Valéria Régia Franco Sousa

Inquérito soroepidemiológico de leishmaniose canina em áreas endêmicas de Cuiabá, Estado de Mato Grosso

Leishmaniases are zoonoses that are undergoing expansion in Brazil. Dogs are of importance regarding transmission and dispersion of the disease, especially in areas presenting visceral leishmaniasis. The aim of this study was to evaluate the seroprevalence of leishmaniasis among domestic dogs in the urban area of Cuiabá. For this investigation, four districts of Cuiabá were selected, one in each administrative region. The dog sampling was defined statistically, taking the prevalence to be 8.4%. Among the 468 dogs examined, 16 presented an indirect immunofluorescence reaction, thus resulting in an overall prevalence of 3.4%. There was no predisposition towards canine leishmaniasis occurrences in relation to breed, sex or age. The main risk factors for occurrences of canine infection identified in the city of Cuiabá were the presence of dogs living in areas surrounding homes and the proximity of homes to forests. Thus, there have been changes in leishmaniasis occurrences within the urban environment.

Soroprevalência de anticorpos anti-Ehrlichia canis em cães de Cuiabá, Mato Grosso

Canine ehrlichiosis is a disease transmitted by ticks Rhipicephalus sanguineus and caused by Ehrlichia canis, obligatory intracellular bacteria. The present study examined the prevalence of anti-E. canis in 254 dogs from four administrative regions of Cuiabá, Mato Grosso, by indirect immunofluorescence assay. There was a prevalence of 42.5% (108/254) without significant difference between the studied regions. The variables age, breed, sex, habitat, access to rural and ticks were analyzed. The antibody titers ranged from 1:40 to 1:2,560. Only 32 (29.63%) seropositive dogs were infested with ticks, all R. sanguineus. The results confirm that do not have breed, sex or age predisposition to ehrlichiosis due E. canis, while the lowest occurrence of reactive dogs indoors probably related to low tick infestation, although no significant difference between dogs with or without infestation with the tick vector.

Canine visceral leishmaniasis: diagnostic approaches based on polymerase chain reaction employing different biological samples.

The accurate diagnosis of canine visceral leishmaniasis (CanL) is essential for visceral leishmaniasis control. To this end, DNA detection on different biological samples has been employed. In this study, we report the use of polymerase chain reaction (PCR) assay on samples such as buffy coat, bone marrow, intact skin and cutaneous ulcers fragments, and lymph node aspirate collected from 430 dogs to determine the suitable biological sample for use in CanL diagnosis. The PCR results were correlated with clinical status and other tests previously performed. Leishmania chagasi DNA was detected in 14.6% (n = 63) of the dogs investigated, regardless of the sample analyzed. Our results showed that symptomatic cases were easily diagnosed when compared to asymptomatic animals; however, the PCR proved to be very useful for Leishmania DNA detection, mainly in lymph node aspirate (41; 9.6%), irrespective of the clinical status of the dog. The finding that the lymph node aspirate produced high positivity rates and the fact that this specimen was obtained by noninvasive methods highlight its use in epidemiological survey by PCR for CanL diagnosis.

Use of Parasitological Culture to Detect Leishmania (Leishmania) chagasi in Naturally Infected Dogs

In Brazil, although the domestic dog is a major target for the control actions for visceral leishmaniasis, knowledge gaps of the Leishmania species present in those animals still exist in many endemic areas. The objective of this study was the use of parasitological culture as a diagnosis tool and identification of species of Leishmania and other trypanosomatids in the canine population in the city of Cuiaba/Mato Grosso. Biological samples such as blood, intact skin fragments, cutaneous ulcers, and bone marrow were collected during a cross-sectional study and cultured on biphasic medium (Novy-MacNeil-Nicolle [NNN]/Schneiders). Leishmania isolates were characterized through isoenzyme electrophoresis. Isolates were obtained from 11.2% (n=54) of the 482 animals studied considering the different anatomical sites investigated. Leishmania chagasi was confirmed in 8.3% (n=40) dogs and Trypanosoma caninum in 2.9% (n=14). The sample of intact skin presented a higher chance of isolation of L. chagasi in symptomatic dogs and bone marrow in asymptomatic dogs (p<0.05). The results presented in this study emphasize the value of culture and confirm, for the first time, the circulation of L. chagasi in the canine population in different neighborhoods of the city of Cuiaba and broaden the knowledge of the geographical distribution of T. caninum in Brazil.

Leishmania (Leishmania) chagasi in captive wild felids in Brazil

This study used a PCR-RFLP test to determine the presence of Leishmania (Leishmania) chagasi in 16 captive wild felids [seven Puma concolor (Linnaeus, 1771); five Panthera onca (Linnaeus, 1758) and four Leopardus pardalis (Linnaeus, 1758)] at the zoological park of the Federal University of Mato Grosso, Brazil. Amplification of Leishmania spp. DNA was seen in samples from five pumas and one jaguar, and the species was characterized as L. chagasi using restriction enzymes. It is already known that domestic felids can act as a reservoir of L. chagasi in endemic areas, and further studies are necessary to investigate their participation in the epidemiological chain of leishmaniasis.

Prevalência e epidemiologia da leishmaniose visceral em cães e humanos, na cidade de Cuiabá, Mato Grosso, Brasil

Visceral Leishmaniasis is an infectious disease endemic in several regions of Brazil, including the state of Mato Grosso. In Cuiaba, from January 2006 to December 2008, a research was performed in canine cases of infection with Leishmania sp. by serology and cytology, focusing on its geographical distribution, correlating to the occurrence of human visceral Leishmaniasis cases. From 150 dogs with suspected infection, 57 (38%) were serological or parasitologically positive. Seroprevalence was observed (P≤0.05) in districts with low per capita income, besides a larger number of canine cases in the East regional, but there was a diffuse distribution of the canine disease in the city of Cuiaba, in contrast to cases focused mainly on human in the northern municipality. This suggests risk throughout the municipality and further epidemiological studies should be carried out, as well as vector distribution, to promote better understanding of canine infection by Leishmania, in order to promote appropriate measures for disease control.

Leishmania (Leishmania) infantum chagasi in wild canids kept in captivity in the State of Mato Grosso

INTRODUCTION Visceral leishmaniasis is a zoonosis that affects many mammals, and domestic canids are the main reservoirs in urban environments. This note describes infection by Leishmania (Leishmania) infantum chagasi among wild canids kept in captivity in the State of Mato Grosso, Brazil. METHODS Skin, bone marrow and lymph node samples were collected from six crab-eating foxes (Cerdocyon thous) and one bush dog (Spheotos venaticus), in order to detect and characterize Leishmania using the PCR-RFLP technique. RESULTS All the animals studied were positive for Leishmania (L.) infantum chagasi. CONCLUSIONS This study highlights the importance of adequate monitoring of these animals, as well as greater control of this disease, given that these animals are in a public recreation environment.

Occurrence of Trypanosoma caninum in areas overlapping with leishmaniasis in Brazil: what is the real impact of canine leishmaniasis control?

Trypanosoma caninum is a parasite of the Trypanosoma genus recently described in the natural infection of dogs in the municipality of Rio de Janeiro, Brazil. Suspecting the existence of a natural cycle and the circulation of this new species, the objective of this study was the taxonomic identification of samples of Trypanosoma spp. isolated from dogs in different Brazilian regions. Parasites were solely obtained from skin fragments culture and characterized by nested-PCR targeting the partial sequence of 18S rRNA gene and PCR products were sequenced. Thirty-three samples, obtained in São Paulo, Minas Gerais, Goiás, Mato Grosso and Rio de Janeiro states were analyzed. PCR and sequencing showed that the isolates were genetically identical or closely similar and confirmed T. caninum identity. This report broadens the geographical distribution of T. caninum in Brazil and discusses the impact of the presence of this parasite in areas of canine leishmaniasis occurrence.

Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil.

Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.

Natural Infection of Leishmania (Viannia) braziliensis in Mus musculus Captured in Mato Grosso, Brazil

We report natural infection by Leishmania (Viannia) braziliensis in Mus musculus and Necromys lasiurus using molecular analyses (PCR-RFLP) of femoral bone marrow and skin fragments. The aim of this study was to detect infection by pathogenic species of Leishmania in small mammals in the state of Mato Grosso, Brazil. The animals were captured in Peixoto de Azevedo, a cutaneous leishmaniasis-endemic region located in the north of the state, from October 30 to November 3, 2008. Natural infection by Leishmania in synanthropic rodents may be a threat to humans due to cohabitation of human domiciles in this area.