Piroplasms in feral and domestic equines in rural areas of the Danube Delta, Romania, with survey of dogs as a possible reservoir.

This study explored the prevalence of piroplasmids, a type of blood parasite, in equines (horses and donkeys) and dogs in rural Romania, specifically within and around the Danube Delta. The findings showed a 25.4% overall prevalence of piroplasmids in equines, with four distinct genotypes found in horses, and a single genotype found in donkeys and a dog.

Research Methodology

• The study was conducted in the rural area of Danube Delta, Romania between 2010 and 2012, considering the high density of domestic animals here and their close interaction with humans and the natural environment.
• A total of 178 horses, 15 donkeys and 177 dogs were sampled from 18 localities both inside and outside the Danube Delta.
• None of these animals exhibited clinical symptoms typical for piroplasmoses — diseases caused by piroplasmids.
• The researchers used “catch-all” primers followed by multiplex PCR to detect subtypes of piroplasmids. Sequencing of the 18S rRNA gene was employed to identify specific genotypes of these blood parasites.
• The study examined not just the prevalence but also the genetic diversity of the piroplasmids.

Key Findings

• The overall prevalence of piroplasmids parasites in the equines studied was 25.4%.
• Of the total equines examined, 20.3% were found infected by Theileria equi (T. equi), 2.2% by Babesia caballi (B. caballi), and 3.0% were found to have mixed infections.
• Among the piroplasmids detected in horses, four different genotypes were found — ‘A’, ‘C’, ‘D’, and ‘E’. Of these, ‘A’ was the most commonly found genotype.
• All sequences of B. caballi clustered within a single ‘A’ genotype.
• A single instance of a dog infected with T. equi genotype ‘D’ was also found, suggesting potential zoonotic transmission — or the ability of a disease to pass from animals to humans.
• The prevalence of piroplasmid infection was found to be higher inside the Danube Delta, possibly influenced by environmental conditions, variations in tick density, and limited availability of veterinary services.
• The findings also highlight the limited host specificity of piroplasmid, meaning they can infect a wide range of host species.

Implications

• This research contributes significantly towards understanding the epidemiology and host specificity of piroplasmids. Such understanding can be used to inform disease control measures in equine populations in the area.
• The possibility of zoonotic transmission of piroplasmids may be a public health concern, and further research is needed to explore this potential. This signifies that dogs could possibly be a reservoir for piroplasmids and contribute to its spread to humans and equines.
• The researchers suggest that efforts need to be made to improve access to veterinary services in rural areas like the Danube Delta to control and prevent the spread of such infectious diseases among the animal population and possibly to humans.