Clinical aspects and diagnosis of leishmaniasis in equids: a systematic review and meta-analysis.

The study is a systematic review and meta-analysis on occurrences of leishmaniasis, a zoonotic disease, in horses and other equids. It focuses on identifying clinical symptoms, diagnosing techniques and need for standardised diagnostic methods.

Objective of the Research

The aim of the study was to conduct a systematic review and meta-analysis on the incidents and effects of leishmaniasis in equids like horses, donkeys, and mules.

• Leishmaniases are diseases transmitted by the bite of female sandflies and caused by over 20 species of protozoa of the genus Leishmania.
• The disease is zoonotic, meaning it can be transmitted from animals to humans, with domestic dogs considered to be the main reservoir.
• However, more recently, other vertebrates which may serve as reservoirs for the parasites have been under investigation, including equids.

Clinical Symptoms in Equids

The study reports clinical symptoms of leishmaniasis in equids based on case reviews. The primary symptom appears as changes in their skin.

• Cutaneous symptoms of equine leishmaniasis were characterised by the development of skin conditions like papules, nodules, ulcers, or crusts primarily on the heads and limbs.
• Upon investigation, these symptoms were found to be caused by three specific species of protozoa: Leishmania braziliensis, Leishmania infantum, and Leishmania siamensis.

Results from the Meta-Analysis

The meta-analysis showed varying prevalence rates among the studies, with a combined overall prevalence of 25%.

• However, high heterogeneity was found among the studies, which was believed to be due to the various methods employed in diagnosing the disease.
• Despite the benign nature of leishmaniasis in equids, it should not be overlooked and should be included in the differential diagnosis of cutaneous diseases amongst these species.

Need for Standardized Diagnostic Methods

Seroepidemiological studies were found to be vital in investigating and monitoring suspected exposure of these hosts to the parasite, particularly in areas where the disease is endemic.

• However, researchers point out that there is a need to standardise the diagnostic methods used in determining the existence of the disease in equids as the lack of standardisation can lead to discrepancies and misdiagnosis.
• This will help in better understanding, diagnosing, treating and eradicating leishmaniasis in equids, and preventing zoonotic transmission to humans.