Vector and reservoir surveillance study in a canine and human leishmaniasis endemic area in most western part of Turkey, Karaburun

Vector-borne diseases imported to Poland between 2021 and 2023

Introduction

The aim of the study was to monitor the occurrence of selected vector-borne diseases in anaemic dogs arriving in or returning to Poland from areas endemic for these diseases.

Material and Methods

The study involved 497 dogs, of which 184 came to Poland from Ukraine with their owners fleeing the war. Other animals returned to the country from holidays spent in Croatia (n = 96), Turkey (n = 79), Italy (n = 48), Bulgaria (n = 42), Albania (n = 36) and Romania (n = 12). Molecular biology methods were used for detection of pathogens transmitted by the vectors.

Results

Molecular tests revealed the presence of vector-borne pathogens in 79 dogs. The most commonly diagnosed infection was caused by Babesia canis (27 dogs), followed by infections with Anaplasma phagocytophilum (in 20 dogs), Mycoplasma haemocanis (15 dogs), Bartonella henselae (7 dogs), Ehrlichia canis (4 dogs), Hepatozoon canis (3 dogs), Babesia gibsoni (2 dogs) and Leishmania infantum (1 dog). Most of the sick dogs (n = 39) came from Ukraine. In dogs spending holidays with their owners outside Poland, vector-borne diseases were most often detected after their return from Turkey (n = 16), and next in descending order from Croatia (n = 7), Italy (n = 6), Albania (n = 4), Bulgaria (n = 4) and Romania (n = 3).

Conclusion

The wider migration crisis and increasingly frequent trips of owners with their dogs to areas of endemic infectious and parasitic diseases observed in recent years are the main risk factors for the occurrence of these diseases in Poland. Therefore, constant monitoring of vector-borne diseases, especially in dogs returning from holidays and arriving in Poland from abroad, seems to be crucial for their early detection and introduction of appropriate therapy.

A review of non-invasive samples and tools in kala-azar diagnosis and test of cure

The recurrence of visceral leishmaniasis (VL), also called kala-azar (KA), in endemic regions of tropical countries like India, is primarily attributed to asymptomatic VL, post-kala azar dermal leishmaniasis (PKDL), and human immunodeficiency virus (HIV) co-infection. To effectively manage VL cases and elimination targets, an early and rapid diagnosis as well as accurate field surveillance is highly essential. The traditional sampling methods like bone marrow (BM), spleen, and lymph node (LN) tissue aspirations are invasive, painful, tedious, and prone to nosocomial infections, require skilled persons and hospital facilities, and are not feasible in rural areas. Therefore, there is an urgent requirement for the adoption of a patient-friendly, non-invasive, non-hospitalized sampling procedure that ensures an effective VL diagnosis. This review aims to meticulously evaluate the most recent scientific research that focuses on the precision, feasibility, and applicability of non-invasive sampling (NIS) and techniques for the diagnosis and test of cure of VL, particularly in resource-limited settings. Apart from that, the non-invasive techniques (NIT) that have shown promising results while monitoring VL treatment response and relapse are also reviewed. The limitations associated with NIT and possible improvements in this regard are discussed as well to improve the diagnosis and management of VL.

The current epidemiology of leishmaniasis in Turkey, Azerbaijan and Georgia and implications for disease emergence in European countries

Leishmania spp. are sand fly-borne protozoan parasites causing leishmaniasis in humans and animals. The aim of the study was to analyse the epidemiology of leishmaniasis in Turkey, Azerbaijan and Georgia from 2005 to 2020 and evaluate the associated risk for disease emergence in European countries. It is based on an analysis of WHO and OIE reported cases between 2005 and 2020, a review of scientific articles published in SCOPUS between 2009 and 2020 and a questionnaire survey to public health and veterinary authorities in these countries. Endemic Leishmania spp. include L. infantum in the three countries, L. major in Azerbaijan and Turkey and L. tropica and L. donovani in Turkey. Leishmaniasis is reported in humans, animals and sand flies and incidence is spatially and temporarily variable. In the southern Caucasus and particularly in Georgia, reported incidence of human visceral leishmaniasis by L. infantum remains high. However, whilst Georgia experienced a gradual decrease from >4.0 cases per 100,000 population in 2005-09 to 1.13 cases per 100,000 population in 2020, the period with highest incidence in Azerbaijan, which ranged between 0.40 and 0.61 cases per 100,000 population, was 2016-2019, and no cases have so far been reported for 2020. Visceral leishmaniasis in the Southern Caucasus affects mostly young children from deprived urban areas and its closely associated to canine leishmaniasis. Turkey reported cases of visceral leishmaniasis between 2005 and 2012 and in 2016 only, and incidence ranged between 0.02 and 0.05 per 100,000 population. In contrast, the reported annual incidence of cutaneous leishmaniasis in Turkey was much greater and peaked at 7.02 cases per 100,000 population in 2013, associated to imported cases from cutaneous leishmaniasis endemic Syria. Leishmaniasis by L. infantum in Azerbaijan and Georgia represents a regional public and animal health challenge that requires support to improve diagnosis, treatment and control. The unprecedented rise of cutaneous leishmaniasis and the spread of L. tropica and L. donovani in Turkey is an important risk factor for their emergence in Europe, especially in Mediterranean countries where competent vectors are widespread.

Evaluation of Cases with Suspected Canine Leishmaniasis History: A Five-year Retrospective Study (2016-2021)

OBJECTIVE

This study aimed to evaluate the polymerase chain reaction (PCR) and immunofluorescence antibody test (IFAT) results of suspected samples with canine leishmaniasis (CanL) that were sent to the Parasitology Department Laboratories of the Veterinary Faculty in Aydın Adnan Menderes University.

METHODS

The age, gender, and breed of the dogs to be evaluated for CanL were recorded, and IFAT was performed using 80 blood serum samples collected from them. Additionally, after the isolation of genomic DNA of 27 blood samples, PCR of these samples was performed using primers that amplify the 145 bp kDNA region of Leishmania species.

RESULTS

Thirty-seven (46.25%) of the serum samples were seropositive in at least one dilution (1/64 or 1/128) according to IFAT. Five (18.5%) of the twenty-seven samples were positive for Leishmania DNA according to PCR. According to IFAT, 38.7% of male dogs and 59% of female dogs were positive. The highest number of seropositive samples were detected in dogs aged 3-5 years (11/27).

CONCLUSION

Considering the zoonotic potential of leishmaniasis, which is considered endemic in the region, and the high positivity of the IFAT/PCR results, veterinarians should use advanced diagnostic methods, especially serological and molecular tests, in dogs with suspected CanL. The data obtained show that the risk of infection caused by Leishmania spp. is high in the region. Therefore, it is important to routinely ensure the control of CanL to protect both human and animal health.

Investigation of Phlebotominae (Diptera: Psychodidae) Fauna, Seasonal Dynamics, and Natural Leishmania spp. Infection in Muğla, Southwest of Turkey

Due to its geographical location, Muğla province is one of the most frequently used places by refugees. Although leishmaniasis have been previously reported in this region, there is a lack of information on the etiological agent and possible vectors. The main objectives of this study were; i) to investigate the sand fly fauna, ii) to reveal the natural Leishmania spp. infection in wild caught sand flies using molecular tools, and iii) to determine the annual seasonal dynamics of the sand flies in Muğla region. Totally, 2093 specimens belonging to 15 species [12 Phlebotomus, three Sergentomyia; 51 unidentified] were collected during the one-year (June 2016- June 2017) period. Of the collected sand flies, 1928 (92.12%) were caught by the Centers for Disease Control (CDC) light traps, while 165 (7.88%) of them were caught by sticky traps. Phlebotomus major sensu lato (s.l.), the potential vector of visceral leishmaniasis (VL) and canine leishmaniasis (CanL) in the Mediterranean and Aegean region, was detected in all sampling locations and found as the dominant taxon (n=1035; 49.45%) of the study area and followed by Phlebotomus tobbi (n=371; 17.72%). During the sampling period, sand fly activity was started in March and peaked in August. Sand fly population size reduced dramatically between mid-September and early October. The number of collected specimens was peaked in August, while there is only one sample collected both in November and March. The majority of the sand flies (78.66%) were collected at an altitude range of 200-400 m. Seventy-two monospecific pools were screened for the presence of Leishmania DNA by real time ITS1 PCR and 24 (nine P. major s.l., eight P. tobbi, two P. papatasi, two S. minuta, one P. alexandri, one P. similis, and one Phlebotomus (Transphlebotomus spp.) of them (33.8%) were found positive (L. infantum, L. tropica, and L. major). To the best of our knowledge, the presence of fifteen sand fly species and their distribution, seasonal dynamics, molecular detection of Leishmania parasites in Muğla province was reported for the first time. The presence of vector species in the study area, appropriate temperature and humidity conditions, long sand fly activity season, and presence of Leishmania parasite suggests that there is a serious risk in the transmission of leishmaniasis in Muğla.

First molecular identification of Leishmania major in Phlebotomus papatasi in an outbreak cutaneous leishmaniasis area in Iraq

Cutaneous leishmaniasis (CL) is transmitted by Phlebotomine sand fly vectors, among which Phlebotomus papatasi is prevalent in Western Asia, Northern Africa and Southern Europe, and it is known as a vector for Leishmania major parasite in the world. However, in Iraq, morphological studies showed that P. papatasi is a predominant sand fly species and hypothesised to transmit CL causing Leishmania species including L. major and L. tropica. Few studies have found Leishmania species in sand flies in mixed pools of samples in this country. Accurate identification of sand flies as vectors of Leishmania species is required in Iraq. The current study aims to identify sand fly species, using both morphological and molecular phylogenetic analyses, in a region where CL tends to be endemic. Furthermore, molecular phylogenetic analysis has also used to confirm Leishmania species in the sand fly samples collected in 11 villages between Diyala and Sulaymaniyah Provinces. For the first time, we have found L. major in three individual sand flies, one engorged (with fresh blood meal) and two non-engorged (without visible fresh blood meal) P. papatasi females in an area of CL outbreaks since 2014-till now due to civil wars and internal conflicts happen in the region. Further study should be performed on sand fly population and Leishmania reservoirs in this region.

Leishmania infection in cats and feline leishmaniosis: An updated review with a proposal of a diagnosis algorithm and prevention guidelines

Leishmaniosis is a vector-borne disease caused by protozoans of the genus Leishmania, which are transmitted to vertebrates, including cats, through the bites of female phlebotomine sand flies. An increasing number of epidemiological and experimental studies concerning Leishmania infection in cats, as well as case reports of clinical leishmaniosis in these felids, have been published in recent years. In the present study, a comprehensive review was made by sourcing the National Library of Medicine resources to provide updated data on epidemiology, immunopathogenesis, diagnosis, treatment, and prevention of feline leishmaniosis. Cats were found infected with Leishmania parasites worldwide, and feline leishmaniosis appears as an emergent disease mostly reported in countries surrounding the Mediterranean Sea and in Brazil. Cats with impaired immunocompetence seem to have a higher risk to develop clinical disease. The main clinical and clinicopathological findings are dermatological lesions and hypergammaglobulinemia, respectively. Diagnosis of feline leishmaniosis remains a challenge for veterinarians, in part due to the lack of diagnosis support systems. For this reason, a diagnostic algorithm for clinical decision support is herein proposed. No evidence-based treatment protocols are currently available, and these remain empirically based. Control measures are limited and scarce. Thus, a set of prevention guidelines are herein suggested.

First molecular detection and identification of Leishmania species in small wild rodents from Turkey

Leishmaniasis is a parasitic disease infecting animals and humans. Two clinical forms (Visceral and cutaneous leishmaniasis) and four species are reported to be present in Turkey. Several studies have investigated canine and human leishmaniasis in Turkey but no study was performed to screen the infection among wild rodents, so far. The present study aims to investigate the role of small wild rodents as reservoir animals for Leishmania spp. in different regions of Turkey. Formalin-preserved tissue samples (spleen, liver, lung) of 712 rodents from 30 provinces were screened for the presence of Leishmania spp. DNA. Before DNA extraction, tissues were dried, rehydrated, and homogenated. Leishmania screening in rodent tissues and species determination was performed with a combination of real-time kDNA and ITS1 polymerase chain reaction protocols. Eight (1.12%) out of 712 animals were found to be positive for Leishmania spp. DNA and species typing revealed five L. infantum, two L. tropica and one L. major among positives. Leishmania major and L. infantum DNA were detected in Apodemus spp. from Zonguldak province located in the Western Black Sea Region, while L. tropica DNA was found in Meriones sp. and Gerbillus dasyurus from Adana and Hatay provinces located in Eastern Mediterranean Region of Turkey. The present study is first to report natural infection of L. infantum, L. major and L. tropica in small wild rodents in Turkey, suggesting their possible roles as reservoirs. Further studies are needed for planning epidemiological studies and also for developing rodent control measures in risky endemic areas to break the transmission cycle.

Noninvasive Biological Samples to Detect and Diagnose Infections due to Trypanosomatidae Parasites: A Systematic Review and Meta-Analysis

Unicellular eukaryotes of the Trypanosomatidae family include human and animal pathogens that belong to the Trypanosoma and Leishmania genera. Diagnosis of the diseases they cause requires the sampling of body fluids (e.g., blood, lymph, peritoneal fluid, cerebrospinal fluid) or organ biopsies (e.g., bone marrow, spleen), which are mostly obtained through invasive methods. Body fluids or appendages can be alternatives to these invasive biopsies but appropriateness remains poorly studied. To further address this question, we perform a systematic review on clues evidencing the presence of parasites, genetic material, antibodies, and antigens in body secretions, appendages, or the organs or proximal tissues that produce these materials. Paper selection was based on searches in PubMed, Web of Science, WorldWideScience, SciELO, Embase, and Google. The information of each selected article (n = 333) was classified into different sections and data were extracted from 77 papers. The presence of Trypanosomatidae parasites has been tracked in most of organs or proximal tissues that produce body secretions or appendages, in naturally or experimentally infected hosts. The meta-analysis highlights the paucity of studies on human African trypanosomiasis and an absence on animal trypanosomiasis. Among the collected data high heterogeneity in terms of the I2 statistic (100%) is recorded. A high positivity is recorded for antibody and genetic material detection in urine of patients and dogs suffering leishmaniasis, and of antigens for leishmaniasis and Chagas disease. Data on conjunctival swabs can be analyzed with molecular methods solely for dogs suffering canine visceral leishmaniasis. Saliva and hair/bristles showed a pretty good positivity that support their potential to be used for leishmaniasis diagnosis. In conclusion, our study pinpoints significant gaps that need to be filled in order to properly address the interest of body secretion and hair or bristles for the diagnosis of infections caused by Leishmania and by other Trypanosomatidae parasites.

Revision of the species composition and distribution of Turkish sand flies using DNA barcodes

Background

Currently, knowledge regarding the phlebotomine sand fly (Diptera: Psychodidae) fauna of Turkey is restricted to regions with endemic leishmaniasis. However, rapidly changing environmental and social conditions highlight concerns on the possible future expansion of sand fly-borne diseases in Turkey, promoting risk assessment through biosurveillance activities in non-endemic regions. Traditional morphological approaches are complicated by extensive cryptic speciation in sand flies, thus integrated studies utilizing DNA markers are becoming increasingly important for correct sand fly identification. This study contributes to the knowledge of the sand fly fauna in understudied regions of Turkey, and provides an extensive DNA barcode reference library of expertly identified Turkish sand fly species for the first time.

Methods

Fly sampling was conducted at 101 locations from 29 provinces, covering all three biogeographical regions of Turkey. Specimens were morphologically identified using available keys. Cytochrome c oxidase I (cox1) barcode sequences were analyzed both for morphologically distinct species and those specimens with cryptic identity. A taxon identity tree was obtained using Neighbor Joining (NJ) analysis. Species boundaries among closely related taxa evaluated using ABGD, Maximum Likelihood (ML) and haplotype network analyses. Sand fly richness of all three biogeographical regions were compared using nonparametric species richness estimators.

Results

A total of 729 barcode sequences (including representatives of all previously reported subgenera) were obtained from a total of 9642 sand fly specimens collected in Turkey. Specimens belonging to the same species or species complex clustered together in the NJ tree, regardless of their geographical origin. The species delimitation methods revealed the existence of 33 MOTUs, increasing the previously reported 28 recorded sand fly species by 17.8%. The richest sand fly diversity was determined in Anatolia, followed by the Mediterranean, and then the Black Sea regions of the country.

Conclusions

A comprehensive cox1 reference library is provided for the sand fly species of Turkey, including the proposed novel taxa discovered herein. Our results have epidemiological significance exposing extensive distributions of proven and suspected sand fly vectors in Turkey, including those areas currently regarded as non-endemic for sand fly-borne disease.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3669-3) contains supplementary material, which is available to authorized users.