying serological methods in two Italian regions where angiostrongylosis is endemic in foxes. 265 dog serum samples from Tuscany (central Italy - site A) and 447 from Liguria (north-western Italy - site B) were tested with a sandwich-ELISA for detection of circulating antigen, and with an ELISA using A. vasorum adult somatic antigen purified by monoclonal antibodies for specific antibody detection. During previous examinations dogs naturally infected with Leishmania infantum (n=149), Dirofilaria immitis (n=40), Dirofilaria repens (n=30), Acanthocheilonema reconditum (n=27), Crenosoma vulpis (n=1), A. vasorum (n=2), Capillaria aerophila (n=35), Capillaria boehmi (n=3), Toxocara canis (n=68), Toxascaris leonina (n=5), hookworms (n=37) and Trichuris vulpis (n=39) were detected. Sera of these dogs were used to evaluate cross reactions. In site A, 2 dogs (0.8%) were seropositive for antibody and antigen detection and 4 (1.5%) for antibody detection only. From site B, 4 dogs (0.9%) were seropositive for both tests, while other 4 dogs (0.9%) for antigen detection only and 9 dogs (2%) for antibody detection only. Considering a subgroup of 347 dogs from site B which had also been tested with the Baermann technique, 2 (0.6%) were positive for both tests, 4 (1.2%) for antigen detection only and 9 (2.6%) for antibody detection only. The two dogs which were positive for both serological tests were also positive for A. vasorum L1 in the faeces. No significant difference in seropositivities was observed in the group of dogs with other proven parasitic infections. A. vasorum serology presents significant advantages (diagnosis before patency, single serum sample instead of repeated faecal samples, rapidity and affordability particularly in case of large number of samples) and it can be considered a valid alternative for diagnosis in individuals and in epidemiological studies.

A novel clonality assay for the assessment of canine T cell proliferations.

Polymerase chain reaction (PCR) based clonality assays are an important tool to differentiate neoplastic from reactive lymphocyte populations. A recent description of the canine T cell receptor γ locus identified a large number of formerly unknown genes, and determined the locus topology consisting of 8 cassettes with up to 3 variable (V) genes, 2 joining (J) genes and one constant (C) gene each. Given that these data were not available when existing canine T cell clonality assays were developed, it is likely that they will fail to detect a subset of clonal lymphocyte populations. The objective of this study was to gauge the potential of canine T cell clonality assays to detect all rearranged T cell receptor γ genes and to develop an improved clonality assay. The primer sequences of existing clonality assays were aligned to the reference sequences of all rearranged genes and genes were scored as to the likelihood of being recognized by a primer. All four assays likely recognized subgroup Vγ2 and Vγ6 genes but 3 out of 4 assays were unlikely to detect subgroup Vγ3 and Vγ7 genes. All assays likely recognized Jγx-2 genes, but only two assays were likely to detect most Jγx-1 genes. Two assays had forward primers located as close as four nucleotides to the junctional region. A new multiplex PCR was designed with all primers combined in a single tube. An alternative primer set allowed identification of variable gene usage through gene specific forward primers. The coverage of all rearranged genes facilitated the detection of multiple clonal rearrangements per neoplastic sample. The new assay detected clonal DNA at a concentration of 5% within polyclonal background but detection thresholds were dependent on the gene usage of clonal rearrangements as well as the position of the clonal peak in respect to the polyclonal background. The new multiplex assay recognized 12/12 (100%) of confirmed neoplastic samples as compared to 2/12 (17%) by an existing assay. On a series of 60 diagnostic samples the concordance rate of both assays was 41/60 (68.3%). In 14/60 (23.3%) of the cases, the new multiplex assay yielded a clonal result while the existing assay gave a non-clonal result. In 5/60 (8.3%) of cases, the new assay yielded a non-clonal result while the existing primer set gave a clonal result. These findings suggest that the new multiplex assay has an improved sensitivity over traditional assays and is suited to reduce the rate of false-negative results.

Assessment of urine solute and matrix effects on the performance of an enzyme-linked immunosorbent assay for measurement of interleukin-6 in dog urine.

Measurement of cytokine concentrations within body fluids is a means of recognizing subclinical and/or unresolved, infectious and inflammatory states in patients. In the urinary tract, such information may be useful for identifying patients with pyelonephritis, asymptomatic bacteriuria, recurrent infections, and cystitis. One such cytokine, interleukin-6 (IL-6), is recognized as a primary cytokine that is produced following exposure of the urothelium to bacterial virulence factors. Complicating reliable testing for this and other cytokines is the nature of urine itself. Urine varies widely in its composition as indicated by the range of pH and urine specific gravity (USG) observed in healthy patients. An additional variable is the protein and carbohydrate matrix capable of hindering immunologic testing modalities, such as enzyme-linked immunosorbent assays (ELISAs). The purpose of the current study was to examine the role of urine pH, USG, and matrix while optimizing a canine-specific chemiluminescent ELISA for the measurement of IL-6 in the urine of dogs. Urine spiked with IL-6 obtained maximal IL-6 quantitative recoveries of only 55 ± 10% (mean ± 1 standard deviation) when an ELISA optimized for cell culture supernatants was used. The urine matrix and variations in USG were determined to by contributing to this poor IL-6 recovery. Using specific matrix inhibitors and optimal dilutions improved the IL-6 quantitative recovery to 91 ± 5%. Urine pH (5.5-9.5) had no effect. The current work underscores the importance of critically optimizing testing modalities for biomarkers, particularly if they are immunologic in origin.

Assessment of exposure to Leptospira serovars in veterinary staff and dog owners in contact with infected dogs.

OBJECTIVE: To assess patterns of seroreactivity to Leptospira serovars in veterinary professional staff and dog owners exposed to dogs with acute leptospirosis and to contrast these patterns in people with those observed in dogs. DESIGN: Cross-sectional study. SAMPLE POPULATION: Human subjects consisted of 91 people (50 veterinarians, 19 technical staff, 9 administrative personnel, and 13 dog owners) exposed to dogs with leptospirosis. Canine subjects consisted of 52 dogs with naturally occurring leptospirosis admitted to the University of Bern Vetsuisse Faculty Small Animal Clinic in 2007 and 2008. PROCEDURES: People were tested for seroreactivity to regionally prevalent Leptospira serovars by use of a complement fixation test. A questionnaire designed to identify risk factors associated with seropositivity was used to collect demographic information from each study participant. Dogs were tested for seroreactivity to Leptospira serovars by use of a microscopic agglutination test. RESULTS: On the basis of microscopic agglutination test results, infected dogs were seropositive for antibodies against Leptospira serovars as follows (in descending order): Bratislava (43/52 [83%]), Australis (43/52 [83%]), Grippotyphosa (18/52 [35%]), Pomona (12/52 [23%]), Autumnalis (6/52 [12%]), Icterohemorrhagiae (4/52 [8%]), Tarassovi (2/52 [4%]), and Canicola (1/52 [2%]). All 91 people were seronegative for antibodies against Leptospira serovars. Therefore, statistical evaluation of risk factors and comparison of patterns of seroreactivity to Leptospira serovars between human and canine subjects were limited to theoretical risks. CONCLUSIONS AND CLINICAL RELEVANCE: Seroreactivity to Leptospira serovars among veterinary staff adhering to standard hygiene protocols and pet owners exposed to dogs with acute leptospirosis was uncommon.

Transmission dynamics and economics of rabies control in dogs and humans in an African city.

Human rabies in developing countries can be prevented through interventions directed at dogs. Potential cost-savings for the public health sector of interventions aimed at animal-host reservoirs should be assessed. Available deterministic models of rabies transmission between dogs were extended to include dog-to-human rabies transmission. Model parameters were fitted to routine weekly rabid-dog and exposed-human cases reported in N'Djaména, the capital of Chad. The estimated transmission rates between dogs (beta(d)) were 0.0807 km2/(dogs x week) and between dogs and humans (beta(dh)) 0.0002 km2/(dogs x week). The effective reproductive ratio (R(e)) at the onset of our observations was estimated at 1.01, indicating low-level endemic stability of rabies transmission. Human rabies incidence depended critically on dog-related transmission parameters. We simulated the effects of mass dog vaccination and the culling of a percentage of the dog population on human rabies incidence. A single parenteral dog rabies-mass vaccination campaign achieving a coverage of least 70% appears to be sufficient to interrupt transmission of rabies to humans for at least 6 years. The cost-effectiveness of mass dog vaccination was compared to postexposure prophylaxis (PEP), which is the current practice in Chad. PEP does not reduce future human exposure. Its cost-effectiveness is estimated at US $46 per disability adjusted life-years averted. Cost-effectiveness for PEP, together with a dog-vaccination campaign, breaks even with cost-effectiveness of PEP alone after almost 5 years. Beyond a time-frame of 7 years, it appears to be more cost-effective to combine parenteral dog-vaccination campaigns with human PEP compared to human PEP alone.

Quantification of mRNA encoding cytokines and chemokines and assessment of ciliary function in canine tracheal epithelium during infection with canine respiratory coronavirus (CRCoV).

One of the first lines of defence against viral infection is the innate immune response and the induction of antiviral type I interferons (IFNs). However some viruses, including the group 2 coronaviruses, have evolved mechanisms to overcome or circumvent the host antiviral response. Canine respiratory coronavirus (CRCoV) has previously been shown to have a widespread international presence and has been implicated in outbreaks of canine infectious respiratory disease (CIRD). This study aimed to quantify pro-inflammatory cytokine mRNAs following infection of canine air-interface tracheal cultures with CRCoV. Within this system, immunohistochemistry identified ciliated epithelial and goblet cells as positive for CRCoV, identical to naturally infected cases, thus the data obtained would be fully transferable to the situation in vivo. An assay of ciliary function was used to assess potential effects of CRCoV on the mucociliary system. CRCoV was shown to reduce the mRNA levels of the pro-inflammatory cytokines TNF-alpha and IL-6 and the chemokine IL-8 during the 72 h post-inoculation. The mechanism for this is unknown, however the suppression of a key antiviral strategy during a period of physiologic and immunological stress, such as on entry to a kennel, could potentially predispose a dog to further pathogenic challenge and the development of respiratory disease.