Predominant risk factors for tick-borne co-infections in hunting dogs from the USA

Background

Both incidence and geographical range of tick-borne disease has increased across the USA. Similar to people, dogs are hosts for Anaplasma spp., Babesia spp., Ehrlichia spp. and Borrelia burgdorferi. Dogs also share our homes and beds, making them both a sentinel for the ticks in our backyards but also increasing our exposure to ticks. Measures to better track, prevent, and/or treat tick-borne diseases in companion animals can lead to better control and prevention of human tick-borne disease. This study identifies demographic and co-infection risk factors for canine seropositivity to tick-borne infections in a cohort of hunting dogs across the USA.

Results

Human patterns of tick-borne disease co-infection in the USA have been predominantly driven by the geographical distribution of the tick vector. Dogs who tested seropositive for Anaplasma spp. were 1.40 times more likely (P = 0.0242) to also test seropositive for Babesia spp. and vice versa (1.60 times more likely, P = 0.0014). Dogs living in the West had 5% lower risk (P = 0.0001) for Ehrlichia spp. seropositivity compared to other regions. Controlling for age and Anaplasma spp. seroprevalence, dogs in all three other regions were 2.30 times more likely (P = 0.0216) to test seropositive for B. burgdorferi than dogs in the West. Dogs seropositive for B. burgdorferi were 1.60 times more likely (P = 0.0473) to be seropositive for Anaplasma spp.

Conclusions

Tick geographical distributions have a prominent impact on the regional distribution of hunting dog exposure to tick-borne diseases. Education concerning regional tick prevalence and disease risk is important for everyone, but particularly dog owners, regarding ticks in their region and protection from infection and co-infection of tick-borne pathogens as they travel or move with their dogs. Dogs are sentinel species for human exposure to ticks, and as such surveillance of canine tick-borne infections and understanding the probability that these infections might be seen together as co-infections helps predict emerging areas where people are more likely to be exposed as well.

Liquid Chromatographic Method for Determination of Vanillin and Ethyl Vanillin in Imitation Vanilla Extract (Modification of AOAC Official Method 990.25): Collaborative Study

A collaborative study of a method for analysis of vanillin and ethyl vanillin in fortified and imitation vanilla flavors was performed. The method, which is an extension of AOAC Official Method 990.25, Vanillin, Vanillic Acid, p-Hydroxybenzaldehyde, and p-Hydroxybenzoic Acid in Vanilla Extract, Liquid Chromatographic Method, involves reversed-phase high-pressure liquid chromatography (LC) of the sample on a Cβ column with a water-methanol-acetic acid (89 + 10 + 1) mobile phase and UV detection at 254 nm. The method yields good recoveries of vanillin at 484 and 723 mg/100 mL and of ethyl vanillin from 37 to 400 mg/100 mL. For vanillin, repeatability (r) values were 8 mg/100 mL at a level of 155 mg/100 mL, 12 mg/100 mLat a level of 484 mg/100 mL, and 31 mg/100 mL at a level of 723 mg/100 mL. Reproducibility (R) values were 20 mg/100 mL, 55 mg/100 mL, and 137 mg/100 mL over the same range. For ethyl vanillin, r values were 2.4 mg/100 mL at a level of 37 mg/100 mL, 3.2 mg/100 mL at a level of 74 mg/100 mL, and 8.6 mg/100 mL at a level of 180 mg/100 mL. R values were 6.4 mg/100 mL, 5.4 mg/100 mL, and 22.0 mg/100 mL over the same range. AOAC Official Method 990.25 has been modified to include determination of ethyl vanillin in vanilla extract and artificial vanilla flavor.

Comorbid infections induce progression of visceral leishmaniasis

BACKGROUND

Visceral leishmaniasis (VL) is a vector borne zoonotic disease endemic in humans and dogs in Brazil. Due to the increased risk of human infection secondary to the presence of infected dogs, public health measures in Brazil mandate testing and culling of infected dogs. Despite this important relationship between human and canine infection, little is known about what makes the dog reservoir progress to clinical illness, significantly tied to infectiousness to sand flies. Dogs in endemic areas of Brazil are exposed to many tick-borne pathogens, which are likely to alter the immune environment and thus control of L. infantum.

RESULTS

A cross-sectional study of 223 dogs from an area of Natal, in the Rio Grande do Norte, Brazil, were studied to determine the association between comorbid tick-borne disease and Leishmania infection in this endemic area. The risk of Leishmania seropositivity was 1.68× greater in dogs with tick-borne disease seropositivity compared to those without (Adjusted RR: 1.68, 95% CI: 1.09-2.61, P = 0.019). A longitudinal study of 214 hunting dogs in the USA was conducted to determine the causal relationship between infection with tick-borne diseases and progression of VL. Hunting dogs were evaluated three times across a full tick season to detect incident infection with tick-borne diseases. A logistic regression model with generalized estimating equations to estimate the parameters was used to determine how exposure to tick-borne disease altered VL progression over these three time points when controlling for other variables. Dogs infected with three or more tick-borne diseases were 11× more likely to be associated with progression to clinical VL than dogs with no tick-borne disease (Adjusted RR: 11.64, 95% CI: 1.22-110.99, P = 0.03). Dogs with exposure to both Leishmania spp. and tick-borne diseases were five times more likely to die during the study period (RR: 4.85, 95% CI: 1.65-14.24, P = 0.0051).

CONCLUSIONS

Comorbid tick-borne diseases dramatically increased the likelihood that a dog had clinical L. infantum infection, making them more likely to transmit infection to sand flies and people. As an important consequence, reduction of tick-borne disease exposure through topical or oral insecticides may be an important way to reduce progression and transmissibility of Leishmania infection from the canine reservoir to people.

Randomized, controlled, double-blinded field trial to assess Leishmania vaccine effectiveness as immunotherapy for canine leishmaniosis

Better tools are necessary to eliminate visceral leishmaniasis (VL). Modeling studies for regional Leishmania elimination indicate that an effective vaccine is a critical tool. Dogs are the reservoir host of L. infantum in Brazil and the Mediterranean basin, and therefore are an important target for public health interventions as well as a relevant disease model for human VL. No vaccine has been efficacious as an immunotherapy to prevent progression of already diagnostically positive individuals to symptomatic leishmaniasis. We performed a double-blinded, block-randomized, placebo-controlled, vaccine immunotherapy trial testing the efficacy of a recombinant Leishmania A2 protein, saponin-adjuvanted, vaccine, LeishTec®, in owned hunting dogs infected with L. infantum. The primary outcome was reduction of clinical progression, with reduction of mortality as a secondary outcome. Vaccination as an immunotherapy reduced the risk of progression to clinically overt leishmaniasis by 25% in asymptomatic dogs (RR: 1.33 95% C.I. 1.009-1.786 p-value: 0.0450). Receiving vaccine vs. placebo reduced all-cause mortality in younger asymptomatic dogs by 70% (RR: 3.19 95% C.I.: 1.185-8.502 p-value = 0.0245). Vaccination of infected-healthy animals with an anti-Leishmania vaccine significantly reduced clinical progression and decreased all-cause mortality. Use of vaccination in infected-healthy dogs can be a tool for Leishmania control.

Safety Analysis of Leishmania Vaccine Used in a Randomized Canine Vaccine/Immunotherapy Trial

In Leishmania infantum-endemic countries, controlling infection within dogs, the domestic reservoir, is critical to public health. There is a need for safe vaccines that prevent canine progression with disease and transmission to others. Protective vaccination against Leishmania requires mounting a strong, inflammatory, Type 1 response. Three commercially available canine vaccines on the global veterinary market use saponin or inflammatory antigen components (Letifend) as a strong pro-inflammatory adjuvant. There is very little information detailing safety of saponin as an adjuvant in field trials. Safety analyses for the use of vaccine as an immunotherapeutic in asymptomatically infected animals are completely lacking. Leishmania infantum, the causative agent of canine leishmaniasis, is enzootic within U.S. hunting hounds. We assessed the safety of LeishTec^® after use in dogs from two different clinical states: 1) without clinical signs and tested negative on polymerase chain reaction and serology or 2) without clinical signs and positive for at least one Leishmania diagnostic test. Vaccine safety was assessed after all three vaccinations to quantify the number and severity of adverse events. Vaccinated animals had an adverse event rate of 3.09%, whereas placebo animals had 0.68%. Receiving vaccine was correlated with the occurrence of mild, site-specific, reactions. Occurrence of severe adverse events was not associated with having received vaccine. Infected, asymptomatic animals did not have a higher rate of adverse events. Use of vaccination is, therefore, likely to be safe in infected, asymptomatic animals.

Loss of the Sall3 gene leads to palate deficiency, abnormalities in cranial nerves, and perinatal lethality

Members of the Spalt gene family encode putative transcription factors characterized by seven to nine C2H2 zinc finger motifs. Four genes have been identified in mice--Spalt1 to Spalt4 (Sall1 to Sall4). Spalt homologues are widely expressed in neural and mesodermal tissues during early embryogenesis. Sall3 is normally expressed in mice from embryonic day 7 (E7) in the neural ectoderm and primitive streak and subsequently in the brain, peripheral nerves, spinal cord, limb buds, palate, heart, and otic vesicles. We have generated a targeted disruption of Sall3 in mice. Homozygous mutant animals die on the first postnatal day and fail to feed. Examination of the oral structures of these animals revealed that abnormalities were present in the palate and epiglottis from E16.5. In E10.5 embryos, deficiencies in cranial nerves that normally innervate oral structures, particularly the glossopharyngeal nerve (IX), were observed. These studies indicate that Sall3 is required for the development of nerves that are derived from the hindbrain and for the formation of adjacent branchial arch derivatives.

Test characteristics of a level I or II fetal ultrasound in detecting structural heart disease

At the University of California Davis Medical Center, a screening fetal ultrasound examination (level I or II) incorporates a comprehensive segmental evaluation of the fetal heart. This study evaluated the reliability of the fetal ultrasound exam in the detection of abnormal heart anatomy. Our retrospective study reviewed results of 614 antenatal patients that had a screening fetal ultrasound exam. All patients subsequently underwent a detailed targeted fetal cardiac ultrasound exam performed by a pediatric cardiac sonographer and reviewed by a board-certified pediatric cardiologist. Of these 614 patients, 60 fetuses had structural heart disease by the targeted fetal exam. The screening fetal ultrasound exam correctly identified 55 of the 60, with 5 false negatives (8.3% false-negative rate) and 1 false positive (1.7% false-positive rate). Our study suggests that if a screening fetal ultrasound exam incorporates a segmental evaluation of the fetal heart it can reliably detect abnormal heart anatomy. At our institution a targeted fetal cardiac exam is now used to confirm and provide detailed assessment of the heart anatomy when a screening fetal exam is positive for heart disease.

A new member of the spalt like zinc finger protein family, Msal-3, is expressed in the CNS and sites of epithelial/mesenchymal interaction

We have identified a new member of the spalt-like gene family in mice, msal-3. We compared the expression patterns of msal-3 and msal-1 during development and show that they exhibit overlapping yet exclusive patterns of expression in the developing forebrain, diencephalon, midbrain/hindbrain boundary and spinal cord. Both genes are expressed from E7 in opposite gradients in primitive streak mesoderm. Subsequently their transcripts are localized to regions of mesenchyme/epithelial interaction in the palate, heart, limbs, anal and urogenital region.

Absent pulmonary valve with tricuspid atresia or severe tricuspid stenosis: report of three cases and review of the literature

Absence of the pulmonary valve occurs usually in association with tetralogy of Fallot and occasionally with an atrial septal defect or as an isolated lesion. Very rarely it occurs with tricuspid atresia, intact ventricular septum, and dysplasia of the right ventricular free wall and of the ventricular septum. We present the clinical, anatomic, and histologic findings of a new case, and for the first time, the data from two patients with absent pulmonary valve and severe tricuspid stenosis, who exhibited similar histologic findings. We also reviewed the clinical and anatomic data of 24 previously published cases and compared them with the new cases. In all three new cases, the myocardium of the right ventricle was very abnormal. In the two cases with tricuspid stenosis, large segments of myocardium were replaced with sinusoids and fibrous tissue. In the case with tricuspid atresia, the right ventricular free wall contained only fibroelastic tissue. The ventricular septum in all three patients showed asymmetric hypertrophy and in two of the three patients, multiple sinusoids had replaced large segments of myocardial cells. The left ventricular free wall myocardium and the walls of the great arteries were unremarkable. Our data indicate that myocardial depletion involving the right ventricular free wall and the ventricular septum and its replacement by sinusoids and fibroelastic tissue occur not only in cases of absent pulmonary valve with tricuspid atresia but also in cases of absent pulmonary valve with tricuspid stenosis. The degree of myocardial depletion varies and is more severe when the tricuspid valve is atretic.

Family adaptation to a child's feeding and swallowing disorder: a social work perspective

The various tasks and demands faced by families of children with feeding and swallowing disorders are complex and multifaceted. While families' adaptations are idiosyncratic, there are systemic patterns of adaptation which consistently reflect issues of crisis, resilience, and change. A family systems perspective is used to describe the various cognitive, emotional, and social adaptation tasks of families with children who have dysphagia. Kubler-Ross's model (1969) for the grieving process is applied to the process of coming to terms with a child's difficulties and reaching an adaptive status.

A review of the dosimetry of 1% silver sulfadiazine cream in burn wound treatment

A review of the periodical literature relating to burn topical antibacterial agents as listed in the Cumulated Index Medicus from January 1, 1965, through November 30, 1992, as well as bound volumes and unpublished material reveals that the optimal dose and mode of deployment of 1% silver sulfadiazine cream in burn wound therapy have not been fully defined. Defining these should provide better control of sepsis in burn facilities. The effectiveness of a burn topical antibacterial agent depends in part upon the extent to which it is absorbed. The process of absorption of a burn topical antibacterial agent may be likened to that of an in vitro model in which the absorption of a test solute through an isolated preparation of the stratum corneum is determined in a diffusion cell. Some of the determinants are the concentration of the solute, the volume of the solvent, the duration of contact with the membrane, the binding tendency of the solute to the membrane, the integrity and wetness of the membrane, intrinsic factors of the solute/membrane interaction (distribution and diffusion coefficients), and the adjuvant formulation. Three of these (solvent volume, duration of solute contact, and membrane wetness) are readily adjusted. As a possible preliminary to the more effective clinical use of 1% silver sulfadiazine, a ranging of these three factors and of the silver sulfadiazine concentration, should be carried out in a rat model with septic burns. Though control of burn wound bacteria remains of overriding importance, the absorption of silver through the burn wound treated with silver sulfadiazine, binding to normal tissues, is a source of rising concern and requires further investigation.

Tubular ectasia of the rete testis

Tubular ectasia of the rete testis is an uncommon entity that is usually discovered incidentally during ultrasound evaluation of epididymal abnormalities. The characteristic ultrasound appearance, its frequent association with spermatoceles and the lack of a palpable mass are the main features that permit identification of this entirely benign lesion.

Nystagmus in motor neuron disease: clinicopathological study of two cases

Two patients with amyotrophic lateral sclerosis proved postmortem had nystagmus in addition to typical clinical signs of motor neuron disease. The first patient had gaze-evoked rotatory nystagmus that was followed by horizontal nystagmus in the primary position with supranuclear paresis of horizontal gaze and upgaze. The second patient had rotatory nystagmus that was evoked by lateral gaze, with normal range of eye movements. Nystagmus is so rare in motor neuron disease that these observations may imply another disease, but postmortem examination did not provide any other explanation. These two cases add to the increasing evidence that motor neuron disease comprises a heterogeneous group of disorders.

Hypnotic age-regression and magnitudes of the Ponzo and Poggendorff illusions

The effect of hypnotically induced age-regression on the magnitudes of the Ponzo and Poggendorff illusions was determined for ten college students. The results, when compared with normative developmental data, are more typical of younger ages than of the chronological ages of the subjects.