Mayaro Virus Infection another Alphavirus Causing Prolonged Joint Symptoms
Abstract & Commentary
By Stan Deresinski, MD, FACP, FIDSA
Clinical Professor of Medicine, Stanford University, Hospital Epidemiologist, Sequoia Hospital, Redwood City, CA, Editor of Infectious Disease Alert
SYNOPSIS: Mayaro virus, like other alphaviruses such as chikungunya, may cause incapacitating joint symptoms that persist for prolonged periods
SOURCE: Halsey ES, et al. Mayaro virus infection, Amazon Basin Region, Peru, 2010-2013. Emerg Infect Dis 2013;19:1839-42.
As part of a passive febrile surveillance study of individuals >5 years of age in 4 Peruvian cities within the Amazon Basin Region, Halsey and colleagues identified acute Mayaro infection in 16 of 2094 (0.8%). All were positive by cell culture (11) and/or RT-PCR (13) and all demonstrated IgM seroconversion by ELISA between their acute phase and their 20 day follow-up visit. No seroconversion for non-alphaviruses was identified, but this was seen with another alphavirus, Venezuelan equine encephalitis virus, apparently as the result of serological cross-reactivity.
All 16 subjects, by definition, were febrile. Additional symptoms commonly reported were malaise, headache, arthralgia, myalgia, and retro-orbital discomfort. Joint pain, most commonly involving joints of the hand, wrist, elbow, feet and knee, was a prominent part of the symptom complex and persisted in 54% of subjects for at least 12 months. The discomfort was often sufficient to interfere with activities of daily living.
COMMENTARY
Mayaro is an alphavirus, most of which are arthritogenic.1 In addition to Mayaro virus, the other arthritogenic alphaviruses are Ross River, Barmah Forest, Sindbis, o’nyong-nyong, and chikungunya virus. Other alphaviruses, Venezuelan, Eastern Equine, and Western equine viruses, predominantly cause, as their names imply, encephalitis. All are arboviruses transmitted mostly by mosquitoes.
Chikungunya is a Swahili word for "that which bends up," describing the effects of the severe joint pains associated with this disease on the posture of the affected individual. This virus caused as many as 6.5 million cases during its recent (and continuing) explosion. Chikungunya is seen in Africa, and in and along the Indian Ocean littoral, as well as in Southeast Asia. The name of the highly related alphavirus, o’nyong-nyong, and also found in Africa, is derived from the Acholi word for "joint breaker." Ross River and Barmah Forest virus infections are acquired in northern Australia during the wet season (December to February); Ross River virus is also found in Papua New Guinea. Sindbis group viruses (Karelian, Ockelbo, Posogosta) are found in Eurasia, Africa, and Oceania, but human cases are largely limited to northern Europe.
Mayaro virus is enzootic in the northern regions of South America, mostly in humid forested areas and is believed to be maintained in small mammals. It has been identified in French Guinea, Suriname, Venezuela, Peru, Bolivia, and Brazil. Its primary vector is likely to be Haemogogus mosquitoes, although laboratory studies indicate that Aedes aegypti is also a competent vector.
While the incubation period of Mayaro virus infection is uncertain, that of other arthritogenic alphaviruses may range from 2 to 10 days. In addition to fever, 30%-50% of patients develop a rash and as many as 90% complain of joint pain. Headache and retro-ocular pain are also common.
Prolonged joint disability has also been reported after infection with sindbis virus as well as with chikungunya virus in which it has been reported to persist for >3 years. The study reviewed here found that half of patients with Mayaro virus infection have persisting joint complaints for at least one year and that these symptoms may be of sufficient severity to interfere with daily activities. Prolonged joint symptoms have also been reported in returning travelers who have acquired this infection.
References
1. Suhrbier A, et al. Arthritogenic alphaviruses--an overview. Nat Rev Rheumatol 2012;8:420-9.
