Seroprevalence of dogs to Leishmania infantum antigens in the territory of Crna Gora

Abstract

Due to expansion of vector borne diseases and their importance for human health we have investigated the prevalence of antibodies to Leishmania infantum antigens in serum samples of dogs. Leishmaniasis is a disease caused by protozoan parasites of the genus Leishmania. According to the World Health Organization the disease is a constant threat to 350 million people in 88 countries, provided that most Mediterranean countries belong to the area designated as endemic. Since Crna Gora is a country of Mediterranean basin, it is important to present the results of the investigation on the presence of antibodies on L. infantum antigens in blood serum of dogs, considering that dogs can be reservoirs and source of infection for humans. In the period from 2006. to 2010., there were tested 433 serum samples of dogs with clinical symptoms and 68 serum samples of dogs without symptoms of the disease. Those were dogs with visible symptoms of the disease such as alopecia, weight loss and lymphadenomegalia. In 66% of cases, there was known hematological profile with predominant hypochromic anemia and neutrophilic leukocytosis. As mentioned above, the investigation included also 68 asymptomatic dogs in good condition, out of which 45 were service dogs in use in military and police as well as 23 dogs from the asylum. By Indirect immunofluorescence test or Indirect Fluorescent Antibody Technique (IF-AT) and Direct Agglutination Test (DAT), there was determined the presence of specific antibodies to L. infantum antigens. Positive findings in the serum dilution 1:160 was deter?mined in 258 samples (59.58%) in the group of dogs with clinical symptoms, and in 5.9% in the tested asymptomatic dogs. A part of the territory of Crna Gora with its average annual air temperature of 14.6 - 17.8?C and mediterranean climate (long, warm and dry summer and mild, rainy winter) has all the prerequisites for the development and maintenance of the infection. The confirmed presence of five kinds of Phlebotomines on the territory of Crna Gora which are essential in the cycle of developing and maintaining of Leishmania species with dominant Phlebotomus neglectus species, additionally proves a great risk of occur?rence and maintenance of the disease. The obtained results of seroprevalence in dogs are in correlation with the results of 55 cases of visceral leishmaniasis recorded by the Institute for Public Health in people from 1992 to 2009. Taking into consideration that seronegative findings and absence of symptoms does not exclude the infection, as well as that seropositive finding does not necessarily confirm it, a high level of seroprevalence (of 59.58%) in dogs in urban regions of Crna Gora, recorded during 5 years period, is by itself an alarming epizootiological and epidemiological fact.