Insectivorous bats (Chiroptera) as reservoirs of rabies virus from Santa Fe, Argentina

COLOMBO, V. C.; ANTONIAZZI, L. R.; ARANCIO, M. V.; CARABALLO, D. A.; CHAMBI, MICAELA; FERNÁNDEZ, C.; GAMBOA, M.; LEEN, S.; MARTÍNEZ, L. M.; MONTANI, M. E.; NAUWEALERS, I.; TERRYN, S.; ULMAN, S.; CISTERNA, D. M.

San Salvador de Jujuy

Congreso; XXXIV Jornadas Argentinas de Mastozoología; 2023

Sociedad Argentina para el Estudio de los Mamíferos (SAREM)

In Argentina, the main reservoir of rabies virus (RABV) nowadays are bats. To shed light on the links between RABV and its chiropteran hosts, bats were live-captured with mist nets during the warm seasons (November-March) from 2017 to 2020 in 4 localities of Santa Fe province. Oral swabs were collected from each bat together with morphometric and physiological data. Blood samples were collected from bats weighing more than 10 grams. Species were determined following taxonomic characters and then confirmed by Cytb amplification from tissue samples when necessary. Before releasing, bats were marked with a numbered ring. Oral swabs were tested for the presence of RABV by a pan-lyssavirus Taqman RT-qPCR with the primers and probe LN34. A rabies fluorescent foci inhibition test (RFFIT) was used to evidence the presence of neutralizing antibodies in blood samples (cut-off value = 0.3 IU/ml). In total, 289 insectivorous bats (Vespertilionidae and Molossidae) were sampled. None of the bats were positive to RABV by qPCR. From the 185 serum samples tested, 129 showed conclusive RFFIT results. Neutralizing antibodies were detected only in one Molossops temminckii and two Eumops bonariensis from Recreo and Santa Fe city. The E. bonariensis belonged to the same colony and sampling date. Overall seroprevalence was 2.3%, for the same year was 1.4% (2018) and 5.4% (2019), and across all E. bonariensis sampled was 2.6%, while 1 seropositive M. temminckii was detected from 2 tested. To our knowledge, this is the first RABV seroprevalence study in insectivorous bats from Argentina, which results are similar to previous studies in South America. The presence of rabies antibodies in PCR negative bats can be an evidence of non-lethal rabies exposure. However, the immunological response of RABV in bats is still poorly understood. Further studies to understand these host-pathogen dynamics are needed in addition to serology tests in Argentina able to detect seropositive bats from small quantities of serum.