Mayaro Virus Disease

Abstract

Mayaro virus produces a nonspecific, sublethal disease in man with symptoms that are often confused with dengue. The symptoms of arthralgia, often associated with these viral infections, can cause an incapacitating disability. To date, outbreaks have been localized and sporadic within the Pan-Amazonia forest since its first isolation in 1954 (Trinidad and Tobago). The available literature is diverse, scarce and dispersed. Mayaro virus is an alphavirus, which is phylogenetically related to the Semliki forest antigenic complex. In the New World, Mayaro and the related UNA viruses are the only members of this complex that have been isolated. The genome of Mayaro consists of single-stranded RNA with a positive charge and a length of 12 kb that can be subdivided into genomic and subgenomic regions that encode nonstructural and structural proteins, respectively. Mayaro has shown great plasticity in hosts for vertebrate infections, but high specificity in invertebrates towards the family Culicidae (mosquitoes). Risk factors for infection are forested areas in northern South America and the rainy season. Two genotypes of MAYV have been identified, L (restricted to Belterra, Brazil) and D (widely distributed in the Pan-Amazonia). The enzootic cycle is similar to the jungle cycle of yellow fever, which involves Haemagogus mosquitoes and monkeys as reservoirs. Of concern is the potential spread of the virus by the involvement of other secondary vectors and hosts such as Aedes aegypti, Aedes albopictus and Aedes scapularis that have been shown experimentally to efficiently transmit the virus. Together with the observed high viremia levels of infected individuals, a significant risk exists for an emerging disease in urban, rural and peridomestic locations close to enzootic foci of Mayaro virus.