Mayaro y Chikungunya; dos alfavirus con similitudes clínicas y epidemiológicas

In 1780, Philadelphia suffered an unusual outbreak of hemorrhagic fever, which years later was identified as dengue (1). One hundred years later, in Memphis, 1500 people died from yellow fever, which caused residents to abandoned the city (2). Even though these stories may seem anecdotes, they show how dramatic hemorrhagic arbovirus outbreaks can be.

The tropic host arboviruses such as Chikungunya (CHIKV), Dengue, and Zika (ZIKV); but there are others, such as Mayaro, Oropuche, and Bussuquara, among others, which have still not been studied in depth by the public health systems of our countries.

Mayaro fever is a febrile illness caused by the Mayaro (MAYV) virus, a RNA alphavirus of the Togaviridae family. There are 29 species of alphaviruses, including relevant arboviruses that cause human and animal health problems, like the Venezuelan encephalitis virus, East encephalitis virus, West encephalitis virus, and CHIKV, new to the Latin American and the Caribbean epidemiology since 2014.

MAYV was first isolated in Trinidad in 1954, from blood samples obtained from farmers who lived in an area called Mayaro, after which it was named (1). MAYV has been detected in Mexico, Costa Rica, Panama, Peru, Colombia, Surinam, Guyana, Venezuela, Ecuador, Bolivia, and Brazil. Two genotypes of MAYV have been described in the Americas: genotype D, found in Trinidad, Peru, Venezuela, Colombia, Argentina, Guyana, Surinam, Bolivia, and Brazil, and genotype L, found in the amazon region of Brazil (4). MAYV outbreaks have occurred in rural and urban regions in Brazil, MAYV and the Oropuche viruses are, aside from Dengue, common causes of febrile syndromes in Brazil. Thus, since 2011 it was included as a notifiable disease (2,3).

MAYV is transmitted onto humans by infected mosquitoes of the Haemagogus genus, especially Haemagogus janthinomys. Other vectors include the Culex and Psophors sabethes genera. Primates and birds act as primary amplifying hosts. Evidence of MAYV infection has been found in primates (Callithix argentata, Callithix sp, Alouatta seniculus, Pithecia pithecia, Saimiri sciureus), marsupials (Philander oposum, Caluromyis philander), rodents (Agutíes sp., Oryzomys sp., Proechimys sp., Nectomys) and birds.

MAYV produces an acute febrile illness, with signs and symptoms similar to CHIKV, yellow fever, and dengue. Incubation period is 3-5 days; signs include fever, chills, myalgia, arthralgia, and maculopapular exanthema. Rash appears by the fifth day of illness, and lasts three days. Most of the symptoms disappear in 3-10 days; unlike CHIKV, it does not show recurrence. However, arthralgia can persist between two and twelve months. Unusual symptoms such as hemorrhage, thrombocytopenia, jaundice, and encephalitis have been described in patients with MAYV in Mexico, and one of them died of encephalitis (2,3). There are no vaccines or specific treatment against MAYV. Those infected must remain resting, and they are treated for their symptoms with acetaminophen and non-steroid anti-inflammatories (5).

A study carried out between 2010 and 2013 in the Peruvian amazon showed that arthralgia produced by MAYV were present in over 50% of the patients. The virus mainly affected joints in hands, wrists, elbows, feet, and knees, and in rare occasions, hips (6). Like CHIKV, articular pain in MAYV patients causes temporary disability, but patients with CHIKV have shown arthralgia for up to 3 years after the acute disease. Joints that are mainly affected include fingers, wrists, knees, and ankles (9). The economic and social impact of Mayaro fever has been less than those caused by Chikungunya and Dengue.

The jungle distribution of vectors and hosts of Mayaro fever has limited human outbreaks to rural areas close to tropical forests. However, MAYV can be introduced to other regions in the Americas by sick travelers or migratory birds, and it may adapt to compatible urban vectors such as Aedes aegypti and albopictus (10).

Many of the vectors and hosts for MAYV are found in Colombia, but it is unclear if the virus is silently circulating among other arbovirosis with similar symptoms like dengue and Chikungunya. There are no publications in Colombia about the MAYV isolation by culture. However, in 1964, seroprevalence of MAYV or an antigenically similar virus was studied in the Gulf of Uraba, the Eastern plains, and the valleys of the high and middle Magdalena. In humans and primates Alouatta, Cebus y Saimiri sera were positive by neutralization and hemagglutination tests (11).

As described in previous editorials, emerging viruses in Latin America such as Zika, Chikungunya, Oropuche, and Heartland require a more serious study, because not all tropical fevers are dengue.

Marco González T. M.Sc.

Salim Mattar V. Ph.D.

REFERENCES

1. Anderson CR, Downs WG, Wattley GH, Ahin NW, Reese AA. Mayaro virus: a new human disease agent. II. Isolation from blood of patients in Trinidad, BW I. Am J Trop Med Hyg 1957; 6(6):1012-6.

2. Napoleão-Pego P, Gomes L, Provance-Jr D, De-Simone S. Mayaro Virus Disease. J Hum Virol Retrovirol 2014; 1(3):00018.

3. Slegers C, Keuter M, Günther S, Schmidt-Chanasit J, van der Ven A, de Mast Q. Persisting arthralgia due to Mayaro virus infection in a traveler from Brazil: Is there a risk for attendants to the 2014 FIFA World Cup?. J Clin Virol 2014; 60(3):317-319.

4. Powers AM, Aguilar PV, Chandler LJ, Brault AC, Meakins TA, Watts D, et al. Genetic relationships among Mayaro and Una viruses suggest distinct patterns of transmission. Am J Trop Med Hyg 2006; 75(3):461-469.

5. Figueiredo MLGd, Figueiredo LTM. Emerging alphaviruses in the Americas: Chikungunya and Mayaro. Rev Soc Bras Med Trop 2014; 47(6):677-83.

6. Halsey ES, Siles C, Guevara C, Vilcarromero S, Jhonston EJ, Ramal C, et al. Mayaro virus infection, Amazon basin region, Peru, 2010-2013. Emerg Infect Dis 2013; 19(11):1839.

7. Forshey B, Guevara C, Laguna-Torres V, Cespedes M, Vargas J, Gianella A, et al. Arboviral etiologies of acute febrile illnesses in Western South America, 2000-2007. PLoS Negl Trop Dis 2010; 4(8):e787.

8. Muñoz M, Navarro JC. Virus Mayaro: un arbovirus reemergente en Venezuela y Latinoamérica. Biomédica 2012; 32(2):288-302.

9. Schilte C, Staikowsky F, Couderc T, Madec Y, Carpentier F, Kassab S, et al. Chikungunya virus-associated long-term arthralgia: a 36-month prospective longitudinal study. PLoS Negl Trop Dis 2013;7(3):e2137.

10. Long KC, Ziegler SA, Thangamani S, Hausser NL, Kochel TJ, Higgs S, et al. Experimental transmission of Mayaro virus by Aedes aegypti. Am J Trop Med Hyg 2011; 85(4):750-7.

11. Groot H. Estudios sobre virus transmitidos por artrópodos en Colombia. Rev Acad Colomb Cien Exac Fis Nat 1964; 12:3-23.