Equine infectious anemia (EIA) has a worldwide distribution, and is widespread in Brazil. The Brazilian Pantanal presents with high prevalence comprising equine performance and indirectly the livestock industry, since the horses are used for cattle management. Although EIA is routinely diagnosed by the agar gel immunodiffusion test (AGID), this serological assay has some limitations, so PCR-based detection methods have the potential to overcome these limitations and act as complementary tests to those currently used. Considering the limited number of equine infectious anemia virus (EIAV) sequences which are available in public databases and the great genome variability, studies of EIAV detection and characterization molecular remain important. In this study we detected EIAV proviral DNA from 23 peripheral blood mononuclear cell (PBMCs) samples of naturally infected horses from Brazilian Pantanal using a semi-nested-PCR (sn-PCR). The serological profile of the animals was also evaluated by AGID and ELISA for gp90 and p26. Furthermore, the EIAV PCR amplified DNA was sequenced and phylogenetically analyzed. Here we describe the first EIAV sequences of the 5' LTR of the tat gene in naturally infected horses from Brazil, which presented with 91% similarity to EIAV reference sequences. The Brazilian EIAV sequences also presented variable nucleotide similarities among themselves, ranging from 93,5% to 100%. Phylogenetic analysis showed that Brazilian EIAV sequences grouped in a separate clade relative to other reference sequences. Thus this molecular detection and characterization may provide information about EIAV circulation in Brazilian territories and improve phylogenetic inferences.

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The aetiological agent of equine infectious anaemia (EIA), a disease that requires compulsory notification (OIE-a, 2019), is the equine infectious anemia virus (EIAV). It belongs to the Retroviridae family and Lentivirus genus, from the same taxonomic group as human immunodeficiency virus (HIV) (ICTV, 2018). This virus infects all members of the Equidae family, and the transmission is mechanical by bites of insects of the Diptera order or by fomites (Issel et al., 1998;Silva et al., 2001).

SUMMARYRotavirus has been considered the main agent of infectious diarrhea especially among younger children. We addressed the prevalence of rotavirus-associated diarrhea and the diversity of circulating electropherotypes by immunochromatography and RNA electrophoresis. Stool samples were taken from 391 children (267 with diarrhea) from the lower socioeconomic stratum who sought treatment in the Hospital Infantil João Paulo II/Belo Horizonte, during 2005 and 2006. Rotavirus was detected in 79/20.2% of subjects, 64/24.0% with diarrhea and 15/12.1% with no diarrhea. The virus was strongly associated with diarrhea (p = 0.003). A total of 76/19.4% and 69/17.6% rotavirus-positive children were identified by immunochromatography and electrophoresis, respectively. Rotavirus-associated diarrhea was more frequently detected in dry months (p < 0.001) and almost exclusively in children aged up to three years. Long profile strains prevailed (54/78.3%) but a shift toward short electropherotype was identified. Despite the decrease seen in 2006, rotavirus infection is still very common in our area. Although viral RNA electrophoresis is useful as a typing method, it should not be used exclusively in the diagnosis of rotavirus infection. We confirmed a shift from long to short profile strains, as already described for other South American countries.