Encefalitis equina en el Hospital del Niño Dr. José Renán Esquivel (Panamá): Revisión bibliográfica y revisión de casos . / Equine encephalitis at Hospital del Niño Dr. José Renán Esquivel (Panama): Bibliographic and case review .

Introducción: En junio de 2019 surgió un nuevo brote de infección por virus de encefalitis equina del este (EEE) y encefalitis equina venezolana (EEV) en Panamá, en pacientes provenientes de la misma área. La infección tiene un amplio espectro de sintomatología pudiendo provocar graves cuadros de encefalitis. En este artículo se pretenden analizar las características de los casos en los que hubo confirmación serológica de la infección, centrándose en la población menor a 16 años atendida en el Hospital del Niño Dr. José Renán Esquivel. Material y métodos: Se realizó un estudio observacional retrospectivo de los casos reportados como encefalitis equina por el sistema de vigilancia epidemiológica del servicio de Epidemiología del Hospital del Niño Dr. José Renán Esquivel de Panamá en los meses de junio y julio de 2019. Los datos fueron analizados con el programa estadístico SPSS. Resultados: Se notificaron 12 casos sospechosos de encefalitis, 6 de ellos fueron confirmados como encefalitis equina del este y/o venezolana. En todos los casos, los pacientes tuvieron una fase prodrómica con fiebre y presentaron convulsiones. Un 66.6% de los pacientes precisó ventilación mecánica. Hubo un fallecimiento. Conclusiones: La infección por el virus de la encefalitis equina puede dar lugar a cuadros neurológicos severos e incluso conducir a la muerte. Dado que no existe un tratamiento específico, es necesaria la vigilancia epidemiológica así como investigación en la prevención de esta infección a través de nuevas vacunas.

Introduction: In June 2019 a new Eastern equine encephalitis (EEE) and Venezuelan equine encephalitis (VEE) outbreak emerged in Panamá in patients coming from the same area. The infection has a large spectrum of symptoms being able to lead to severe encephalitis. This article aims to analyze the characteristics of the cases in which it was serological confirmation, focusing on the population under 16 years old attended at the Hospital del Niño Dr. José Renán Esquivel. Material and methods: An observational retrospective study was carried out among the cases reported as encephalitis by the surveillance system of the Epidemiology Service at Hospital del Niño Dr. José Renán Esquivel from Panama in June and July 2019. Results: 12 cases were notified as suspected encephalitis cases, 6 of them were confirmed with serology tests as Eastern equine encephalitis (EEE) and/or Venezuelan equine encephalitis (VEE). All cases had a prodromic phase with fever and in all cases patients had seizures. A 66.6% of patients needed mechanic ventilation. There was one decease. Conclusions: Equine encephalitis virus can cause severe neurological symptoms and even lead to death. Since there is no specific treatment, it's necessary a close epidemiologic surveillance as well as more investigation in the prevention of this infection trough new vaccines.

Recent vaccine technology in industrial animals

Various new technologies have been applied for developing vaccines against various animal diseases. Virus-like particle (VLP) vaccine technology was used for manufacturing the porcine circovirus type 2 and RNA particle vaccines based on an alphavirus vector for porcine epidemic diarrhea (PED). Although VLP is classified as a killed-virus vaccine, because its structure is similar to the original virus, it can induce long-term and cell-mediated immunity. The RNA particle vaccine used a Venezuela equine encephalitis (VEE) virus gene as a vector. The VEE virus partial gene can be substituted with the PED virus spike gene. Recombinant vaccines can be produced by substitution of the target gene in the VEE vector. Both of these new vaccine technologies made it possible to control the infectious disease efficiently in a relatively short time.

Neutralising antibodies for Mayaro virus in Pantanal, Brazil

The Pantanal hosts diverse wildlife species and therefore is a hotspot for arbovirus studies in South America. A serosurvey for Mayaro virus (MAYV), eastern (EEEV), western (WEEV) and Venezuelan (VEEV) equine encephalitis viruses was conducted with 237 sheep, 87 free-ranging caimans and 748 equids, including 37 collected from a ranch where a neurologic disorder outbreak had been recently reported. Sera were tested for specific viral antibodies using plaque-reduction neutralisation test. From a total of 748 equids, of which 264 were immunised with vaccine composed of EEEV and WEEV and 484 had no history of immunisation, 10 (1.3%) were seropositive for MAYV and two (0.3%) for VEEV using criteria of a ≥ 4-fold antibody titre difference. Among the 484 equids without history of immunisation, 48 (9.9%) were seropositive for EEEV and four (0.8%) for WEEV using the same criteria. Among the sheep, five were sero- positive for equine encephalitis alphaviruses, with one (0.4%) for EEEV, one (0.4%) for WEEV and three (1.3%) for VEEV. Regarding free-ranging caimans, one (1.1%) and three (3.4%), respectively, had low titres for neutralising antibodies to VEEV and undetermined alphaviruses. The neurological disorder outbreak could not be linked to the alphaviruses tested. Our findings represent strong evidence that MAYV and all equine encephalitis alphaviruses circulated in the Pantanal.

First detection of Rio Negro virus (Venezuelan equine encephalitis complex subtype VI) in Córdoba, Argentina

Rio Negro virus (RNV) (Venezuelan equine encephalitis subtype VI) circulates only in Argentina; in northern provinces, isolates have been obtained from mosquitoes and rodents since 1980 and have been associated with acute febrile illness in humans. However, no studies of RNV have been performed in the central area of the country. We carried out molecular and serological detection of RNV in Córdoba, a province of the central part of the country, in mosquitoes and humans, respectively. One mosquito pool tested positive for alphavirus RNA by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR). Subsequent sequencing determined that this alphavirus grouped with RNV. Serological studies detected antibodies to RNV in one human serum sample, which was obtained during the same period that RNV was detected using the aforementioned molecular methods. This is the first report of RNV circulation in the central area of Argentina, indicating an expansion of its original distribution. These results highlight the importance of strengthening surveillance procedures in endemic areas, as well as in new regions where RNV may emerge.