Spatial Distribution and Burden of Emerging Arboviruses in French Guiana.

Despite the health, social and economic impact of arboviruses in French Guiana, very little is known about the extent to which infection burden is shared between individuals. We conducted a large multiplexed serological survey among 2697 individuals from June to October 2017. All serum samples were tested for IgG antibodies against DENV, CHIKV, ZIKV and MAYV using a recombinant antigen-based microsphere immunoassay with a subset further evaluated through anti-ZIKV microneutralization tests. The overall DENV seroprevalence was estimated at 73.1% (70.6-75.4) in the whole territory with estimations by serotype at 68.9% for DENV-1, 38.8% for DENV-2, 42.3% for DENV-3, and 56.1% for DENV-4. The overall seroprevalence of CHIKV, ZIKV and MAYV antibodies was 20.3% (17.7-23.1), 23.3% (20.9-25.9) and 3.3% (2.7-4.1), respectively. We provide a consistent overview of the burden of emerging arboviruses in French Guiana, with useful findings for risk mapping, future prevention and control programs. The majority of the population remains susceptible to CHIKV and ZIKV, which could potentially facilitate the risk of further re-emergences. Our results underscore the need to strengthen MAYV surveillance in order to rapidly detect any substantial changes in MAYV circulation patterns.

Emergent arboviruses in Brazil.

Brazil is a large tropical country (8,514,215 km(2)) with 185,360,000 inhabitants. More than one third of its territory is covered by tropical forests or other natural ecosystems. These provide ideal conditions for the existence of many arboviruses, which are maintained in a large variety of zoonotic cycles. The risk that new arboviruses might emerge in Brazil is related to the existence of large, densely populated cities that are infested by mosquitoes such as Culex and the highly anthropophilic Aedes aegypti. Infected humans or animals may come into these cities from ecological-epidemiological settings where arbovirus zoonoses occur. This study analyzes the risk of emergence of the alphaviruses Mayaro, Venezuelan equine encephalitis, Eastern equine encephalitis and Chikungunya; the flaviviruses yellow fever, Rocio, Saint Louis encephalitis and West Nile; and the orthobunyavirus Oropouche.

Emergent arboviruses in Brazil

Brazil is a large tropical country (8,514,215km²) with 185,360,000 inhabitants. More than one third of its territory is covered by tropical forests or other natural ecosystems. These provide ideal conditions for the existence of many arboviruses, which are maintained in a large variety of zoonotic cycles. The risk that new arboviruses might emerge in Brazil is related to the existence of large, densely populated cities that are infested by mosquitoes such as Culex and the highly anthropophilic Aedes aegypti. Infected humans or animals may come into these cities from ecological-epidemiological settings where arbovirus zoonoses occur. This study analyzes the risk of emergence of the alphaviruses Mayaro, Venezuelan equine encephalitis, Eastern equine encephalitis and Chikungunya; the flaviviruses yellow fever, Rocio, Saint Louis encephalitis and West Nile; and the orthobunyavirus Oropouche.

O Brasil é país tropical de grande extensão territorial (8.514.215km²) e com 185.360.000 habitantes. Mais de 1/3 deste território é recoberto por florestas tropicais ou outros ecossistemas naturais com condições ideais para a ocorrência de diversas arboviroses as quais são mantidas em uma grande variedade de ciclos zoonóticos. O risco para a emergência de novos arbovirus no Brasil relaciona-se à existência de cidades grandes, populosas e infestadas por mosquitos Culex bem como o altamente antropofílico Aedes aegypti. Nas cidades poderiam ser introduzidos seres humanos ou animais infectados oriundos de sítios eco-epidemiológicos onde existem zoonoses arbovíricas. Neste trabalho, analisa-se o risco de emergência dos alphavirus Mayaro, da encefalite eqüina venezuelana, da encefalite eqüina do leste e Chikungunya, dos flavivirus, da febre amarela, Rocio, da encefalite de Saint Louis e do Nilo Ocidental, e do orthobunyavirus Oropouche.

The growing threat of arbovirus transmission and outbreaks in Kenya: a review.

OBJECTIVE: To review the trend in arbovirus outbreaks and activity in Kenya in the last ten years. DATA SOURCE: Published reports of past outbreak investigations and more recent data available at the Arbovirology and Viral haemorrhagic fevers reference centre, Centre for Virus Research, Nairobi. STUDY SELECTION: Past and recent outbreaks and active transmission reports of arboviruses of medical importance in Kenya including Yellow fever (YF), Rift Valley Fever (RVF), Dengue and Crimean Congo haemorrhagic fever. SYNTHESIS: Each of the viruses was reviewed providing critical information on classification, incidence, outbreak, and activity in Kenya, mode of transmission, recognition of cases, management and control. CONCLUSION: There is increased frequency of outbreaks and detection of arbovirus activity in humans and vectors in the last ten years including re-emergence of YF virus as a public health concern in Kenya. The importance of recognition of cases and diagnosis (especially in malaria endemic areas) is critical to management and control. Effective countrywide surveillance backed by diagnostic centres is highly recommended.