Review of animal leishmaniosis in Jordan: An alarming discovery with implications for public health and animal welfare.

Overview

• This study reports the first documented cases of leishmaniosis in animals in Jordan, identifying two different Leishmania species infecting a horse and a stray dog.
• The findings highlight potential public health risks and emphasize the need for awareness and diagnosis of animal leishmaniosis in the region.

Background on Leishmaniosis

• Leishmaniosis is a parasitic disease endemic to Jordan and the wider Middle East.
• It is caused by protozoan parasites of the genus Leishmania, transmitted primarily through the bite of infected sandflies.
• The disease typically affects humans but can also infect animals, acting as reservoirs for transmission.
• Despite frequent reports of human leishmaniosis in Jordan, there have been no documented clinical cases in animals before this report.

Key Findings

• The study documents two distinct cases of animal leishmaniosis for the first time in Jordan:
• Case 1: An adult horse exhibited cutaneous leishmaniosis characterized by multiple skin nodules, some ulcerated.
  • Diagnosis was confirmed by cytology, histopathology, and molecular techniques detecting Leishmania amastigotes in macrophages.
  • The parasite species identified was Leishmania tropica, which typically causes cutaneous manifestations.
• Case 2: A stray dog was diagnosed with visceral leishmaniosis.
  • The diagnosis was likewise confirmed by cytological, histopathological, and molecular methods.
  • The causative parasite identified was Leishmania infantum, commonly responsible for visceral disease in canines and humans.

Diagnostic Techniques Used

• Cytological examination: Detection of Leishmania amastigotes inside macrophages in the affected tissue samples.
• Histopathology: Microscopic study of infected tissue to identify parasite presence and associated pathological changes.
• Molecular methods: DNA-based techniques to confirm the specific Leishmania species involved.

Implications for Public Health and Animal Welfare

• Detection of two different Leishmania species in separate animal hosts suggests multiple reservoirs in Jordan, increasing the complexity of transmission dynamics.
• Animals like horses and stray dogs can serve as reservoirs, potentially increasing zoonotic transmission to humans.
• The presence of distinct tissue tropisms (cutaneous in the horse, visceral in the dog) indicates varied clinical presentations, necessitating tailored approaches to diagnosis and treatment.
• These findings underscore the importance of:
  • Raising awareness among veterinarians and public health officials about animal leishmaniosis in Jordan.
  • Implementing improved diagnostic capabilities for timely and accurate detection in animals.
  • Considering animal health in the broader context of leishmaniosis control and prevention strategies.

Conclusion

• This study is the first to document clinical cases of leishmaniosis in animals in Jordan, identifying L. tropica in a horse and L. infantum in a dog.
• The discovery highlights a previously unrecognized zoonotic risk and reinforces the critical need for surveillance and diagnostic readiness to mitigate public health threats and protect animal welfare in endemic regions.