Mayaro: La cuarta arbovirosis de relevancia médica

La fiebre Mayaro es una arbovirosis aguda que ocasiona un compromiso articular incapacitante. Se identificó por primera vez en Venezuela en un brote epidémico familiar de la región de Barlovento en el edo. Miranda en el año 2000. Los estudios clínicoepidemiológicos y la determinación etiológica identificaron al alfavirus Mayaro como responsable de la enfermedad. Se ha identificado en varias naciones del continente americano, resaltándose su aparición en casos esporádicos y brotes epidémicos, siendo su presentación selvática y rural. Los vectores responsables de la infección son los mosquitos del género Haemagogus. Mayaro es la cuarta arbovirosis de importancia médica descrita en Venezuela, la primera identificada fue la fiebre amarilla, seguida de la encefalitis equina venezolana, el dengue y la quinta el chikungunya, ya que recorrió la geografía nacional como epidemia en 2014. Mediante una revisión de la bibliografía médica disponible y la colaboración de estudiantes del curso regular de Medicina Tropical, siguiendo el programa Docencia en Medicina Tropical centrada en el estudiante se actualizaron los aspectos clínicos, epidemiológicos, etiopatogénicos, diagnósticos, terapéuticos y preventivos de esta enfermedad infecciosa viral. Como su aparición es esporádica y de predominio selvático, debe ser considerada cuando se atienden pacientes con síndrome febril agudo con compromiso articular, sean residentes o viajeros procedentes de áreas endémicas. Por considerar que se mantiene en un ciclo enzoótico en la naturaleza, su prevención debe ser claramente definida.

Mayaro fever is an acute mosquito-borne viral infectious disease that produces disabling joint involvement. It was identified for the first time in Venezuela the year 2000 in a family outbreak in the region of Barlovento of the Miranda State. Clinical and epidemiological studies permitted to identify the Mayaro Alphavirus as responsible for the disease. The virus has been identified in several countries of the American continent, the clinical presentation being as sporadic cases, clusters and outbreaks in the rural and forest areas. Being a mosquito-borne zoonosis, the vectors responsible for the infection are mosquitoes of the Haemagogus genus. Mayaro is the fourth arbovirus infectious disease of medical importance described in Venezuela, being the first identified yellow fever, followed by the Venezuelan equine encephalomyelitis, followed by dengue fever and the fifth is chikungunya that swept over the country as an epidemic in 2014. Through a review of the available medical literature and collaboration of students from the regular course of Tropical Medicine, as part of the Student-based Teaching Tropical Medicine Program, a revision of the epidemiology, etiology, diagnosis, treatment and prevention of this viral disease was updated. As it appears sporadically and occurs predominantly in the rural and forest areas, it should be considered when patients with acute febrile syndromes have also joint involvement, whether they are residents or travellers from endemic areas. Considering the enzootic cycle in nature, prevention must be clearly established.

Arboviral diseases in the Western Brazilian Amazon: a perspective and analysis from a tertiary health & research center in Manaus, State of Amazonas

The Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), located in Manaus, the capital of the State of Amazonas (Western Brazilian Amazon), is a pioneering institution in this region regarding the syndromic surveillance of acute febrile illness, including arboviral infections. Based on the data from patients at the FMT-HVD, we have detected recurrent outbreaks in Manaus by the four dengue serotypes in the past 15 years, with increasing severity of the disease. This endemicity has culminated in the simultaneous circulation of all four serotypes in 2011, the first time this has been reported in Brazil. Between 1996 and 2009, 42 cases of yellow fever (YF) were registered in the State of Amazonas, and 71.4% (30/42) were fatal. Since 2010, no cases have been reported. Because the introduction of the yellow fever virus into a large city such as Manaus, which is widely infested by Aedes mosquitoes, may pose a real risk of a yellow fever outbreak, efforts to maintain an appropriate immunization policy for the populace are critical. Manaus has also suffered silent outbreaks of Mayaro and Oropouche fevers lately, most of which were misdiagnosed as dengue fever. The tropical conditions of the State of Amazonas favor the existence of other arboviruses capable of producing human disease. Under this real threat, represented by at least 4 arboviruses producing human infections in Manaus and in other neighboring countries, it is important to develop an efficient public health surveillance strategy, including laboratories that are able to make proper diagnoses of arboviruses.

Emerging alphaviruses in the Americas: Chikungunya and Mayaro

Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are emergent arthropod-borne viruses that produce outbreaks of acute febrile illness with arthropathy. Despite their different continental origins, CHIKV and MAYV are closely related and are components of the Semliki Forest Complex of the Alphavirus (Togaviridae). MAYV and, more recently, CHIKV, which are both transmitted by Aedes mosquitoes, have resulted in severe public health problems in the Americas, including Brazil. In this review, we present aspects of the pathogenesis, clinical presentation and treatment of febrile illnesses produced by CHIKV and MAYV. We also discuss the epidemiological aspects and effects related to the prophylaxis of infections by both viruses.