TDK conference 2011

Those phenomena of nature which are connected to the climate changing have getting more and more interest in the last couple of years. These processes can help the changing of habitat of certain arthropods and the spreading of the vector transmitted pathogens. The ECDC (Europian Centre for Disease Prevention and Control) also attends increased attention to the study of these vector-borne diseases. The cutan dirofilariosis of carnivores caused by the Dirofilaria repens also belongs to this group. This disease was endemic in the Mediterranean region, but in the last few years it spread in Europe and many cases have been published in different European countries. In Hungary the first cases were diagnosed at the turn of last millennium. Data of a comprehensive study showed that the infection rate of the Hungarian dogs was 14%.

The aim of my study was to examine the prevalence of D. repens in dogs and the vector role of Culicidae mosquito population in a new area (Komárom-Esztergom county), where it has never been examined. Further on the survey was extended to study the relationship in the epidemiological states. Between the December of 2009 and the July of 2010 blood samples were collected from 121 dogs (living in this area) and the samples were examined with modified Knott’s method. It was detected that 36 samples were microfilaria positive, so the prevalence was 29.8%. Then mosquitoes were collected by trapping from those areas where the infection rate was the highest among the dogs. The trapped mosquitoes were identified and dissected, then pool samples were prepared in which the head-and-thoracic and abdominal parts were separately detected. These samples were checked with PCR method to examine the presence of DNA of D. repens. From the 24 samples 10 (41.7%) proved to be positive. The high infection rate of the dogs was supported by the detected infection of vectors. It was found four mosquito species which could play an important role as a vector of the D. repens. The most common among these mosquitoes was the Culex pipiens (78.8%) but the other three species (Anopheles maculipennis, Anopheles claviger, Aedes vexans) seems to be more important, because in those the infective third larval state might developed. This hypotheses seemed to be proved with the detection of D. repens DNA in the samples prepared from the head-and-thoracic part of the mosquitoes.

From the examined region the most important area with main epidemiological state for ideal living and reproduction place of the vector mosquitoes seemed to be the Által-streamlet which flows through the countryside and is connected with the Danube, and where the most of the positive blood samples were found.