Oronasal or Intramuscular Immunization with a Thermo-Attenuated ASFV Strain Provides Full Clinical Protection against Georgia 2007/1 Challenge

African swine fever (ASF) is a contagious viral disease of suids that induces high mortality in domestic pigs and wild boars. Given the current spread of ASF, the development of a vaccine is a priority. During an attempt to inactivate the Georgia 2007/1 strain via heat treatment, we fortuitously generated an attenuated strain called ASFV-989. Compared to Georgia, the ASFV-989 strain genome has a deletion of 7458 nucleotides located in the 5'-end encoding region of MGF 505/360, which allowed for developing a DIVA PCR system. In vitro, in porcine alveolar macrophages, the replication kinetics of the ASFV-989 and Georgia strains were identical. In vivo, specific-pathogen-free (SPF) pigs inoculated with the ASFV-989 strain, either intramuscularly or oronasally, exhibited transient hyperthermia and slightly decreased growth performance. Animals immunized with the ASFV-989 strain showed viremia 100 to 1000 times lower than those inoculated with the Georgia strain and developed a rapid antibody and cell-mediated response. In ASFV-989-immunized pigs challenged 2 or 4 weeks later with the Georgia strain, no symptoms were recorded and no viremia for the challenge strain was detected. These results show that the ASFV-989 strain is a promising non-GMO vaccine candidate that is usable either intramuscularly or oronasally.

Malignant Melanoma in a Long-legged Buzzard (Buteo rufinus): Characterization of Clinical and Histologic Lesions

A 17-year-old, male long-legged buzzard (Buteo rufinus) presented for acute lethargy and black gelatinous tissue in both nostrils. Despite intensive care, the bird died within 2 days. A postmortem computed tomographic scan of the head revealed a complete obstruction of the rostral infraorbital sinus, later confirmed by necropsy. Postmortem examination also highlighted multifocal, black, infiltrating nodules of various sizes (2 mm to 2 cm in diameter) in almost all internal organs: lungs, heart (pericardium, myocardium, endocardium), kidneys, pancreas, adrenals, muscles, and bones (periosteum and medulla). Histologically, the nodules were composed of anaplastic cells containing abundant melanin pigment, consistent with a disseminated melanoma. Malignant melanomas are aggressive neoplasms frequently reported in mammals but rarely found in avian species. In Accipitridae and Falconidae, only 2 cases have been reported.

Oronasal and Oroantral Fistulas Secondary to Periodontal Disease: A Retrospective Study Comparing the Prevalence Within Dachshunds and a Control Group

The prevalence of oronasal and oroantral fistulas (ONF/OAF) was retrospectively identified in a population of dachshund patients (dachshund group) and was compared to a population of small breed dogs of significantly similar age and weight (control group). When compared with the control group, the dachshund group was significantly more likely to have an ONF/OAF (P < .0001). The odds ratio indicates that dachshunds were 3.3 times more likely to have an ONF/OAF than individuals within the control group. This study statistically confirms previous reports and clinical observations that dachshunds are predisposed to ONF/OAFs. When ONF/OAFs are present, the maxillary canines are the most commonly affected dentition in both study groups.

Computed tomographic description of the highly variable imaging features of equine oromaxillary sinus and oronasal fistulae

Oronasal and oromaxillary sinus fistulae are well-documented complications following removal or loss of a maxillary cheek tooth. Diagnosis is currently based on a combination of oral examination, videoendoscopy, radiography, and computed tomography (CT). The objective of this retrospective, case series study was to describe the CT characteristics of confirmed oronasal and oromaxillary sinus fistulae in a group of horses. Inclusion criteria were a head CT acquired at the authors' hospital during the period of 2012-2017, a CT diagnosis of oronasal or oromaxillary sinus fistulae, and a confirmed diagnosis based on a method other than CT. Signalment, clinical findings, oral examination findings, presence of a confirmed fistula, and method for confirmation of the diagnosis were recorded. A veterinary radiologist reviewed CT studies for all included horses and recorded characteristics of the fistulae. Seventeen horses were sampled. Fourteen oromaxillary sinus fistulae and three oronasal fistulae were identified. All fistulae appeared as variably sized focal defects in the alveolar bone. Defects frequently contained a linear tract of heterogeneous material interspersed with gas bubbles, considered consistent with food. Computed tomographic attenuation of the material (Hounsfield units, HU) varied widely within and between cases. In 16 of 17 cases, there was evidence of concurrent dental disease in addition to the fistulae. Although the gold standard diagnostic test remains identification of feed material within the sinus or nasal passages, findings from the current study support the use of CT as an adjunctive diagnostic test for assessing the extent of involvement and presurgical planning.

Choosing an Oronasal Mask to Deliver Continuous Positive Airway Pressure May Cause More Upper Airway Obstruction or Lead to Higher Continuous Positive Airway Pressure Requirements than a Nasal Mask in Some Patients: A Case Series

STUDY OBJECTIVES

The choice of mask interface used with continuous positive airway pressure (CPAP) therapy can affect the control of upper airway obstruction (UAO) in obstructive sleep apnea (OSA). We describe a case series of four patients with paradoxical worsening of UAO with an oronasal mask and the effect of changing to a nasal mask.

METHODS

We retrospectively reviewed the case histories of 4 patients and recorded patient demographics, in-laboratory and ambulatory CPAP titration data, CPAP therapy data, type of mask interface used and potential confounding factors.

RESULTS

The 4 cases (mean ± SD: age = 59 ± 16 y; BMI = 30.5 ± 4.5 kg/m(2)) had a high residual apnoea-hypopnea index (AHI) (43 ± 14.2 events/h) and high CPAP pressure requirements (14.9 ± 6.6 cmH2O) with an oronasal mask. Changing to a nasal mask allowed adequate control of UAO with a significant reduction in the average residual AHI (3.1 ± 1.5 events/h). In two of the four cases, it was demonstrated that control of UAO was obtained at a much lower CPAP pressure compared to the oronasal mask (Case one = 17.5 cmH2O vs 12cmH2O; Case two = 17.9 cmH2O vs 7.8 cmH2O). Other potential confounding factors were unchanged. There are various physiological observations that may explain these findings but it is uncertain which individuals are susceptible to these mechanisms.

CONCLUSIONS

If patients have OSA incompletely controlled by CPAP with evidence of residual UAO and/or are requiring surprisingly high CPAP pressure to control OSA with an oronasal mask, the choice of mask should be reviewed and consideration be given to a trial of a nasal mask.

COMMENTARY

A commentary on this article appears in this issue on page 1209.

Equivalence of nasal and oronasal masks during initial CPAP titration for obstructive sleep apnea syndrome

STUDY OBJECTIVE

Continuous positive airway pressure (CPAP) titration studies are commonly performed using a nasal mask but some patients may prefer a full-face or oronasal mask. There is little evidence regarding the equivalence of different mask interfaces used to initiate treatment. We hypothesized that oronasal breathing when using an oronasal mask increases upper airway collapsibility and that a higher pressure may be required to maintain airway patency. We also assessed patient preferences for the 2 mask interfaces.

DESIGN

Prospective, randomized, cross-over design with 2 consecutive CPAP titration nights.

SETTING

Accredited laboratory in a university hospital.

PATIENTS OR PARTICIPANTS

Twenty-four treatment-naive subjects with obstructive sleep apnea syndrome and respiratory disturbance index of greater than 15 events per hour.

INTERVENTIONS

CPAP titration was performed using an auto-titrating machine with randomization to a nasal or oronasal mask, followed by a second titration night using the alternate mask style.

MEASUREMENTS AND RESULTS

There was no significant difference in the mean pressures determined between nasal and oronasal masks, although 43% of subjects had nasal-to-oronasal mask-pressure differences of 2 cm H(2)O or more. Residual respiratory events, arousals, and measured leak were all greater with the oronasal mask. Seventy-nine percent of subjects preferred the nasal mask.

CONCLUSIONS

Patients with obstructive sleep apnea syndrome can generally switch between nasal and oronasal masks without changing machine pressure, although there are individual differences that may be clinically significant. Measured leak is greater with the oronasal mask. Most patients with obstructive sleep apnea syndrome prefer a nasal mask as the interface for initiation of CPAP.

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN: ACTRN12611000243910. URL: http://www.ANZCTR.org.au/ACTRN12611000243910.aspx