Visceral Leishmaniasis Endemic Areas Research Articles

Hematological Changes in Dogs with Visceral Leishmaniasis Are Associated with Increased IFN-γ and TNF Gene Expression Levels in the Bone Marrow.

Visceral leishmaniasis is associated with a variety of hematological abnormalities. In this study, we correlated the hematological changes in the peripheral blood of dogs naturally infected with Leishmania infantum (L. infantum) with the distribution of cell lineages and cytokine gene expression patterns in the bone marrow. Samples from 63 naturally semidomiciled dogs living in an endemic area of visceral leishmaniasis were analyzed. L. infantum infection was detected in 50 dogs (79.3%). Among those, 18 (32%) had positive splenic cultures and showed more clinical signs. They also had lower red blood cell counts and leukocytosis with an increased number of neutrophils and monocytes in peripheral blood compared to dogs negative to this test. L. infantum DNA was detected in the bone marrow of 8/14 dogs with positive splenic culture. Dogs with L. infantum infection in the bone marrow presented with histiocytosis (p = 0.0046), fewer erythroid cell clusters (p = 0.0127) and increased gene expression levels of IFN-γ (p = 0.0015) and TNF (p = 0.0091). The data shown herein suggest that inflammatory and cytokine gene expression changes in bone marrow may contribute to the peripheral blood hematological changes observed in visceral leishmaniasis.

PpSP32-like protein as a marker of human exposure to Phlebotomus argentipes in Leishmania donovani foci in Bangladesh

Phlebotomus argentipes is a predominant vector of Leishmania donovani, the protozoan parasite causing visceral leishmaniasis in the Indian subcontinent. In hosts bitten by P. argentipes, sand fly saliva elicits the production of specific anti-salivary protein antibodies. Here, we have utilised these antibodies as markers of human exposure to P. argentipes in a visceral leishmaniasis endemic area in Pabna district, Bangladesh. The use of whole salivary gland homogenate as an antigen to detect these antibodies has several limitations, therefore it is being superseded by the use of specific recombinant salivary proteins. We have identified three major P. argentipes salivary antigenic proteins recognised by sera of bitten humans, expressed them in a recombinant form (rPagSP04, rPagSP05 and rPagSP06) and tested their applicability in ELISA and immunoblot. One of them, PpSP32-like protein rPagSP06, was identified as the most promising antigen, showing highest resemblance and correlation with the IgG response to P. argentipes salivary gland homogenate. Furthermore, we have validated the applicability of rPagSP06 in a large cohort of 585 individuals and obtained a high correlation coefficient for anti-rPagSP06 and anti-P. argentipes saliva IgG responses. The anti-rPagSP06 and anti-P. argentipes salivary gland homogenate IgG responses followed a similar right-skewed distribution. This is the first report of screening human sera for anti-P. argentipes saliva antibodies using recombinant salivary protein. The rPagSP06 was proven to be a valid antigen for screening human sera for exposure to P. argentipes bites in a visceral leishmaniasis endemic area.

Label-Free Quantitative Proteomic Analysis of Three Strains of Viscerotropic Leishmania Isolated from Patients with Different Epidemiological Types of Visceral Leishmaniasis in China.

There are three epidemiological types of visceral leishmaniasis in China, which are caused by Leishmania strains belonging to the L. donovani complex. The mechanisms underlying their differences in the population affected, disease latency, and animal host, etc., remain unclear. We investigated the protein abundance differences among Leishmania strains isolated from three types of visceral leishmaniasis endemic areas in China. Promastigotes of the three Leishmania strains were cultured to the log phase and harvested. The protein tryptic digests were analyzed with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), followed by label-free quantitative analysis. The MS experiment was performed on a Q Exactive mass spectrometer. Raw spectra were quantitatively analyzed with the MaxQuant software (ver 1.3.0.5) and matched with the reference database. Differentially expressed proteins were analyzed using the bioinformatics method. The MS analysis wasrepeatedthreetimes for each sample. A total of 5012 proteins were identified across the KS-2, JIASHI-5 and SC6 strains in at least 2 of the three samples replicate. Of them, 1758 were identified to be differentially expressed at least between 2 strains, including 349 with known names. These differentially expressed proteins with known names are involved in biological functions such as energy and lipid metabolic process, nucleotide acid metabolic process, amino acid metabolic process, response to stress, cell membrane/cytoskeleton, cell cycle and proliferation, biological adhesion and proteolysis, localization and transport, regulation of the biological process, and signal transduction. The differentially expressed proteins and their related biological functions may shed light on the pathogenicity of Leishmania and targets for the development of vaccines and medicines.

Epidemiological aspects of visceral leishmaniasis in the municipality of Montes Claros-MG

Visceral leishmaniasis (VL), also known as ‘calazar’, is a serious chronic disease caused by Leishmania species from Leishmania (Leishmania) donovani complex, which the disease is characterized by abdominal swelling (hepatosplenomegaly) and may evolve to death in extreme cases. In this sense, the aim of our study was to assess the epidemiological profile of the cases found in Montes Claros (Minas Gerais state). A retrospective or cross-sectional study was carried out using secondary data provided by Health Information System (SINAN/HM) of Brazil from January 2010 to February 2020. Our data has shown that VL is an endemic disease in Montes Claros region, with 413 VL cases reported, 62.00% (252) male, average age ± standard deviation (years), and 93.46% (386) lived in Montes Claros city. The presence of comorbidities was observed in 13.70% (54) of the patients and in 7.26% (30). As for the evolution of the disease, 246 (59.56%) were cured, 30 (7.26%) died due to VL. Between 2010 and 2015, Glucantime® stands out, in which 46 (11.13%) patients used the drug, followed by common Amphotericin B 24 (13.48%) and liposomal Amphotericin B 38 (21.34%). In the period between 2016 and 2020, the most prevalent drug was liposomal Amphotericin B, with 71 (29.83%) patients using it, followed by Glucantime® 45 (18.9%). The condition evolved to death. We conclude that Montes Claros is still an endemic area for VL with an increased number of cases over time and a noticeable shift in patient profile towards children and young people. Joint efforts from different areas of scientific knowledge and public health services are needed to improve the effectiveness of visceral leishmaniasis surveillance and control actions. The population can contribute to this process of disease prevention and control, through educational actions in health and the environment.

Pediatric visceral leishmaniasis: a retrospective study to propose the diagnostic tests algorithm in southern Iran.

Leishmania infantum is the most common cause of visceral leishmaniasis (VL) in Iran, where mainly the patients are children under the age of 5 years. Timely, less invasive, and accurate diagnosis and proper treatment of the disease are necessary. This retrospective study aimed to search for a less invasive but robust algorithm on VL diagnostic tests in children. Four hundred and fifteen patients with clinical suspicion of VL, 50 healthy children from VL endemic areas, 46 healthy individuals from non-endemic VL areas, and 47 non-VL diseases were tested using three diagnostic tests: indirect immunofluorescent antibody test (IFAT), rK39-rapid diagnostic test (rK39-RDT), and quantitative PCR (qPCR). One hundred and two suspected VL cases were positive in at least one test and were cured after receiving appropriate treatment. Of these 102 VL patients, 94 were positive in qPCR, 84 in IFAT, and 79 in rK39-RDT. None of the tests detected all the patients, but overall, qPCR is capable of detecting more VL patients than serological tests, i.e., 92.2%, compared to IFAT, 82.4%, and rK39, 77.5%. There was only a significant difference between the sensitivity of qPCR and rK39-RDT (p = 0.024). The specificity was 100% for qPCR and IFAT (≥128) and 98.6% for rK39-RDT. qPCR alone is capable of detecting most of the VL-suspected children. Serological tests like IFAT and rk39-RDT are recommended to increase the overall sensitivity of detection in patients with a negative molecular test. Combining qPCR with a serological test (IFAT or rK39-RDT) can help diagnose 98% of VL. In laboratories without molecular facilities, we recommend testing with the combination of rK39-RDT and IFAT yielding a combined sensitivity of 93.1% equivalent to that of qPCR in our study.

Study of epidemiological features of visceral leishmaniasis in endemic areas of the republic of Uzbekistan

In the study of the clinical and epidemiological course of visceral leishmaniasis in the regions studied by the author, all 70 patients were children. The average age of the patients was 5.8 ± 0.8. 58.6% (41 people) were girls and 41.4% (29) were boys. In terms of regions studied, the highest rate is in Navoi region-from 3.3 to 4.1 per 100,000 population,the incidence rate increased by 1.2 times, followed by Samarkand region-by 2.2 times. In Namangan region, there was a 2-fold decrease.

Basic knowledge about visceral leishmaniasis before and after educational intervention among primary health care professionals in Midwestern Brazil.

ABSTRACTHealth education and training of primary health care (PHC) professionals are highly recommended to reduce the occurrence and lethality of visceral leishmaniasis (VL). This study assessed the impact of an educational intervention on the basic knowledge about visceral leishmaniasis (VL) among PHC professionals from the Brazilian municipality of Rondonopolis, an important endemic area for VL. Responses provided by physicians, nurses, nursing technicians and community health agents from 12 PHC facilities were recorded through the application of self-completed and semi-structured questionnaires before (n=92) and after (n=64) an in-person health training course covering various aspects of VL. Closed- and open-ended responses were compared by the chi-square test and analyses of word clouds, respectively. The proportion of professionals aware of the correct etiological agent (p<0.001) and transmission route (p<0.001) of VL increased post-intervention. In addition, they increased their ability to recognize fever (p<0.001), weakness (p<0.001), weight loss (p<0.001), pallor (p<0.001) and abdominal distention (p=0.013) as clinical manifestations of human VL, and weakness (p<0.001), alopecia (p<0.001) and weight loss (p=0.019) as signs of canine VL. Analyses of word clouds suggested that the participants became more aware of the role of dogs in VL transmission and the role of environmental management in the prevention of VL. In conclusion, the intervention positively impacted the baseline knowledge concerning VL among the professionals. This can support the planning of educational activities for the PHC team regarding early case detection, prevention and control of VL in endemic areas.

Study of clinical features of visceral leishmaniasis in endemic areas of the Republic of Uzbekistan

Study of clinical features of visceral leishmaniasis in endemic areas of the Republic of Uzbekistan

Anti-Brucella canis antibodies in dogs naturally infected with Leishmania infantum and associated histological alterations in the genital tract.

In canine visceral leishmaniasis, coinfections can aggravate the disease. Our aim was to investigate Brucella canis in dogs infected with Leishmania infantum. One hundred and six L. infantum-seropositive dogs were submitted to serology for B. canis, PCR for B. canis and L. infantum, and histopathological analysis of the genital tract. Anti-B. canis antibodies were detected in seven dogs whose clinical signs, L. infantum load and histological alterations were similar to those of seronegative animals. The circulation of anti-B. canis antibodies was low but demonstrates the exposure of dogs to this bacterium in a visceral leishmaniasis-endemic area.

Development of a Multi-Epitope Recombinant Protein for the Diagnosis of Human Visceral Leishmaniasis.

Background:Iran is one of the endemic areas of Mediterranean Visceral Leishmaniasis, a disease caused by Leishmania infantum. In this work, we examined whether Proteína quimérica 10 (PQ10) recombinant protein is suitable for immunological diagnosis of human visceral leishmaniasis.Methods:The study was carried out in Tarbiat Modares University during 2016–2018. The coding sequence of PQ10 recombinant protein was sub-cloned in pET28 expression vector and was commercially synthesized by GENERAY Biotechnology, China. Sequencing with proper primers was done, the expression, optimization of expression and protein purification were performed, and the purified recombinant protein was confirmed by western blot. The efficacy of PQ10 for serodiagnosis was evaluated with 50 positive and 50 negative serum samples, which confirmed by the direct agglutination test and collected from individuals living in the visceral leishmaniasis endemic areas of Iran. ELISA was performed with the PQ10 recombinant protein.Results:The 95% CI sensitivity of ELISA that was evaluated with sera from naturally infected individuals was 84%. The 95% CI specificity value of the ELISA determined with sera from healthy individuals (50 serum samples) and from individuals with other infectious diseases was 82%. The 95% CI positive predictive value (PPV) and negative predictive value (NPV) were exterminated 82.35% and 83.67%, respectively.Conclusion:We have used a recombinant synthetic protein to improve serodiagnosis of human visceral leishmaniasis. PQ10 could be useful for diagnosis of asymptomatic cases, as well as in the early phase of infections.

Assessment of Knowledge, Attitudes, and Practices about Visceral Leishmaniasis in Endemic Areas of Malda District, West Bengal, India

Community participation is an important aspect for the success of kala-azar (KA) elimination program implemented in five Southeast Asian countries by the WHO. The participation of community depends on the level of knowledge of, attitude toward, and practice around risk factors associated with KA transmission among the population. We assessed the knowledge, attitude, and practice toward KA elimination in endemic areas of Malda district, West Bengal, India. A total of 709 individuals from different villages of 12 sub-centers were interviewed during April-July 2019. Data were recorded in a structured questionnaire under four categories: sociodemographic parameters, knowledge, attitude, and practice. The association of dependent variables such as knowledge, attitude, and practice with independent variables such as the economy and sociodemographic parameters was analyzed by binary logistic regression model and chi-square test using SPSS software. Despite the endemicity of the disease for a long time, the adequacy of knowledge about the disease was found to be poor that can be attributed to low education level and socioeconomic status, but the attitude and practices were good. So, there is a scope of improvement in knowledge of the disease through proper health education. This will further improve the level of attitude and practices that will be helpful for the smooth implementation of different activities of the program by more active participation of the community.

Seropositivity of Visceral leishmaniasis on people of VL endemic three districts of Nepal.

Visceral leishmaniasis (VL) is a life-threatening vector borne disease caused by the Leishmania donovani species complex. In Nepal, it is transmitted to humans by L donovani infected Phlebotomus argentipes sand flies [12]. The pathogenesis of VL is complex, and the clinical presentation ranges from asymptomatic infection to severe and fatal disease. Asymptomatic infection may act as potential reservoirs for sustained transmission of VL in endemic areas. We investigated the sero-prevalence of symptomatic and asymptomatic infection of VL in people of three endemic districts of Nepal by serology targeting family members and neighbors of VL patients. Sero-survey was conducted among 189 people of villages endemic to VL from Palpa, Sarlahi and Saptari districts during 2016 to 2018 using the rK39 rapid diagnostic test (InBios International, Seattle, WA) to detect anti-Leishmania antibodies. Sero-positivity was 35.7% (10/28) in people tested from Sarlahi districts, 6% (3/50) in Saptari district and 1.7% (1/59) from the Palpa district. In Sarlahi, sero-positivity was found to be highest among the age group below 15years (44.5%). All family members of diagnosed VL cases in Saptari and Palpa districts were found to be rK39 test negative. In Sarlahi district, among the ten sero-positive cases, nine were febrile and became symptomatic VL cases after few days and one case remained asymptomatic during the six month follow up. Asymptomatic cases in VL endemic districts of Nepal were found to be sero-positive, screening of people in VL endemic districts would be important for prevention of VL transmission.

Chromosomal segments may explain the antibody response cooperation for canine leishmaniasis pathogenesis

Visceral leishmaniasis (VL) is marked by hyperactivation of a humoral response secreting high quantity of immunoglobulins (Igs) that are inaccessible to intracellular parasites. Here we investigated the contributions of the antibody response to the canine leishmaniasis pathogenesis. Using correlation and genome-wide association analysis, we investigated the relationship of anti-Leishmania infantum immunoglobulin classes levels with parasite burden, clinical response, renal/hepatic biochemical, and oxidative stress markers in dogs from endemic areas of VL. Immunoglobulin G (IgG) and IgA were positively correlated with parasite burden on lymph node and blood. Increased IgG, IgA and IgE levels were associated with severe canine leishmaniasis (CanL) whereas IgM was elevated in uninfected exposed dogs. Correlations of IgM, IgG and IgA with creatinine, urea, AST and ALT levels in the serum were suggested an involvement of those Igs with renal and hepatic changes. The correlogram of oxidative radicals and antioxidants revealed a likely relationship of IgM, IgG and IgA with oxidative stress and lipid peroxidation in the blood, suggested as mechanisms mediating tissue damage and CanL worsening. The gene mapping on chromosomal segments associated with the quantitative variation of immunoglobulin classes identified genetic signatures involved with reactive oxygen species generation, phagolysosome maturation and rupture, free iron availability, Th1/Th2 differenciation and, immunoglobulin clearance. The findings demonstrated the roles of the antibody response as resistance or susceptibility markers and mediators of CanL pathogenesis. In addition we pinpointed candidate genes as potential targets for the therapy against the damage caused by exacerbated antibody response and parasitism in VL.

Detection of Leishmania infantum Infection in Reservoir Dogs Using a Multiepitope Recombinant Protein (PQ10).

Visceral leishmaniasis is a neglected disease caused by Leishmania infantum and transmitted via female sand flies. Canine visceral leishmaniasis diagnosis should be performed as soon as possible, even on the basis of only a few or even a single clinical sign, to enhance the prediction of disease and to avoid both dog and human transmission and unnecessary euthanasia of apparently positive dogs. In the present work, we examined whether PQ10 recombinant protein could be suitable for immunological detection of Leishmania infantum infection. The coding sequence of PQ10 recombinant protein was sub-cloned in pET28 expression vector and was commercially synthesized by GENERAY Biotechnology, China. In the following process, sequencing with proper primers was done and the expression, optimization of expression and protein purification were performed. The efficacy of PQ10 for serodiagnosis was evaluated with 100 serum samples collected from dogs living in the visceral leishmaniasis endemic areas of Iran. Samples (n=20) of the dogs with other infectious disease were also be collected. The synthesized colones verified by the sequencing with proper primers. In the following process, expression, optimization of expression and protein purification performed and the purified recombinant protein confirmed by western blot. The ELISA was performed with PQ10 recombinant protein. The sensitivity of ELISA that was evaluated with sera from naturally infected dogs was 94%. The specificity value of the ELISA determined with sera from healthy dogs and from dogs with other infectious diseases was 86%. The positive predictive value (PPV) and negative predictive value (NPV) determined 87.03% and 93.47% respectively. Our findings indicated to the potential use of this recombinant protein in the diagnosis of canine visceral leishmaniasis.

Knowledge about human visceral leishmaniosis in an endemic area in Pernambuco, Brazil

Abstract The timely detection and adequate attention of cases of Human Visceral Leishmaniasis can provide a reduction in the morbidity and mortality of this disease. This study evaluated the degree of knowledge about Human Visceral Leishmaniasis among professionals from basic health units in the municipality of Caruaru, an endemic area for Visceral Leishmaniasis in the state of Pernambuco-Brazil. From June to August 2017, questionnaires were applied to doctors and nurses of the units that presented cases and / or deaths due to LVH between the years 2006 and 2015. Regarding the results, it was possible to verify, from the analysis of multiple correspondence, important interdependence relations such as the lack of knowledge of the endemicity of the Municipality in question with the misinformation about treatment, in addition to the association between not knowing the etiologic agent of the disease and the lack of knowledge about the treatment and the municipal health unit, suggesting an impediment to the control of LVH. The results also demonstrated a general lack of knowledge regarding the etiological, epidemiological, assistance and surveillance aspects of this condition in the city and the need to train these professionals on the subject, considering that knowledge about visceral leishmaniasis is considered a protective factor and capable to reduce the risk of this disease occurring. Therefore, we emphasize the need to maintain, review and restructure the control and prevention measures already known and implemented. However, it is necessary to strengthen a valuable and fundamental area in the fight against the disease, that of health education, focusing mainly on primary care professionals, who are still the main source of welcome for sick individuals. These are fundamental to reduce the morbidity and mortality of human VL, as a link in the transmission chain, but also as perpetuators of information about the disease in order to prevent it through attitudes. Key messages One of the main impacts of this work is the applicability and utility in health services in Brazil and other countries that face neglected diseases such as visceral leishmaniasis. Another great contribution of this work is to demonstrate, in a practical example, how education is fundamental in prevention and health promotion strategies.

Leishmania ITS1 Is Genetically Divergent in Asymptomatic and Symptomatic Visceral Leishmaniasis: Results of a Study in Southern Iran.

It has been documented that the genotypic traits in symptomatic and asymptomatic cases of visceral leishmaniasis (VL) may be different. The current study aimed to find out and compare the genotype and intraspecies diversity of Leishmania Internal Transcribed Spacer 1 (ITS1) from asymptomatic and symptomatic VL cases in southern Iran. Methods. Buffy coat samples from seven VL patients, with clinical signs and symptoms, and seven asymptomatic VL cases, were evaluated in this study. Samples of asymptomatic individuals were obtained from children living in a VL endemic area in southern Iran, while the samples of symptomatic subjects were obtained from patients admitted to hospitals with a diagnosis of VL. DNA was extracted from the buffy coats of the samples and PCR-amplified, targeting the ITS1of Leishmania. The PCR products were sequenced, and the consensus sequences were assembled and multiple-aligned with a set of Leishmania strains retrieved from the GenBank, using Clustal W. The phylogenetic tree was rooted, using MEGAX software, and the diversities based on haplotype and nucleotides, as well as the number of polymorphic sites, were measured using DnaSP v5.0 software. The results of ITS1 sequencing in 5 out of 7 asymptomatic VL cases showed 99.25% to 100% similarity with the Leishmania infantum ITS1 sequence (accessed number: MN648746), and one isolate was considered as just Leishmania sp. In one sample, 99.75% similarity was seen with the ITS1 sequence of Crithidia fasciculata. Of the symptomatic VL patients, the PCR product revealed a 340 bp band corresponding to L. infantum in all of the samples. By analyzing the ITS1 sequences, all seven sequences formed a clade somewhat different from other Leishmania species and considered as Leishmania sp. Haplotype and nucleotide diversity were much more prevalent in symptomatic cases where six haplotypes were seen in the ITS1 of Leishmania from symptomatic patients and only two haplotypes were observed in the samples from asymptomatic cases. The findings of the current study showed that the Leishmania ITS1 from symptomatic VL and asymptomatic cases has significant genetic differences. Besides, infection with Crithidia fasciculata was reported, for the first time, in an asymptomatic case, which deserves further study.

In vitro Infectivity of Strains Isolated From Dogs Naturally Infected With Leishmania infantum Present a Distinct Pathogenic Profile in Hamsters.

Visceral leishmaniasis (VL) is a severe disease caused by Leishmania infantum. Dogs are the parasite's main reservoir, favoring its transmission in the urban environment. The analysis of L. infantum from infected dogs contributes to the identification of more virulent parasites, thereby supporting basic and applied studies such as vaccinal and therapeutic strategies. We proposed the in vitro and in vivo characterization of L. infantum strains from naturally infected dogs from a VL endemic area based on an infectivity and pathogenicity analysis. DH82 canine macrophages were infected in vitro with different strains for infectivity analysis, showing distinct infectivity profiles. The strains that showed greater and lesser infectivity using in vitro analyses (616 and 614, respectively) were used to infect hamsters for pathogenicity analysis. The group infected with strain 616 showed 100% survival while the group infected with strain 614 showed 50% after seven months of follow up. Furthermore, the 614 strain induced more noticeable clinicopathological changes and biochemical abnormalities in liver function, along with high inflammation and parasite load in the liver and spleen. We confirmed high variability of infectivity and pathogenicity in L. infantum strains from infected dogs. The results support the belief that screening for L. infantum infectivity using in vitro experiments is inadequate when it comes to selecting the most pathogenic strain.

Conversion of asymptomatic infection to symptomatic visceral leishmaniasis: Astudy of possible immunological markers.

IntroductionPresence of asymptomatic individuals in endemic areas is common. The possible biomarkers in asymptomatic individuals once they get exposed to infection as well as following conversion to symptomatic disease are yet to be identified.We identified asymptomatic Visceral leishmaniasis (VL) infection amongst rK39+sorted direct agglutination test positive (DAT+) endemic healthy population and confirmed it by quantitative PCR(qPCR).The immunological determinants such as Adenosine deaminase (ADA), Interferon gamma (IFN-γ), Tumour Necrosis Factor alpha (TNF-α) and Interleukin 10 (IL-10)were examined to predict probable biomarkers for conversion to symptomatic VL.MethodsSample size was 5794 healthy individuals from VL endemic region. Antibody tests(DAT &rK39) were performed and later a qPCR assay was employed using kDNA specific primers and probes. Immunological biomarkers examined were ADA level by ADA–MTP kit and quantitative cytokines(IFN-γ, IL-10 and TNF-α) by ELISA.Results120 asymptomatic individuals of 308 rK39 sero-positives were DAT positive comprising of 56 with previous history and 64 with no history of VL. RT-PCR confirmed asymptomatic VL in 42 sero-positives. These were followed up through repeated qPCR and evaluation of immunological determinants. We observed10 symptomatic cases converted from a total of 42 asymptomatic individuals identified at base-line. The level of ADA, IL-10 and IFN-γ remained consistently high in asymptomatic cases and amongst these, ADA and IL-10 but not IFN-γ remained higher at the development of clinical symptoms into active VL. On the contrary, there was no significant change in the mean concentration of TNF-α at both stages of the disease.DiscussionWe surmise from our data that considerable proportion of asymptomatic cases can be a reservoir and may play a crucial role in transmission of visceral leishmaniasis in endemic areas.The data also suggests that ADA and IL-10 can serve as a potential biomarker during the conversion of asymptomatic into symptomatic VL.

Immunity to vector saliva is compromised by short sand fly seasons in endemic regions with temperate climates

Individuals exposed to sand fly bites develop humoral and cellular immune responses to sand fly salivary proteins. Moreover, cellular immunity to saliva or distinct salivary proteins protects against leishmaniasis in various animal models. In Tbilisi, Georgia, an endemic area for visceral leishmaniasis (VL), sand flies are abundant for a short period of ≤3 months. Here, we demonstrate that humans and dogs residing in Tbilisi have little immunological memory to saliva of P. kandelakii, the principal vector of VL. Only 30% of humans and 50% of dogs displayed a weak antibody response to saliva after the end of the sand fly season. Likewise, their peripheral blood mononuclear cells mounted a negligible cellular immune response after stimulation with saliva. RNA seq analysis of wild-caught P. kandelakii salivary glands established the presence of a typical salivary repertoire that included proteins commonly found in other sand fly species such as the yellow, SP15 and apyrase protein families. This indicates that the absence of immunity to P. kandelakii saliva in humans and dogs from Tbilisi is probably caused by insufficient exposure to sand fly bites. This absence of immunity to vector saliva will influence the dynamics of VL transmission in Tbilisi and other endemic areas with brief sand fly seasons.

Leishmaniasis and Tuberculosis Concurrent Infection in Humans and Animals in Kala-azar Endemic Areas of Bangladesh

Introduction: Co-infection of parasitic disease and pulmonary tuberculosis are increasing public health problem especially in developing countries like Bangladesh. More than 81% of cases and deaths from TB are in developing countries and is aggravated by concurrency with parasitic diseases, where in Bangladesh suffer a substantial no of Kala-azar cases in each year. Cattle are found to have bovine tuberculosis but at the same areas of Kala-azar endemicity, whether this animal found to be positive.&#x0D; Objectives: To findout the concurrent infection in humans and animals in Kala-azar endemic areas of Bangladesh.&#x0D; Materials and Methods: This study was conducted at Surya Kanto Hospital, Mymensingh and four Kala-azar endemic Upazilla of Mymensingh, Tangail and Pabna District. A total of 300 highly suspected tuberculosis patients reported from Kala-azar endemic areas and 170 cattle’s blood sample, 110 cattle spleen samples were included in this study. Cattle blood and spleen samples were investigated for both TB and Kalaazar and all the TB cases were investigated for Kala-azar. Buffy coat from venous blood was taken for ELISA and PCR. Spleen samples were sonicated and then were examined by PCR. All patients’ blood was tested with ICT (rK39) for Visceral Leishmaniasis. ICT positive patient’s splenic aspiration was examined by smear microscopy with 10x 100 magnifications. After that, all these samples were tested by ELISA and PCR.&#x0D; Results: Out of total 300 patients 162(54%) were found positive for TB. Blood sample of 180 patients was tested with ICT rK39 and 12(7%) patients were found positive for leishmaniasis who suffered from Tuberculosis. These 12(7%) patient’s splenic smear were examined of which 11(92%) of them were found positive for leishmania. But using ELISA all 12(100%) patient smears were found positive. Out of 170 cattle blood 12(7.1%) were ICT positive indicating prevalence of bovine tuberculosis and of these 170 cattle blood 20(11.8%) were found positive for antileishmania antibody. With PCR of these 20, no one was found positive for Leishmania.&#x0D; Conclusion: Visceral leishmaniasis and tuberculosis coinfection have drawn attention clinically. This study found the presence of leishmaniasis and tuberculosis concurrently in humans in Kala-azar endemic areas, wherein bTB antibody was detected in cattle. Though concurrently leishmania antibody was found in cattle but was not proved by PCR which requires further studies.&#x0D; Journal of Armed Forces Medical College Bangladesh Vol.14 (2) 2018: 91-96