The origin of the virus responsible for the ongoingyellow feverepidemic in Brazil, the worst for 40 years, has just been identified by scientists affiliated with two Brazilian institutions: Adolfo Lutz Institute (IAL) and the University of Sao Paulo (USP).
By means of a molecular study ofyellow feverviruses found in dead monkeys and in mosquitoes, the group discovered that the strain behind the current epidemic originated in Pará State in North Brazil in 1980.
The virus infected monkeys in Pará and spread from there throughout the Amazon region until it reached Venezuela and Suriname. From 2000 on, always via infection of monkeys, the disease migrated to the Center-West and Southeast of Brazil, finally reaching Sao Paulo State in 2013. The first deaths of humans in Sao Paulo occurred in 2016.
Findings of the study, which was supported bySao Paulo Research Foundation - FAPESP,are published inScientific Reports.
The investigation was led by Mariana Sequetin Cunha, a researcher in IAL's Vector-Borne Disease Group. Scientists at the University of Sao Paulo's Tropical Medicine Institute (IMT-USP), the Federal University of Pará (UFPA) and the Federal University of Sao Paulo (UNIFESP) also took part. The project was also funded by Brazil's National Council for Scientific and Technological Development (CNPq).
Since mid-2016, when the ongoingyellow feverepidemic began, 2,245 cases of the disease have been confirmed, with 764 deaths, according to the Health Ministry. The largest number of cases since 1980, when the government made notification mandatory, had previously been reported in 2000. In that year, 40 people died fromyellow fever.
Another face of the problem is the infection of monkeys by the same mosquitoes that transmit the virus to humans. Since 2016, public health authorities responsible for epidemiological surveillance in the Center-West, Southeast and South, where the epidemic is concentrated, have collected the carcasses of more than 10,000 monkeys found in forests and parks, mainly howler monkeys (Alouatta spp.), marmosets (Callithrix spp.) and capuchins (Sapajus spp).Yellow fevervirus was detected in 3,403, according to the Health Ministry (Boletim Epidemiológico de Febre Amarela).
SAO PAULO, Brazil
Source: Fundacao de Amparo a Pesquisa do Estado de Sao Paulo