Challenges in foot-and-mouth disease virus strain selection as an input to attain broad vaccine intraserotype cross-protection.

Introduction: Vaccination against foot-and-mouth disease virus is regarded as the most effective way to prevent disease. Selection of appropriate vaccine strains is challenging due to lack of cross-protection between serotypes and incomplete protection between some strains within a serotype. Vaccine effectiveness can be affected by vaccine formulation, vaccination approaches, and also by emerging field variants. Therefore, a precise evaluation of the protective capacity of the selected vaccine virus is essential.Areas covered: This article discusses the limitations of currently in use in vitro methods to assess the protective capacity of vaccine strains. It includes the assessment of well-established South American vaccine strains, O1/Campos and A24/Cruzeiro, against outbreaks/emergencies in the continent, as well as against recent isolates from East and Southeast Asia.Expert opinion: In vitro methods, and particularly r1 values, used to evaluate the protective capacity of vaccine strains are not conclusive and do not cover the variety of field scenarios. At present, an option when facing emergencies could be to use well-established vaccine strains with broad antigenic/immunogenic coverage, including conditions that lead to increased coverage such as vaccine formulations and vaccination schemes.

Non-discriminatory Exclusion Testing as a Tool for the Early Detection of Foot-and-Mouth Disease Incursions.

Endemic circulation of foot-and-mouth disease (FMD) in Africa and Asia poses a continuous risk to countries in Europe, North America, and Oceania which are free from the disease. Introductions of the disease into a free region have dramatic economic impacts, especially if they are not detected at an early stage and controlled rapidly. However, farmers and veterinarians have an obvious disincentive to report clinical signs that are consistent with FMD, due to the severe consequences of raising an official suspicion, such as farm-level quarantine. One way that the risk of late detection can be mitigated is offering non-discriminatory exclusion testing schemes for differential diagnostics, wherein veterinarians can submit samples without the involvement of the competent authority and without sanctions or costs for the farmer. This review considers the benefits and limitations of this approach to improve the early detection of FMD in free countries and gives an overview of the FMD testing schemes currently in use in selected countries in Europe and the Americas as well as in Australia.

FMD vaccine matching: Inter laboratory study for improved understanding of r1 values.

Foot-and-mouth disease virus (FMDV) is a highly variable RNA virus existing as seven different serotypes. The antigenic variability between and within serotypes can limit the cross-reactivity and therefore the in vivo cross-protection of vaccines. Selection of appropriate vaccine strains is crucial in the control of FMD. Determination of indirect relationships (r1-value) between potential vaccine strains and field strains based on antibody responses against both are routinely used for vaccine matching purposes. Aiming at the investigation of the repeatability, reproducibility and comparability of r1-value determination within and between laboratories and serological tests, a small scale vaccine matching ring test for FMDV serotype A was organized. Well-characterized serum pools from cattle vaccinated with a monovalent A24/Cruzeiro/Brazil/55 (A24) FMD vaccine with known in vivo protection status (homologous and heterologous) were distributed to four laboratories to determine r1-values for the heterologous FMD strains A81/Argentina/87, A/Argentina/2000 and A/Argentina/2001 using the virus neutralization tests (VNT) and liquid phase blocking ELISA (LPBE). Within laboratories, the repeatability of r1-value determination was high for both antibody assays. VNT resulted in reproducible and comparable r1-values between laboratories, indicative of a lack of antigenic relatedness between the A24 strain and the heterologous strains tested in this work, thus corresponding to some of the in vivo findings with these strains. Using LPBE, similar trends in r1-values were observed in all laboratories, but the overall reproducibility was lower than with VNT. Inconsistencies between laboratories may at least in part be attributed to differences in LPBE protocols as well as the in preexisting information generated in each laboratory (such as antibody titer-protection correlation curves). To gain more insight in the LPBE-derived r1-values standard bovine control sera were included in the antibody assays performed in each laboratory and a standardization exercise was performed.

Protective effects of high-potency FMDV O1 Manisa monovalent vaccine in cattle challenged with FMDV O/SKR/2010 at 7 or 4 days post vaccination.

Serotype O foot-and-mouth disease (FMD) virus belonging to the SEA topotype continues to be a significant problem in the Eastern Asia region, with outbreaks in Japan and South Korea resulting in the culling of over 3.5 million cattle and pigs in recent years. High-potency O1 Manisa vaccine was previously shown to provide protection in cattle 21days post vaccination (dpv) following challenge with a representative virus, O/SKR/2010. This study tested the ability of the O1 Manisa vaccine to protect cattle from infection and disease with the O/SKR/2010 virus within just 4 or 7days post vaccination. The vaccine protected 50% of cattle from clinical disease when administered 7days prior to challenge, but was not protective with just 4days between vaccination and challenge. Viraemia was significantly reduced in animals challenged 7 dpv but not 4 dpv, compared to unvaccinated controls, however, there were no effects on the level of virus detected in nasal and oral secretions regardless of vaccination time. The level of neutralising antibodies detected in cattle challenged 7 dpv correlated with protection from clinical disease. All animals seroconverted to FMDV non-structural proteins, suggesting no sterile protection. An equal number of animals became persistently infected in both vaccine groups. The results indicated that high-potency O1 Manisa vaccine administered just 7days prior to challenge should provide partial protection of cattle if an outbreak of O/SKR/2010, or related viruses, occurs, and would be useful to limit spread of FMDV when used in conjunction with other control measures.

[Validation of a real time RT-PCR assay to detect foot-and-mouth disease virus and assessment of its performance in acute infection]. / Validación de una técnica de RT-PCR en tiempo real para la detección del virus de fiebre aftosa y evaluación de su desempeño en la infección aguda.

A specific real time reverse transcription polymerase chain reaction (RT-PCRrt) for the detection of foot-and-mouth disease virus was validated using the LightCycler thermocycler 2.0 and its reagents as recommended by the World Organization for Animal Health and was assessed for the detection of the virus in acute infection of cattle experimentally vaccinated and challenged with virus A Argentina/2001 or A24 Cruzeiro. The technique proved to be robust, showing coefficients of variation lower than 4% for different ARN extractions, days or repetitions and was able to detect up to 0,4 TCID 50%, and/or up to 100 RNA molecules. In probang samples, diagnostic sensitivity was 93.1 (95% CI 86.5-96.6) and diagnostic specificity 100 (95% CI 96.3-100). The results of the challenge in vaccinated or multivaccinated bovines showed that although there were high levels of clinical protection in the vaccinated group, FMDV could be detected in all challenged groups. However, detection was 100 times lower in immunized animals.

Emergence of antigenic variants of Foot-and-Mouth Disease Virus serotype O in Ecuador and preliminary evaluation of a field strain as a vaccine candidate.

Foot-and-Mouth Disease Virus serotype O has been circulating regularly throughout most provinces of Ecuador, one of the two South American countries that still remain endemic, although satisfactory vaccination coverage was reported. This study concentrates in the characterization of isolates collected during 2008-2011, focusing particularly on the antigenic and immunogenic relationships of the field viruses with the O1/Campos vaccine strain in use in the region and with an experimental vaccine formulated with a representative strain of the 2010 epidemic. The results established that antigenically divergent variants poorly protected by the vaccine in use emerged and co-circulated in a limited period of time. A monovalent vaccine formulated with the representative 2010 strain elicited high antibody titers and protected against challenge with homologous virus. In addition, cross-reactive antibodies to predominant viruses in the region were established. In overall this study indicates the ability of the virus to diversify under field conditions in which a vaccine strain with poor match is applied, and the potential of the selected 2010 field virus as a vaccine candidate for incorporation into strategic antigen banks and/or for addition to current formulations for systematic vaccination, in order to prevent the emergence of even more divergent isolates in the future.

Validación de una técnica de RT-PCR en tiempo real para la detección del virus de fiebre aftosa y evaluación de su desempeño en la infección aguda. / [Validation of a real time RT-PCR assay to detect foot-and-mouth disease virus and assessment of its performance in acute infection].

A specific real time reverse transcription polymerase chain reaction (RT-PCRrt) for the detection of foot-and-mouth disease virus was validated using the LightCycler thermocycler 2.0 and its reagents as recommended by the World Organization for Animal Health and was assessed for the detection of the virus in acute infection of cattle experimentally vaccinated and challenged with virus A Argentina/2001 or A24 Cruzeiro. The technique proved to be robust, showing coefficients of variation lower than 4

for different ARN extractions, days or repetitions and was able to detect up to 0,4 TCID 50

, and/or up to 100 RNA molecules. In probang samples, diagnostic sensitivity was 93.1 (95

CI 86.5-96.6) and diagnostic specificity 100 (95

CI 96.3-100). The results of the challenge in vaccinated or multivaccinated bovines showed that although there were high levels of clinical protection in the vaccinated group, FMDV could be detected in all challenged groups. However, detection was 100 times lower in immunized animals.

Characterization of a type O foot-and-mouth disease virus re-emerging in the year 2011 in free areas of the Southern Cone of South America and cross-protection studies with the vaccine strain in use in the region.

Molecular, antigenic and vaccine matching studies, including protective response in vivo, were conducted with a foot-and-mouth disease type O virus isolated during the outbreak in September 2011 in San Pedro, Paraguay, country internationally recognized as free with vaccination in 1997. The phylogenetic tree derived from complete VP(1) sequences as well as monoclonal antibody profiling indicated that this isolate was related to viruses responsible for previous emergencies in free areas of the Southern Cone of South America occurring sporadically between the years 2000 and 2006. Marked differences with the vaccine strain O(1)/Campos, including the loss of reactivity with neutralizing MAbs, were recognized. Levels of protective antibodies induced by the vaccine containing the O(1)/Campos strain against the San Pedro virus and the virus responsible for the previous emergency in 2006 in the Southern Cone assessed by in vitro vaccine matching studies pointed to an insufficient protective response 30 days after vaccination (DPV), which was properly attained at 79 DPV or after revaccination. In agreement with the in vitro assessment, the in vivo challenge in the Protection against Podal Generalization test in cattle indicated appropriate protection for the San Pedro strain at 79 DPV or after revaccination. The complementary conclusions that can be derived from vaccine matching tests designed differently to fit the various objectives intended: prophylaxis, emergency vaccination or incorporation of new field strains into antigen banks, is evaluated. This is the first report of the antigenic and immunogenic characterization of the variants responsible for emergencies in the Southern Cone of South America and the putative impact of the changes on the cross protection conferred by the vaccine strain.

Characterization of foot-and-mouth disease virus from outbreaks in Ecuador during 2009-2010 and cross-protection studies with the vaccine strain in use in the region.

During the years 2009 and 2010 relevant epidemic waves of foot-and-mouth disease (FMD) serotype O occurred in Ecuador, representing a great drawback for the last stages of the ongoing eradication program in South America. This study describes the molecular and antigenic characterizations of 29 isolates collected from various regions in the country and their relationship to the vaccine strain. The phylogenetic tree derived from sequences spanning the complete VP(1) protein showed that, despite the widespread origin of the viruses, they were all related among themselves and to previous isolates occurring in 2008, with around 10% difference with the vaccine strain O1/Campos. The high level of sequence conservation among different isolates in the various regions of Ecuador pointed to a common origin, suggesting animal movements as possible sources of viral spread. Monoclonal antibody profiling grouped the isolates in two major reactivity patterns which differed from that of the vaccine strain. Both profiles showed loss of reactivity with the same four MAbs, three of them with neutralizing properties. Additional sites were lost in the profile representing most of the 2010s viral samples. Levels of protective antibodies induced by the vaccine against the field strains assessed by in vitro vaccine matching studies also pointed to an increased temporal pattern of loss of a protective response. Moreover, results obtained with in vivo challenge in the protection against podal generalization test in cattle, clearly indicated lack of appropriate protection of the Ecuadorian field strains by the vaccine virus in use, which in the case of a 2010 variant was observed even after revaccination.

Reducing animal experimentation in foot-and-mouth disease vaccine potency tests.

The World Organisation for Animal Health (OIE) Terrestrial Manual and the European Pharmacopoeia (EP) still prescribe live challenge experiments for foot-and-mouth disease virus (FMDV) immunogenicity and vaccine potency tests. However, the EP allows for other validated tests for the latter, and specifically in vitro tests if a "satisfactory pass level" has been determined; serological replacements are also currently in use in South America. Much research has therefore focused on validating both ex vivo and in vitro tests to replace live challenge. However, insufficient attention has been given to the sensitivity and specificity of the "gold standard"in vivo test being replaced, despite this information being critical to determining what should be required of its replacement. This paper aims to redress this imbalance by examining the current live challenge tests and their associated statistics and determining the confidence that we can have in them, thereby setting a standard for candidate replacements. It determines that the statistics associated with the current EP PD(50) test are inappropriate given our domain knowledge, but that the OIE test statistics are satisfactory. However, it has also identified a new set of live animal challenge test regimes that provide similar sensitivity and specificity to all of the currently used OIE tests using fewer animals (16 including controls), and can also provide further savings in live animal experiments in exchange for small reductions in sensitivity and specificity.

Confidence in indirect assessment of foot-and-mouth disease vaccine potency and vaccine matching carried out by liquid phase ELISA and virus neutralization tests.

The necessity of avoiding the use of animals in vaccine potency testing has been widely recognized. The repeatability and reproducibility of the Expected Percentage of Protection (EPP) as a serological potency surrogate for A24 Cruzeiro foot-and-mouth disease virus (FMDV) strain was assessed, and compared with the results obtained with challenge in the Protection against Podal Generalization (PPG) test. To determine the EPPs, the serum titers obtained by liquid phase blocking competitive ELISA (lpELISA) and virus neutralization (VNT) in 10 potency trials using the same A24 Cruzeiro vaccine, were interpolated into previously validated logit transformation curves that correlate PPG with serology. Indirect serological assessment of vaccine matching between the serotype A FMDV strains A24 Cruzeiro and A/Argentina/01 was also carried out by lpELISA and VNT. The results obtained in this study strongly support the replacement of challenge tests for vaccine potency by indirect serological assays, at least for A24 Cruzeiro FMDV strain. While determination of EPPs by lpELISA titers showed an excellent repeatability, reproducibility and concordance with PPG for vaccine potency, assessments of cross-protection by VNT titers were more consistent with the PPG outcome.

Rapid methodology for antigenic profiling of FMDV field strains and for the control of identity, purity and viral integrity in commercial virus vaccines using monoclonal antibodies.

Monoclonal antibodies (MAbs) developed against different foot-and-mouth disease virus (FMDV) vaccine strains were extensively used to study any possible antigenic variations during vaccine production in Argentine facilities. Additionally, a typing ELISA using strain specific MAbs was developed to detect potential cross contaminations among FMDV strains in master and working seeds with high specificity and sensitivity and to confirm strains identity in formulated vaccines. This assay was carried out for the South American strains currently in use in production facilities in Argentina (A24/Cruzeiro, A/Argentina/01, O1/Campos and C3/Indaial) and for the strain O/Taiwan, produced only for export to Asia. These non-cross reactive MAbs were also used to analyze the integrity of viral particles belonging to each one of the individual strains, following isolation of 140S virions by means of sucrose density gradients from the aqueous phase of commercial polyvalent vaccines. Antigenic profiles were defined for FMDV reference strains using panels of MAbs, and a coefficient of correlation of reactivity with these panels was calculated to establish consistent identity upon serial passages of master and production seeds. A comparison of vaccine and field strain antigenic profiles performed using coefficients of correlation allowed the rapid identification of two main groups of serotype A viruses collected during the last FMD epidemic in Argentina, whose reactivity matched closely to A/Argentina/2000 and A/Argentina/2001 strains.

Some guidelines for determining foot-and-mouth disease vaccine strain matching by serology.

The selection of matching strains for use in outbreaks of foot-and-mouth disease (FMD) virus can be assessed in vivo or by serological r-value determination. Sera from animals involved in vaccine potency and cross-protection trials performed using the "Protection against Podal Generalization" (PPG) test for two serotype A strains were collected and analyzed by the virus neutralization test (VNT) and liquid-phase ELISA (lpELISA) in three laboratories. The average VNT r-values for medium and high serum titer classes from the A(24) Cruzeiro vaccinated animals were in line with the A/Arg/01 heterologous PPG outcome for all testing laboratories, suggesting that the vaccine strain A(24) Cruzeiro is unlikely to protect against the field isolate A/Arg/01. The corresponding lpELISA r-values were slightly higher and indicate a closer relationship between both strains. Pooling of serum samples significantly reduced the inter-animal and inter-trial variation. The results suggest that a suitable reference serum for vaccine matching r-value experiments might be a pool or a medium to high VNT or lpELISA titer serum. Furthermore, the VNT seems to produce the most reproducible inter-laboratory results. More work is, however, needed in order to substantiate these claims.

Updating of the correlation between lpELISA titers and protection from virus challenge for the assessment of the potency of polyvalent aphtovirus vaccines in Argentina.

Routine vaccination campaigns are carried out in Argentina twice a year, involving more than 100 million doses of foot-and-mouth disease (FMD) vaccine. Although the challenge test in cattle has not been totally replaced for the assessment of FMD vaccine potency, Argentine Animal Health authorities have used an indirect alternative method based on specific correlation studies of protection against podal generalization (PPG) tests performed in cattle with a validated liquid phase blocking ELISA (lpELISA). The change of vaccine formulations that took place after the 2000-2001 outbreaks, generated a gap in the correlation between lpELISA titers and PPG for the new FMD virus strains. A reappraisal of the correlation between lpELISA titers measured at 60 dpv and virus challenge by the PPG method at 90 dpv, performed for the four virus strains presently included in the Argentine vaccine is presented in this work. The data were obtained from 40 bovine challenge trials (647 sera) performed using exclusive batches of commercial vaccine from the year 2001 to January 2008 for A24/Cruzeiro, A/Argentina/2001, O1/Campos and C3/Indaial FMD virus strains. Curves of percentage of expected protection (EPP) versus lpELISA titers were obtained by logit regression for A/Argentina/2001, O1/Campos and C3/Indaial strains, but not for A24/Cruzeiro strain. The concordance between the direct and indirect tests using an EPP cut off value of 75% (82%, kappa = 0.62), in agreement with data originating from many years of vaccine control in Argentina, remarks the relevance of the acceptance of indirect alternatives to in vivo potency testing.

Intubação nasotraqueal às cegas em paciente acordada candidata à hemimandibulectomia: relato de caso / Blind nasotracheal intubation in awaken patient scheduled for hemimandibulectomy: case report

JUSTIFICATIVA E OBJETIVOS: A abordagem à via aérea pode utilizar diversos recursos. Manter o paciente acordado, cujo controle seguro da ventilação/oxigenação é incerto, constitui uma opção quando há dúvida quanto à intubação. A intubação nasotraqueal (INT) às cegas é uma alternativa à fibroscopia. RELATO DO CASO: Paciente do sexo feminino, 75 anos, 56 kg, candidata à hemimandibulectomia, com imobilidade cervical por artrodese, abertura bucal de 2,2 cm, retrognatismo moderado, sem protrusão voluntária da mandíbula, distância mento-esternal de 11 cm e mento-tireoidiana de 6 cm, recebendo 5 pontos na escala Wilson. A paciente previamente orientada consentiu com o procedimento. Após monitoração e oxigenação, foi iniciada infusão contínua de dexmedetomidina. Realizado bloqueio dos nervos laríngeo superior e inferior com lidocaína a 2,0 por cento sem vasoconstritor e instilação de lidocaína spray em hipofaringe. Previamente à INT foram administrados ondansetron, midazolam, fentanil e droperidol, permanecendo a paciente acordada e cooperativa. A inserção via nasal de tubo traqueal foi orientada pela sua opacificação e ruídos respiratórios e confirmada por ausculta pulmonar e capnografia. Iniciada infusão contínua de propofol e remifentanil, administrados rocurônio e ventilação controlada. A operação de 60 minutos não teve intercorrências. Ao término, a paciente apresentava ventilação espontânea, sendo extubada e encaminhada à recuperação pós-anestésica, recebendo alta sem queixas. CONCLUSÕES: A INT é alternativa à fibroscopia quando a segurança do controle das vias aéreas é incerta. O prévio esclarecimento da paciente foi essencial. Houve segurança, sem depressão respiratória ou instabilidade hemodinâmica.

BACKGROUND AND OBJECTIVES: Several resources can be used for the approach of the airways. Maintaining a patient awake when control of ventilation/oxygenation is uncertain is an option when intubation is doubtful. Blind nasotracheal intubation (NTI) is an alternative to fiberoptic endoscopy. CASE REPORT: A 75-year old patient, weighing 56 kg, was scheduled for hemimandibulectomy; she presented cervical immobility secondary to arthrodesis, mouth opening of 2.2 cm, moderate retrognatism, voluntary protrusion of the mandible was absent, mentosternal distance of 11 cm and mento-thyroid distance of 6 cm, therefore receiving a score of 5 on the Wilson scale. The patient signed an informed consent after being informed about the procedure. After monitoring and oxygenation, continuous infusion of dexmedetomidine was initiated. Superior and inferior laryngeal nerve block was performed with 2.0 percent lidocaine without vasoconstrictor and the hypopharinx was anesthetized with a lidocaine spray. Before NTI, ondansetron, midazolam, fentanyl, and droperidol were administered and the patient remained awake and cooperative. Nasal insertion of the tracheal tube was oriented by its opacification and respiratory sounds and the placement was confirmed by pulmonary auscultation and capnography. Continuous infusion of propofol and remifentanil was instituted, vecuronium was administered and controlled ventilation was initiated. The surgery lasted 60 minutes without intercurrences. At the end, the patient was breathing spontaneously, so she was extubated and transferred to the recovery room from where she was discharged without any complaints. CONCLUSION: Nasotracheal intubation is an alternative to fiberoptic endoscopy when safety and control of the airways is uncertain. Informing the patient about the procedure was essential. Safety was assured and respiratory depression and hemodynamic instability was not observed.

JUSTIFICATIVA Y OBJETIVOS: El abordaje a la vía aérea puede utilizar diversos recursos. Mantener el paciente despierto cuyo control seguro de la ventilación/oxigenación no es muy regular y es una opción cuando existe una duda en cuanto a la intubación. La intubación nasotraqueal (INT) a ciegas es una alternativa a la fibroscopía. RELATO DEL CASO: Paciente del sexo femenino, 75 años, 56 kg, candidata a la hemimandibulectomia, con inmovilidad cervical por artrodesis, abertura bucal de 2,2 cm, retrognatismo moderado, sin profusión voluntaria de la mandíbula, distancia mento-esternal de 11 cm y mento-tiroidiana de 6 cm, recibiendo 5 puntos en la escala Wilson. La paciente previamente orientada consintió con el procedimiento. Después de la monitorización y oxigenación, se inició la infusión continua de dexmedetomidina. Realizado el bloqueo de los nervios laríngeo superior e inferior con lidocaína a 2,0 por ciento sin vasoconstrictor e instilación de lidocaína spray en hipofaringe. Previamente a la INT se administraron ondansetrona, midazolam, fentanil y droperidol, permaneciendo la paciente despierta y cooperante. La inserción vía nasal de tubo traqueal fue orientada por su opacificación y ruidos respiratorios y confirmada por auscultación pulmonar y capnografía. Iniciada infusión continua de propofol y remifentanil, administrados rocuronio y ventilación controlada. La operación de 60 minutos no tuvo intercurrencias. Al término de la cirugía, la paciente presentaba ventilación espontánea, siendo extubada y llevada a la recuperación postanestésica, recibiendo alta sin quejas. CONCLUSIONES: La INT es una alternativa a la fibroscopía cuando la seguridad del control de las vías aéreas no es segura. La previa clarificación de la paciente fue esencial. Hubo seguridad, sin depresión respiratoria o inestabilidad hemodinámica.

Blind nasotracheal intubation in awaken patient scheduled for hemimandibulectomy. Case report.

BACKGROUND AND OBJECTIVES: Several resources can be used for the approach of the airways. Maintaining a patient awake when control of ventilation/oxygenation is uncertain is an option when intubation is doubtful. Blind nasotracheal intubation (NTI) is an alternative to fiberoptic endoscopy. CASE REPORT: A 75-year old patient, weighing 56 kg, was scheduled for hemimandibulectomy; she presented cervical immobility secondary to arthrodesis, mouth opening of 2.2 cm, moderate retrognatism, voluntary protrusion of the mandible was absent, mentostemal distance of 11 cm and mento-thyroid distance of 6 cm, therefore receiving a score of 5 on the Wilson scale. The patient signed an informed consent after being informed about the procedure. After monitoring and oxygenation, continuous infusion of dexmedetomidine was initiated. Superior and inferior laryngeal nerve block was performed with 2.0% lidocaine without vasoconstrictor and the hypopharinx was anesthetized with a lidocaine spray. Before NTI, ondansetron, midazolam, fentanyl, and droperidol were administered and the patient remained awake and cooperative. Nasal insertion of the tracheal tube was oriented by its opacification and respiratory sounds and the placement was confirmed by pulmonary auscultation and capnography. Continuous infusion of propofol and remifentanil was instituted, vecuronium was administered and controlled ventilation was initiated. The surgery lasted 60 minutes without intercurrences. At the end, the patient was breathing spontaneously, so she was extubated and transferred to the recovery room from where she was discharged without any complaints. CONCLUSION: Nasotracheal intubation is an alternative to fiberoptic endoscopy when safety and control of the airways is uncertain. Informing the patient about the procedure was essential. Safety was assured and respiratory depression and hemodynamic instability was not observed.

Phylogenetic analysis of foot-and-mouth disease virus type O re-emerging in free areas of South America.

The nucleotide sequences of the complete VP(1)-coding region of foot-and-mouth disease viruses (FMDV), type O, isolated during the recent emergencies of the disease in free areas of South America (Mato Grosso do Sul, Brazil, October 2005, and Corrientes, Argentina, February 2006), were determined. Also established were the complete VP(1)-coding sequences of viruses occurring in neighbouring locations between the years 2000 and 2003. A phylogenetic analysis was performed based on comparison with continental relevant field and vaccine strains, as well as with extra-continental representative viruses. The results show that the emergencies in Argentina and Brazil were caused by viruses presenting 93% genetic relatedness. Both variants are endogenous to South America, as they were placed within the Europe-South America topotype. When compared with the continental viruses available for the phylogenetic studies, they show the closest relationship with viruses responsible for previous emergencies in neighbouring free areas, or for sporadic outbreaks in the adjacent places with advanced eradication stages, presenting similarity values of at least 90% among them, and clustering together in a unique lineage. This lineage represents the only one sporadically appearing in the Southern Cone and differs from those including viruses presently circulating in the Andean region, reflecting the different livestock circuits and epidemiological scenarios.

Foot-and-mouth disease polyvalent oil vaccines inoculated repeteadly in cattle do not induce detectable antibodies to non-structural proteins when evaluated by various assays.

The use of foot-and-mouth disease (FMD) vaccines that do not induce antibodies against non-structural proteins (NSP) is extremely relevant for the demonstration of regions "free of FMDV infection" and control strategies. In this study cattle were primed and boosted with five doses of oil vaccines containing high antigenic payloads on days 0, 90, 130, 160 and 200. The serological response against NSP was measured using four commercially available assays: two 3ABC-ELISAs; one 3B-ELISA (and complementary 3A-ELISA) and an enzyme-immunotransfer blot assay (EITB). Additionally, locally produced NSP antibodies detection reagents and VIAA antibodies were evaluated. A high level of specific immune response against vaccine strains was shown. After four doses of vaccine, non-reactive animals were detected by any of the NSP assays. After the fifth immunization, 2 of 17 animals were reactive in one ELISA kit, but these samples proved negative by confirmatory tests. Antibodies against NSP were not detected in single dose immunized cattle. The principle of the NSP-ELISA used as a screening test for large sero-surveys in South America is established and this paper emphasizes the importance of using vaccines that have demonstrated no interference with NSP antibodies detection assays.