Diagnosis and epidemiology of canine leishmaniasis in southeastern Bahia, Brazil.

Leishmaniasis is a disease caused by protozoa of the genus Leishmania. Two distinct forms are recognized: visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). In the Americas, the causative agent of VL is L. infantum chagasi, whereas L. braziliensis is principally responsible for CL. Domestic dogs constitute the main source of VL in urban environments, and have also been implicated in CL epidemiology. We carried out molecular and serological surveys to detect Leishmania infection in dogs from the municipality of Ituberá in Bahia, Brazil. Furthermore, we identified risk factors associated with illness in dogs from this locality. Blood samples were collected from 399 dogs and tested using an indirect immunofluorescence assay (IFA) and polymerase chain reaction (PCR) to detect Leishmania spp antibodies and L. infantum chagasi and L. braziliensis DNA, respectively. Dogs were clinically evaluated and tissue samples from those exhibiting skin lesions were examined for parasites. In addition, the dog owners completed an epidemiological questionnaire to identify factors associated with infection. Skin lesions consistent with CL were found on 37 (9.3%) of the evaluated animals, but parasitological examination was negative for all samples. The IFA returned positive results for 60 (15%) dogs. PCR identified DNA from L. braziliensis in 86 (21.6%) animals, where as all samples proved negative for L. infantum chagasi. The 134 dogs (33.6%) testing positive using IFA and/ or PCR were considered infected, and of these, only 13 demonstrated skin lesions. Animals from rural areas were 3.39-times more likely to be infected compared to those in urban environments.

Canine hepatozoonosis in southeastern Bahia, Brazil.

In Brazil, canine hepatozoonosis is a tick-borne subclinical hemoparasitosis caused by a protozoa Hepatozoon canis and is highly prevalent in dogs in rural areas. An epizootiological study was conducted to investigate the prevalence of H. canis in the canine population of Ituberá, Bahia, and to analyze any associated risk factors. Blood samples were collected from 380 dogs and determined the presence of the protozoan by performing capillary blood smear and polymerase chain reaction (PCR). Epizootiological data were collected by asking dog owners to answer a structured questionnaire. H. canis gamonts were not detected in the blood smears. However, PCR detected H. canis in 163/380 (42.9%) dogs examined. Physical examination and anamnesis indicated 105 (64.4%) positive asymptomatic dogs. Hematological alterations were observed in 115 (70.5%) infected dogs. No clinical, hematological, or epizootiological variable was found to be significantly associated to the infection. In conclusion, the high prevalence of H. canis infection in local dogs may be because of the peri-urban features of this municipality. Moreover, to the best of our knowledge, this study the first study to report H. canis infection in the State of Bahia.