Skip to main content
Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Retrospective molecular investigation of Mayaro and Oropouche viruses at the human-animal interface in West-central Brazil, 2016–2018

  • Helver Gonçalves Dias ,

    Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Visualization, Writing – original draft, Writing – review & editing

    helvergd@gmail.com (HGD); pauvolid@gmail.com (APC)

    Affiliation Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil

  • Raquel Curtinhas de Lima,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil

  • Luciana Santos Barbosa,

    Roles Investigation, Writing – review & editing

    Affiliations Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil, Laboratório de Genética, Instituto de Puericultura e Pediatria Martagão Gesteira (IPPMG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil

  • Thiara Manuele Alves de Souza,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil

  • Jessica Badolato-Correa,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil

  • Laura Marina Siqueira Maia,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Raquel da Silva Ferreira,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Nilvanei Aparecido da Silva Neves,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Michell Charlles de Souza Costa,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Leticia Ramos Martins,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Emerson Marques de Souza,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Michellen dos Santos Carvalho,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Alexandre de Araujo-Oliveira,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Diptera, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil

  • William de Almeida Marques,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Diptera, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil

  • Gilberto Sabino-Santos,

    Roles Investigation, Writing – review & editing

    Affiliations Center for Virology Research, Ribeirão Preto Medical School University of São Paulo, Ribeirão Preto-SP, Brazil, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans-LA, United States of America

  • Marcio Schafer Marques,

    Roles Investigation, Writing – review & editing

    Affiliation Center for Virology Research, Ribeirão Preto Medical School University of São Paulo, Ribeirão Preto-SP, Brazil

  • Gabriel Carvalho de Macedo,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Biologia Parasitária, Programa de Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Universidade Católica Dom Bosco, Campo Grande, Brazil

  • Wesley Arruda Gimenes Nantes,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Biologia Parasitária, Programa de Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Universidade Católica Dom Bosco, Campo Grande, Brazil

  • Filipe Martins Santos,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Biologia Parasitária, Programa de Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Universidade Católica Dom Bosco, Campo Grande, Brazil

  • Claudia Coutinho Netto,

    Roles Investigation, Writing – review & editing

    Affiliation Centro de Reabilitação de Animais Silvestres (CRAS), Campo Grande, Brazil

  • Thais Oliveira Morgado,

    Roles Investigation, Writing – review & editing

    Affiliation Hospital Veterinário, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Mateus de Assis Bianchini,

    Roles Investigation, Writing – review & editing

    Affiliation Hospital Veterinário, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Sandra Helena Ramiro Correa,

    Roles Investigation, Writing – review & editing

    Affiliation Hospital Veterinário, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Júlia Ramos de Almeida,

    Roles Investigation, Writing – review & editing

    Affiliation Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Larissa Pratta Campos,

    Roles Investigation, Writing – review & editing

    Affiliation Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Isabelle Marino de Souza,

    Roles Investigation, Writing – review & editing

    Affiliation Faculdade de Medicina Veterinária, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Wanessa Teixeira Gomes Barreto,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Ecologia de Populações e do Movimento, Programa de Ecologia e Conservação, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, Brazil

  • Grasiela Porfírio,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Biologia Parasitária, Programa de Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Universidade Católica Dom Bosco, Campo Grande, Brazil

  • Jeronimo Augusto Fonseca Alencar,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Diptera, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil

  • Heitor Miraglia Herrera,

    Roles Investigation, Writing – review & editing

    Affiliations Laboratório de Biologia Parasitária, Programa de Pós-Graduação em Ciências Ambientais e Sustentabilidade Agropecuária, Universidade Católica Dom Bosco, Campo Grande, Brazil, Laboratório de Ecologia de Populações e do Movimento, Programa de Ecologia e Conservação, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, Brazil

  • Renata Dezengrini Shlessarenko,

    Roles Investigation, Writing – review & editing

    Affiliation Laboratório de Virologia, Faculdade de Medicina, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil

  • Rivaldo Venancio da Cunha,

    Roles Investigation, Writing – review & editing

    Affiliations Fiocruz, Campo Grande, Mato Grosso do Sul, Brazil, Departamento de Clínica Médica, Universidade Federal do Mato Grosso do Sul, Campo Grande (UFMS), Campo Grande, Brazil

  • Elzinandes Leal de Azeredo,

    Roles Funding acquisition, Investigation, Resources, Writing – review & editing

    Affiliation Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil

  • Stephanie J. Salyer,

    Roles Funding acquisition, Investigation, Resources, Writing – review & editing

    Affiliation Division of Global Health Protection, Center for Global Health, U.S. Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America

  • Nicholas Komar,

    Roles Funding acquisition, Investigation, Resources, Writing – review & editing

    Affiliation Arboviral Diseases Branch, Division of Vector-borne Diseases, U.S. Centers for Disease Control and Prevention (CDC), Fort Collins, Colorado, United States of America

  • Alex Pauvolid-Corrêa ,

    Roles Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Resources, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

    helvergd@gmail.com (HGD); pauvolid@gmail.com (APC)

    Affiliation Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, MG, Brazil

  •  [ ... ],
  • Flávia Barreto dos Santos

    Roles Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Resources, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Laboratório de Imunologia Viral, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil

  • [ view all ]
  • [ view less ]

Abstract

Mayaro virus (MAYV, Togaviridae) and Oropouche orthobunyavirus (OROV, Peribunyaviridae) are emerging enzootic arboviruses in Latin America. Outbreaks of febrile illness associated with MAYV and OROV have been reported among humans mainly in the northern region of Brazil since the 1980s, and recent data suggest these viruses have circulated also in more populated areas of western Brazil. MAYV shares mosquito vectors with yellow fever virus and it has been historically detected during yellow fever epidemics. Aiming to investigate the transmission of OROV and MAYV at the human-animal interface during a yellow fever, chikungunya and Zika outbreaks in Brazil, we conducted a retrospective molecular investigation in 810 wild and domestic animals, 106 febrile patients, and 22.931 vectors collected from 2016 to 2018 in Cuiaba and Campo Grande metropolitan regions, western Brazil. All samples tested negative for OROV and MAYV RNA by RT-qPCR. Findings presented here suggest no active circulation of MAYV and OROV in the sampled hosts. Active surveillance and retrospective investigations are instrumental approaches for the detection of cryptic and subclinical activity of enzootic arboviruses and together serve as a warning system to implement appropriate actions to prevent outbreaks.

1. Introduction

Epidemic arthropod-borne viruses (arboviruses) such as dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) cause a significant public health burden throughout the globe. Arboviruses are spread across different regions of the world and have a major health impact on populated areas of Latin America [1, 2]. Brazil is one of the world’s most affected countries, and the West-Central region of the country has been severely hit by arbovirus epidemics in the last decade [35]. Enzootic arboviruses, such as yellow fever virus (YFV), have great potential for emergence and urbanization, requiring special attention from one-health surveillance systems. The neglected Mayaro virus (MAYV, Togaviridae) and Oropouche orthobunyavirus (OROV, Peribunyaviridae) are a great concern, as they have been historically involved in outbreaks in rural communities of the Amazon region, and more recently been suggested to be involved in sporadic febrile cases in the West-central and northeast regions of Brazil [612].

MAYV, one of the nine enzootic alphaviruses reported in Brazil, can cause acute febrile illness with headache and marked arthralgia [13]. After CHIKV, which is involved in urban epidemics, MAYV is the most important cause of human illness due to alphaviruses in the country [7, 14, 15]. Maculopapular rash is seen in a great proportion of patients with mayaro fever, and arthralgia can become chronic and persist for about 2–3 months [14, 15]. MAYV is believed to be primarily maintained in enzootic cycles of transmission involving mainly non-human primates such as the Silvery (Mico argentatus), Santarem (Mico humeralifer), and White (Mico leucippe) marmosets, and acrodendrophilic mosquito species as Haemagogus janthinomys, which is also the main vector of YFV in Brazil [7]. Several other studies have demonstrated that not only other species of vertebrates, but also vectors have been found infected and can potentially participate in MAYV cycles of transmission [1619]. Because MAYV and YFV share the same main vector and have a similar enzootic cycle of transmission, MAYV has been historically detected during yellow fever outbreaks reported in the north region of the country [7].

Clinical infection caused by OROV is characterized by an abrupt onset and fever, headache, myalgia, arthralgia, dizziness, chills and photophobia [14]. Oropouche fever has a high attack rate and large outbreaks have been reported in Brazil [20]. A portion of patients present clinical recurrence of symptoms after an initial period of improvement [9, 14, 15, 21]. OROV-associated neurological disease, especially aseptic meningitis, has been reported in immunocompromised individuals, and more recently in healthy individuals [14, 2225]. OROV has unclear and apparently complex cycles of transmission involving different ecological niches with different species of vertebrates and hematophagous arthropods acting as amplifying hosts and vectors, respectively. It is suggested that OROV is maintained in sylvatic cycles involving sloths, such as Bradypus tridactylus and non-human primates, including Callithrix spp. as amplifying hosts, and mosquito species Aedes serratus and Coquillettidia venezuelensis as vectors [26, 27]. Additionally, outbreaks of oropouche fever in rural villages have been attributed to epidemic transmission between humans and Culicoides paraensis midges and Culex quinquefasciatus mosquitoes, which is corroborated by the large number of virus isolations and molecular detection from blood samples of affected patients [9, 15, 28].

For both MAYV and OROV, birds are believed to eventually act as secondary amplifying hosts [17, 2931]. Several studies have demonstrated, by serological methods, that other groups of vertebrates, including wild and domestic species are eventually exposed to both arboviruses [16, 3234]. Studies focused on the potential capacity of these vertebrates to present viremia and ultimately potential role in enzootic cycles of transmission of MAYV and OROV have been less reported. The west-central Brazil, especially the metropolitan regions of Cuiabá and Campo Grande, have socio-economic, environmental and climatic characteristics favorable to the proliferation of arboviruses. This region has been historically affected by arbovirus epidemics and in recent years silent circulation of MAYV and OROV has been reported. The main objective of the present study is to investigate OROV and MAYV in samples from humans, wild and domestic vertebrates, and mosquitoes collected during epidemics of ZIKV, CHIKV and YFV between 2016 and 2018 at the human-animal interface in West-Central Brazil.

2. Materials and methods

2.1 Ethics statement

This study was approved by the research ethics committee, and the Ethics Committee of Plataforma Brasil, FIOCRUZ (CAAE 57221416.0.1001.5248). All subjects were informed about the research and signed a written consent document. Biological samples were also reported to the National System for Access to Genetic Heritage and Associated Traditional Knowledge (SISGEN) according to the Law 13.123/2015 and Decree 8772/2016. Animal sampling was approved by the U.S. Centers for Disease Control and Prevention Institutional Animal Care and Use Committee (Protocol number 2808SALMULX-A2).

2.2 Sampling sites

Sampling was performed between 2016 and 2018 in different sites in urban and peri-urban areas of two cities from two different states of Brazil: Cuiabá, state of Mato Grosso (MT) and Campo Grande, state of Mato Grosso do Sul (MS). Geographical coordinates of all samples, including animals, mosquitoes, and humans, are available as supplementary information, as previously described [35, 36]. For the map construction, collection subsites were geo-referenced and the shape files were extracted from the open access (public domain) cartographic base of Brazilian Institute of Geography and Statistics (IBGE) accessed at https://www.ibge.gov.br/geociencias/downloads-geociencias.html.

2.3 Mosquito sampling

To collect different species of mosquitoes, we used multiple traps types, including CDC light traps, Insectazooka or Prokopak aspirators, and BG-sentinel traps in several types of microhabitats in each study site. Urban and peri-urban species, including Ae. aegypti, Cx quinquefasciatus and sylvatic species such as Sabethes spp. and Haemagogus spp. were sampled (Table 1). After collection, the mosquitoes were kept frozen (-70°C) and sent to the laboratory, where they were later identified, keeping the cooling to preserve the viral RNA and the integrity of the material. Mosquitoes were organized into pools of up to 25 individuals, according to species, sex, place and date of collection and type of trap.The mosquito sampling procedures, as well as the previous molecular testing conducted with all these samples showing that none of them was positive for ZIKV RNA were previously described [35].

thumbnail
Table 1. Non-human vertebrates and mosquitoes sampled in central-western Brazil between 2017 and 2018 and tested for OROV and MAYV, by state.

MT, state of Mato Grosso; MS, state of Mato Grosso do Sul.

https://doi.org/10.1371/journal.pone.0277612.t001

2.4 Wild and domestic animals sampling

Animal sampling targeted abundant domestic species including horses, cattle, dogs and cats, as well as free-ranging and captive peri-urban synanthropic wildlife species including opossums, coatis and non-human primates (Table 1). Domestic animal sampling was conducted primarily in residential neighborhoods, shelters, ranches, state police equine facilities and equestrian societies. For the sampling of wildlife, campuses of local universities, veterinary hospitals, residential neighborhoods and nature reserves were used as sampling locations. A whole blood sample was collected from each animal by venipuncture and placed in a tube with anticoagulant (sodium citrate). When enough volume was available, plasma was separated from blood samples by centrifugation. Although whole blood and plasma samples were collected from all animals and kept frozen (-70°C) until viral RNA extraction, only whole blood was used in the present study. The vertebrate sampling procedures, as well as the previous molecular testing conducted with all these samples, showing that none of them was positive for ZIKV RNA, were previously described [35]. RNA samples were thawed only once for initial testing for ZIKV and here we use the same samples for the investigation of OROV and MAYV.

2.5 Human clinical sampling

We selected 106 clinical samples collected from February to March 2016 from acute febrile patients (onset of disease ≤7 days) attended at the Walfrido Arruda Emergency Care Unit, Campo Grande, MS, Brazil. No human samples were collected in MT. Blood samples were collected, allowed to coagulate at ambient temperature, and centrifuged for separation of serum, which was stored at −70°C. In addition to the investigation carried out here, these serum samples were previously tested for ZIKV, CHIKV and DENV, and results reported elsewhere [36].

2.6 Real-Time Reverse Transcriptase Polymerase Chain Reaction (RT-qPCR) for Mayaro and Oropouche viruses

Viral nucleic acid was extracted from whole blood samples of animals, triturated mosquito pools and serum of human samples using the ZR-Viral RNA or DNA/RNA kits (Zymo Research, Irvine, CA, USA) according to the manufacturer’s instructions. Extracted RNA/DNA was subjected to a specific TaqMan duplex RT-qPCR method for the detection of a region of non-structural protein 1 (NSP1) gene of MAYV and of segment S of OROV, as previously described [37]. The RT-qPCR used is also capable of detecting Oropouche-like viruses that carry the OROV S segment. We used the GoTaq® Probe 1-Step RT-qPCR (Promega) for amplification with the recommended cycling parameters. RNA (5 μL) sample was used as a template in a reaction final volume of 25 μL, and all assays were performed using the 7500 Real-Time PCR Systems (Applied Biosystems). RT-qPCR was performed using positive (MAYV ATCC VR 66, strain TR 4675, GenBank #MK070492 and OROV strain BeAn 19991, GenBank accession #KP052852.1, #KP052851.1, #KP052850.1) and negative viral controls for both viruses and we considered Ct value lower than 38 as positive with a limit of detection between two and 20 copies per reaction (mean Ct values, 28.9 and 31.2 for MAYV and OROV, respectively).

3. Results

A total of 595 domestic animals from four species, 215 wild mammals from 12 species, 106 human serum samples of acute febrile cases, and 22,931 specimens of mosquitoes of 37 species were tested for OROV and MAYV by RT-qPCR.

The sampling strategy for vertebrates and mosquitoes was previously described, and non-human vertebrates and mosquitoes were collected in 30 sub-sites of the state of Mato Grosso (MT) and 14 sub-sites of the state of Mato Grosso do Sul (MS) (Fig 1).

Domestic species tested in both states were: Bos indicus/taurus (n = 176), Canis lupus familiaris (n = 174), Equus ferus caballus (n = 160) and Felis silvestris catus (n = 85). Regarding wild animals, the three species with the highest number of individuals were: Nasua nasua (n = 83), Didelphis albiventris (n = 73) and Mico melanurus (n = 29) (Table 1).

A total of 22,931 adult mosquitoes from MT and MS, belonging to 37 species and distributed in 951 pools were tested for OROV and MAYV. A total of 6,603 specimens were non-engorged females and 16,328 were males. Culex spp. (n = 21.418; 93,4%) was the most sampled genera, followed by Aedes spp. (n = 537; 2,3%), Psorophora spp. (n = 528; 2,3%), Wyeomyia spp. (n = 313; 1,3%), Haemagogus spp. (n = 85; 0,4%), Mansonia spp. (n = 34; 0,15%), and Sabethes spp. (n = 16; 0,07%).

Human samples of cases of acute febrile illness were all from the city of Campo Grande, MS. A total of 106 samples were tested, being 69 (63,9%) female and 38 (36,1%) male, both sex with a medium age of 34 years. All vertebrate and mosquito samples included in this study tested negative for MAYV and OROV.

4. Discussion

The RNA used in the present study was extracted and used primarily for the detection of ZIKV in mosquitoes and whole blood of animals, as previously mentioned. Aware that improper and excessive handling of samples after collection can have an effect on RNA degradation, we found opportune the fact that the samples were thawed only once (then kept frozen at -70°C) and tested them for MAYV and OROV with all the necessary precautions to avoid degradation.

The negative RT-qPCR results presented here suggest no viremia caused by MAYV or OROV during the sampling period in the domestic and wild species of vertebrates from Cuiaba and Campo Grande metropolitan areas. Even using a very sensitive RT-qPCR multiplex protocol, which is capable of detecting a low number of RNA copies, the samples were negative.

All sera from humans with acute febrile illness were also negative for OROV and MAYV RNA. Of the 106 human samples tested, 42 were positive by RT-qPCR for DENV and/or ZIKV, as previously described [36], suggesting that febrile patients from Campo Grande were exposed to the most common epidemic arboviruses as DENV and ZIKV other than MAYV and OROV.

The results described here do not align with previous studies in humans temporally and/or geographicaly related [3841], but previous studies have reported evidence of MAYV infection in humans from other areas of MT and MS [16, 34, 42, 43]. Additional molecular and serological evidences of MAYV have also been reported in the neighboring state of Goiás (GO), corroborating the circulation of MAYV in central-western Brazil [4446]. These evidences highlight the need for differential diagnosis for MAYV and OROV in acute human febrile cases suspected of DENV, ZIKV or CHIKV infections in central-western Brazil. Notably, a growing number of studies have reported the detection of MAYV during outbreaks of epidemic arboviruses as DENV in Brazil and elsewhere [4749].

One of the limitations of the present study is the non use of serological methods to investigate MAYV and OROV circulation in humans, wildlife and domestic animals. Antibody detection is instrumental for investigating infections for which the pathogen may be detected ephemerally by molecular methods while the resulting antibodies may be detected for the remaining life of the host. In a previous investigation of ZIKV conducted with the same non- human vertebrates and vectors, all samples tested negative for ZIKV RNA, but some domestic animals presented specific neutralizing antibodies for ZIKV [35]. Antibodies for MAYV and OROV have been found in patients and domestic animals from other areas of the same region, and also in other regions of the country [16, 32, 34, 44, 50, 51].

Regarding wildlife, evidence of MAYV and OROV circulation in non-human primates has been reported in MS, and from GO where an Alouatta caraya individual presented antibodies for OROV [27, 5254]. In a study carried out with primates in French Guiana, 66% of the Colombian red howler monkey (Alouatta seniculus) and 18% of the Golden-headed tamarin (Saguinus midas) had antibodies for MAYV [17, 18].

In the present study, we investigated by RT-qPCR the circulation of MAYV and OROV in 56 non-human primates, including Mico and Callithrix marmosets and howler monkey, which are potential amplifying hosts. Of these, 29 were free-ranging Black-tailed marmoset (Mico melanurus), which was the most common non-human primate observed in the public parks sampled in the metropolitan area of Cuiaba, MT. The exposure of this species to arboviruses in the region is unknown [55, 56].

Regarding Campo Grande, MS, common marmoset (Callithrix jacchus), Hooded cappuchin (Sapajus cay) and black howler monkey (Alouatta caraya) were the most common non-human primates sampled and most of them were captive. Despite potential candidates for OROV and MAYV amplification, all individuals were negative by RT-qPCR which may be explained by either the absence of active infection in sampled animals or by the short viremia making unreliable a proper evaluation in the absence of complementary serological investigation [35, 54, 57]. The limited number of individuals tested from each species may also have influenced the results. The prevalence of exposure of non-human vertebrates to OROV and MAYV in the region is unknown and low prevalences may require greater number of individuals tested for detection.

Regarding vectors, the mosquito species that would be potentially involved in the transmission of MAYV and OROV at the human-animal interface in western Brazil remain unknown. Haemagogus spp., which are the main vector of MAYV, are diurnal acrodendrophilic mosquitoes and are more active in forested areas [7, 58]. Transmission in more urbanized areas could be hypothetically related to either sylvatic species in the genera Haemagogus and Sabethes reaching human settlements or by vectors that are fairly or very adapted to more urbanized environments, such as Ae albopictus, Ae. aegypti and Cx. quinquefasciatus.

In the present study, 85 individuals of Haemagogus were captured by different methods, including aspiration in tree canopies [35]. Of these, most were Haemagogous janthinomys, which is the most important vector for MAYV and all of them tested negative for both viruses. Also negative were 21,000 Culex mosquitoes, which included 75 Cx. quinquefasciatus, which is considered a secondary urban vector for OROV [38, 59, 60]. Evidence of arbovirus circulation in the absence of epidemics and epizootics frequently relies on the detection or isolation of arboviruses from vectors and sporadic cases [22, 39, 40, 43]. In the present study, all mosquito samples tested negative by molecular methods for OROV and MAYV.

These findings suggest absence of active circulation of both enzootic viruses in the mosquito population assessed in both cities. Despite some reports of OROV and MAYV in urban vector species in Brazil [38, 40, 46], the transmission and maintenance of these arboviruses by these anthropophilic species remains unclear in the country. Some vector competence studies have already shown that Ae. albopictus and Cx. quinquefasciatus are not efficient vectors for OROV under laboratory conditions [5961]. Similar experimental studies using different populations of Ae. Aegypti and Cx. quinquefasciatus with MAYV have demonstrated that transmission by these species of vectors requires a high viremia, a feature not usually observed in human MAYV infections. These data suggest the vector competence of these urban vectors for MAYV transmission is limited [6264].

The active surveillance reported here suggests low or absent circulation of MAYV and OROV in vertebrate and mosquito samples collected in MT and MS between 2016 and 2018. Active surveillance and retrospective investigations are instrumental approaches for the detection of enzootic arboviruses and together serve as a warning system to implement appropriate actions to prevent outbreaks.

5. Conclusions

Despite the absence of molecular evidence of MAYV and OROV in hundreds of vertebrate and vector samples reported here, we stress the importance of active surveillance at the human-animal interface in order to detect cryptic activity of neglected and emerging arboviruses in Brazil, as a warning system to implement appropriate actions to reduce outbreaks.

Supporting information

S1 Table. Sampling sites information.

Additional information and geographic coordinates of sampling sites.

https://doi.org/10.1371/journal.pone.0277612.s001

(XLSX)

Acknowledgments

We deeply appreciate the contribution to this paper made by our teammates during sample collections and technical assistance during the Zika Virus Ecology Project in Brazil. We thank members of the Multi-user Research Facility of Biosafety Level 3 Platform of Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.

References

  1. 1. Stanaway J.D.; Shepard D.S.; Undurraga E.A.; Halasa Y.A.; Coffeng L.E.; Brady O.J.; et al. The Global Burden of Dengue: An Analysis from the Global Burden of Disease Study 2013. The Lancet Infectious Diseases 2016, 16, 712–723, pmid:26874619
  2. 2. Ndeffo-Mbah M.L.; Pandey A. Global Risk and Elimination of Yellow Fever Epidemics. The Journal of Infectious Diseases 2020, 221, 2026–2034, pmid:31545372
  3. 3. Rodrigues N.C.P.; Lino V.T.S.; Daumas R.P.; Andrade M.K. de N.; O’Dwyer G.; Monteiro D.L.M.; et al. Temporal and Spatial Evolution of Dengue Incidence in Brazil, 2001–2012. PLoS ONE 2016, 11, e0165945, pmid:27832129
  4. 4. Fares R.C.G.; Souza K.P.R.; Añez G.; Rios M. Epidemiological Scenario of Dengue in Brazil. BioMed Research International 2015, 2015, 1–13, pmid:26413514
  5. 5. Ministério da Saúde Boletim Epidemiológico 2. V. 49; Secretaria de Vigilância em Saúde/Ministério da Saúde: Brasil, 2018; p. 1;.
  6. 6. Dixon K.E.; Travassos da Rosa A.P.; Travassos da Rosa J.F.; Llewellyn C.H. Oropouche Virus. II. Epidemiological Observations during an Epidemic in Santarém, Pará, Brazil in 1975. Am J Trop Med Hyg 1981, 30, 161–164. pmid:7212162
  7. 7. LeDuc J.W.; Pinheiro F.P.; Peterson N.E.; Hoch A.L. An Outbreak of Mayaro Virus Disease in Belterra, Brazil: III. Entomological and Ecological Studies*. The American Journal of Tropical Medicine and Hygiene 1981, 30, 689–698, pmid:6266265
  8. 8. Pinheiro F.; Pinheiro M.; Bensabath G.; Causey O.; Shope R. Epidemia de Vírus Oropouche Em Belém. Revista do Serviço Especial de Saúde 1962, 12, 15–23.
  9. 9. Pinheiro F.P.; Travassos da Rosa A.P.; Travassos da Rosa J.F.; Ishak R.; Freitas R.B.; Gomes M.L.; et al. Oropouche Virus. I. A Review of Clinical, Epidemiological, and Ecological Findings. Am J Trop Med Hyg 1981, 30, 149–160. pmid:6782898
  10. 10. Rosa A.P.A.T.; Rodrigues S.G.; Nunes M.R.T.; Magalhães M.T.F.; Rosa J.F.S.T.; Vasconcelos P.F.C. Epidemia de Febre Do Oropouche Em Serra Pelada, Município de Curionópolis, Pará, 1994. Rev. Soc. Bras. Med. Trop. 1996, 29, 537–541, pmid:9011877
  11. 11. Vasconcelos H.B.; Azevedo R.S.S.; Casseb S.M.; Nunes-Neto J.P.; Chiang J.O.; Cantuária P.C.; et al. Oropouche Fever Epidemic in Northern Brazil: Epidemiology and Molecular Characterization of Isolates. Journal of Clinical Virology 2009, 44, 129–133, pmid:19117799
  12. 12. Fonseca L.M. dos S.; Carvalho R.H.; Bandeira A.C.; Sardi S.I.; Campos G.S. Oropouche Virus Detection in Febrile Patients’ Saliva and Urine Samples in Salvador, Bahia, Brazil. Jpn J Infect Dis 2020, 73, 164–165, pmid:31787741
  13. 13. Causey O.R.; Maroja O.M. Mayaro Virus: A New Human Disease Agent. III. Investigation of an Epidemic of Acute Febrile Illness on the River Guama in Pará, Brazil, and Isolation of Mayaro Virus as Causative Agent. Am J Trop Med Hyg 1957, 6, 1017–1023. pmid:13487974
  14. 14. Vasconcelos P.; Rosa A.; Dégallier N.; Rosa J.; Pinheiro F. Clinical and Epidemiological Situation of Human Arboviruses in Brazilian Amazonia. Ciência e Cultura (SBPC) 1992, 44, 117–124.
  15. 15. Vasconcelos P.; Travassos da Rosa A.; Pinheiro F.; Shope R.; Travassos da Rosa J.; Rodrigues S. Arboviruses Pathogenic for Man in Brasil. In An overview of arbovirology in Brazil and neighbouring countries; Instituto Evandro Chagas: Belém, Pará, 1998; pp. 72–99.
  16. 16. Pauvolid-Corrêa A.; Juliano R.S.; Campos Z.; Velez J.; Nogueira R.M.R.; Komar N. Neutralising Antibodies for Mayaro Virus in Pantanal, Brazil. Mem. Inst. Oswaldo Cruz 2015, 110, 125–133, pmid:25742272
  17. 17. de Thoisy B.; Gardon J.; Salas R.A.; Morvan J.; Kazanji M. Mayaro Virus in Wild Mammals, French Guiana. Emerg. Infect. Dis. 2003, 9, 1326–1329, pmid:14609474
  18. 18. Kazanji M.; Bourreau E.; Talarmin A.; Shope R.E.; Lelarge J.; Labeau B.; et al. Mayaro Virus Fever in French Guiana: Isolation, Identification, and Seroprevalence. The American Journal of Tropical Medicine and Hygiene 1998, 59, 452–456, pmid:9749643
  19. 19. Celone M.; Okech B.; Han B.A.; Forshey B.M.; Anyamba A.; Dunford J.; et al. A Systematic Review and Meta-Analysis of the Potential Non-Human Animal Reservoirs and Arthropod Vectors of the Mayaro Virus. PLoS Negl Trop Dis 2021, 15, e0010016, pmid:34898602
  20. 20. Pinheiro F.P.; Travassos da Rosa A.P.; Travassos da Rosa J.F.; Bensabath G. An Outbreak of Oropouche Virus Disease in the Vicinity of Santarem, Para, Brazil. Tropenmed Parasitol 1976, 27, 213–223.
  21. 21. Martins-Luna J.; del Valle-Mendoza J.; Silva-Caso W.; Sandoval I.; del Valle L.J.; Palomares-Reyes C.; et al. Oropouche Infection a Neglected Arbovirus in Patients with Acute Febrile Illness from the Peruvian Coast. BMC Res Notes 2020, 13, 67, pmid:32041646
  22. 22. Vernal S.; Martini C.C.R.; da Fonseca B.A.L. Oropouche Virus–Associated Aseptic Meningoencephalitis, Southeastern Brazil. Emerg. Infect. Dis. 2019, 25, 380–382, pmid:30666950
  23. 23. Chiang J.O.; Azevedo R.S.; Justino M.C.A.; Matos H.J.; Cabeça H.L.S.; Silva S.P.; et al. Neurological Disease Caused by Oropouche Virus in Northern Brazil: Should It Be Included in the Scope of Clinical Neurological Diseases? J Neurovirol 2021, 27, 626–630, pmid:34115330
  24. 24. Pinheiro F.P.; Rocha A.G.; Freitas R.B.; Ohana B.A.; Travassos da Rosa A.P.; Rogério J.S.; et al. [Meningitis associated with Oropouche virus infections]. Rev Inst Med Trop Sao Paulo 1982, 24, 246–251.
  25. 25. Pinto de Figueiredo R.M.; Pivoto João G.; Naveca F.G.; Monte R.L.; Bastos M. de S.; Ramasawmy R.; et al. Identification of Oropouche Orthobunyavirus in the Cerebrospinal Fluid of Three Patients in the Amazonas, Brazil. The American Journal of Tropical Medicine and Hygiene 2012, 86, 732–735, pmid:22492162
  26. 26. Anderson C.R.; Spence L.; Downs W.G.; Aitken T.H. Oropouche Virus: A New Human Disease Agent from Trinidad, West Indies. Am J Trop Med Hyg 1961, 10, 574–578, pmid:13683183
  27. 27. Nunes M.R.T.; Martins L.C.; Rodrigues S.G.; Chiang J.O.; Azevedo R. do S. da S.; Travassos da Rosa A.P.A.; et al. Oropouche Virus Isolation, Southeast Brazil. Emerg. Infect. Dis. 2005, 11, 1610–1613, pmid:16318707
  28. 28. Roberts D.R.; Hoch A.L.; Dixon K.E.; Llewellyn C.H. Oropouche Virus. III. Entomological Observations from Three Epidemics in Pará, Brazil, 1975. Am J Trop Med Hyg 1981, 30, 165–171. pmid:7212163
  29. 29. Hervé J.-P.; Dégallier N.; Travassos da Rosa A.; Pinheiro F.; Sá Filho G. Arboviroses: Aspectos Ecológicos. In Instituto Evandro Chagas: 50 anos de contribuição às Ciências Biológicas e à Medicina Tropical; Fundação Serviços de Saúde Pública: Belém, 1986; Vol. 1, pp. 409–437.
  30. 30. Dégallier N; Travassos da Rosa APA; Silva JMC; Rodrigues SG; Vasconcelos PFC; Travassos da Rosa JFS; Silva GP; Silva RP As Aves Como Hospedeiras de Arbovírus Na Amazônia Brasileira. Boletim do Museu Paraense Emilio Goeldi. Serie Zoologia 1992, 8, 69–111.
  31. 31. Calisher C.H.; Gutiérrez E.; Maness K.S.; Lord R.D. Isolation of Mayaro Virus from a Migrating Bird Captured in Louisiana in 1967. Bull Pan Am Health Organ 1974, 8, 243–248. pmid:4418030
  32. 32. Casseb A.; Chiang J.; Martins L.; Silva S.; Henriques D.; Casseb L.; et al. Alphavirus Serosurvey in Domestic Herbivores in Pará State, Brazilian Amazon. 2012, 3, 43–48.
  33. 33. Casseb A. do R.; Brito T.C.; Silva M.R.M. da; Chiang J.O.; Martins L.C.; Silva S.P. da; Henriques D.F.; et al. Prevalence of Antibodies to Equine Alphaviruses in the State of Pará, Brazil. Arq. Inst. Biol. 2016, 83,
  34. 34. Pauvolid-Corrêa A.; Campos Z.; Soares R.; Nogueira R.M.R.; Komar N. Neutralizing Antibodies for Orthobunyaviruses in Pantanal, Brazil. PLoS Negl Trop Dis 2017, 11, e0006014, pmid:29091706
  35. 35. Pauvolid-Corrêa A.; Gonçalves Dias H.; Marina Siqueira Maia L.; Porfírio G.; Oliveira Morgado T.; Sabino-Santos G.; et al. Zika Virus Surveillance at the Human–Animal Interface in West-Central Brazil, 2017–2018. Viruses 2019, 11, 1164, pmid:31888285
  36. 36. Sánchez-Arcila J.C.; Badolato-Correa J.; de Souza T.M.A.; Paiva I.A.; Barbosa L.S.; Nunes P.C.G.; et al. Clinical, Virological, and Immunological Profiles of DENV, ZIKV, and/or CHIKV-Infected Brazilian Patients. Intervirology 2020, 63, 33–45, pmid:32966990
  37. 37. Naveca F.G.; Nascimento V.A. do; Souza V.C. de; Nunes B.T.D.; Rodrigues D.S.G.; Vasconcelos P.F. da C. Multiplexed Reverse Transcription Real-Time Polymerase Chain Reaction for Simultaneous Detection of Mayaro, Oropouche, and Oropouche-like Viruses. Mem. Inst. Oswaldo Cruz 2017, 112, 510–513, pmid:28591313
  38. 38. Cardoso B.F.; Serra O.P.; Heinen L.B. da S.; Zuchi N.; Souza V.C. de; Naveca F.G.; et al. Detection of Oropouche Virus Segment S in Patients and InCulex Quinquefasciatus in the State of Mato Grosso, Brazil. Mem. Inst. Oswaldo Cruz 2015, 110, 745–754, pmid:26517653
  39. 39. Serra O.P.; Cardoso B.F.; Ribeiro A.L.M.; Santos F.A.L. dos; Slhessarenko R.D. Mayaro Virus and Dengue Virus 1 and 4 Natural Infection in Culicids from Cuiabá, State of Mato Grosso, Brazil. Mem. Inst. Oswaldo Cruz 2016, 111, 20–29, pmid:26784852
  40. 40. Maia L.M.S.; Bezerra M.C.F.; Costa M.C.S.; Souza E.M.; Oliveira M.E.B.; Ribeiro A.L.M.; et al. Natural Vertical Infection by Dengue Virus Serotype 4, Zika Virus and Mayaro Virus in Aedes (Stegomyia) Aegypti and Aedes (Stegomyia) Albopictus. Med Vet Entomol 2019, 33, 437–442, pmid:30776139
  41. 41. de Souza Costa M.C.; Siqueira Maia L.M.; Costa de Souza V.; Gonzaga A.M.; Correa de Azevedo V.; Ramos Martins L.; et al. Arbovirus Investigation in Patients from Mato Grosso during Zika and Chikungunya Virus Introdution in Brazil, 2015–2016. Acta Tropica 2019, 190, 395–402, pmid:30552880
  42. 42. Neel J.V.; Andrade A.H.; Brown G.E.; Eveland W.E.; Goobar J.; Sodeman W.A.; et al. Further Studies of the Xavante Indians. IX. Immunologic Status with Respect to Various Diseases and Organisms. Am J Trop Med Hyg 1968, 17, 486–498. pmid:4297406
  43. 43. Coimbra T.L.M.; Santos C.L.S.; Suzuki A.; Petrella S.M.C.; Bisordi I.; Nagamori A.H.; et al. Mayaro Virus: Imported Cases of Human Infection in São Paulo State, Brazil. Rev. Inst. Med. trop. S. Paulo 2007, 49, 221–224, pmid:17823750
  44. 44. Brunini S.; França D.D.S.; Silva J.B.; Silva L.N.; Silva F.P.A.; Spadoni M.; et al. High Frequency of Mayaro Virus IgM among Febrile Patients, Central Brazil. Emerg. Infect. Dis. 2017, 23, 1025–1026, pmid:28518022
  45. 45. de Paula Silveira-Lacerda E.; Laschuk Herlinger A.; Tanuri A.; Rezza G.; Anunciação C.E.; Ribeiro J.P.; et al. Molecular Epidemiological Investigation of Mayaro Virus in Febrile Patients from Goiania City, 2017–2018. Infection, Genetics and Evolution 2021, 95, 104981, pmid:34197917
  46. 46. de Curcio J.S.; Salem-Izacc S.M.; Pereira Neto L.M.; Nunes E.B.; Anunciação C.E.; de Paula Silveira-Lacerda E. Detection of Mayaro Virus in Aedes Aegypti Mosquitoes Circulating in Goiânia-Goiás-Brazil. Microbes and Infection 2022, 104948, pmid:35108606
  47. 47. Aguilar-Luis M.A.; del Valle-Mendoza J.; Sandoval I.; Silva-Caso W.; Mazulis F.; Carrillo-Ng H.; et al. A Silent Public Health Threat: Emergence of Mayaro Virus and Co-Infection with Dengue in Peru. BMC Res Notes 2021, 14, 29, pmid:33478539
  48. 48. Gonzalez-Escobar G.; Churaman C.; Rampersad C.; Singh R.; Nathaniel S. Mayaro Virus Detection in Patients from Rural and Urban Areas in Trinidad and Tobago during the Chikungunya and Zika Virus Outbreaks. Pathogens and Global Health 2021, 115, 188–195, pmid:33645470
  49. 49. Zuchi N.; Heinen L.B. da S.; Santos M.A.M. dos; Pereira F.C; Slhessarenko R.D. Molecular Detection of Mayaro Virus during a Dengue Outbreak in the State of Mato Grosso, Central-West Brazil. Mem. Inst. Oswaldo Cruz 2014, 109, 820–823, pmid:25141284
  50. 50. Batista P.M.; Andreotti R.; Chiang J.O.; Ferreira M.S.; Vasconcelos P.F. da C. Seroepidemiological Monitoring in Sentinel Animals and Vectors as Part of Arbovirus Surveillance in the State of Mato Grosso Do Sul, Brazil. Rev. Soc. Bras. Med. Trop. 2012, 45, 168–173, pmid:22534986
  51. 51. Cruz A.C.R.; Prazeres A. do S.C. dos; Gama E.C.; Lima M.F. de; Azevedo R. do S.S.; Casseb L.M.N.; et al. Vigilância Sorológica Para Arbovírus Em Juruti, Pará, Brasil. Cad. Saúde Pública 2009, 25, 2517–2523, pmid:19936489
  52. 52. Batista P.M.; Andreotti R.; Almeida P.S. de; Marques A.C.; Rodrigues S.G.; Chiang J.O.; et al. Detection of Arboviruses of Public Health Interest in Free-Living New World Primates (Sapajus Spp.; Alouatta Caraya) Captured in Mato Grosso Do Sul, Brazil. Rev. Soc. Bras. Med. Trop. 2013, 46, 684–690, pmid:24474008
  53. 53. Catenacci L.S.; Ferreira M.; Martins L.C.; De Vleeschouwer K.M.; Cassano C.R.; Oliveira L.C.; et al. Surveillance of Arboviruses in Primates and Sloths in the Atlantic Forest, Bahia, Brazil. EcoHealth 2018, 15, 777–791, pmid:30117001
  54. 54. Rocha T.C. da; Batista P.M.; Andreotti R.; Bona A.C.D.; Silva M.A.N. da; Lange R.; et al. Evaluation of Arboviruses of Public Health Interest in Free-Living Non-Human Primates (Alouatta Spp., Callithrix Spp., Sapajus Spp.) in Brazil. Rev. Soc. Bras. Med. Trop. 2015, 48, 143–148, pmid:25992927
  55. 55. Rímoli J.; Milagres A. Mamíferos—Mico Melanurus—Sagui Marrom. Avaliação Do Risco de Extinção de Mico Melanurus (É. Geofrroy Em Humboldt, 1812) No Brasil. Processo de Avaliação Do Risco de Extinção Da Fauna Brasileira. ICMBio 2012.
  56. 56. Sauer A.; Barroso W.; Santos U.; Portela M.; Machado A.; Camera B.; et al. Efeito Da Sazonalidade Sobre o Padrão Comportamental de Um Grupo de Saguis-Do-Rabo-Preto (Mico Melanurus) Em Um Fragmento Florestal Urbano.
  57. 57. Bittar C.; Machado R.R.G.; Comelis M.T.; Bueno L.M.; Morielle-Versute E.; Beguelini M.R.; et al. Lack of Serological and Molecular Evidence of Arbovirus Infections in Bats from Brazil. PLoS ONE 2018, 13, e0207010, pmid:30403749
  58. 58. Hendy A.; Hernandez-Acosta E.; Valério D.; Mendonça C.; Costa E.R.; Júnior J.T.A.; et al. The Vertical Stratification of Potential Bridge Vectors of Mosquito-Borne Viruses in a Central Amazonian Forest Bordering Manaus, Brazil. Sci Rep 2020, 10, 18254, pmid:33106507
  59. 59. Hoch A.L.; Pinheiro F.P.; Roberts D.R.; Gomes M.L. Laboratory Transmission of Oropouche Virus by Culex Quinquefasciatus Say. Bull Pan Am Health Organ 1987, 21, 55–61. pmid:3607353
  60. 60. Smith G.C.; Francy D.B. Laboratory Studies of a Brazilian Strain of Aedes Albopictus as a Potential Vector of Mayaro and Oropouche Viruses. J Am Mosq Control Assoc 1991, 7, 89–93. pmid:1646286
  61. 61. de Mendonça S.F.; Rocha M.N.; Ferreira F.V.; Leite T.H.J.F.; Amadou S.C.G.; Sucupira P.H.F.; et al. Evaluation of Aedes Aegypti, Aedes Albopictus, and Culex Quinquefasciatus Mosquitoes Competence to Oropouche Virus Infection. Viruses 2021, 13, 755, pmid:33923055
  62. 62. Pereira T.N.; Carvalho F.D.; De Mendonça S.F.; Rocha M.N.; Moreira L.A. Vector Competence of Aedes Aegypti, Aedes Albopictus, and Culex Quinquefasciatus Mosquitoes for Mayaro Virus. PLoS Negl Trop Dis 2020, 14, e0007518, pmid:32287269
  63. 63. Dieme C.; Ciota A.T.; Kramer L.D. Transmission Potential of Mayaro Virus by Aedes Albopictus, and Anopheles Quadrimaculatus from the USA. Parasites Vectors 2020, 13, 613, pmid:33298165
  64. 64. Tesh R.B.; Higgs S.; Hausser N.L.; Thangamani S.; Kochel T.J.; Ziegler S.A.; et al. Experimental Transmission of Mayaro Virus by Aedes Aegypti. The American Journal of Tropical Medicine and Hygiene 2011, 85, 750–757, pmid:21976583