Seroepidemiology of Mayaro Virus in high-risk pregnant women from the Zika Jundiaí Cohort seropositive for Chikungunya Virus

Abstract

Introduction: The Mayaro Virus (MAYV) is an enveloped RNA virus of Togaviridae family that causes febrile syndrome and arthritis (similar to that caused by chikungunya virus - CHIKV), and is considered the main arthritic virus in South America. It´s endemic in the north and midwest region of Brazil and affects all ages and genders, with a higher incidence of rain. The transmission cycle occurs mainly by the Hemagogues mosquitoes, but studies show that they can be transmitted by Aedes aegypti and Ae. albopictus. Thus, the cycle can also be urban, using humans as viral amplifiers and contributing to new outbreaks of MAYV in the country. Viral infection can present symptoms such as fever, headache, malaise, myalgia, arthralgia of large joints and arthritis, which is similar to that caused by CHIKV. Due to the absence of MAYV-specific antiviral, treatment is symptomatic with non-steroidal anti-inflammatory drugs and analgesics to relieve pain and fever, the same treatment used for other arboviruses like CHIKV. Currently, there are no vaccines available for the prophylaxis of MAYV infection, but there are already some prototypes in preclinical tests. Due to the similarity of the clinic caused by MAYV when compared to other arboviruses such as CHIKV, studies show that there is still an ineffective epidemiological surveillance in endemic areas due to the supposed underreporting. Only the clinical diagnosis can check false positive cases for other viruses, such as CHIKV, underestimating the real numbers of MAYV infection. CHIKV, like MAYV, is an enveloped RNA alphavirus in the Togaviridae family. Both belong to the Semliki complex, a serological group within the alphavirus genus, with sharing of antigenic points that can lead to cross-reaction between these species, making laboratory diagnosis more difficult. Due to the antigenic and symptom similarity between CHIKV and MAYV, it is necessary to expand the availability and laboratory methods in order to provide a correct and accurate diagnosis, thus contributing to the epidemiological surveillance of MAYV. Besides that, with the correct diagnosis of MAYV and differential for CHIKV, it is possible to specifically analyze the clinical manifestations and repercussions of MAYV infection in the region's population and in high-risk pregnant patients and their babies, checking the need for monitoring of mother for possible gestational and obstetric complications, in addition to her newborn. Information about the relation of MAYV infection in pregnant women and its consequences during pregnancy is scarce in the literature, as well as vertical transmission, neonatal repercussions of the infection and decay of anti-MAYV IgG titers in the concept of mothers seropositive for arbovirus. Objectives: To verify the serological frequency of MAYV through the presence of IgM and IgG antibodies during delivery in high-risk pregnant women who were seropositive for Chikungunya Virus. From these data, the possible endemic of MAYV in the region covered by the Zika Jundiaí Cohort can be verified and the need for monitoring during the gestation period for MAYV in order to check for possible complications, such as worsening maternal comorbidities, possible obstetric complications (death fetal, abortion, preterm birth), as well as assessment of the newborn (small for gestational age and follow-up of newborns positive or exposed during the first year of life) and to analyze the decay of anti-IgG antibody titers -MAYV in the first year of life of the exposed concepts. Materials and methods: This study is part of the Zika Jundiaí Cohort study and uses IgG and / or IgM anti-CHIKV as seropositive samples. The samples of these pregnant women will be tested serologically by means of an enzyme immunoassay (ELISA) to detect anti-MAYV attacks.