Assessing the Sylvatic Yellow Fever Vectors in Southern Brazil
by
, , , , , ,
Sabrina Fernandes Cardoso
1,2,*
,
Larissa Akemi Oliveira Kikuti
1,
Andre Akira Gonzaga Yoshikawa
1,
Iara Carolini Pinheiro
1,
João Victor Costa Guesser
1,
Maycon Sebastião Alberto Santos Neves
3,
Dinair Couto-Lima
3,
Renata Rispoli Gatti
2,
Josiane Somariva Prophiro
4,
André Nóbrega Pitaluga
5,6,* and
Luísa Damazio Pitaluga Rona
1,6,* 1
Departamento de Biologia Celular, Embriologia e Genética, Universidade Federal de Santa Catarina, Florianópolis 88037-000, SC, Brazil
2
Secretaria da Saúde do Estado de Santa Catarina, Diretoria de Vigilância Epidemiológica, Florianópolis 88015-130, SC, Brazil
3
Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, RJ, Brazil
4
Programa de Pós-Graduação em Ciências da Saúde (PPGCS), Universidade do Sul de Santa Catarina (UNISUL), Tubarão 88704-900, SC, Brazil
5
Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-Fiocruz, Rio de Janeiro 21040-900, RJ, Brazil
6
Instituto Nacional de Ciência, Tecnologia e Inovação em Entomologia Molecular, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Rio de Janeiro 21945-970, RJ, Brazil
*
Authors to whom correspondence should be addressed.
Insects 2026, 17(5), 464; https://doi.org/10.3390/insects17050464
Submission received: 6 November 2025
/
Revised: 4 December 2025
/
Accepted: 12 December 2025
/
Published: 30 April 2026
(This article belongs to the Special Issue Biology, Ecology and Management of Mosquitoes Affecting Humans and Animals—2nd Edition)
Simple Summary
This study investigated sylvatic mosquito populations in a region of southern Santa Catarina, Brazil, recently affected by a yellow fever outbreak. Yellow fever is a serious mosquito-borne disease that can affect both humans and non-human primates (NHPs). Nearly 4400 mosquitoes from various species were collected, and, for the first time in southern Brazil, natural infection with yellow fever virus (YFV) was detected in Sabethes (Sabethes) albiprivus Theobald, 1903. This finding suggests that Sa. albiprivus may play a previously unrecognised role in maintaining YFV in the environment. The known vector Haemagogus (Conopostegus) leucocelaenus (Dyar & Shannon, 1924) was found in all sampled locations, indicating that it may have been the primary vector responsible for virus transmission in the region. These results enhance our understanding of YFV’s natural transmission cycles and provide new insights into how the virus persists in sylvatic environments. This research contributes to the fields of biology, ecology, and public health by reinforcing the importance of ongoing entomological surveillance and preventive vaccination, both of which are essential for preventing future outbreaks and protecting vulnerable populations.
Abstract
Yellow fever (YF) is an infectious disease caused by the yellow fever virus (YFV), an arbovirus of the Flaviviridae family. It is transmitted through the bite of infected mosquitoes of the Culicidae family and affects both humans and non-human primates (NHPs). This study aimed to investigate the sylvatic Culicidae fauna and the occurrence of natural YFV infection in a microregion of southern Santa Catarina, Brazil, an area recently affected by a sylvatic YF outbreak. Entomological collections were conducted between January and February 2023 in five municipalities with confirmed viral circulation. Natural YFV infection was assessed using RT-LAMP. A total of 4352 female culicids were collected, representing at least 32 species, including several key sylvatic YFV vectors. Haemagogus leucocelaenus was identified in all sampled municipalities, whereas Haemagogus (Haemagogus) janthinomys Dyar, 1921, historically considered the primary vector of sylvatic YFV in Brazil, was not detected. Mosquitoes from the genera Aedes Meigen, 1818; Haemagogus Williston, 1896; Psorophora Robineau-Desvoidy, 1827; and Sabethes Robineau-Desvoidy, 1827 were tested for YFV. Only one pool, composed of Sabethes albiprivus, tested positive, yielding a minimum infection rate (MIR) of 11.6. This is the first record of natural YFV infection in Sa. albiprivus in southern Brazil, and only the third record globally, highlighting its potential role as a secondary vector in maintaining viral circulation in sylvatic environments. Based on species presence and abundance, Hg. leucocelaenus is likely to have acted as the primary YFV vector in the study area. The composition of the culicid fauna, coupled with the detection of YFV in sylvatic vectors, indicates an ongoing epidemiological risk. These findings underscore the need to strengthen entomological surveillance and expand YF vaccination coverage in affected and neighbouring regions.
Keywords:
yellow fever; Sabethes; Haemagogus; Aedes; Psorophora
