Participation of Rhipicephalus sanguineus (Acari: Ixodidae) in the epidemiology of canine visceral leishmaniasis

New records of pathogenic bacteria in different species of fleas collected from domestic and peridomestic animals in Spain. A potential zoonotic threat?

Climate change is causing many vectors of infectious diseases to expand their geographic distribution as well as the pathogens they transmit are also conditioned by temperature for their multiplication. Within this context, it is worth highlighting the significant role that fleas can play as vectors of important pathogenic bacteria. For this purpose, our efforts focused on detecting and identifying a total of 9 bacterial genera (Rickettsia sp.; Bartonella sp.; Yersinia sp.; Wolbachia sp., Mycobacterium sp., Leishmania sp., Borrelia sp., Francisella sp. and Coxiella sp.) within fleas isolated from domestic and peridomestic animals in the southwestern region of Spain (Andalusia). Over a 19-months period, we obtained flea samples from dogs, cats and hedgehogs. A total of 812 fleas was collected for this study. Five different species were morphologically identified, including C. felis, C. canis, S. cuniculi, P. irritans, and A. erinacei. Wolbachia sp. was detected in all five species identified in our study which a total prevalence of 86%. Within Rickettsia genus, two different species, R. felis and R. asembonensis were mainly identified in C. felis and A. erinacei, respectively. On the other hand, our results revealed a total of 131 fleas testing positive for the presence of Bartonella sp., representing a prevalence rate of 16% for this genus identifying two species B. henselae and B. clarridgeiae. Lastly, both Y. pestis and L. infantum were detected in DNA of P. irritans and C. felis, respectively isolated from dogs. With these data we update the list of bacterial zoonotic agents found in fleas in Spain, emphasizing the need to continue conducting future experimental studies to assess and confirm the potential vectorial role of certain synanthropic fleas.

Ein Update zur Leishmaniose des Hundes: Diagnostik, Therapie und Monitoring

Aufgrund von steigenden Importzahlen von Hunden aus dem Ausland, zunehmendem Reiseverkehr sowie den Veränderungen klimatischer Bedingungen in Europa gewinnen Infektionen mit Leishmania (L.) infantum bei Hunden in Deutschland zunehmend an Bedeutung. Daher sollten auch Hunde aus dem Ausland, die keine klinischen Symptome zeigen, direkt nach Import sowie erneut 6 Monate später auf vektorübertragene Infektionserreger getestet werden. Bei Hunden mit klinischer Symptomatik, die hinweisend auf eine Leishmaniose sind, werden direkte und indirekte Nachweisverfahren sowie eine hämatologische und biochemische Untersuchung unter Einbezug von Serumeiweißelektrophorese sowie Bestimmung des C-reaktiven Proteins empfohlen. Als Leitfaden für die Therapie sowie das Monitoring stehen die LeishVet-Guidelines zur Verfügung. Es stehen leishmanizide und leishmaniostatische Wirkstoffe zur Verfügung, die in first-line, second-line und third-line unterschieden werden. Zur Anpassung der Allopurinol-Dosierung wird der Stufenplan empfohlen. Aufgrund der Veränderung der klimatischen Bedingungen kommt es zu einer Ausbreitung der Habitate von Sandmücken, die als Vektoren der Leishmaniose bekannt sind. Als weitere Infektionsquellen sind Deckakte, transplazentare Infektionen, Bisswunden und Bluttransfusionen beschrieben. Leishmania infantum hat zoonotisches Potential und ist daher auch in Hinblick auf den „One-Health“-Gedanken bedeutend.

Quantitative Detection of Leishmania in Rhipicephalus microplus and Amblyomma sabanerae in the Peruvian Amazon Basin

Leishmaniasis is a disease of public importance with a complex transmission cycle. A quantitative PCR was developed by using the small subunit of the ribosomal RNA gene (SSU rRNA) as a DNA target, which is conserved in all Leishmania species. A TaqMan ^® probe was designed to have a high specificity. In all, 22 out of 23 (95.7%) ticks classified as R. microplus tested positive for Leishmania sp. The quantification was between 34.1 and 2197.1 parasites per tick in a range of 12 to 769 fg/uL. In addition, 9 out of 10 (90%) ticks classified as Amblyomma sabanerae tested positive for Leishmania sp. The quantification was between 448.6 and 5428.6 parasites per tick in a range of 157 to 1900 fg/µL. Leishmania sp. was identified in very high percentages in Rhipicephalus microplus and Amblyomma sabanerae from wild Pecari tajacu and Chelonoidis denticulata, in quantities of 34.1 and 5428.6 parasites per arthropod, and this could suggest that the ticks were parasitized by sucking blood from the animals from which they were collected. This is the first report about Leishmania parasites found in wild Rhipicephalus microplus and Amblyomma sabanerae, adding new information about the distribution and epidemiology of the parasite in sylvatic areas.

Report of the presence of Leishmania infantum in the milk of a naturally infected female dog in Brazil

Dogs are the most important reservoir of Leishmania infantum, the causal agent of visceral leishmaniasis in Brazil. Although lymphoid tissue is the most important biological tissue where amastigotes can be found, this paper describes the presence of L. infantum DNA in the milk of a lactating naturally infected female dog. This finding suggests the need for further studies to elucidate whether breastfeeding can be a route of infection.

Detection of Leishmania sp. kDNA in questing Ixodes ricinus (Acari, Ixodidae) from the Emilia-Romagna Region in northeastern Italy

To date, sand flies (Phlebotominae) are the only recognized biological vectors of Leishmania infantum, the causative agent of human visceral leishmaniasis, which is endemic in the Mediterranean basin and also widespread in Central and South America, the Middle East, and Central Asia. Dogs are the main domestic reservoir of zoonotic visceral leishmaniasis, and the role of secondary vectors such as ticks and fleas and particularly Rhipicephalus sanguineus (the brown dog tick) in transmitting L. infantum has been investigated. In the present paper, the presence of Leishmania DNA was investigated in questing Ixodes ricinus ticks collected from 4 rural areas included in three parks of the Emilia-Romagna Region (north-eastern Italy), where active foci of human visceral leishmaniasis have been identified. The analyses were performed on 236 DNA extracts from 7 females, 6 males, 72 nymph pools, and 151 larvae pools. Four samples (1.7%) (i.e., one larva pool, 2 nymph pools, and one adult male) tested positive for Leishmania kDNA. To the best of our knowledge, this is the first report of the presence of Leishmania kDNA in questing I. ricinus ticks collected from a rural environment. This finding in unfed larvae, nymphs, and adult male ticks supports the hypothesis that L. infantum can have both transstadial and transovarial passage in I. ricinus ticks. The potential role of I. ricinus ticks in the sylvatic cycle of leishmaniasis should be further investigated.

Oral and Intragastric: New Routes of Infection by Leishmania braziliensis and Leishmania infantum?

Although Leishmania transmission in nature is associated with the bite of an infected sandfly vector, other possible transmission routes are speculated to occur, such as the oral route. We evaluated the possibility of infection by this route in golden hamsters (Mesocricetus auratus) using Leishmania braziliensis (Lb) and Leishmania infantum (Li). Hamsters were exposed to experimental oral or intragastrical infection with axenic promastigotes, besides oral ingestion of a suspension of cultivated macrophages infected with amastigotes, lesion-fed Lutzomyia longipalpis, skin lesion or infective spleen fragment. The parasite's isolation, besides a positive PCR and IFAT, confirmed the intragastric infection by promastigote parasites. The oral ingestion of macrophages infected with L. braziliensis amastigotes was also infective. These results confirmed that Leishmania parasites could infect mammals by the intragastric route through the ingestion of promastigote forms (what can happen after a sandfly ingestion) and by the oral ingestion of infected macrophages (what can happen in nature in a predator-prey interaction). The better understanding of these alternative routes is essential to understand their transmission dynamics in nature. As far as we know, this is the first time that oral and intragastric Leishmania transmission has been experimentally demonstrated, constituting new infection routes, at least for L. infantum and L. braziliensis.

Detection of Trypanosoma cruzi infection by PCR in Canis lupus familiaris and their ectoparasites in Chile

Chronic Chagas disease affects humans and animals, involving rural and urban inhabitants. Dogs participate in the maintenance and transmission of Trypanosoma cruzi. The objective of this study was to evaluate the presence of T. cruzi in dogs and their ticks and fleas, in a rural area of Central Chile. Trypanosoma cruzi was detected by PCR both in dogs and ectoparasites. From the blood samples obtained, 57% were infected by T. cruzi, 5.4% of the ticks detected were positive, and all fleas were negative. Additionally, we performed electrocardiograms and found supraventricular arrhythmia in 44% of T. cruzi-positive dogs. Nevertheless, their risk for supraventricular arrhythmias was not higher in infected versus noninfected dogs. Considering the detected infection levels, dogs act as T. cruzi hosts in Central Chile, and ticks could be used as an indicator of infection when blood samples are not available. However, at this point, there is no indication that these ticks could pass on the parasite to another host. Periodic ectoparasitic treatment of pets should reduce the chance of vectorial transmission of T. cruzi and improve canine health; however, this is an uncommon practice among rural communities, so governmental programs are encouraged to tackle this problem.

Canine visceral leishmaniasis and Rhipicephalus sanguineus: evaluation and comparison of classical techniques

The aim of this study was evaluating the association and correlation between the diagnostics tests used for Leishmania spp. detection in dogs and ticks. We evaluated 99 dogs and 990 Rhipicephalus sanguineus. In dogs, we used bone marrow aspirates and lymph node fine-needle aspiration biopsy (FNAB) for direct parasitological examinations and real time-polymerase chain reaction (RT-PCR) and collected blood samples for enzyme-linked immunosorbent assays (ELISA). In ticks, two laboratory techniques [immunohistochemistry to lipophosphoglycan (IHC) and RT-PCR] were performed in the intestine, ovaries and salivary glands. With respect to the measurement of diagnostic performance in dogs, lymph node RT-PCR proved to be the best test followed by ELISA and bone marrow RT-PCR. In ticks, intestine IHC were considered as a gold standard for diagnosis of leishmaniasis with intestinal RT-PCR being the best diagnostic test. To arrive at the correlation between laboratory techniques for dogs and their ticks, we evaluated the diagnostic test used for dogs with tests performed in R. sanguineus, which used lymph node FNAB as the gold standard. The intestine IHC technique showed strongest association. We demonstrated that the best tissue for Leishmania spp. detection in dogs was the lymph node and the intestine in case of ticks. As for laboratory techniques, the isolated analysis of each species presented a strong agreement between immunohistochemistry and RT-PCR when compared to its gold standard. In addition, we concluded that the immunohistochemistry of ticks' intestines was a better technique for diagnosing Leishmania spp. in R. sanguineus, thereby showing almost perfect correlation with the lymph node FNAB.

High seroprevalence and associated factors for visceral leishmaniasis in dogs in a transmission area of Paraíba state, Northeastern Brazil

Dogs have been implicated as main reservoirs for visceral leishmaniasis (VL) in urban areas. Therefore, studies on this species provide important data for public health. Thus, the objective of the present study was to ascertain the seroprevalence of canine VL (CVL) and the associated factors in the Brejo Paraibano microregion, northeastern Brazil. A total of 409 dogs were sampled from the eight municipalities of the microregion: Alagoa Grande, Alagoa Nova, Areia, Bananeiras, Borborema, Matinhas, Pilões and Serraria. The diagnosis of CVL was made using an enzyme-linked immunosorbent assay (ELISA S7®), through which the prevalence observed was 29.3%. By robust Poisson regression analysis two factors were associated with seroprevalence: illiterate/incomplete elementary owner's education level (prevalence ratio = 1.57; 95% CI = 1.05-2.34; p-value = 0.027) and tick infestation (prevalence ratio = 1.82; 95% CI = 1.27-2.61; p-value = 0.001). It is concluded that the seroprevalence of CVL in the Brejo Paraibano microregion is high. The factors associated with seroprevalence indicated the importance to develop socioeducational actions on the population, and the finding that tick infestation was associated with seroprevalence shows that there is a need for investigation regarding the role of ticks in the epidemiology of CVL.

Risk of establishment of canine leishmaniasis infection through the import of dogs into South Africa

Canine leishmaniasis is a vector-borne disease caused by protozoa of the genus Leishmania that affect dogs, humans and wildlife. Sandflies of the genera Phlebotomus and Lutzomyia are the primary vectors. Canine leishmaniasis is an exotic and controlled disease in South Africa. The main purpose of our risk assessment study was to evaluate the likelihood that this exotic disease could enter and be established in South Africa through importation of live dogs. Risk analysis to the spread of the disease follows the World Organization for Animal Health (OIE) formal method of quantitative risk assessment documented as a step-by-step process. We have identified and discussed 11 possible risk factors involved in three steps for final assessment. The annual average number of diagnostic tests performed on imported dogs from 44 countries for 2011-2015 was 1158. Leishmania is reported to occur in 21/44 (47.7%) exporting countries. A total of 71.1% of Leishmania positive dogs were imported from these endemic countries. The yearly percentage of Leishmania positive dogs ranged from 0.2% to 2%. Three confirmed clinical and fatal cases of leishmaniasis in dogs of unidentified origin have been reported by our laboratory and the state veterinarians. The disease has been reported in neighbouring countries as well as the putative sandfly vectors. This study concluded that the risk for the introduction and degree of uncertainty of Leishmania in imported dogs in South Africa are moderate. Risk mitigation and recommendations such as investigations into possible occurrence of autochthonous leishmaniasis in the country, surveillance in its wildlife reservoirs and systematic surveillance of sandfly populations are discussed.

Multi-locus characterization and phylogenetic inference of Leishmania spp. in snakes from Northwest China

BACKGROUND

Leishmaniasis caused by protozoan parasite Leishmania is a neglected disease which is endemic in the northwest of China. Reptiles were considered to be the potential reservoir hosts for mammalian Leishmaniasis, and Leishmania had been detected in lizards from the epidemic area in the northwest of China. To date, few studies are focused on the natural infection of snakes with Leishmania.

METHODS

In this study, 15 snakes captured from 10 endemic foci in the northwest of China were detected Leishmania spp. on the base of mitochondrial cytochrome b, heat shock protein 70 gene and ribosomal internal transcribed spacer 1 regions, and identified with phylogenetic and network analyses.

RESULT

In total, Leishmania gene was found in 7 snakes. The phylogenetic inference trees and network analysis suggests that the species identification was confirmed as Leishmania donovani, L. turanica and L. (Sauroleishmania) sp.

CONCLUSION

Our work is the first time to investigate the natural Leishmania spp. infection of snakes in the northwest of China. Mammalian Leishmania (L. donovani and L. turanica) was discovered in snakes and the reptilian Leishmania (Sauroleishmania sp.) was closely related to the clinical strains both prompt the importance of snakes in the disease cycle. To indicate the epidemiological involvement of snakes, a wide sample size in epidemic area and the pathogenic features of reptilian Leishmania promastigotes are recommended in the future research.

Leishmaniosis in a dog with no travel history outside of the UK

A 3-year-old male neutered Shih Tzu cross was presented for investigation of a three-week history of weight loss, seborrhoea, vomiting and diarrhoea. Initial clinicopathological findings included pancytopenia, mild hypercalcaemia and marked hyperglobulinaemia. Subsequent bone marrow and skin biopsies revealed the presence of Leishmania amastigotes. Quantitative serology was positive for Leishmania species and PCR on the bone marrow sample confirmed a Leishmania infantum infection. The patient had been in the owner's possession since a puppy, had no travel history outside of the UK and had never received a blood transfusion or been used for breeding. However, another dog in the household that had been imported from Spain had been euthanased six months previously due to severe leishmaniosis. To the authors' knowledge, this is the first reported case of canine leishmaniosis in the UK without a history of travel to an endemic area, and most likely represents a case of dog-to-dog transmission.

PREVALÊNCIA DA LEISHMANIOSE VISCERAL CANINA E COINFECÇÕES EM REGIÃO PERIURBANA NO DISTRITO FEDERAL – BRASIL

Resumo Objetivou-se verificar a prevalência da leishmaniose visceral canina (LVC) em área periurbana com foco de transmissão no Distrito Federal (DF) e também avaliar a prevalência de coinfecções como dirofilariose, anaplasmose, erliquiose e doença de Lyme em cães sororreagentes para LVC. Inicialmente, amostras de soros dos cães da área de estudo foram testadas à reação imunocromatográfica que contém dois antígenos recombinantes ̶ rK39 e rK26 − (DPP) para Leishmania sp. O soro dos animais reagentes ao teste de DPP foi confirmado para LVC com ELISA. As amostras reagentes a ambos os testes foram analisadas para possíveis coinfecções através do teste de SNAP (IDEXX 4Dx Plus). Foram avaliados 240 cães, dos quais 132 (55%) obtiveram resultados reagentes para DPP e para ELISA concomitantemente, sendo diagnosticados com LVC. Destes, 26 (20%) foram reagentes para Ehrlichia canis ou E. ewangii, 9 (7%) apresentaram positividade para Anaplasma phagocytophilum ou A. platys e, nessas amostras que se apresentaram reagentes, observou-se a ocorrência de coinfecção de anaplasmose, erliquiose e leishmaniose em 3 (2,3%) animais. Verificou-se alta prevalência da LVC na região periurbana do DF, destacando-se a necessidade de diagnóstico mais preciso quanto a coinfecções que possivelmente podem influenciar no prognóstico e manifestação do quadro clínico desses pacientes.

Molecular diagnosis of Trypanosoma cruzi/Leishmania spp. coinfection in domestic, peridomestic and wild mammals of Venezuelan co-endemic areas

American trypanosomiasis and leishmaniases are diseases caused by protozoans of the Trypanosomatidae family. In Venezuela, although several endemic foci of both diseases coincide, there are no reports of coinfection in mammals. The molecular diagnosis of the coinfection T. cruzi-Leishmania spp. was done in 527 blood samples collected on filter paper of several species of mammals (Canis familiaris, Equus asinus, Didelphis marsupialis, Equus mulus, Rattus rattus, Equus caballus, Artibeus fraterculus, Felis catus, Sus scrofa, Bos taurus, Capra hircus and Sciurus granatensis) from the states Cojedes, Aragua, Anzoátegui, Guárico, Miranda and Capital District. The T. cruzi infection was determined through PCR amplification of DNA of kinetoplast minicircles (kDNA) and satellite DNA (sDNA). The Leishmania spp. infection was detected by Leishmania nested PCR (Ln-PCR), and ribosomal DNA internal transcribed spacer 1 PCR (ITS1-PCR). The percentage of infection by T. cruzi was 23.5%, by Leishmania spp. 12.9% and coinfection was 5.7%. D. marsupialis was the species with the highest percentage of infection for each parasitosis (T. cruzi 34.3%, Leishmania spp. 20.0%) and coinfection (14.3%). Anzoátegui was the state with the highest percentage of infection for each parasitosis (T. cruzi 64.9%, Leishmania spp. 64.9%) and coinfection (43.2%). Infections were determined in species not reported as natural reservoirs of T. cruzi (E. asinus and E. mulus) and of Leishmania spp. (E. mulus and S. scrofa). Coinfection was a frequent phenomenon in mammals in several co-endemic zones evaluated.

Assessing the cellular and humoral immune response in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) infected with Leishmania infantum (Nicolle, 1908)

The aim of this study was to evaluate aspects of the innate cellular and humoral immune response by evaluating hemocyte dynamics, phagocytosis, phenoloxidase (PO) activity and nitric oxide (NO) production in Rhipicephalus sanguineus sensu lato (s.l.) (Acari: Ixodidae) infected with Leishmania infantum and to assess the persistence of parasites at time 0 and 1, 2, 5, and 7 days post-infection (dpi). The total and differential count of the five types of hemocytes circulating in the hemolymph of R. sanguineus s.l. females showed the average total number of hemocytes in the group infected with L. infantum to be significantly higher (p < 0.05) on the 1st and 2nd dpi compared to the control group. The hemocyte differential count showed that the average number of plasmatocytes and granulocytes increased significantly on the 1st, 2nd, and 5th dpi with L. infantum compared to the control group (p < 0.001). Phagocytosis assays revealed that plasmatocytes and granulocytes were able to perform phagocytosis of latex beads and L. infantum on the 1st and 2nd dpi, respectively. NO production was significantly increased (p < 0.001) on the 1st, 2nd, and 5th dpi with L. infantum and PO activity increased significantly (p < 0.05) only on the 5th dpi. L. infantum DNA was significantly increased (p < 0.001) on the 5th and 7th dpi compared to time 0. Although there are no studies describing the response of R. sanguineus s.l. to an infection with L. infantum, these results suggest that R. sanguineus s.l. activates the cellular and humoral immune response after infection with L. infantum. Further studies are however, needed to assess the impact of such a response on fighting infection.

Natural transovarial and transstadial transmission of Leishmania infantum by naïve Rhipicephalus sanguineus ticks blood feeding on an endemically infected dog in Shiraz, south of Iran

BACKGROUND

The visceral leishmaniasis parasite, Leishmania infantum, is naturally transmitted through the bites of phlebotomine sand flies. Alternative routes of transmission are questioned. The main aim is to verify the passage of L. infantum kDNA in ticks, Rhipicephalus sanguineus, blood feeding on a parasitemic dog in Shiraz, south of Iran.

METHODS

A total of 180 Leishmania-free ticks collected from fields and bred on lab rodents, were divided into eight groups and allowed to feed on a dog (Canis familiaris) for fixed periods of time. These and all third generation stages of ticks were checked for L. infantum kDNA using conventional PCR protocol.

RESULTS

The infection rate was significantly higher in female than male ticks (p=0.043). The rates were higher among nymphs (25/60; 42%) than adult ticks (37/120; 30.8%). The kDNA of L. infantum was not detected in ticks 24 h post-feeding. It was, however, positive among the second to fourth groups of nymphs (4/10; 40%, 10/20; 50% and 11/20; 55%) and adult (12/30; 40%, 14/30; 46.6% and 11/30; 36.6%) ticks. Eggs and unfed larvae recovered from the third and fourth adult groups (2 weeks, 4 weeks) were 100% PCR-positive. The data revealed the passage of L. infantum kDNA in nymphs and adults of brown dog tick following fixed time intervals post blood feeding on an infected dog.

CONCLUSIONS

The natural transovarial and transstadial passage of kDNA through ticks was shown by PCR.

Mutation in the Sodium Channel Gene Corresponds With Phenotypic Resistance of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) to Pyrethroids

The brown dog tick, Rhipicephalus sanguineus sensu lato (Latreille), is a cosmopolitan ectoparasite and vector of pathogens that kill humans and animals. Pyrethroids represent a class of synthetic acaricides that have been used intensely to try to control the brown dog tick and mitigate the risk of tick-borne disease transmission. However, acaricide resistance is an emerging problem in the management of the brown dog tick. Understanding the mechanism of resistance to acaricides, including pyrethroids, is important to adapt brown dog tick control strategies. The main objective of this study was to determine if target-site mutations associated with pyrethroid resistance in other pests could be associated with phenotypic resistance detected in a brown dog tick population from Florida. We amplified segment 6 of the domain III of the voltage-sensitive sodium channel protein, using cDNAs synthesized from pyrethroid-susceptible and pyrethroid-resistant tick strains. A single nucleotide point mutation (SNP) identified in a highly conserved region of domain III S6 in the resistant ticks resulted in an amino acid change from phenylalanine to leucine. This mutation is characteristic of resistance phenotypes in other tick species, and is the first report of this mutation in R. sanguineus. Molecular assays based on this knowledge could be developed to diagnose the risk for pyrethroid resistance, and to inform decisions on integrated brown dog tick management practices.

Leishmania infantum is present in vaginal secretions of naturally infected bitches at lower levels in oestrogenized bitches than in non-oestrogenized bitches

Naturally Leishmania infantum infected bitches were divided into oestrogenized (n = 11) and non-oestrogenized (n = 6) groups. Vaginal secretions were collected for polymerase chain reaction (PCR), and vulval, vaginal and uterine tissues were collected for the immunohistochemical (IHQ) identification of L. infantum. Parasite DNA was identified in vaginal secretions of non-oestrogenized (41.8%) and oestrogenized (18.2%) bitches (P<0.05; Fisher's Exact test). IHQ was positive in vulvar dermis (23.5%) and vaginal mucosa (17.7%) but negative in endometrium of all bitches. Poor association between positive vaginal secretion PCR and tissue IHQ (Kappa index) were observed. The results showed that genital secretions are a potential source for dog contamination.

Dinotefuran-induced morphophysiological changes in semi-engorged females Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae) ticks: Ultra-structural evaluation

The present study demonstrated the effects of dinotefuran (active ingredient of the acaricide Protetor Pet^®) on the ovary and midgut cells of semi engorged R. sanguineus females exposed to different concentrations of this chemical. For this, 120 semi-engorged females were divided into four treatment groups with 30 individuals each: group I or control (distilled water), group II (5000ppm), groups III (6250ppm) and group IV (8334ppm of dinotefuran). All the ticks were immersed in the different concentrations of dinotefuran or in distilled water for 5min and then dried and kept in BOD incubator for 7days. The results showed alterations mainly regarding the damaged cell structures, such as yolk granules, organelles and the plasma membrane of the germ cells. In addition, structures related with defense mechanisms were found, such as vacuoles, cytoskeletal filaments, and myelin figures in the germ cells. Damages in the generative cells of the midgut, alterations in the size of digestive cells, the number of endosomes, digestive vacuoles, digestive residues, lipid drops and organelles in the cytoplasm of the digestive cells and the presence of microvilli in the plasma membrane of these cells also demonstrate the progressive damages caused by the action of dinotefuran in the midgut and germ cells of R. sanguineus semi-engorged females. The concentrations applied partially impaired the digestive processes; and, without proper nutrition, all the ectoparasite's physiologic events are prevented from occurring, leading the individual to death. The germ cells were also damaged, and probably would not be able to advance in their development (I-V) and complete the vitellogenesis, which would affect the fertility of the female and consequently impede the formation of a new individual.

Natural canine infection by Leishmania infantum and Leishmania amazonensis and their implications for disease control

Leishmaniasis is a major public health problem worldwide. Because Leishmania can adapt to new hosts or vectors, knowledge concerning the current etiological agent in dogs is important in endemic areas. This study aimed to identify the Leishmania species detected in 103 samples of peripheral blood from dogs that were naturally infected with these protozoa. The diagnosis of leishmaniasis was determined through parasitological examination, the indirect enzyme-linked immunosorbent assay (ELISA) and the polymerase chain reaction (PCR). The Leishmania species were identified by means of PCR-restriction fragment length polymorphism (PCR-RFLP). The samples were subjected to PCR using oligonucleotide primers that amplify the intergenic region ITS1 of the rRNA gene in order to identify the species. The amplified DNA was digested using the restriction enzyme HaeIII. A restriction profile identical to L. amazonensis was shown in 77/103 samples and the profile was similar to L. infantum in 17/103. However, a mixed profile was shown in 9/103 samples, which impeded species identification. In conclusion, the infection in these dogs was predominantly due to L. amazonensis, thus indicating that diagnosing of cases of canine leishmaniasis needs to be reexamined, since the causative agent identified is not restricted to L. infantum.

Detection of Leishmania DNA in wild foxes and associated ticks in Patagonia, Argentina, 2000 km south of its known distribution area

BACKGROUND

Zoonotic Visceral Leishmaniasis (ZVL) is a vector-borne disease affecting humans and other mammals and caused by the protozoan parasite Leishmania (Leishmania) infantum (syn. L. chagasi), belonging to the L. donovani complex. The regions in Northern Argentina (above 32 °S) are its southern distribution limit in South America.

RESULTS

We detected Leishmania sp. DNA (most likely belonging to the L. donovani complex) in 37.5% of 32 grey foxes (Pseudalopex griseus) captured in Argentinean Patagonia (48°S and 50°S). Eleven monosexual pools of Amblyomma tigrinum ticks from eight different foxes (six grey foxes and two culpeo foxes P. culpaeus) were also positive. The southernmost known distribution limit for L. infantum, and the southernmost reported capture of a phlebotominae, had previously been 2000 and 750 km north of our study area, respectively.

CONCLUSIONS

This finding is significant because it markedly extends the distribution area of leishmaniasis; supports the existence of a sylvatic cycle in the absence of dogs; and has implications in transmission, indicating that either sand fly distribution is broader than currently thought or non-sand fly Leishmania maintenance is possible. Additional molecular, parasitological, epidemiological and entomological studies are still needed.

Histochemical and molecular evaluation of the prevalence of Leishmania spp. in hematophagous insects

The prevalence study of Leishmania spp. in hematophagous insects captured from the environment in bat roosts and pigeon nests, or feeding their hosts (cattle, pigs, horses, dogs and humans) in urban, peri-urban and rural areas, between 2012 and 2014. For this study, the amastigotes present in these insects were detected by histochemical and PCR techniques. Positive gene amplification for Leishmania was found in two horseflies of the species Tabanus importunus collected in the environment, and amastigote forms of Leishmania spp., as well as erythrocytes and leukocytes, were histochemically detected in one of that insect. The other analyzed insects were not positive by PCR our by direct parasitological examination. Only horseflies captured in urban and peri-urban areas were positive. During the collection, no phlebotomine sand flies were captured in rural areas far from the city limits. It can be concluded that the discovery of horseflies positive for Leishmania spp. in urban and peri-urban areas indicates the likelihood that urban areas and their surroundings provide vector parasites with an environment suitable for the spread and consequent perpetuation of the biological cycle of this protozoan.

Rhipicephalus sanguineus (ACARI: IXODIDAE) BITING A HUMAN BEING IN PORTO ALEGRE CITY, RIO GRANDE DO SUL, BRAZIL

We report the finding of a female brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae) on the scalp of a male patient inPorto Alegre, Rio Grande do Sul, Brazil. Human parasitism by this tick is rare and has seldomly been reported in the literature, despite its recognized importance since it can act as a vector of Rickettsia rickettsii, the agent of spotted fever.

Dinotefuran-induced morphophysiological changes in the ovaries and midgut of semi-engorged females Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae) ticks

The present study demonstrated the effects of dinotefuran (active compound of the Protetor Pet® acaricide) in germ cells and the digestive processes of semi-engorged females of R. sanguineus exposed to different concentrations of the chemical. For this purpose, 120 semi-engorged females were divided into four treatment groups with 30 individuals each: group I or control (distilled water), group II (5000 ppm), group III (6250 ppm), and group IV (8334 ppm of dinotefuran). All ticks were immersed in different concentrations of dinotefuran or in distilled water for 5 min and then were dried and stored in biological oxygen demand (BOD) incubator for 7 days. The results show the action of this compound, exhibiting morphohistologic and histochemical changes in the oocytes and the midgut cells of individuals of different groups, which were compared with those of group I (control). The alterations occurred mainly in relation to the size of the germ cells and yolk granules; presence, quantity, size, and location of vacuoles found in the cytoplasm of these germ cells; the damage occurred in the generative cells of the midgut; the size of the digestive cells; the quantity of blood elements captured, accumulated digestive wastes and digestive vacuoles found in the cytoplasm of the digestive cells of the midgut, as well as the amount and distribution of proteins, polysaccharides, lipids of all cells in both organs. So, it has demonstrated the effectiveness of dinotefuran in the reduction of fertility and digestive processes of semi-engorged females of R. sanguineus, data that points the possibility of employing this chemical to control these ectoparasites.

Hemocytes of Rhipicephalus sanguineus (Acari: Ixodidae): Characterization, Population Abundance, and Ultrastructural Changes Following Challenge with Leishmania infantum

Few studies have examined the cellular immune response of ticks, and further research on the characterization of the hemocytes of ticks is required, particularly on those of Rhipicephalus sanguineus (Latreille) because of the medical and veterinary importance of this tick. The aims of this study were to characterize the morphology and the ultrastructure of the different types of hemocytes of adult R. sanguineus and to determine the population abundance and the ultrastructural changes in the hemocytes of ticks infected with Leishmania infantum. The hemocytes were characterized through light and transmission electron microscopy. Within the variability of circulating cells in the hemolymph of adult R. sanguineus, five cell types were identified, which were the prohemocytes, plasmatocytes, granulocytes, spherulocytes, and adipohemocytes. The prohemocytes were the smallest cells found in the hemolymph. The plasmatocytes had polymorphic morphology with vesicles and cytoplasmic projections. The granulocytes had an elliptical shape with the cytoplasm filled with granules of different sizes and electrodensities. The spherulocytes were characterized by several spherules of uniform shapes and sizes that filled the entire cytoplasm, whereas the adipohemocytes had an irregular shape with multiple lipid inclusions that occupied almost the entire cytoplasmic space. The total counts of the hemocyte population increased in the group that was infected with L. infantum. Among the different cell types, the numbers increased and the ultrastructural changes occurred in the granulocytes and the plasmatocytes in the infected group of ticks.

Successful isolation of Leishmania infantum from Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) collected from naturally infected dogs

BACKGROUND

The main transmission route of Leishmania infantum is through the bites of sand flies. However, alternative mechanisms are being investigated, such as through the bites of ticks, which could have epidemiological relevance. The objective of this work was to verify the presence of Leishmania spp. in Rhipicephalus sanguineus sensu lato collected from naturally infected dogs in the Federal District of Brazil.

METHODS

Ticks were dissected to remove their intestines and salivary glands for DNA extraction and the subsequent amplification of the conserved region of 120 bp of kDNA and 234 bp of the hsp70 gene of Leishmania spp. The amplified kDNA products were digested with endonucleases HaeIII and BstUI and were submitted to DNA sequencing. Isolated Leishmania parasites from these ticks were analyzed by multilocus enzyme electrophoresis, and the DNA obtained from this culture was subjected to microsatellite analyses.

RESULTS

Overall, 130 specimens of R. sanguineus were collected from 27 dogs. Leishmania spp. were successfully isolated in culture from five pools of salivary glands and the intestines of ticks collected from four dogs. The amplified kDNA products from the dog blood samples and from the tick cultures, when digested by HaeIII and BstUI, revealed the presence of L. braziliensis and L. infantum. One strain was cultivated and characterized as L. infantum by enzyme electrophoresis. The amplified kDNA products from the blood of one dog showed a sequence homology with L. braziliensis; however, the amplified kDNA from the ticks collected from this dog showed a sequence homology to L. infantum.

CONCLUSION

The results confirm that the specimens of R. sanguineus that feed on dogs naturally infected by L. infantum contain the parasite DNA in their intestines and salivary glands, and viable L. infantum can be successfully isolated from these ectoparasites.

Prevalence of ixodid ticks on cattle, sheep and goats in Ilam County, Ilam Province, Iran

This survey was performed to find out the infestation rate of Ixodidae ticks in domestic ruminants in Ilam County during 21 March 2009 to 23 August 2009. Sampling was performed in 25 villages and 15 animal farm from different areas of this County. A total of 1,316 ticks were collected from 416 cattle, 208 sheep and 147 goats. The overall prevalence of ticks was recorded: 43, 23.5, and 49/6 % in cattle, sheep, and goats respectively. The number of ticks that collected from cattle, sheep, and goat were 328, 573, and 415 respectively. According to the host, Hyalomma anatolicum anatolicum (71.4 %), Hyalomma asiaticum asiaticum (17.6 %) and Rhipicephalus bursa (11 %) were collected from cattle. Hy. anatolicum (32.1 %), Rh. bursa (42.2 %), Rhipicephalus sanguineus (17.3 %) and Haemaphysalis inermis (8.4 %) were collected in sheep. Rh. bursa (41.5 %), Rh. sanguineus (43.2 %) and Ha. inermis (15.3 %) were observed in goats. In this study, ticks infestation rate of cattle, sheep and goat were (43 %), (23.5 %) and (49.6 %) respectively. In this survey the ticks distribution on the body surface of infested ruminants the highest infestation was found in the udder and tail (21 %) in cattle, ear (42.5 %) and tail (30 %) in sheep and ear (63 %) and tail (17 %) in goats. The lowest number of ticks in body surface of ruminants was observed in the ear and shoulder (2 %) in cattle, head and neck (2 %) in sheep and udder (7 %) in goats. Hy. anatolicum anatolicum, Rh. Sanguineus and Rh.bursa were dominant tick in domestic ruminants of Ilam County.

Participation of ticks in the infectious cycle of canine visceral leishmaniasis, in Teresina, Piauí, Brazil

In this study, we detected Leishmania spp. infection in R. sanguineus collected from dogs that were naturally infected with L. (L.) infantum. We examined 35 dogs of both sexes and unknown ages. The infected dogs were serologically positive by the immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), and Quick Test-DPP (Dual Path Platform), as well as parasitological examination of a positive skin biopsy or sternal bone marrow aspiration. Ten negative dogs were included as controls. The ticks that infested these dogs were collected in pools of 10 adult females per animal. The PCR was performed with specific primers for Leishmania spp., which amplified a 720-bp fragment. Of the 35 analyzed samples, a product was observed in eight samples (8/35; 22.9%). We conclude that the presence of parasite DNA suggests that ticks participate in the zoonotic cycle of canine visceral leishmaniasis, in the city of Teresina, Piauí.

Level of awareness regarding some zoonotic diseases, among dog owners of ithaca, new york

OBJECTIVES

Worldwide, dogs and cats are the two most common household companion animals. Because of this, they can be direct or indirect source of many human infections. Fortunately, most of these zoonotic infections can be clinically prevented by appropriate prophylactic interventions.

MATERIALS AND METHODS

Present kind of cross-sectional study, for the first time, was conducted in city of Ithaca, New York. People visiting local animal hospitals, dog parks, library and shoppers at Walmart supermarket were personally interviewed and a pre-tested questionnaire was got filled from every individual. The collected data were analyzed for percentage proportions using Microsoft Excel(®) and the results had been presented in graphical as well as tabulated forms.

RESULTS

Out of 100 participants responding to the request for participation, gender-wise, 45% of the participants were male while 55% of the participants were females. Demographically, 50% participants lived in rural, 35% in urban while 15% participants lived in suburban areas. Educational background of the participants ranged from High school pass-outs to Graduates.

CONCLUSIONS

Participants were aware about the zoonotic potential of leptospirosis, giardiasis, rabies, hookworms, coccidiosis, lyme disease, roundworms, toxoplasma, leishmaniasis, salmonellosis and ringworm disease. Knowledge gaps in the sampled population, in terms of lack of awareness about zoonotic diseases vectored by mosquitoes, ticks and fleas; practice of not doing regular deworming and prophylactic control of fleas and ticks on pet dogs; and lack of practice among physicians to discuss zoonotic canine diseases with their clients were revealed by this study.

Detection of Leishmania infantum in the smegma of infected dogs

Considering the venereal transmission of visceral leishmaniasis from dogs to bitches, the aim of this study was to verify if the penile surface and smegma from infected dogs can be the source of parasites in bitches. Twelve Leishmania infantum infected dogs had semen and smegma samples collected for submission to PCR identification of the DNA of the parasite. Semen (41.7%) and smegma (50.0%) have similar positive incidence (P>0.05; Fisher's exact test), with 58.3% of the dogs positive for semen and/or smegma samples. The proportion of positivity for both semen and smegma was 33.3%, but 8.3% was positive only for semen, and 16.7% only for smegma, revealing a moderate agreement between tests (K=0.5; Kappa index). It was concluded that Leishmania infantum is present in the smegma of contaminated dogs and it can be a source of parasites for the semen and the bitch.

Tick-borne infections of animals and humans: a common ground

A wide variety of pathogens is transmitted from ticks to vertebrates including viruses, bacteria, protozoa and helminths, of which most have a life cycle that requires passage through the vertebrate host. Tick-borne infections of humans, farm and companion animals are essentially associated with wildlife animal reservoirs. While some flying insect-borne diseases of humans such as malaria, filariasis and Kala Azar caused by Leishmania donovani target people as their main host, major tick-borne infections of humans, although potentially causing disease in large numbers of individuals, are typically an infringement of a circulation between wildlife animal reservoirs and tick vectors. While new tick-borne infectious agents are frequently recognised, emerging agents of human tick-borne infections were probably circulating among wildlife animal and tick populations long before being recognised as clinical causes of human disease as has been shown for Borrelia burgdorferi sensu lato. Co-infection with more than one tick-borne infection is common and can enhance pathogenic processes and augment disease severity as found in B. burgdorferi and Anaplasma phagocytophilum co-infection. The role of wild animal reservoirs in co-infection of human hosts appears to be central, further linking human and animal tick-borne infections. Although transmission of most tick-borne infections is through the tick saliva, additional routes of transmission, shown mostly in animals, include infection by oral uptake of infected ticks, by carnivorism, animal bites and transplacentally. Additionally, artificial infection via blood transfusion is a growing threat in both human and veterinary medicine. Due to the close association between human and animal tick-borne infections, control programs for these diseases require integration of data from veterinary and human reporting systems, surveillance in wildlife and tick populations, and combined teams of experts from several scientific disciplines such as entomology, epidemiology, medicine, public health and veterinary medicine.

Speculations on biting midges and other bloodsucking arthropods as alternative vectors of Leishmania

Sand flies remain the only proven vectors of Leishmania spp. but recent implementation of PCR techniques has led to increasing speculation about "alternative vectors", including biting midges. Here, we summarize that PCR has considerable limits for studing the role of bloodsucking arthropods in the epidemiology of leishmaniasis. The Leishmania life cycle in the sand fly includes a complex series of interactions which are in many cases species-specific, the early phase of the infection is, however, non-specific to sand flies. These facts should be considered in detection of Leishmania in ,"alternative" or "new" vectors to avoid mistaken speculation about their vector competence.

First detection of Leishmania infantum (Kinetoplastida: Trypanosomatidae) in Culicoides spp. (Diptera: Ceratopogonidae)

BACKGROUND

Culicoides (Diptera: Ceratopogonidae) species are known to be the vectors of Bluetongue virus and African Horses Sickness virus (AHSV) in different areas of the world. Nevertheless, other researchers have hypothesized that these arthropods could be involved in the transmission of other pathogens such as Schmallenberg virus, Plasmodium and Leishmania parasites. Identification of the Culicoides' potential vector competence is crucial in understanding the worldwide Culicoides/Leishmania life cycle.

FINDINGS

Blood fed and parous females of biting midges Culicoides spp. were collected between 2009 and 2010 in Central Tunisia. DNA was extracted from individual blood fed Culicoides and used as a template in a genus-specific PCR. Leishmania DNA was detected in 14 Culicoides imicola specimens and one Culicoides circumscriptus. In a second step, parasite identification was performed based on a single copy Topo-isomerase II gene specific amplification and sequencing. Leishmania infantum was identified in two infected Culicoides spp.

CONCLUSION

This is the first report of Leishmania DNA detection from naturally infected wild caught Culicoides spp. Our finding supports the assumption that Culicoides spp. are a potential vector for L. infantum.

Molecular and parasitological detection of Leishmania spp. in dogs caught in Palmas, TO, Brazil

This study evaluated occurrences of Leishmania infantum in dogs in the municipality of Palmas, Tocantins, comparing diagnostic data obtained using the polymerase chain reaction (PCR) and parasitological diagnosis. Blood samples and lymph node aspirates were collected from 63 dogs of males and females and various ages and races, with or without owners, between August 2009 and June 2010. Slides containing smears of lymph node aspirates were stained with Giemsa stained. In PCR, the 145 bp target sequence of the LT1 fragment, located in the Leishmania donovani kDNA minicircle was detected using the RV1 and RV2 oligonucleotide primers. The chi-square test revealed that there was a significant relationship between the symptoms and dogs that were positive for visceral leishmaniasis (VL). The parasitological investigation showed concordance of 66.7% with PCR on blood and 84.1% with PCR on lymph node aspirate. In addition to these tests, evaluations of the diagnoses in parallel and in series were conducted, which showed concordances with the parasitological test of 76.2% and 74.6%, respectively. The results make it possible to suggest that PCR on lymph nodes should be used in evaluating large populations (surveys) and that the parasitological test should be used for initial clinical evaluations in veterinary consultation offices.

Molecular and parasitological detection of Leishmania spp. in a dipteran of the species Tabanus importunus

Leishmaniasis is an important chronic zoonosis caused by protozoa of the genus Leishmania spp. The major vectors of this protozoosis are sand flies, and Lutzomyia longipalpis is considered the main species implicated in the transmission of American Visceral Leishmaniasis in Brazil. The presence of the parasite's deoxyribonucleic acid (DNA) in ectoparasites such as ticks and fleas has prompted speculations about the existence of new vectors in the cycle of leishmaniasis. The aim of this paper is to report the molecular detection of Leishmania spp. in a horse fly of the species Tabanus importunus which parasitized an oligosymptomatic dog infected with Leishmania spp. Molecular amplification of the protozoan's DNA in the head, thoracic region and abdomen of the tabanid tested positive for Leishmania complex. This is the first report of the presence of DNA from Leishmania spp. in dipterous insects of the species T. importunus.

Ixodid fauna and zoonotic agents in ticks from dogs: first report of Rickettsia rickettsii in Rhipicephalus sanguineus in the state of Mato Grosso do Sul, mid-western Brazil

Ticks from 148 dogs from the urban area of the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil, were collected, classified and analyzed using polymerase chain reaction (PCR) for the identification of Rickettsia spp., Trypanosoma cruzi and Leishmania spp. A total of 2015 ticks were collected. The species Rhipicephalus sanguineus (98.9 %) and Amblyomma cajennense (1.1 %) were identified. Molecular analysis revealed that no tick samples were infected by T. cruzi. Regarding Leishmania spp., tick samples from 36 dogs spread across all regions of the municipality were positive for L. chagasi. One tick sample was positive for Rickettsia spp. (gltA gene) in the PCR reaction. This sample was submitted to further PCR based on the ompA gene and the amplicon was sequenced. Identity of 100 % was found with homologous sequences of R. rickettsii available in GenBank. This paper is the first to report the natural infection of R. sanguineus by R. rickettsii in the municipality of Campo Grande, state of Mato Grosso do Sul, mid-western Brazil.

Detection of Leishmania infantum in animals and their ectoparasites by conventional PCR and real time PCR

Visceral leishmaniosis (VL) is a parasitic disease caused by Leishmania infantum, which is primarily transmitted by phlebotomine sandflies. However, there has been much speculation on the role of other arthropods in the transmission of VL. Thus, the aim of this study was to assess the presence of L. infantum in cats, dogs and their ectoparasites in a VL-endemic area in northeastern Brazil. DNA was extracted from blood samples and ectoparasites, tested by conventional PCR (cPCR) and quantitative real time PCR (qPCR) targeting the L. infantum kinetoplast DNA. A total of 280 blood samples (from five cats and 275 dogs) and 117 ectoparasites from dogs were collected. Animals were apparently healthy and not previously tested by serological or molecular diagnostic methods. Overall, 213 (76.1 %) animals and 51 (43.6 %) ectoparasites were positive to L. infantum, with mean parasite loads of 795.2, 31.9 and 9.1 fg in dogs, cats and ectoparasites, respectively. Concerning the positivity between dogs and their ectoparasites, 32 (15.3 %) positive dogs were parasitized by positive ectoparasites. The overall concordance between the PCR protocols used was 59.2 %, with qPCR being more efficient than cPCR; 34.1 % of all positive samples were exclusively positive by qPCR. The high number of positive animals and ectoparasites also indicates that they could serve as sentinels or indicators of the circulation of L. infantum in risk areas.

Detection and quantification of Leishmania braziliensis in ectoparasites from dogs

American cutaneous leishmaniasis (ACL) is a disease caused by different species of Leishmania protozoa, Leishmania braziliensis being the main species found in Brazil. In this study, two rural areas in Pernambuco, northeastern Brazil, where ACL is endemic, were selected. Genomic DNA was extracted from canine ectoparasites (ticks, fleas, and lice) and tested using a conventional PCR and a quantitative real time PCR. A total of 117 ectoparasites were collected, being 50 (42.74%) of them positive for L. braziliensis (in at least one PCR protocol), with a mean parasite load of 14.14 fg/μL. Furthermore, 46 (92.00%) positive ectoparasites were collected from positive dogs and 4 (8.00%) from negative ones. This study reports the detection of L. braziliensis DNA in ectoparasites, but does not prove their vector competence. Certainly, experimental transmission studies are necessary to assess their role, if any, in the transmission of Leishmania parasites to dogs.

Seroepidemiological aspects ofLeishmania spp. in dogs in the Itaguai micro-region, Rio de Janeiro, Brazil

This study evaluated factors associated with the frequency ofLeishmania spp. antibodies in dogs residing in the Itaguai micro-region, State of Rio de Janeiro, Brazil. Blood samples were collected from 524 dogs. The serum samples were submitted to indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) forLeishmania spp. The frequency of seropositive dogs was 28.24% (n = 148) in the micro-region, and among the three municipalities within that region, the highest frequency (p < 0.05) was observed in Seropedica (59.46%), followed by Itaguai (29.05%) and Mangaratiba (11.49%). Regarding factors associated with the host, mongrel dogs and those over the age of two presented higher frequency of antibodies to Leishmaniaspp. (p < 0.05). Concerning factors related to the environment and habits of the animal, dogs residing in rural areas (FR = 1.67, p = 0.0002), living outside the residence (FR = 1.42, p = 0.0197), with access to forest, streams and pastures (FR = 2.81, p = 0.0007), remaining loose (FR = 1.66, p = 0.0073), and those that had no shelter (FR = 2.16, p < 0.0001) were more likely to be seropositive. Canine leishmaniasis is a disease with high occurrence in the Itaguai micro-region, and aspects such as the definition of breed, age, habits and care by owners showed significant association in this micro-region.

Morphology of the midgut of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) adult ticks in different feeding stages

The intestinal epithelial cells of ticks are fundamental for their full feeding and reproductive success, besides being considered important sites for the development of pathogens. Rhipicephalus sanguineus ticks are known for their great medical and veterinary importance, and for this reason, the knowledge of their intestinal morphology may provide relevant subsidies for the control of these animals, either by direct acaricidal action over these cells or by the production of vaccines. Therefore, this study aimed to describe the midgut morphology of male and female R. sanguineus ticks in different feeding stages, by means of histological analysis. Significant differences were observed between the genders, and such alterations may refer mainly to the distinct demands for nutrients, much higher in females, which need to develop and carry out the egg-laying process. In general, the midgut is coated by a thin muscle layer and presents a pseudostratified epithelium, in which two basic types of cells can be observed, connected to a basal membrane-generative or stem and digestive cells. The latter was classified as follows: residual, deriving from the phase anterior to ecdysis; pinocytic, with vesicles containing liquid or pre-digested components of blood; phagocytic, with entire cells or remnants of nuclear material inside cytoplasmic vesicles; and mature, free in the lumen. Digestion is presumably intracellular and asynchronous and corresponds to a process which starts with the differentiation of generative cells into pinocytic digestive cells, which subsequently start to phagocytize intact blood cells and finally detach from the epithelium, being eliminated with feces.