A participatory surveillance of marsh deer (Blastocerus dichotomus) morbidity and mortality in Argentina: first results

Abstract

Background: In an era of unprecedented socio-ecological changes, managing wildlife health demands high-quality data collection and the engagement of local communities. Blastocerus dichotomus, the largest South American deer, is Vulnerable to extinction mainly due to habitat loss. Diseases have been recognised as a potential threat, and winter mortality has been historically described in marsh deer populations from Argentina. Field difficulties have, however, prevented in-depth studies of their health status. Results: Between May 2014 and April 2017, we investigated marsh deer morbidity and mortality in the two largest populations in Argentina. We collected data by means of a passive surveillance system that involved a network of researchers, field partners (veterinarians, park rangers, and local community), and decision makers. We sampled marsh deer during as well as outside mortality events. A total of 44 marsh deer with different body condition scores were evaluated. We obtained haematology and biochemistry values from animals with good body condition score. Marsh deer with poor body condition had a high burden of the ticks Amblyomma triste and Rhipicephalus microplus. Vectorborne agents such as Theileria cervi, Trypanosoma theileri, Trypanosoma evansi, Ehrlichia chaffeensis, Anaplasma platys, Anaplasma odocoilei, Anaplasma marginale, and Candidatus Anaplasma boleense were also found. Haemonchus spp., Ostertagia spp., and Trichostrongylus spp. were the most frequent gastrointestinal parasites in deer with poor body condition. A Multiple Correspondence Analysis reinforced a possible association of winter period with lower body score condition, high tick loads, infection with E. chaffeensis, and presence of harmful gastrointestinal parasites.

Closing the Gaps to Understand the Tick Transmission of Anaplasma marginale among Giant Anteaters (Myrmecophaga tridactyla) in Argentina

“…Regarding the genus Anaplasma in the wildlife, there are reports of A. marginale and other species in the region. In a recent surveillance study of Blastocerus dichotomus (marsh deer) morbidity and mortality in Argentina, A. marginale, A. platys, A. odocoilei, and Candidatus Anaplasma boleense were found [16]. These findings are in accordance with previous reports for the same deer species and Mazama gouazoubira from Brazil, in which A. marginale and Anaplasma spp.…”

High diversity of Rickettsia spp., Anaplasma spp., and Ehrlichia spp. in ticks from Yunnan Province, Southwest China

“…In 2020, Ca. A. boleense was reported to infect marsh deer in Argentina, South America ( Orozco et al, 2020 ). Furthermore, some sequences submitted to the GenBank database suggest that this Anaplasma exists in Australia (MH500004) and South Africa (MK814450), suggesting that it is distributed worldwide.…”

First Molecular Identification of Babesia, Theileria, and Anaplasma in Goats from the Philippines

“…A. odocoilei is a species causing chronic Anaplasma infection in white-tailed deer discovered in the US [ 59 ]. A. odocoilei does not cause severe clinical disease in experimentally infected white-tailed deer, and natural infections have only been detected from North America and South America [ 60 , 61 , 62 ]. Additionally, we obtained isolates (OP351261 and OP351271) highly similar to A. platys (99.10% and 99.46% identity with other A. platys isolates, respectively) and OP351272, a potential novel A. platys -like isolate (97.30% highest identity with GenBank A. platys isolates).…”