Canine leishmaniosis and first report of Leishmania infantum in the blood of equids in Kabylia (Algeria)

Abstract

Purpose: Canine leishmaniosis is a severe zoonotic disease that affects millions of dogs. Algeria is the most affected country in the Mediterranean basin. Both diseased and sub-clinically infected dogs are infectious to sand fly vectors, allowing transmission of the parasite to other dogs, animals or humans. That is why prompt diagnosis of infected dogs is essential. The occurrence Leishmania infantum was assessed in domestic dogs from Kabylia (Algeria), by means of PCR and serological analyses. Methods & Materials: 214 dogs, a donkey and a horse were sampled, in June 2018, from three locations in the Kabylia region: Bouira, Tizi-Ouzou and Sétif. Sera were analyzed using rapid immunomigration test (Witness® Leishmania, Zoetis, France) followed by immunofluorescence test (IFAT) with 1/50 as positivity threshold. Blood samples were analyzed by a real-time PCR pan-Leishmania designed system, targeting 28S rRNA gene followed by qPCR targeting L. infantum kDNA. All dogs were examined and classed into one of the clinical scores (CS), from CS0 to CS4, per the frequency of their clinical signs. Results: The total prevalence is of 34.5% (74/214) when at least one of the tests is positive. IFAT was more sensible and the prevalence collected scored a 31.8% (68/214), followed by Witness® Leishmania (29.9%, 64/214) and PCR (4.7%, 10/214). All positive samples on Leishmania spp. PCR 28S rRNA were positives for kDNA L. infantum specific PCR. The donkey and the horse were, also, positives by the two PCR systems. The equids lived near Leishmania infected dogs. Each infected dog where diagnosed in different stages of the disease: 74.3% (55/74) had at least one clinical sign and 25.7% (19/74) were asymptomatics; 43.2% (32/74) had CS1, 21.6% (16/74) had CS2, 5.4% (4/74) had CS3 and 4% had CS4. Conclusion: Kabylia remains an active focus for CanL with a high prevalence; this epidemiological situation requires the implementation of a national program against this protozoosis. This study highlights, for the first time, L. infantum in equids from Algeria which suggests the possible involvement of these animals in the epidemiological chain of L. infantum in high-transmission areas. This preliminary study deserves further investigation due to the lack of equids.