AUTHOR=Graff Selina Laura , Eibner Georg Joachim , Ochieng James Robert , Jones Terry C. , Nsubuga Anthony Mutebi , Lutwama Julius Julian , Rwego Innocent Bidason , Junglen Sandra 

TITLE=Detection of two alphaviruses: Middelburg virus and Sindbis virus from enzootic amplification cycles in southwestern Uganda

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1394661

DOI=10.3389/fmicb.2024.1394661

ISSN=1664-302X

ABSTRACT=<p>Our knowledge of alphavirus genetic diversity is mainly based on viruses isolated from anthropophilic mosquito species, humans, and livestock during outbreaks. Studies on alphaviruses from sylvatic amplification cycles in sub-Saharan Africa have been conducted less often than from epizootic environments. To gain insight into alphavirus diversity in enzootic transmission cycles, we collected over 23,000 mosquitoes in lowland rainforest and savannah gallery forest in southwestern Uganda and tested them for alphavirus infections. We detected Sindbis virus (SINV) in a <italic>Culex Culex</italic> sp. mosquito and Middelburg virus (MIDV) in <italic>Eretmapodites intermedius</italic> and <italic>Mansonia africana</italic>. MIDV is a mosquito-borne alphavirus that causes febrile illness in sheep, goats, and horses and was previously not known to occur in Uganda. SINV, also a mosquito-borne alphavirus, causes mild infections in humans. Full genomes of SINV and MIDV were sequenced, showing a nucleotide identity of 99% to related strains. Both isolates replicated to high titres in a wide variety of vertebrate cells. Our data suggest endemic circulation of SINV and MIDV in Uganda.</p>