TABLE 2. Epidemiological database of confirmed and presumptive Mayaro cases reported in academic literature and by health authorities, from Mayoro’s discovery in 1954 through May 2019, by country^a.

Reference source(s)	Country	Year cases were reported	No. of reported cases	Diagnostic procedures implemented to detect confirmed or presumptive MAYV cases
Diaz, 2003 (35)	Argentina	2001	3	Human sera of citizens aged 44-89 from Córdoba were collected and assessed at the Instituto Nacional de Previsión Social (PAMI) in 2001. 79 samples were tested by neutralization assay. Three out of the 79 sera were positive for Una virus (UNAV), a subtype of Mayaro. Due to the low titers of neutralizing antibodies detected, the UNAV infections could have occurred years ago but they demonstrate circulation of the virus in humans
Schmidt, 1959 (15)	Bolivia	1955	2	Uruma virus was isolated from the blood of 2 febrile Okinawan colonists living in the rainforest of Eastern Bolivia. The Uruma virus is now considered to be a strain of the Mayaro virus. Virus dilution neutralization tests were conducted on the sera of 21 healthy individuals that had not been involved in the outbreak, living in Puerto Cespedes. Acute and convalescent phase sera from the patient of whom the virus was first isolated, as well as convalescent phase sera from 38 Okinawan patients from whom acute phase sera was not obtained. Since no acute phase serum was obtained from the 38 Okinawans who experienced febrile illness, a definitive etiologic diagnosis was not established. 8 of the 21 healthy individuals living in Puerto Cespedes showed detectable antibodies to the virus. This demonstrates that infection with Uruma virus, or an antigenic relative, is common among residents of the rainforest.
Auguste, 2015 (14)	Bolivia	2007	12	Further information was not provided.
Forshey, 2010 (16)	Bolivia	2000-2007	6	3 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 3 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Bolivia	2000-2007	3	1 confirmed case (virus isolation, RT-PCR, or IgM seroconversion), and 2 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Bolivia	2000-2007	16	10 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 6 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Bolivia	2000-2007	21	10 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 11 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Alves Esposito, 2017 (1)	Brazil	1955	6	On April 15, 53 of the 115 individuals that arrived at the lab with an illness had a fever. Only 34 of the 53 sera were inoculated and the remaining 18 were taken to the lab the following day. Four strains of the virus were isolated in this initial round of testing. A second round of testing was conducted on May 7. Samples were collected from the 37 people who were bled on April 15 and serum was collected from an additional 37 individuals that had not been bled previously. An additional two samples, from the sera samples of those who had not been previously bled, yielded virus strains.
Alves Esposito, 2017 (1)	Brazil	1977-1978	55	A total of 807 clinically suspected cases were recorded from a rubber plantation located in Belterra. This epidemic coincided with a yellow fever outbreak. 72 persons were examined, the virus being confirmed in 55 during the acute and subacute stages of the illness. 43 cases were detected with virus isolation and serology and 12 with serological conversion using HI tests.
Alves Esposito, 2017 (1); Munoz, 2012 (19)	Brazil	1978-1981	Number of cases not provided	Further information was not provided.
Alves Esposito, 2017 (1); Munoz, 2012 (19)	Brazil	1981-1991 (1981, 1984, 1988, 1991)	Number of cases not provided	Further information was not provided.
Alves Esposito, 2017 (1)	Brazil	1991	Number of cases not provided	Further information was not provided.
Pinto De Figueiredo, 2004 (34)	Brazil	1998-1999	8	8 557 serum samples were taken from March 1998-December 1999. Exanthematic diseases were tested from 1 107 dengue negative samples. Of those samples, 22 were tested for Mayaro. 8 of the 22 samples tested positive for Mayaro. Diagnoses were performed using serological tests to detect IgM antibodies by ELISA CDC/PAHO or with commercial kits.
Coimbra, 2007 (32)	Brazil	2000	3	Serum samples were collected four days and two months after the onset of symptoms. Virus isolation was obtained from only one acute blood sample, but convalescent sera samples revealed monotypic seroconversion to MAYV, and a final identification of MAYV was further obtained in a RT-PCR assay. The three men were visiting from other areas of Brazil to fish. The patients were infected between March 11-19, 2000
Terzian, 2015 (18)	Brazil	2000	1	MAYV was isolated from the patient, who had been fishing. Further information was not provided.
Terzian, 2015 (18)	Brazil	2004	1	A 27-year-old female patient was identified during an ongoing epidemiological survey in the area. The patient was malaria-negative and presented with fever and chills. There were no signs or symptoms of joint pain or swelling, but no follow-up was performed to confirm the presence or absence of arthralgia following the initial examination of the patient. The patient’s RT-PCR sample was positive for MAYV. Bayesian phylogeny supported that the strain of MAYV isolated in this case was closely related to the Bolivian strains isolated between 2002 and 2006, a finding not completely unexpected given the proximity of the state of Acre to Bolivia.
Alves Esposito, 2017 (1); Azevedo, 2009 (9)	Brazil	2008	36	A dengue-like illness was reported in the Pau d’Árco settlement, a rural community in the middle of a native forest. 105 individuals were examined in house-to-house surveys. 53 lived in the settlement and were agricultural workers, and 52 were agronomy students at the public university in the city of Belém, Pará. IgM was detected in 36 (34%) serum samples. Of those 36 samples, 23 (64%) were collected from residents of the settlement, and 13 (36%) were from residents of the city of Belém, Pará, and the city of Ananindeua, Pará; these persons had visited the settlement area for a week. 36 of these individuals had IgM antibodies against MAYV.
Munoz, 2012 (19)	Brazil	2011	33	Further information was not provided.
Pinheiro, 1977 (20)	Brazil	1973-1974	13	Studies were carried out in patients who attended the hospital in the city of Altamira and the health posts. Most of these patients were colonists. Between January 1973 and June 1974, 549 blood samples were taken. Only one arbovirus strain of Mayaro was isolated from a febrile case. The low rate of virus isolation is likely due to the fact that the majority of patients were bled after the third day of illness, when viremia tends to be absent. 160 of 832 demonstrated serological conversion to arboviruses using HI test from Jan 1973-June 1974. 60 of the seroconversions where to arboviruses of other antigenic groups; 12 were for MAYV
Tavares-Neto, 2004 (21)	Brazil	1999-2000	2	Tests were done on individuals in August 1999 and again in January 2000. Results reflect seroconversion during that period.
Alves Esposito, 2017 (1)	Brazil	2007-2008	33	IgM antibodies against MAYV reported in 33 individuals. A viral genome was detected for one of the cases in the city of Manaus. Further information was not provided.
Cruz, 2009 (22)	Brazil	2007-2008	5	The 113 and 102 serum samples that presented titers equal to or greater than 40 by HI test to Oropouche virus and MAYV, respectively, were analyzed by ELISA for detection of IgM antibodies, and identified 23 recent infections for Oropouche viruses and 5 for MAYV.
Alves Esposito, 2017 (1); Zuchi, 2014 (23)	Brazil	2011-2012	15	15 out of 604 patients during a dengue outbreak tested positive for MAYV RNA
Vieira, 2015 (46)	Brazil	2011-2012	6	The presence of Brazilian arboviruses was investigated in the sera of 200 patients with acute febrile illness during a dengue outbreak in the city of Sinop. Results showed that 6 samples were positive to MAYV. Molecular and evolutionary analyses also showed that two MAYV genotypes are co-circulating in Mato Grosso. DENV negative samples were tested by using multiplex-nested-PCR to identify MAYV. If it had not been for the intensive RT-PCR surveillance for the other arboviruses, the detection of MAYV cases might have been missed.
Alves Esposito, 2017 (1)	Brazil	2014-2016	183	Further information was not provided.
Brunini, 2017 (48)	Brazil	2014-2015 (June)	16	Of 27 CHIKV-negatives samples, 16 of the samples tested by HI were reactive to alphaviruses. 15 of the samples were confirmed positive for MAYV by IgM MAC-ELISA and one sample was borderline. The article did not mention whether the 16 samples had a negative RT-PCR MAYV result in the acute phase specimen or whether an acute phase specimen was taken. Since this information was not provided, it cannot be inferred that the IgM MAC-ELISA results are confirmed or probable cases. All the individuals that tested positive for MAYV IgM had travelled to rural areas in the 15 days before the onset of symptoms. Identification of recent infections in rural and forested areas around the city of Goiânia suggests active foci in the forest cycle where a MAYV forest cycle is established.
Nunes, 2009 (24)	Brazil	Not specified (article published in 2009)	78	Among the samples, 78 monotypic reactions were observed for MAYV. Of those, 10 presented anti-MAYV IgM antibodies. Of those 10 samples, 4 were from the municipality of Trairão and 6 came from the municipality of Novo Progresso.
Estofolete, 2016 (47)	Brazil	Not specified (article published in 2016)	1	A case report revealed that an HIV-infected patient that returned from a work trip to the Amazon basin presented symptoms of febrile illness. After testing negative for DENV and CHIKV, MAYV was confirmed by RT-PCR and subsequently followed by next-generation sequencing and phylogenetic reconstruction. The test was developed in the in-house laboratory for the E1 gene. The interplay between arboviral diseases and HIV is poorly understood. In theory, HIV-induced immunosuppression can lead to more atypical and aggressive manifestations of arboviral infections.
Forshey, 2010 (16)	Ecuador	2000-2007	1	1 confirmed case (virus isolation, RT-PCR, or IgM seroconversion) was identified.
PAHO, 2019 (38)	Ecuador	2019	5	34 samples that were negative for Zika, leptospirosis, dengue, and Chikungunya were tested for Mayaro. Five of the samples were positive. Two of the cases were from the city of Guayaquil, one was from the city of Portoviejo, one case was from the city of Santo Domingo, and one other case was from the city of Babahoyo. The cases were detected through laboratory surveillance of MAYV.
Talarmin, 1998 (25)	French Guiana	1996	1	Mayaro virus was isolated from the acute-phase serum of a woman who had been living in French Guiana for several months and presented with a febrile illness for two days. Immunofluorescent antibody testing with specific mouse antibody was initially performed and confirmed by plaque-reduction neutralization and RT-PCR. A total of 1,962 sera (from 896 women and 1066 men) were tested for antibodies to MAYV. Antibodies to this virus were found in 124 (6.3%) sera but IgM was only detected once.
Lednicky, 2016 (26)	Haiti	2015	1	The patient was an eight-year-old boy from a rural/semi-rural area of Haiti, reflecting an ecologic setting that differs greatly from forest Amazon regions where many of the other reported MAYV infections have occurred. Little is known about vectors for MAYV in Haiti. A blood sample was collected, and RNA was extracted via RT-PCR. The sample confirmed DENV-1. In addition, an alphavirus amplicon similar in size to the expected size of MAYV was also detected in the viral RNA extracted from the infected Vero cells. Sequencing of the amplicon confirmed that it corresponded to MAYV.
Navarrete-Espinosa, 2006 (27)	Mexico	2001	2	35 patients at the Mexican Institute of Social Security were isolated and tested by PCR and two tested positive for MAYV. These patients were hemorrhagic cases; one patient died.
Srihongse, 1973 (33)	Panama	1966-1967	1	A significant rise of antibody titers was identified in the sera of an individual who was positive for MAYV. The patient was part of a group of U.S. citizens who were conducting sea-level-canal feasibility studies in Panama and Colombia. Due to study group crossover, it was difficult to ascertain in which country the virus was acquired.
Tesh, 1999 (28)	Peru	1995-1998	26	From April 1995 to April 1998, 26 cases of MAYV were diagnosed in people living and working in Peru. 20 of the cases were isolated from acute-phase serum samples (confirmed cases), and the remaining 6 cases (presumptive) were diagnosed by serology. Demographic data was only collected on 24 individuals (13 females, 11 males). Ages of the 24 patients ranged from 9-65 years. 17 patients had occupational information available, including general laborer, agricultural worker, missionary, biologist, soldier, student and housekeeper. It was not clear which of the cases were presumptive or confirmed at each location. 15 of the 26 cases were detected accidentally by the isolation of MAYV from serum samples from patients with presumptive yellow fever or dengue, and 11 of the 26 cases were detected during prospective surveillance of patients with febrile illness in Iquitos.
Institutional study, Peruvian Ministry of Health, 2005 (36)	Peru	2000-2001	1	Between May 2000 and July 2001, a longitudinal and descriptive study was performed across four health facilities. Febrile patients aged 5-65 years with negative smears of Bartonella and malaria were included. IgM-IgG was performed for Mayaro; MAYV IgM was found in one patient.
Forshey, 2010 (16)	Peru	2000-2007	5	4 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 1 presumptive case (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Peru	2000-2007	2	2 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Peru	2000-2007	20	10 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 10 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Peru	2000-2007	107	48 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 59 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Forshey, 2010 (16)	Peru	2000-2007	16	11 confirmed cases (virus isolation, RT-PCR, or IgM seroconversion), and 5 presumptive cases (elevated IgM without 4-fold rise between acute and convalescent phases) were identified.
Halsey, 2013 (29)	Peru	2010-2013	16	16 of the 2 094 febrile participants enrolled had Mayaro fever. Of the 16 persons with Mayaro fever, 11 had MAYV isolated by cell culture assays (11 in both Vero 76 and C6/36), 13 were MAYV positive by RT-PCR, and all had IgM ELISA seroconversion between the acute phase and 20-day follow-up visits. In all 16 participants, no IgM ELISA seroconversion occurred for endemic non-alphavirus viruses. Four participants showed IgM ELISA seroconversion against another alphavirus, Venezuelan equine encephalitis virus, but these 4 all had MAYV identified by immunofluorescence assay and by RT-PCR.
PAHO, 2019 (38)	Peru	2018	35	Additional information was not provided.
PAHO, 2019 (38)	Peru	2019	2	One case originated from Quispicanchis, Cusco Region and the other case originated
Anderson, 1957 (37)	Trinidad and Tobago	1954	5	from La Mar, Ayacucho Region. The virus was isolated from the blood samples of four male forest workers and one female urban dweller who presented with febrile illness.
Torres, 2004 (30)	Venezuela	2000	4	Serum samples were tested using IgM MAC-ELISA. Assay of serum samples were obtained 3 months after onset of symptoms and again three months after the initial samples were taken. Three of the family members showed high specific Mayaro viral IgM antibody ranging from 3 200 to 6 400 and IgG antibody titers ranging from 6 400 to 12 800. Testing of samples from the fourth patient were positive for MAYV IgG antibody only. MAYV may have been circulating in a cycle involving Haemagogus mosquitoes and red howler monkeys.
Auguste, 2015 (14)	Venezuela	2010	77	77 cases were reported and 19 were confirmed as seropositive. Of 19 acute-phase serum samples, MAYV was isolated from 6 symptomatic patients. 27 complete genomes were sequenced, which facilitated the detection of a new genotype, referred to as N. The Mayaro fever outbreak at La Estación in 2010 is noteworthy because, with the exception of a family found to be seropositive, it represents the first outbreak documented in Venezuela.

Source: This table was prepared by the authors, based on the study results.

^aThis table does not include the 16 imported cases of Mayaro.

CHIKV, Chikungunya virus; DENV, dengue virus; HI, hemagglutination inhibition; IgM MAC-ELISA, IgM antibody capture enzyme-linked immunosorbent assay; MAYV, Mayaro virus; PAHO, Pan American Health Organization; RT-PCR, reverse transcription polymerase chain reaction.