Rocio encephalitis


Rocio virus is an arthropod borne virus transmitted by mosquitoes, belonging to genus Ochleratus. The reservoir of the virus in nature is sparrows Zonotrichia capensis. The Rocio virus is transmitted through the bite of infected mosquitoes. The epidemic and epizootic cycle of the virus are not exactly defined.

Clinical manifestations caused by Rocio virus, include of the disease included fever, lassitude, malaise, vomiting, lethargy, severe headache, dizziness, photophobia and expressed neurologic disorders. With the development of a coma, the disease progresses rapidly, about a third of patients with symptoms of coma die in 5 days after the onset of the disease. Permanent consequences manifest themselves n the form of paralysis and cerebral dysfunction specific means of prevention and treatment for Rocio encephalitis have not been developed.

The organization of genomic RNA of Rocio virus and some others flaviviruses of Ntaya group are viewed in this article. The reservoir and the vector of transmission of the studied infectious agent are considered separately. The opinion was expressed that during the natural evolution of the Rocio virus the occurrence of a variant of pathogen, capable of introduction from an endemic region, is possible, that happened to the pathogens of Chikungunya and West Nile fevers.

Possible outbreaks of Rocio encephalitis may lead to severe consequences for health care. Due to the possible spread of the Rocio virus from an endemic region it is necessary to develop effective diagnostic sets of reagents for the detection and identification of this pathogen.

Keywords:Rocio virus; Rocio encephalitis; flaviviruses; vector of transmission; mosquitoes; reservoir of agent

Funding. The study had no sponsor support.

Conflict of interest. The authors declare no conflict of interest.

Contribution. Collection and synthesis of data on the organization of genomic RNA of the Rosio virus and others flaviviruses of Ntaya groups, the analysis of possible approaches for the development of diagnostics, forming of article – Sizikova T.E.; collection and synthesis of data on clinical manifestations of the disease caused by the Rocio virus – Savenko S.V.; collection and synthesis of data on reservoir and the transmission vector of the Rocio virus – Lebedev V.N.; the analysis of possibility of the Rocio virus introduction from endemic region, editing of article – Borisevich S.V.

For citation: Sizikova T.E., Savenko S.V., Lebedev V.N., Borisevich S.V. Rocio encephalitis. Infektsionnye bolezni: novosti, mneniya, obuchenie [Infectious Diseases: News, Opinions, Training]. 2022; 11 (1): 113–8. DOI:


1. Kuno G., Chang G.J. Full-length sequencing and genomic characterization of Bagaza, Kedougou, and Zika viruses. Arch Virol. 2007; 152 (4): 687–96. DOI:

2. Medeiros D.B., Nunes M.R., Vasconcelos P.F., Chang G.J., Kuno G. Complete genome characterization of Rocio virus (Flavivirus: Flaviviridae), a Brazilian flavivirus isolated from a fatal case of encephalitis during an epidemic in Sao Paulo state. J Gen Virol. 2007; 88 (8): 2237–46. DOI:

3. ICTV. Virus taxonomy classification and nomenclature of viruses: report of the international committee on taxonomy of viruses. San Diego: Elsevier Academic Press; 2012.

4. Karabatsos N. International Catalogue of Arboviruses, Including Certain Other Viruses of Vertebrates. 3rd ed. San Antonio, Texas: American Society of Tropical Medicine and Hygiene for The Subcommittee on Information Exchange of the American Committee on Arthropod-borne Viruses; 1985: 1147 p.

5. Kuno G., Chang G.J., Tsuchiya K.R., Karabatsos N., Cropp C.B. Phylogeny of the genus Flavivirus. J Virol. 1998; 72 (1): 73–83. DOI:

6. de Souza Lopes O., de Abreu Sacchetta L., Coimbra T.L., Pinto G.H., Glasser C.M. Emergence of a new arbovirus disease in Brazil. II. Epidemiologic studies on 1975 epidemic. Am J Epidemiol. 1978; 108 (5): 394–401. DOI:

7. Dikid T., Jain S.K., Sharma A., Kumar A., Narain J.P. Emerging and re-emerging arboviral diseases in India: an overview. Indian J Med Res. 2013; 138 (1): 19–31. PMID: 24056553.

8. Pastula D.M., Smith D.E., Beckham J.D., Tyler K.L. Four emerging arboviral diseases in North America: Jamestown Canyon, Powassan, chikungunya, and Zika virus diseases. J Neurovirol. 2016; 22 (3): 257–60. DOI:

9. Amarilla A.A., Setoh Y.X., Periasamy P., Peng N.Y., et al. Chimeric viruses between Rocio and West Nile: the role for Rocio prM-E proteins in virulence and inhibition of interferon-α/β signaling. Sci Rep. 2017; 7: 44642. DOI:

10. Straatmann A., Santos-Torres S., Vasconcelos P.F., da Rosa A.P., et al. Serological evidence of the circulation of the Rocio arbovirus (Flaviviridae) in Bahia. Rev Soc Bras Med Trop. 1997; 30 (6): 511–5. DOI:

11. de Barros V.E., Saggioro F.P., Neder L., de Oliveira Franca R.F., et al. An experimental model of meningoencephalomyelitis by Rocio flavivirus in BALB/c mice: inflammatory response, cytokine production, and histopathology. Am J Trop Med Hyg. 2011; 85 (2): 363–73. DOI:

12. Amarilla A.A., Santos-Junior N.N., Figueiredo M.L., Luiz J.P., et al. CCR2 plays a protective role in Rocio virus-induced encephalitis by promoting macrophage infiltration into the brain. J Infect Dis. 2019; 219 (12): 2015–25. DOI:

13. Chávez J.H., França R.F.O., Oliveir C.J.F., de Aquino M.T.P., et al. Influence of the CCR-5/MIP-1 α axis in the pathogenesis of Rocio virus encephalitis in a mouse model. Am J Trop Med Hyg. 2013; 89 (5): 1013–8. DOI:

14. Amarilla A.A., Fumagalli M., Figueiredo M.L., Lima-Junior D.S., et al. Ilheus and Saint Louis encephalitis viruses elicit cross-protection against a lethal Rocio virus challenge in mice. PLoS One. 2018; 13 (6): e0199071. DOI:

15. Mitchell C.J., Monath T.P., Cropp C.B. Experimental transmission of Rocio virus by mosquitoes. Am J Trop Med Hyg. 1981; 30 (2): 465–72. DOI:

16. Chesnut M., Muñoz L.S., Harris G., Freeman D., et al. In vitro and in silico models to study mosquito-borne Flavivirus Neuropathogenesis, prevention, and treatment. Front Cell Infect Microbiol. 2019; 9: 223. DOI: 2019.00223

17. Wanlapakorn N., Thongmee T., Linsuwanon P., Chattakul P., et al. Chikungunya outbreak in Bueng Kan Province, Thailand, 2013. Emerg Infect Dis. 2014; 20 (8): 1404–6. DOI:

18. Saivish M.V., da Costa V.G., Rodrigues R.L., Féres V.C.R., et al. Detection of Rocio Virus SPH 34675 during Dengue Epidemics, Brazil, 2011–2013. Emerg Infect Dis. 2020; 26 (4): 797–9. DOI:

19. Araújo P.A., Freitas M.O., Chiang J.O., Silva F.A., et al. Investigation about the Occurrence of Transmission Cycles of Arbovirus in the Tropical Forest, Amazon Region. Viruses. 2019; 11 (9): 774. DOI:

20. Turtle L.M., Griffiths J., Solomon T. Encephalitis caused by flaviviruses. QJM. 2012; 105 (3): 219–23. DOI:

21. Ioos S., Mallet H.P., Goffart H., Gauther V., et al. Current Zika virus epidemiology and recent epidemics. Med Mal Infect. 2014; 44 (7): 302–7. DOI:

22. Petersen L.R., Beard C.B., Visser S.N. Combatting the increasing threat of vector-borne disease in the United States with a national vector-borne disease prevention and control system. Am J Trop Med Hyg. 2019; 100 (2): 242–5. DOI:

23. Beard C.B., Visser S.N., Petersen L.R. The need for a national strategy to address vector-borne disease threats in the United States. J Med Entomol. 2019; 56 (5): 1199–203. DOI:

Yushchuk Nikolay Dmitrievich
Academician of the Russian Academy of Sciences, Professor, head of the Infectious Diseases and Epidemiology Department, President of the Moscow State University of Medicine and Dentistry named after A.I. Evdokimov, Board member of the National Scientific Infectiologists? Society.
Medicine today

Уважаемые коллеги! Приглашаем Вас принять участие в VI Научно-практической конференции "Парадигмы лекарственной терапии у онкологических больных" ( ), которая впервые состоится в Москве, в очном формате 08-09 сентября 2022 г. Адрес : г. Москва, ул...

XI Национальный конгресс с международным участием имени Н.О. Миланова "Пластическая хирургия, эстетическая медицина и косметология" - Реконструкция формы. Управление временем С 29 ноября по 1 декабря 2022 года в Москве пройдет XI Национальный конгресс "Пластическая хирургия,...

15-17 сентября на площадке "Рэдиссон Славянская Отель и Бизнес-центр" в Москве состоится XIII международный форум "Росмедобр-2022. Инновационные обучающие технологии в медицине" - крупнейшее ежегодное событие в сфере медицинского образования в русскоязычном пространстве....

Journals of «GEOTAR-Media»