Sunday, November 27, 2016

Wrap Up Against Toga Viruses: Mayaro Virus on the rise?

Mayaro virus, a member of the family Togaviridae, and the genus Alphavirus, has recently begun to raise the eyebrows of WHO virus trackers as a child in Haiti was shown to be infected with the virus–the first reported case outside of South America. Since this virus is in the same genus as chikungunya virus, and shares clinical symptoms with its infamous sister virus, health workers are worried mayaro virus infection may be under diagnosed, and that an outbreak may be imminent.

Human cases of mayaro virus infection are sporadic, and associated with contact with the tropical forests of South America. This virus has two distinct genotypes, with one set of isolates corresponding to Brazil, and the other to Trinidad–where the virus was first isolated in 1954.  This mosquito borne virus has nonhuman primates has the primary host reservoir, and airborne transmission in the laboratory has been documented.

Clinical symptoms include fever, headache, vomiting, diarrhea, a rash that lasts 3-5 days, muscle pain, and joint pain.  Since these symptoms closely resemble those of chikungynya, a clear diagnosis can only be made with the capture of IgM antibodies by enzyme immunoassay (EIA). IgM antibodies, or immunoglobulin, are useful for identifying this disease as they are produced by your body’s immune cells in large amounts in the early course of infection in response to new pathogens.

While this virus does have the disposition of becoming another fierce pathogen of tropical regions, there have only been about 90 documented cases thus far. There is still a lot to learn about this virus, as evidenced by the article that sparked this blog post. In the article there are several factual errors, namely that dengue and mayaro virus are in the same family, as dengue is in the family Flaviviridae. Additionally, alphavirus refers to the genus, not the family, and the author of the article points to outbreak parallels with Zika virus, despite the fact that Zika has transmission routes that have not been documented in Mayaro virus.  Maybe the author chose Zika as it is a popular virus, maybe it was to get more clicks on the article, either way a “zika like outbreak” does not seem to be a concern for this virus–yet.

 -Cynthia Taylor


Page 680: Fields, Bernard N, David M. Knipe, and Peter M. Howley. Fields Virology. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2013.

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