De Souza Nunes Martins et al. (2022) conducted a comprehensive study in Brazil aiming to analyze 1665 samples of bovine blood and 313 aborted fetuses using molecular techniques, alongside serological tests on 596 serum samples. However, no positive samples were detected. Similarly, in Pernambuco, 368 serum samples from goats were subjected to competitive ELISA and were found negative for SBV (Ferreira, 2022).
The interpretation of the suspected serological results (ELISA), as demonstrated in this study, requires caution due to the absence of reported cases of the disease in the country. It has been suggested that suspected cases must be treated as negative (Rasekh; Sarani; Hashemi, 2018). It's crucial to note that the wells of the kits utilized in this study were coated with recombinant SBV nucleocapsid protein, and a potential cross-reactions with other related Simbu serogroups such as Aino (AINV) and Akabane (AKAV) viruses should be considered (Azkur et al., 2020; Rasekh; Sarani; Jafari, 2022). However, as of now, neither of these viruses have not been reported in the bovine population in Brazil.
Factors such as the escalation in international trade over the past three decades, climate change attributable to industrialization, and ecosystem disruptions, all contribute to the potential emergence of diseases in regions where they were previously absent (Zientara; Beck; Lecollinet, 2020).
Over the last decade, there has been a significant rise in the incidence of emerging viral diseases worldwide. Among these emerging or re-emerging pathogenic viruses are a substantial number of arthropod-borne (arbo) viruses, which are transmitted between vertebrate hosts by insects and other arthropods (Sick et al., 2019).
In Brazil, 299 species of Culicoides have been documented, predominantly in the Amazon Region. Recently, in Alagoas, the first report of a member of the Ceratopogonidae, Culicoides insignis, was recorded (Rios et al., 2021). Consequently, SBV has the potential to establish itself and disseminate if introduced into the country.
Implementing a surveillance system for SBV in Brazil is imperative due to several reasons: the disease is vector-borne, potential vectors are abundantly available in the country and are highly competent, and fetal malformations have been observed only weeks after the outbreaks following maternal infection (Roberts et al., 2014), intensifying the need to observe the possible circulation of the virus in Brazil.
In conclusion, this article, although presenting only one possible positive sample, which raised the attention to the disease, found no evidence of Schmallenberg antibodies in the serum bank samples tested, which suggests that there was no viral circulation in the analyzed herds. However, considering the existence of the vector in the country that allows the establishment of SBV in the country, it is necessary to strengthen regional epidemiological surveillance strategies. The constant performance of serological studies in ruminants and detection of SBV in ruminants and vectors is important to monitor the circulation of the agent and detect it early in case of introduction in the country, minimizing economic and health impacts.