Synergising tools for capacity assessment and One Health operationalisation.

Multisectoral, One Health collaboration is essential for addressing national and international health threats that arise at the human-animal-environment interface. Thanks to the efforts of multiple organisations, countries now have an array of One Health tools available to assess capacities within and between sectors, plan and prioritise activities, and strengthen multisectoral, One Health coordination, communication, and collaboration. By doing so, they are able to address health threats at the human-animal-environment interface, including emerging zoonotic and infectious diseases, more efficiently. However, to ensure optimal outcomes for the countries using these One Health tools, the partners responsible for implementation should regularly collaborate and share information such as implementation timelines, results and lessons learned, so that one process can inform the next. This paper presents a consensus framework on how commonly implemented One Health tools might align to best support countries in strengthening One Health systems. Twelve One Health tools were selected based on their high implementation rates, authors' experience with these tools and their focus on multisectoral, One Health coordination. Through a four-step process, the authors: a) jointly carried out a landscape analysis of One Health tools, using a Cloudbased spreadsheet to share the unique characteristics and applications of each tool; b) performed an implementation analysis to identify and share implementation dynamics and identify respective outcomes and synergies; c) jointly created a consensus conceptual model of how the authors suggest the tools might logically work together; and d) extrapolated from steps 1-3 an agreed-upon overarching conceptual framework for how current and future One Health tools could be categorised to best support One Health system strengthening at the national level. Highlighted One Health tools include the States Parties Annual Reporting Tool under the International Health Regulations (IHR), the World Organisation for Animal Health Performance of Veterinary Services (PVS) Pathway, the Joint External Evaluation process, IHR/PVS National Bridging Workshops, the Centers for Disease Control and Prevention One Health Zoonotic Disease Prioritization Tool, the Food and Agriculture Organization (FAO) Laboratory Mapping Tool, the FAO Assessment Tool for Laboratories and Antimicrobial Resistance Surveillance Systems, the FAO Surveillance Evaluation Tool, the One Health Systems Mapping and Analysis Resource Toolkit, the National Action Plan for Health Security, and IHR Monitoring and Evaluation Framework tools for After Action Reviews and Simulation Exercises. A new guidance document entitled, Taking a Multisectoral, One Health Approach: A Tripartite Guide to Addressing Zoonotic Diseases in Countries was also included as a framework that provides guidance to support the implementation of the outputs of the tools described.

La collaboration multisectorielle suivant l'approche Une seule santé est essentielle pour répondre aux menaces sanitaires survenant à l'interface homme­animal­ environnement à l'échelle nationale et internationale. Grâce aux efforts conjugués de nombreuses organisations, les pays disposent désormais d'une gamme d'outils Une seule santé permettant à la fois d'évaluer les capacités intra et intersectorielles, de planifier et prioriser les activités, et de renforcer la coordination, la communication et la collaboration multisectorielles suivant cette approche. Grâce à ces outils, les pays sont mieux armés pour faire face avec efficacité aux menaces sanitaires à l'interface homme­animal­environnement, en particulier celles liées aux maladies zoonotiques et infectieuses émergentes. Néanmoins, pour optimiser les retombées pour les pays du recours aux outils Une seule santé, les partenaires chargés de leur mise en oeuvre devraient régulièrement collaborer et partager leurs informations, notamment le calendrier de mise en oeuvre, les résultats obtenus et les enseignements tirés, afin que chaque processus contribue à l'amélioration des suivants. Les auteurs présentent un cadre consensuel sur la manière dont les outils Une seule santé les plus courants peuvent converger afin d'aider le mieux possible les pays à renforcer leurs systèmes basés sur cette approche. Douze outils ont été choisis en fonction de leur fréquence d'utilisation, de l'expérience acquise par les auteurs et de l'accent mis sur la coordination multisectorielle Une seule santé. Les auteurs ont ensuite procédé à un examen en quatre étapes, comme suit : a) analyse générale des outils sélectionnés, au moyen d'un tableur sur serveur dématérialisé permettant de saisir et de partager les caractéristiques et les applications spécifiques de chaque outil ; b) analyse de la mise en oeuvre des outils, visant à déterminer et à partager la dynamique et les caractéristiques de mise en oeuvre, ainsi que les résultats respectifs et les synergies qui en ressortent ; c) création d'un modèle conceptuel consensuel contenant les propositions des auteurs en vue d'une convergence raisonnée des fonctionnalités de ces outils ; d) à partir des trois étapes précédentes, conception d'un cadre conceptuel transversal destiné à catégoriser les outils Une seule santé actuels et futurs afin d'apporter un soutien optimal au renforcement des systèmes Une seule santé à l'échelle des pays. Parmi les outils examinés figurent l'Outil d'autoévaluation pour l'établissement de rapports annuels par les États Parties de l'Organisation mondiale de la santé (OMS), qui concerne l'application du Règlement sanitaire international (RSI) ; le Processus sur les Performances des Services vétérinaires (PVS) de l'Organisation mondiale de la santé animale (OIE) ; le processus d'Évaluation extérieure conjointe ; les ateliers nationaux de liaison RSI/PVS ; l'outil Une seule santé de priorisation des maladies zoonotiques des Centres pour le contrôle et la prévention des maladies (CDC) ; l'Outil de cartographie des laboratoires de l'Organisation des Nations Unies pour l'alimentation et l'agriculture (FAO) ; l'Outil d'évaluation de la FAO pour les laboratoires et les systèmes de surveillance de l'antibiorésistance ; l'Outil d'évaluation de la FAO sur la surveillance ; la Boîte à outils cartographiques et analytiques sur les systèmes Une seule santé ; les Plans d'action nationaux de sécurité sanitaire ; et enfin les outils d'examen après action et protocoles de simulation du Cadre de suivi et d'évaluation du RSI. Le document d'orientation récemment publié sous le titre Taking a multisectoral One Health approach: a Tripartite guide to addressing zoonotic diseases in countries [Adopter une approche multisectorielle Une seule santé : Guide tripartite pour lutter contre les maladies zoonotiques] est également présenté, en tant qu'il fournit un cadre directeur en appui de la mise en oeuvre des résultats des outils d'évaluation ci-dessus.

La colaboración multisectorial en clave de Una sola salud es esencial para responder a las amenazas sanitarias de dimensión nacional e internacional que surgen en la confluencia de personas, animales y medio ambiente. Gracias al trabajo de numerosas organizaciones, los países disponen ahora de un repertorio de herramientas concebidas desde la óptica de Una sola salud para evaluar las capacidades existentes dentro de los sectores y entre ellos, planificar y jerarquizar actividades y potenciar las labores de coordinación, comunicación y colaboración multisectoriales en clave de Una sola salud. Gracias a todo ello, los países están en condiciones de luchar más eficazmente contra las amenazas sanitarias en la interfaz de personas, animales y medio ambiente, en particular las enfermedades infecciosas y zoonóticas emergentes. No obstante, para que los países obtengan resultados óptimos del uso de estas herramientas de Una sola salud es preciso que los distintos colaboradores encargados de aplicarlas colaboren e intercambien información periódicamente, por ejemplo sobre plazos de ejecución, resultados obtenidos y enseñanzas extraídas, de tal manera que un proceso pueda alimentar el siguiente. Los autores presentan un conjunto de principios consensuados sobre el modo en que cabría armonizar entre sí las herramientas de Una sola salud utilizadas con frecuencia para que los países cuenten con un apoyo idóneo a la hora de fortalecer los sistemas de Una sola salud. Ante todo, los autores seleccionaron doce de esas herramientas atendiendo a su (elevado) nivel de utilización, la experiencia de los propios autores con ellas y la medida en que privilegian la coordinación multisectorial en clave de Una sola salud. Después, siguiendo un proceso en cuatro etapas: a) efectuaron colectivamente un análisis general de las herramientas existentes, empleando una hoja de cálculo situada en la «nube¼ para poner en común las características y aplicaciones únicas de cada herramienta; b) analizaron la utilización práctica de esas herramientas de Una sola salud para dilucidar y poner en común la dinámica de aplicación de cada una y determinar sus respectivos resultados y sinergias; c) elaboraron de forma concertada un modelo teórico del modo en que, a su juicio, sería lógico que las herramientas funcionaran conjuntamente; y d) a partir de los pasos 1 a 3, extrapolaron consensuadamente un marco teórico global con el que se podrían clasificar las herramientas de Una sola salud, actuales y futuras, para prestar un apoyo idóneo al fortalecimiento del sistema de Una sola salud en cada país. Las herramientas de Una sola salud seleccionadas son: el instrumento de evaluación para la presentación anual de informes de los Estados Partes que forma parte del Reglamento Sanitario Internacional (RSI); el proceso PVS (Prestaciones de los Servicios Veterinarios) de la Organización Mundial de Sanidad Animal (OIE); la herramienta de evaluación externa conjunta del RSI; los talleres nacionales de coordinación RSI-PVS; la herramienta de jerarquización de enfermedades zoonóticas en clave de Una sola salud de los Centros para el Control y la Prevención de Enfermedades (CDC); la herramienta de inventario de laboratorios de la Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO); la herramienta de evaluación de laboratorios y sistemas de vigilancia de las resistencias a los antimicrobianos de la FAO; la herramienta de evaluación de la vigilancia de la FAO; el juego de herramientas y material de análisis y cartografía de los sistemas de Una sola salud; los planes de acción nacional de seguridad sanitaria de la OMS; las herramientas del marco de seguimiento y evaluación del RSI para la realización de exámenes posteriores a la acción y ejercicios de simulación. También se incluyó una nueva guía de la Tripartita para combatir las enfermedades zoonóticas en los países desde la lógica multisectorial de Una sola salud (Taking a multisectoral One Health approach: a Tripartite guide to addressing zoonotic diseases in countries), en el cual se ofrecen pautas para secundar la aplicación en la práctica de los resultados obtenidos con las citadas herramientas.

Review of influenza A virus in swine worldwide: a call for increased surveillance and research.

Pigs and humans have shared influenza A viruses (IAV) since at least 1918, and many interspecies transmission events have been documented since that time. However, despite this interplay, relatively little is known regarding IAV circulating in swine around the world compared with the avian and human knowledge base. This gap in knowledge impedes our understanding of how viruses adapted to swine or man impacts the ecology and evolution of IAV as a whole and the true impact of swine IAV on human health. The pandemic H1N1 that emerged in 2009 underscored the need for greater surveillance and sharing of data on IAV in swine. In this paper, we review the current state of IAV in swine around the world, highlight the collaboration between international organizations and a network of laboratories engaged in human and animal IAV surveillance and research, and emphasize the need to increase information in high-priority regions. The need for global integration and rapid sharing of data and resources to fight IAV in swine and other animal species is apparent, but this effort requires grassroots support from governments, practicing veterinarians and the swine industry and, ultimately, requires significant increases in funding and infrastructure.

Contact variables for exposure to avian influenza H5N1 virus at the human-animal interface.

Although the highly pathogenic avian influenza H5N1 virus continues to cause infections in both avian and human populations, the specific zoonotic risk factors remain poorly understood. This review summarizes available evidence regarding types of contact associated with transmission of H5N1 virus at the human-animal interface. A systematic search of the published literature revealed five analytical studies and 15 case reports describing avian influenza transmission from animals to humans for further review. Risk factors identified in analytical studies were compared, and World Health Organization-confirmed cases, identified in case reports, were classified according to type of contact reported using a standardized algorithm. Although cases were primarily associated with direct contact with sick/unexpectedly dead birds, some cases reported only indirect contact with birds or contaminated environments or contact with apparently healthy birds. Specific types of contacts or activities leading to exposure could not be determined from data available in the publications reviewed. These results support previous reports that direct contact with sick birds is not the only means of human exposure to avian influenza H5N1 virus. To target public health measures and disease awareness messaging for reducing the risk of zoonotic infection with avian influenza H5N1 virus, the specific types of contacts and activities leading to transmission need to be further understood. The role of environmental virus persistence, shedding of virus by asymptomatic poultry and disease pathophysiology in different avian species relative to human zoonotic risk, as well as specific modes of zoonotic transmission, should be determined.

Smokeless tobacco use 1992-2002: trends and measurement in the Current Population Survey-Tobacco Use Supplements.

BACKGROUND: As smoking prevalence declines in the United States, it is important to understand if smokeless tobacco (SLT) use is also changing and if so, among what groups. METHODS: We examine the prevalence of SLT use and smoking, 1992-2002, using the Current Population Survey-Tobacco Use Supplements (CPS-TUS), which used US nationally representative samples based on stratified clusters of households. RESULTS: Consistent with declines in smoking, the prevalence of current SLT use declined over the period 1992-2002 for males and females ages 18 and older. The overall separate declines in SLT use and in smoking are mirrored by a decline in concurrent use of SLT and cigarettes. SLT use is becoming more associated with white males, but use is declining faster among the youngest males. CONCLUSIONS: The findings indicate that relative reductions in smoking prevalence are exceeded by relative reductions in SLT use, with sizeable reductions in concurrent use. These results suggest that the stricter cigarette policies of recent years may not only reduce cigarette use, but also the use of alternative tobacco products. In light of potential policy implications of SLT use as a potential reduced exposure product (PREP), current survey methods require more careful measurement of SLT use in terms of initiation, duration, quantity, and cessation.

Risk assessment and surveillance for bovine spongiform encephalopathy.

The national risk of bovine spongiform encephalopathy (BSE) has not been assessed by many countries, and many countries are conducting little or no BSE surveillance. National measures implemented, including import restrictions, surveillance systems, and sanitary controls, should be based on actual BSE risk. Thus, as a first step, the national BSE status must be determined, particularly through assessment of the national risk. The World Organisation for Animal Health (OIE) provides recommendations for surveillance and risk assessment of BSE, which are considered the international standard by the World Trade Organization (WTO). This document describes the variables for determination of BSE status and gives guidance on specific options and practical considerations for meeting the BSE surveillance and risk assessment recommendations of the OIE.

The future of BSE from the global perspective.

Although, the bovine spongiform encephalopathy (BSE) risk of most countries in Europe has been assessed and they have implemented both measures to control BSE and extensive surveillance systems, complete and valid data is still not consistently available. Globally, data is largely unavailable. Assessments based on incomplete or invalid information could lead to false conclusions. The BSE risk of countries throughout the world must continue to be assessed, and improvements in collection of surveillance data must be made, both in countries already reporting BSE cases and worldwide, in order to evaluate the global BSE picture and assure that cattle and products can be safely traded.

Recent trends in home and work smoking bans.

OBJECTIVES: Home and work smoking bans at the national and state level in the USA, and their relation to smoking prevalence and to tobacco control policies, are examined. DATA: The Current Population Survey's 1992/93 and 1998/99 tobacco use supplement surveys are the primary data source, supplemented with information on state level tobacco control policies. METHODS: The national and state rate of bans are estimated, and changes over the course of the 1990s and their relation to smoking rates and tobacco control policies are examined. RESULTS: The prevalence of work and home bans has increased considerably between 1992/93 and 1998/99. By 1999, over 65% of the population age 15 and above work in places with smoking bans, and over 60% live in homes with bans. We found that states with lower than average ban rates in 1993 tended to have had larger increases in ban rates between 1993 and 1999. We also found that home and work bans became more prevalent in states with initially low smoking rates, and that the growth in home bans coincided with a declining prevalence of smoking. States with higher levels of bans by 1999 also tended to have higher cigarette taxes, stricter clean air laws, and media/comprehensive campaigns in place. CONCLUSIONS: The results indicate that lower smoking rates are associated with higher rates of work and home bans, although substantial progress has also been made by those states with initially low rates of bans. While further work is needed to establish the direction of causality, it would appear that reductions in smoking rates, either through stronger tobacco control policies or otherwise, may reduce exposure to tobacco smoke not only by reducing the number of smokers, but also through increasing the number of firms and homes with smoking restrictions.

Occurrence of infectious upper respiratory tract disease and response to vaccination in horses on six sentinel premises in northern Colorado.

REASONS FOR PERFORMING STUDY: Horses vaccinated against common agents of infectious upper respiratory disease (IURD) may not have detectable serum antibody and may not be protected from clinical disease. OBJECTIVES: The objectives of this study were to 1) investigate the serological response of horses to vaccination against influenza virus (H3N8 and H7N7) and equine herpesviruses (EHV) in a field setting and 2) evaluate associations among vaccination status, serum antibody concentrations, and occurrences of IURD in monitored horses. METHODS: In this study, horses on 6 Colorado premises were vaccinated parenterally against influenza virus and EHV, and serological response evaluated. Horses were monitored, and biological samples collected from individuals with clinical IURD and control horses. RESULTS: Of 173 horses, 61 (35.3%), 21 (12.1%) and 4 (2.3%) seroconverted in response to vaccination against EHV, influenza virus H7N7 and influenza virus H3N8, respectively. CONCLUSIONS: Outbreaks of IURD in study horses were associated with influenza virus H3N8 and Streptococcus equi infection, and serological response to vaccination with conventional products was poor. POTENTIAL RELEVANCE: These results confirm that horses may not respond with detectable serological responses to conventional vaccination against common respiratory viruses and, therefore, suggest that alternate methods of protecting horses against common respiratory viruses should be sought.

Oral vesicular lesions in horses without evidence of vesicular stomatitis virus infection.

OBJECTIVE: To report clinical and serologic findings in horses with oral vesicular lesions that were consistent with vesicular stomatitis (VS) but apparently were not associated with VS virus (VSV) infection. DESIGN: Serial case study. ANIMALS: 8 horses. PROCEDURE: Horses were quarantined after appearance of oral lesions typical of VS. Severity of clinical signs was scored every 2 to 5 days for 3 months. Serum samples were tested for antibodies by use of competitive ELISA (cELISA), capture ELISA for IgM, serum neutralization, and complement fixation (CF). Virus isolation was attempted from swab specimens of active lesions. RESULTS: 2 horses with oral vesicular lesions on day 1 had antibodies (cELISA and CF) against VSV; however, results of CF were negative by day 19. Five of the 6 remaining horses were seronegative but developed oral lesions by day 23. Virus isolation was unsuccessful for all horses. CONCLUSIONS AND CLINICAL RELEVANCE: Horses were quarantined for 75 days in compliance with state and federal regulations. However, evidence suggests that oral lesions were apparently not associated with VSV infection. The occurrence in livestock of a vesicular disease that is not caused by VSV could confound efforts to improve control of VS in the United States and could impact foreign trade. Vesicular stomatitis is of substantial economic and regulatory concern.

Vesicular stomatitis and other vesicular, erosive, and ulcerative diseases of horses.

Physical trauma, dietary factors, certain toxins, immune mediated disorders, and vesicular stomatitis virus (VSV) infection are known causes of stomatitis in horses. There is evidence that some outbreaks of equine stomatitis are caused by as yet unidentified infectious agents. It remains to be determined whether stomatitis is an emerging equine infectious disease, or if the increase in reported cases is simply the result of greater public awareness as a consequence of widespread outbreaks of VSV in the southwestern United States in recent years. Focused laboratory and epidemiological studies are necessary to more adequately define non-VS related infectious and noninfectious causes of equine stomatitis.

Management factors affecting the risk for vesicular stomatitis in livestock operations in the western United States.

OBJECTIVE: To identify management factors affecting the risk of animals developing vesicular stomatitis (VS). DESIGN: Case-control study. ANIMALS: Horses, cattle, and sheep with suspected vesicular stomatitis on 395 premises in Colorado, New Mexico, Utah, and Arizona. PROCEDURE: Data were collected during the VS outbreak of 1997. Diagnosticians interviewed livestock owners and completed a supplemental questionnaire. Cases were defined as those premises that had a completed questionnaire and had > or = 1 animal positive for VS. Control premises were all premises investigated that had a completed questionnaire and on which the animals had been tested but VS was not detected. RESULTS: Animals that had access to a shelter or barn had a reduced risk of developing VS (OR, 0.6; 95% confidence interval [CI], 0.35 to 0.99). This effect was more pronounced for equine premises (OR, 0.5; 95% CI, 0.3 to 0.9). Conversely, during an adjusted analysis on equine premises, risk of developing disease was increased slightly where animals had access to pasture (OR, 2.01; 95% CI, 1.1 to 3.7). On all premises where owners reported insect populations were greater than normal, odds of developing disease were significantly increased (OR, 2.5; 95% CI, 1.47 to 4.47). Premises with animals housed < 0.25 miles from running water were more than twice as likely to have clinical signs of VS (OR, 2.6; 95% CI, 1.32 to 5.0). CONCLUSIONS AND CLINICAL RELEVANCE: These results support reports of others that suggest biting insects are a vector in VS virus transmission. Management practices to reduce exposure to biting insects might reduce the risk of VS.

Survey of the large animal diplomates of the American College of Veterinary Internal Medicine regarding percutaneous lung biopsy in the horse.

A survey designed to obtain information on the indications, contraindications, complications, and methodology of percutaneous lung biopsy in the horse was sent to large animal diplomates of the American College of Veterinary Internal Medicine. Sixty-five of 190 diplomates returned the survey (response rate: 34%) and 59 of these 65 respondents (91%) indicated that they worked with horses. Forty-four diplomates had performed a percutaneous lung biopsy in 1 or more horses (i.e. 75% of those diplomates working with horses and 68% of total respondents). Clinical and radiologic diagnoses that prompted diplomates to perform percutaneous lung biopsy in the horse included a pulmonary miliary pattern (93%), suspicion of pulmonary infiltrative disease (91%), suspicion of pulmonary neoplasia (91%), suspicion of chronic obstructive pulmonary disease (COPD) (20%), and suspicion of exercise-induced pulmonary hemorrhage (EIPH) (7%). Only one of the respondents reported the use of percutaneous lung biopsy in the diagnostic workup if pneumonia was suspected, but 11% of respondents reported that suspicion of pulmonary abscessation would prompt them to perform a percutaneous lung biopsy. In contrast, a variable percentage of respondents felt there were contraindications to performance of this technique, which included neonatal septicemia (68%), pulmonary abscessation (65%), pleuropneumonia (55%) and pneumonia (42%), EIPH (41%), and COPD (26%). No respondent indicated that suspicion of neoplasia was a contraindication to percutaneous biopsy. Most common complications observed by respondents were epistaxis (68% of respondents), putative pulmonary hemorrhage (52%), tachypnea (39%), and respiratory distress (32%). Ten of 44 respondents (23%) had not seen any complications with percutaneous lung biopsy. Forty-two of 44 respondents (96%) warned owners about possible complications before performing percutaneous lung biopsy. All respondents to this question reported that they would perform percutaneous lung biopsies in horses in the future, but 4 of 41 would use the procedure only as a last resort.

Public veterinary medicine: public health. Serologic evaluation of vesicular stomatitis virus exposure in horses and cattle in 1996.

OBJECTIVE: To determine potential risk factors for vesicular stomatitis (VS) in Colorado livestock in 1995 and evaluate VS virus (VSV) exposure of Colorado livestock in 1996. DESIGN: Retrospective case-control study of VS risk factors and seroprevalence evaluation. SAMPLE POPULATION: Premises included 52 that had VS-positive animals and 33 that did not have VS-positive animals during the 1995 epidemic, and 8 in the vicinity of premises that had VS-positive animals during the 1995 epidemic. PROCEDURE: Layout and management data for premises were collected during site visits in 1996. Signalment and management data were collected for animals from which samples were obtained, and samples were tested by serologic examination and virus isolation. The VSV seroprevalence rate was estimated for Colorado, using serum obtained for equine infectious anemia testing and from the Market Cattle Identification program in Colorado. RESULTS: At least 1 animal was seropositive for VSV on 35 of 52 (67%) premises, and 71 of 228 (31%) animals tested were seropositive for VSV. Seroprevalence was 63 of 170 (37%) for horses and 8 of 54 (15%) for cattle. Seroprevalence of VSV in animals from non-study premises in Colorado in 1996 was estimated to be 1.1% in cattle and 0.8% in horses. CLINICAL IMPLICATIONS: Overall VSV seroprevalence in Colorado livestock was less than seroprevalence in epidemic areas, and seroprevalence rates in epidemic areas were greater for horses than cattle. Results may indicate that some animals had subclinical VSV infection during epidemics and that animals may be exposed to VSV between epidemics.

Monitoring and detection of acute viral respiratory tract disease in horses.

OBJECTIVE: To develop a system to monitor and detect acute infections of the upper respiratory tract (i.e., nares, nasopharynx, and pharynx) in horses and to assess the association among specific viral infections, risk factors, and clinical signs of disease. DESIGN: Prospective study. ANIMALS: 151 horses with clinical signs of acute infectious upper respiratory tract disease (IURD) from 56 premises in Colorado. PROCEDURE: Health management data, blood samples, and nasal or nasopharyngeal swab samples were obtained for 151 horses with clinical signs of acute IURD. Of these horses, 112 had an additional blood sample obtained during convalescence and were considered to have complete sample sets. Samples were tested for evidence of respiratory tract infection by use of ELISA, virus isolation, and serologic testing of paired serum samples. RESULTS: Viral infections were identified in 65 horses with complete sample sets; influenza virus infection was identified in 43 horses, equine herpesvirus (EHV) infection in 18, and mixed influenza virus and EHV infections in 4. On 14 premises, samples were obtained from more than 1 affected horse. Viral infections were identified in horses on 11 of 14 premises. Equine herpesviruses were isolated from 10 horses. A relationship was not found between vaccination history and identification of EHV or influenza virus infections. An infection with EHV was less likely to be identified in horses with initial (acute) antibody titers > 1:16 to EHV. CLINICAL IMPLICATIONS: Influenza virus (specifically, A/equine/2) was the most common virus associated with acute IURD. Use of multiple diagnostic tests and obtaining samples from more than 1 horse in an outbreak may improve detection of viral infections.

Use of gonadotropin-releasing hormone, estrogen, or a combination to increase releasable pituitary luteinizing hormone in early transitional mares.

A lack of pituitary LH stores has been implicated as the cause of seasonal anestrus and failure to ovulate during the spring transition period in mares. In this experiment, 40 mares were used to study the effects of GnRH, estrogen, and an estrogen-GnRH combination on increasing releasable pituitary LH. Mares were stratified based on their ability to secrete LH in response to a 950-micrograms challenge of GnRH (n = 10 per group) and then assigned to one of four treatment groups: 1) controls, given no treatment; 2) 1 mg of estradiol-17 beta in oil i.m. daily for 8 d; 3) 200 micrograms of GnRH analogue des-Gly10, [D-ala6]-LHRH ethylamide in saline i.m. twice daily for 8 d; or 4) estradiol for 4 d then estradiol plus GnRH for four subsequent days. Blood was collected on d 1, 3, 5, and 7 of treatment, and serum was assayed for LH. On d 10 after initiation of treatment, mares were again challenged with GnRH (950 micrograms), and blood was collected for 4 h. Concentrations of serum LH did not vary significantly in control, estradiol-treated, or estradiol plus GnRH-treated mares among treatment days. In contrast, administration of GnRH alone increased (P < .05) concentrations of LH on d 5 and 7. Response to GnRH challenge, as measured by area under the LH curve (AUC) and peak LH, was greater (P < .05) for mares administered GnRH (7,307.1, 67.6 ng/mL, respectively) and GnRH plus estradiol (5,691.4, 60.3 ng/mL) than for mares given estradiol alone (1,519.4, 22.1 ng/mL) or no treatment (1,213.8, 19.4 ng/mL.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of various doses of a gonadotropin-releasing hormone analogue on induction of ovulation in anestrous mares.

One hundred anestrous mares (early February) were injected s.c. with implants containing 0, .9, 1.8, 3.6, or 5.4 mg of a GnRH analogue (goserelin acetate) in an attempt to induce ovarian cyclicity. Follicular activity and concentrations of progesterone and LH were determined every 3 d, or daily during estrus. In treated mares that ovulated, the interval to the second ovulation of the season was compared to that for an additional group receiving 16 h/d of light beginning December 16 (positive controls). Of the mares that did not ovulate in 30 d, eight from each dose group were challenged on d 33 or 34 with an i.v. bolus of 950 micrograms of GnRH. Blood collected at -2, -1, and 0 h before GnRH and at 15, 30, 45, 60, and 90 min and 2, 3, and 4 h after injection was assayed for serum LH. More mares (P < .05) ovulated when given 3.6- (n = 7) or 5.4-mg (n = 6) implants than when given .9-mg implants (n = 0) or placebo (n = 0). Mares with initial follicles < or = 15 mm in diameter were less (P < .05) likely to ovulate (10 of 88) than were those with follicles 16 to 20 mm in diameter (5 of 12). Area under the curve (AUC) for LH was greater for mares receiving larger doses of GnRH. The AUC and peak LH were similar between ovulating and nonovulating mares. Luteinizing hormone peaked in all mares on approximately d 12. There was no difference (P > .05) in either peak LH or AUC among treatment groups in response to the GnRH challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of antibiotics on motion characteristics of cooled stallion spermatozoa.

The control of bacteria in semen of stallions has been most effective with the use of seminal extenders containing suitable concentrations of antibiotics. However, the detrimental effect of antibiotics on sperm motility may be greater in stored, cooled semen due to the prolonged exposure to the antibiotic. Therefore, a study was conducted to determine the effect of various antibiotics on sperm motion characteristics following short term exposure and during cooled storage of semen. Reagent grade amikacin sulfate, ticarcillin disodium, gentamicin sulfate and polymixin B sulfate were added to a nonfat, dried, skim milk - glucose seminal extender at concentrations of 1000 or 2000 mug or IU/ml. Aliquots of raw semen were diluted with extender-antibiotic combinations to a concentration of 25 x 10(6) spermatozoa/ml. An aliquot was also diluted with extender without antibiotic. Aliquots were incubated at 23 degrees C for 1 h. In addition, portions of the aliquots were cooled from 23 to 5 degrees C and stored for 48 h. During 1 h of incubation of extended semen at 23 degrees C, there was a significant (P<0.05) reduction in the percentage of progressively motile spermatozoa for samples containing gentamicin sulfate. After 24 h of storage at 5 degrees C, 2000 mug/ml of gentamicin and levels equal to and greater than 1000 IU/ml of polymixin B in seminal extender resulted in significant (P<0.05) reductions in the percentages of motile and progressively motile spermatozoa. After 48 h of cooled storage, a level of 1000 mug/ml of gentamicin sulfate. resulted in significant (P<0.05) reductions in the percentages of motile and progressively motile spermatozoa. Levels equal to or greater than 1000 IU/ml of polymixin B sulfate also resulted in a significant (P<0.05) reduction in mean curvilinear velocity. Levels up to 2000 mug/ml of amikacin sulfate and ticarcillin disodium had no significant effect on sperm motion characteristics during short-term incubation at 23 degrees C or storage for 24 h at 5 degrees C. Overall, the addition of antibiotics to extender did not significantly (P>0.05) improve motion characteristics of spermatozoa over control samples. However, levels of gentamicin sulfate greater than 1000 mug/ml and of polymixin B sulfate equal to or greater than 1000 IU/ml should be avoided in seminal extenders used for cooled semen.