Leishmania spp. infection in horses in an endemic area of canine leishmaniosis (north-western Algeria).

Overview

• This study investigated the prevalence of Leishmania infection in horses in Tiaret Province, northwestern Algeria, a region already known to have canine leishmaniosis.
• The research identified a very high infection rate in horses, highlighting potential risks for wider transmission to other animals and humans.

Background

• Leishmaniosis disease: Caused by protozoan parasites of the genus Leishmania.
• Hosts affected: Humans, canids (dogs and related animals), and rodents.
• Transmission: Mainly through bites of infected sand flies, which serve as vectors.
• Endemic areas: Regions where the disease regularly occurs and is present in animal reservoirs and vectors.

Study Objectives

• Estimate the prevalence (how common the infection is) of Leishmania infection in horses in Tiaret Province, Algeria.
• Identify primary risk factors influencing infection rates among the equine population.

Methods

• Population sampled: 75 local Barb horses from different parts of Tiaret Province.
• Diagnostic tools used: Both molecular and serological techniques:
  • Molecular techniques: Detect the genetic material of Leishmania, confirming presence of the parasite.
  • Serological techniques: Detect antibodies against Leishmania, indicating exposure or infection.

Results

• Out of 75 horses tested, 71 were positive for Leishmania infection by at least one diagnostic method.
• This corresponds to a very high overall prevalence of 94.6%, indicating extensive exposure or infection among horses in the area.
• Geographical variation: Horses in the southern part of the province had a 75% lower chance of infection compared to those in other areas, suggesting localized differences in risk factors or vector presence.
• The odds ratio (OR) for infection in southern horses was 0.259 with a 95% confidence interval from 0.067 to 1.004 and statistical significance (p < 0.05).

Significance and Implications

• This is the first documented evidence of Leishmania infection in horses in northwestern Algeria.
• The exceptionally high infection rate in horses suggests an intense transmission cycle of Leishmania parasites in the region.
• Such high prevalence in horses could mean that they act as potential reservoirs or indicators of the level of parasite transmission.
• There is an associated risk that other susceptible hosts, including humans and dogs, could be infected due to the active reservoir and vector presence.
• It signals an urgent need for implementing surveillance and control measures:
  • Monitoring infection rates in multiple host species.
  • Controlling sand fly populations to reduce disease spread.
  • Raising awareness among animal owners and public health authorities.

Conclusions

• The study reveals a widespread, high prevalence of equine leishmaniosis in an area endemic for dog leishmaniosis, demonstrating active transmission.
• Horses in the region are significantly affected, highlighting their importance in understanding local disease epidemiology.
• Preventive and control strategies should be prioritized to mitigate the risk to both animal and human populations.