Incidence Of Visceral Leishmaniasis Research Articles

In silico identification of human microRNAs pointing centrin genes in Leishmania donovani: Considering the RNAi-mediated gene control.

Leishmaniasis, a parasitic disease caused by different species of the protozoa parasite Leishmania, is a neglected tropical human disease that is endemic in about a hundred countries worldwide. According to the World Health Organization (WHO), the annual incidence of cutaneous leishmaniasis (CL) is estimated to be 0.7-1.2 million cases globally, whereas the annual incidence of visceral leishmaniasis is estimated to be 0.2-0.4 million cases. In many eukaryotic organisms, including human beings and protozoan parasites, centrin genes encode proteins that play essential roles within the centrosome or basal body. Human microRNAs (miRNAs) have been linked to several infectious and non-infectious diseases associated with pathogen-host interactions, and they play the emphatic roles as gene expression regulators. In this study, we used the MirTarget bioinformatics tool, which is a machine learning-based approach implemented in miRDB, to predict the target of human miRNAs in Leishmania donovani centrin genes. For cross-validation, we utilized additional prediction algorithms, namely, RNA22 and RNAhybrid, targeting all five centrin isotypes. The centrin-3 (LDBPK_342160) and putative centrin-5 (NC_018236.1) genes in L. donovani were targeted by eight and twelve human miRNAs, respectively, among 2,635 known miRNAs (miRBase). hsa-miR-5193 consistently targeted both genes. Using TargetScan, TarBase, miRecords, and miRTarBase, we identified miRNA targets and off-targets in human homologs of centrin, inflammation, and immune-responsive genes. Significant targets were screened based on GO terminologies and KEGG pathway-enrichment analysis (Log10p-value >0.0001). In silico tools that predict the biological roles of human miRNAs as primary gene regulators in pathogen-host interactions help unravel the regulatory patterns of these miRNAs, particularly in the early stages of inflammatory responses. It is also noted that these miRNAs played an important role in the late phase of adaptive immune response, inclusively their impacts on the immune system's response to L. donovani.

Modelling spatiotemporal patterns of visceral leishmaniasis incidence in two endemic states in India using environment, bioclimatic and demographic data, 2013-2022.

As of 2021, the National Kala-azar Elimination Programme (NKAEP) in India has achieved visceral leishmaniasis (VL) elimination (<1 case / 10,000 population/year per block) in 625 of the 633 endemic blocks (subdistricts) in four states. The programme needs to sustain this achievement and target interventions in the remaining blocks to achieve the WHO 2030 target of VL elimination as a public health problem. An effective tool to analyse programme data and predict/ forecast the spatial and temporal trends of VL incidence, elimination threshold, and risk of resurgence will be of use to the programme management at this juncture. We employed spatiotemporal models incorporating environment, climatic and demographic factors as covariates to describe monthly VL cases for 8-years (2013-2020) in 491 and 27 endemic and non-endemic blocks of Bihar and Jharkhand states. We fitted 37 models of spatial, temporal, and spatiotemporal interaction random effects with covariates to monthly VL cases for 6-years (2013-2018, training data) using Bayesian inference via Integrated Nested Laplace Approximation (INLA) approach. The best-fitting model was selected based on deviance information criterion (DIC) and Watanabe-Akaike Information Criterion (WAIC) and was validated with monthly cases for 2019-2020 (test data). The model could describe observed spatial and temporal patterns of VL incidence in the two states having widely differing incidence trajectories, with >93% and 99% coverage probability (proportion of observations falling inside 95% Bayesian credible interval for the predicted number of VL cases per month) during the training and testing periods. PIT (probability integral transform) histograms confirmed consistency between prediction and observation for the test period. Forecasting for 2021-2023 showed that the annual VL incidence is likely to exceed elimination threshold in 16-18 blocks in 4 districts of Jharkhand and 33-38 blocks in 10 districts of Bihar. The risk of VL in non-endemic neighbouring blocks of both Bihar and Jharkhand are less than 0.5 during the training and test periods, and for 2021-2023, the probability that the risk greater than 1 is negligible (P<0.1). Fitted model showed that VL occurrence was positively associated with mean temperature, minimum temperature, enhanced vegetation index, precipitation, and isothermality, and negatively with maximum temperature, land surface temperature, soil moisture and population density. The spatiotemporal model incorporating environmental, bioclimatic, and demographic factors demonstrated that the KAMIS database of the national programmme can be used for block level predictions of long-term spatial and temporal trends in VL incidence and risk of outbreak / resurgence in endemic and non-endemic settings. The database integrated with the modelling framework and a dashboard facility can facilitate such analysis and predictions. This could aid the programme to monitor progress of VL elimination at least one-year ahead, assess risk of resurgence or outbreak in post-elimination settings, and implement timely and targeted interventions or preventive measures so that the NKAEP meet the target of achieving elimination by 2030.

Effect of environmental variables on the incidence of Visceral Leishmaniasis in Brazil and Colombia

Visceral Leishmaniasis (VL) is the most severe of the three forms of Leishmaniasis. In the Americas, Brazil and Colombia present more than 90 % of the cases in the region. Our aim in this research was to estimate the association of the incidence rate of Visceral Leishmaniasis with the following environmental variables: the percentage of area suitable for the vector Lutzomyia longipalpis, the episodes of La Niña and El Niño, the Brazilian and Colombian biomes. Epidemiological data were obtained from the Brazilian Notifiable Diseases Information System and the Colombian National Public Health Surveillance System. Environmental data were downloaded from the NASA Giovanni web app, the Modis Sensor database, and the meteorological agencies of Australia, Japan, and the United States of America. Records of the presence of Lu. longipalpis were obtained from public databases and previous studies. As a result, the incidence per 10,000 inhabitants with LEBS for each El Niño-Southern Oscillation (ENSO) episode showed the largest values during El Niño 2015–2016, mainly in Brazil's Northeast and Central regions and the Northeast region of Colombia. Compared with the Neutral 2012–2014 episode, the episodes of El Niño 2015–2016 and La Niña 2010–2011 showed an average increase in the monthly incidence rate of VL, and the average increase was higher during El Niño 2015–2016 (aIRR = 2.304 vs.1.453) We found a positive association between the incidence rate of VL and the El Niño 2015–2016 episode and an impressive% of area suitable for the vector Lu. longipalpis in the Amazon region.An increase of 1 % in the area suitable for the vector Lu. longipalpis leads to an average rise of 0.8 % in the monthly incidence rate of VL. Our study shows a possible association between VL incidence and ENSO, with the most considerable incidence rates observed during El Niño 2015–2016 in Brazil's Northeast and Central regions and the Northeast region of Colombia. The present study is very important to better understand the Visceral Leishmaniasis transmission dynamics.

Leishmania (Leishmania) infantum DNA detection in Nyssomyia neivai in Vale do Ribeira, Paraná, Brazil.

The incidence of visceral leishmaniasis (VL) has increased in the Southern region of Brazil in recent years, especially in the State of Paraná. New species have been suggested with potential to act as vector in VL endemic areas. Identify the Leishmania species in sand fly specimens collected from 2016 to 2018 in the municipality of Itaperuçu, Vale do Ribeira, Paraná, Brazil. Light traps were used for collections and for the analysis of sand fly were used the multiplex polymerase chain reaction (PCR) methodology and subsequent sequencing. Among the collected specimens, 88.62% were attributed to the species Nyssomyia neivai, which were grouped into 176 pools. Three positive pools were detected: two with Leishmania (Viannia) braziliensis and one with L. (Leishmania) infantum. The positivity rate for the parasite was 0.25% based on the presence of at least one infected insect in the pool. The detection of L. infantum in Ny. neivai draws attention due to its abundance and anthropophily in the State of Paraná. Moreover, this finding is considered as an alert and suggests that the vector competence of Ny. neivai and the criteria for its incrimination should be carried out, given its wide distribution in southern of Brazil.

Global Distribution and Prediction of Transmission-Risk of Visceral Leishmaniasis

Backgrounds: Visceral leishmaniasis (VL) is a vector-borne disease posing increasing public health concerns. Although efforts to eliminate VL are underway, its global risk distribution remains unclear, because of changes in transmission risk. Methods: Worldwide province-level data on VL incidence were obtained from multiple sources. We analyzed the global evolution features of VL and estimated its ecological niches with boosted regression tree models. A risk map was generated to analyze regions with high VL risk. Results: A total of 558 articles and 2,694 records from 310 provinces were included. The model indicated that precipitation in the warmest quarter and poor socio-demographic index were the most significant risk factors affecting VL distribution. The risk map indicated that Brazil, Iran, Ethiopia, and India were the regions with the highest probability of infection. We estimated that 5.3 billion people live in regions at risk of VL. Conclusions: VL is undergoing geographic expansion. Our study increases understanding of VL’s global-risk distribution and how risk factors influencing the disease transmission. Our findings may aid in promoting disease control in future surveillance activities.

Prediction of visceral leishmaniasis incidence using the Seasonal Autoregressive Integrated Moving Average model (SARIMA) in the state of Maranhão, Brazil.

Visceral leishmaniasis (VL) is an infectious disease predominant in countries located in the tropics. The prediction of occurrence of infectious diseases through epidemiologic modeling has revealed to be an important tool in the understanding of its occurrence dynamic. The objective of this study was to develop a forecasting model for the incidence of VL in Maranhão using the Seasonal Autoregressive Integrated Moving Average model (SARIMA). We collected monthly data regarding VL cases from the National Disease Notification System (SINAN) corresponding to the period between 2001 and 2018. The Box-Jenkins method was applied in order to adjust a SARIMA prediction model for VL general incidence and by sex (male or female) for the period between January 2019 and December 2013. For 216 months of this time series, 10,431 cases of VL were notified in Maranhão, with an average of 579 cases per year. With regard to age range, there was a higher incidence among the pediatric public (0 to 14 years of age). There was a predominance in male cases, 6437 (61.71%). The Box-Pierce test figures for overall, male and female genders supported by the results of the Ljung-Box test suggest that the autocorrelations of residual values act as white noise. Regarding monthly occurrences in general and by gender, the SARIMA models (2,0,0) (2,0,0), (0,1,1) (0,1,1) and (0,1,1) (2, 0, 0) were the ones that mostly adjusted to the data respectively. The model SARIMA has proven to be an adequate tool for predicting and analyzing the trends in VL incidence in Maranhão. The time variation determination and its prediction are decisive in providing guidance in health measure intervention.

Spatial-temporal distribution of visceral leishmaniasis in Brazil from 2007 to 2020Distribución espaciotemporal de la leishmaniasis visceral en Brasil en el período 2007-2020

To analyze the dynamics of the spatial and temporal distribution of visceral leishmaniasis in Brazil from 2007 to 2020. This ecological study focused on the spatial pattern of visceral leishmaniasis cases in Brazil from 2007 to 2020 using data from the Information System for Notifiable Diseases (SINAN). The variables analyzed were the incidence rate of visceral leishmaniasis and the visceral leishmaniasis composite indicator (VLCI), from which triennial thematic maps were constructed. The global Moran index was calculated to assess the existence of spatial autocorrelation, and the local Moran index was used to identify areas with higher and lower risk of visceral leishmaniasis in Brazil. During the study period, there were 48 705 cases of visceral leishmaniasis, with an incidence rate of 25.53 cases per 100 000 population. There was spatial autocorrelation in all triennial blocks, with municipalities in the North and Northeast regions having an incidence equal to or greater than 50 cases per 100 000 population. Regarding the VLCI there was an increase in the number of municipalities classified as low risk for transmission, and a growing presence of state capitals with a classification of very high risk. The incidence of visceral leishmaniasis varied over the trienniums. The border region between the states of Tocantins, Maranhão, and Pará, along with the state of Ceará, stood out in the spatial distribution of the disease incidence and risk stratification by VLCI. These areas should be a priority for surveillance and control efforts for the disease.

Assessing the role of active case detection on visceral leishmaniasis control: A case study

In this paper, we formulate and analyze a compartmental model of visceral leishmaniasis (VL). We validate our model by calibrating it to the yearly VL incidence data for India and Bangladesh. The proposed model’s basic reproduction number ([Formula: see text]) has been derived and estimated. We have proved the existence of backward bifurcation in our system. The phenomenon of backward bifurcation has public health implications because the classical requirement of [Formula: see text], while necessary, is no longer sufficient for effective disease control (or elimination). In such a (backward bifurcation) situation, the initial sizes of the model’s subpopulations (state variables) would determine the effectiveness of disease control or elimination. As a result, it is the first attempt to represent and study VL disease dynamics using active case detection (ACD) as a control strategy, although a few experimental studies have been conducted to evaluate ACD in disease transmission. We use sensitivity analysis to investigate the effects of the model’s controllable parameters for the basic reproduction number. We found that [Formula: see text] (monitoring rate to infected individuals) have negative impacts on [Formula: see text]. The numerical result suggests that the ACD strategy can be useful for the VL elimination program. Due to a small increment in the monitoring rate, the dynamic behavior of infected individuals dramatically decreased. Successful employment of ACD strategy may reduce more than 60–80% symptomatic and post kala-azar dermal leishmaniasis (PKDL) individuals. We found that healthcare organizations should prioritize ACD in symptomatic and PKDL individuals over asymptomatic individuals. We also observed that the use of only culling effect to the reservoirs is not beneficial to society in the control of VL, but spraying of insecticides and the use of treated bednets can be effective control strategies to curtail the outbreak of the disease.

Epidemiological features of Leishmania infantum in dogs (Canis lupus familiaris) suggest a latent risk of visceral leishmaniasis in the metropolitan area of Bucaramanga, Santander, Eastern Colombia.

Visceral leishmaniasis (VL) is a disease caused by species of the Leishmania donovani complex that is mainly transmitted through the urban cycle involving dogs as the primary reservoir. In Colombia, the incidence of VL is increasing, along with the spread of potential vectors. This study aims to investigate the eco-epidemiological factors associated with Leishmania spp. infection in dogs from the Metropolitan Area of Bucaramanga (MAB), Santander, eastern Colombia, which is a region at risk for VL. We conducted molecular and serological surveillance of Leishmania spp. in 207 dogs from MAB to determine the epidemiological factors associated with infection. Subsequently, we carried out a molecular and serological analysis of phlebotomine and humans, respectively, in areas with a higher prevalence of infection, aiming to describe the main features associated with the transmission cycle. Out of the 207 dogs tested, 37 (17.8%, 95% CI=12.6-23.1%) were positive for the presence of Leishmania antibodies by the IFAT test, and only 9 (4.3%, 95% CI=1.55-7.15%) were positive for L. infantum by PCR. Multivariate analyses indicated that canine shelters and dogs with clinical signs commonly associated with canine VL had a higher prevalence of infection (P<0.05). In the entomological survey, 69 blood-fed female phlebotomine of the genus Lutzomyia were captured in canine shelters, among them, 55% were identified as Lutzomyia camposi, 29% as Lu. ovallesi, 7% as Lu. dubitans, 6% as Lu. torvida, and 3% as Lu. cayennensis. The identified meal sources of the phlebotomine included human, pig, avian, cattle, and porcupine (Coendou quichua) blood. However, no phlebotomine positive for Leishmania spp. were detected by molecular analyses. Finally, 14 humans who had frequent contact with L. infantum-positive dogs were analyzed through rK39 test, but none tested was positive for IgG/IgM antibodies. The molecular and serological analyses indicate the circulation of L. infantum in dogs from MAB, with canine shelters having the highest prevalence of infection. The entomological survey of canine shelters showed a significant diversity of phlebotomine without potential vectors of L. infantum, suggesting the presence of infection in dogs from these areas could take place in other locations or through other transmission routes. The circulation of L. infantum in multiple dogs from MAB suggests a latent risk of zoonotic transmission of VL in these cities.

Temporal trend in the incidence of human visceral leishmaniasis in Brazil.

It is an ecological study that analyzed the time trend of visceral leishmaniasis incidence rates in Brazil using segmented time regression by joinpoints. There was a decreasing incidence rate of this disease in the country with an average annual percent change (AAPC) of -5 (CI95%: -9.1; -0.6) and a reduction of 1.69 cases/100 thousand inhabitants in 2007, and 0.91/100 thousand inhabitants in 2020. The Central-West region showed the highest reduction percent (AAPC: -9.1; CI95%: -13.8; -4.3), followed by the Southeast region (AAPC: -8.7; -14.6; -2.5). The North and South regions showed the largest number of joinpoints in the time series. The highest incidences were recorded in the male population, however, stable (AAPC: 2.14; CI95%: -8.3; 0). In the age group analysis, the trend was decreasing for the groups from 0 to 4 years old (AAPC: -7.7; CI95%: -12.6; -2.4), 5 to 9 years old (AAPC: -7.3; CI95%: -13.6; -0,4) and 10 to 14 years old (AAPC: -5.5; CI95%: -10.3; -0.3). It was found that although Visceral Leishmaniasis is an endemic disease in Brazil, there was a decrease in its incidence rate from 2007 to 2020.

The Program for the Control of Visceral Leishmaniasis in Brazil: The Effect of the Systematic Euthanasia of Seropositive Dogs as a Single Control Action in Porteirinha, a Brazilian City with an Intense Transmission of Visceral Leishmaniasis.

Porteirinha is endemic for visceral leishmaniasis (VL), with intense disease transmission of the disease. We evaluated the impact of canine euthanasia as a single control measure on the incidence of VL in humans and canines. A prospective observational cohort study was carried out over four years (1998-2002) in 8 of the 12 neighborhoods of the city. The dynamics of canine visceral leishmaniasis (CVL) transmission were evaluated for 2 years, before beginning the screening-culling intervention. The comparative morbidity index (CMI) was used to stratify areas with the greatest risk of CVL, and the spatial distribution of human and canine VL cases was compared using univariate and bivariate K-functions. Human cases conglomerated in three neighborhoods. Spatial clusters were detected for CVL in 1998, 2000, and 2001, but not in 1999, when greater spatial dispersion occurred. The screening and culling intervention reduced the number of human VL cases and decreased the incidence of CVL, mainly in neighborhoods with a high CMI. The systematic euthanasia of seropositive dogs was shown to be an effective control action of the Program for Control of Visceral Leishmaniasis (PCLV) in Brazil. The fundamental role of domestic dogs in the epidemiological chain of VL was reaffirmed.

Reemergence of Visceral Leishmaniasis in Henan Province, China.

Visceral leishmaniasis (VL) was widely prevalent in Henan Province in the 1950s. Through active efforts by the government, there were no local cases reported from 1984 to 2015. In 2016, local VL cases reoccurred, and there was an increasing trend of VL cases in Henan Province. To provide a scientific control of VL, an investigation was conducted in Henan Province from 2016 to 2021. The data from VL cases were obtained from the Disease Surveillance Reporting System of the Chinese Center for Disease Control and Prevention. The rK39 immunochromatographic test (ICT) and PCR assay were performed among high-risk residents and all dogs in the patients' village. ITS1 was amplified, sequenced, and subjected to phylogenetic analyses. A total of 47 VL cases were reported in Henan Province during 2016-2021. Of the cases, 35 were local, and they were distributed in Zhengzhou, Luoyang, and Anyang. The annual average incidence was 0.008/100,000, showing an upward trend year by year (χ2 = 3.987, p = 0.046). Their ages ranged from 7 months to 71 years, with 44.68% (21/47) in the age group of 0-3 years and 46.81% (22/47) in the age group ≥15 years. The cases occurred throughout the year. The high-risk populations were infants and young children (age ≤3), accounting for 51.06% (24/47), followed by farmers at 36.17% (17/47). The ratio of males to females was 2.13:1. The positive rates of rK39 ICT and PCR were 0.35% (4/1130) and 0.21% (1/468) in the residents. The positive rates of rK39 ICT and PCR were 18.79% (440/2342) and 14.92% (139/929) in the dogs. The ITS1 amplification products in the patients and positive dogs were sequenced. The homology between the target sequence and Leishmania infantum was more than 98%. The phylogenetic analysis indicated that the patients and the positive dogs were infected by the same type of Leishmania, which was consistent with the strains in the hilly endemic areas in China. This paper showed that patients and domestic dogs were infected by the same type of L. infantum and that the positive rate in dogs was relatively high in Henan Province. Because the measures of patient treatment and culling of infected dogs were not effective in reducing VL incidence in Henan Province, it is urgent to develop new approaches for the control of VL, such as wearing insecticide-impregnated collars on dogs, treating the positive dogs, spraying insecticide for sandflies control, and improving residents' self-protection awareness to prevent the further spread of VL in Henan Province.

Development of a Novel Enzyme-Linked Immunosorbent Assay and Lateral Flow Test System for Improved Serodiagnosis of Visceral Leishmaniasis in Different Areas of Endemicity.

Visceral leishmaniasis (VL) is caused by protozoan parasites of the Leishmania donovani complex and is one of the most prominent vector-borne infectious diseases with epidemic and mortality potential if not correctly diagnosed and treated. East African countries suffer from a very high incidence of VL, and although several diagnostic tests are available for VL, diagnosis continues to represent a big challenge in these countries due to the lack of sensitivity and specificity of current serological tools. Based on bioinformatic analysis, a new recombinant kinesin antigen from Leishmania infantum (rKLi8.3) was developed. The diagnostic performance of rKLi8.3 was evaluated by enzyme-linked immunosorbent assay (ELISA) and lateral flow test (LFT) on a panel of sera from Sudanese, Indian, and South American patients diagnosed with VL or other diseases, including tuberculosis, malaria, and trypanosomiasis. The diagnostic accuracy of rKLi8.3 was compared with rK39 and rKLO8 antigens. The VL-specific sensitivity of rK39, rKLO8, and rKLi8.3 ranged from 91.2% over 92.4% to 97.1% and specificity ranged from 93.6% over 97.6% to 99.2%, respectively. In India, all tests showed a comparable specificity of 90.9%, while the sensitivity ranged from 94.7% to 100% (rKLi8.3). In contrast to commercial serodiagnostic tests, rKLi8.3-based ELISA and LFT showed improved sensitivity and no cross-reactivity with other parasitic diseases. Thus, rKLi8.3-based ELISA and LFT offer improved VL serodiagnostic efficiency in East Africa and other areas of endemicity. IMPORTANCE Reliable and field suitable serodiagnosis of visceral leishmaniasis (VL) in East Africa has until now been a big challenge due to low sensitivity and cross-reactivity with other pathogens. To improve VL serodiagnosis, a new recombinant kinesin antigen from Leishmania infantum (rKLi8.3) was developed and tested with a panel of sera from Sudanese, Indian, and South American patients diagnosed with VL or other infectious diseases. Both prototype rKLi8.3-based enzyme-linked immunosorbent assay (ELISA) and lateral flow test (LFT) showed improved sensitivity and no cross-reactivity with other parasitic diseases. Thus, rKLi8.3-based ELISA and LFT offer substantially increased diagnostic efficiency for VL in East Africa and other areas of endemicity, compared to currently commercially available serodiagnostic tests.

SEROPREVALENCE OF VISCERAL LEISHMANIASIS AND ITS ASSOCIATED FACTORS AMONG ASYMPTOMATIC CHILDREN IN HADHRAMOUT VALLEY AND DESERT REGIONS, YEMEN

Background and Aims: Visceral leishmaniasis (VL) is zoonotic and human illness produced by Leishmania species. Protozoan parasite is spread to the host vertebrate via sand fly female bite (Phlebotomus longipalpis), in which the infected promastigotes convert into amastigotes; and VL is associated with high fatality if left untreated. The aims of the current study were to uncover the prevalence and potential risk factors for VL in children in selected districts of Hadhramout governorate, Yemen. Subjects and methods: Six districts were randomly selected from 24 districts in Hadhramout governorate as follows: Al-Sum, Al-Qattan, Tarim, Thamud, Seiyun, and Shibam. Then a target sample size of 400 children were randomly selected, 66 children were selected from each district except 70 children in Seiyun and they were selected from the selected schools and health centers. Serum specimens were assemble from all children to determine the rate of anti-VL antibodies in human by immunochromatographic assay using recombinant K39 antigen. Results: The age of the children from 1-15 years, by a mean of 8.4±2.7 years. The positivity rate of Leishmania species antibodies by immune-chromatographic dipstick strip (rK39) was 5.8%. There was statistically considerable association connecting male gender and VL infection (8.0%, OR=3, CI=1.1-8.2, p=0.02). There was statistically important association linking older children (11-15 years( and contracting VL (9.1%, OR=2.6, CI=1.1- 6.2, p=0.02). There was a considerable association (&lt;0.05) connecting the presence of rats, dogs, and goats in or around live houses and positive VL antibodies with an OR come to to 2.6, 3.7 and 2.8, respectively. There was no significant association between displacement or district location and incidence of VL. Conclusion: Visceral leishmaniasis was highly prevalent in the desert and the valley areas of Hadramout among children, and visceral leishmaniasis potential risk factors were males, older children, dogs, rats, goats, litter, open sewers, and the presence of sand flies in the household. Peer Review History: Received: 8 November 2022; Revised: 12 December; Accepted: 5 January 2023, Available online: 15 January 2023 Academic Editor: Dr. Nuray Arı, Ankara University, Turkiye, ari@ankara.edu.tr Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. Bilge Ahsen KARA, Ankara Gazi Mustafa Kemal Hospital, Turkey, ahsndkyc@gmail.com Rola Jadallah, Arab American University, Palestine, rola@aauj.edu Similar Articles: PREVALENCE OF VISCERAL LEISHMANIASIS AMONG ADULTS IN SANA’A CITY-YEMEN COUMARIN ANALOGUES AS A POTENTIAL INHIBITOR OF LEISHMANIASIS: A MULTI-TARGETING PROTEIN INHIBITION APPROACH BY MOLECULAR DOCKING IN VITRO ANTI-LEISHMANIAL ACTIVITY AGAINST CUTANEOUS LEISHMANIA PARASITES AND PRELIMINARY PHYTOCHEMICAL ANALYSIS OF FOUR YEMENI MEDICINAL PLANTS

Spatial modeling of visceral leishmaniasis in Iran from 2010 to 2018

Kala-Azar is the most lethal type of leishmaniasis, sporadic in most parts of Iran and prevalent in some provinces. Using the Geographical Information System (GIS) and satellite data analysis, we intended to assess the disease's incidence in Iran. Methods: Using GIS, data received from the Ministry of Health and Medical Education in Tehran, Iran, and other associated institutions between 2010 and 2018 were evaluated. The disease's geographical distribution maps were then constructed, and the disease's hotspots in Iran were identified using spatial analysis using ArcGIS10.5 software. Geographically weighted regression (GWR) analysis in ArcGIS10.5 was used to link disease-influencing variables such as temperature, relative humidity, normalized difference vegetation index (NDVI), and incidence of visceral leishmaniasis. Linear regression analysis, SPSS 21 software descriptive statistics, and chi-square test were used to analyze the data. Results: This study revealed that the provinces of Ardabil, East Azarbaijan, North Khorasan, and Fars were the hot spots of VL. The provinces of Ardabil, East Azarbaijan, North Khorasan, Fars, Bushehr, Semnan, Sistan, Baluchistan, Esfahan, Chaharmahal Bakhtiari, Qom, Golestan, and Kerman had the highest correlation between temperature, vegetation density, and the incidence of Kala Azar, as determined by geographical weighted regression analysis.

Spatio-Temporal Pattern and Meteo-Climatic Determinants of Visceral Leishmaniasis in Italy.

Historically, visceral leishmaniasis (VL) in Italy was constrained to Mediterranean areas. However, in the last 20 years, sand fly vectors and human cases of VL have been detected in northern Italy, traditionally classified as a cold area unsuitable for sand fly survival. We aim to study the spatio-temporal pattern and climatic determinants of VL incidence in Italy. National Hospital Discharge Register records were used to identify incident cases of VL between 2009 and 2016. Incident rates were computed for each year (N = 8) and for each province (N = 110). Data on mean temperature and cumulative precipitation were obtained from the ERA5-Land re-analysis. Age- and sex-standardized incidence rates were modeled with Bayesian spatial and spatio-temporal conditional autoregressive Poisson models in relation to the meteo-climatic parameters. Statistical inference was based on Monte Carlo-Markov chains. We identified 1123 VL cases (incidence rate: 2.4 cases/1,000,000 person-years). The highest incidence rates were observed in southern Italy, even though some areas of northern Italy experienced high incidence rates. Overall, in the spatial analysis, VL incidence rates were positively associated with average air temperatures (β&amp;nbsp; for 1 °C increase in average mean average temperature: 0.14; 95% credible intervals (CrI): 0.01, 0.27) and inversely associated with average precipitation (β for 20 mm increase in average summer cumulative precipitation: -0.28, 95% CrI: -0.42, -0.13). In the spatio-temporal analysis, no association between VL cases and season-year specific temperature and precipitation anomalies was detected. Our findings indicate that VL is endemic in the whole Italian peninsula and that climatic factors, such as air temperature and precipitation, might play a relevant role in shaping the geographical distribution of VL cases. These results support that climate change might affect leishmaniasis distribution in the future.

A Composite Recombinant Salivary Proteins Biomarker for Phlebotomus argentipes Provides a Surveillance Tool Postelimination of Visceral Leishmaniasis in India.

Incidence of visceral leishmaniasis (VL) in the Indian subcontinent (ISC) has declined by more than 95% since initiation of the elimination program in 2005. As the ISC transitions to the postelimination surveillance phase, an accurate measurement of human-vector contact is needed to assure long-term success. To develop this tool, we identified PagSP02 and PagSP06 from saliva of Phlebotomus argentipes, the vector of Leishmania donovani in the ISC, as immunodominant proteins in humans. We also established the absence of cross-reactivity with Phlebotomus papatasi saliva, the only other human-biting sand fly in the ISC. Importantly, by combining recombinant rPagSP02 and rPagSP06 we achieved greater antibody recognition and specificity than single salivary proteins. The receiver operating characteristics curve for rPagSP02 + rPagSP06 predicts exposure to Ph. argentipes bites with 90% specificity and 87% sensitivity compared to negative control sera (P >.0001). Overall, rPagSP02 + rPagSP06 provides an effective surveillance tool for monitoring vector control efforts after VL elimination.

Evidence map of diagnosis, treatment, prognosis, prevention, and control in visceral leishmaniasis.

ABSTRACTObjective.To develop an evidence map on visceral leishmaniasis prevention, control, diagnosis, treatment, and prognosis.Methods.Systematic reviews on visceral leishmaniasis were searched using MEDLINE/PubMed and Virtual Health Library. After selection, each included systematic review was assessed, characterized, and categorized by intervention type and by outcomes, according to the methodology offered by the PAHO/WHO Latin American and Caribbean Center on Health Sciences Information (BIREME). The methodological quality was assessed using the AMSTAR2 tool to determine the confidence level of the evidence obtained.Results.Among the prevention and control interventions, insecticide spraying, bednets, dog collars, and dog culling were the most assessed, emphasizing that insecticidal dog collars can reduce visceral leishmaniasis incidence in dogs. Regarding diagnosis, polymerase chain reaction (PCR), rK39 immunochromatographic test (rK39 ICT), and direct agglutination test (DAT) presented high sensitivity and specificity. As for treatment, pentavalent antimonials and amphotericin B were the most analyzed drugs and showed therapeutic success; however, serious adverse events can occur due to their use. The prognostic factors identified were anemia, edema, bleeding, jaundice, age, and HIV coinfection.Conclusions.The evidence map developed shows rK39 ICT and DAT as promising diagnostic alternatives and reinforces the efficacy of liposomal amphotericin B and pentavalent antimonials. Insecticide-impregnated dog collars appear as a promising measure for the control of visceral leishmaniasis, but there is also a need for future studies and reviews with higher methodological quality, especially on prevention and control interventions.

Use of soil moisture active passive satellite data and WorldClim 2.0 data to predict the potential distribution of visceral leishmaniasis and its vector Lutzomyia longipalpis in Sao Paulo and Bahia states, Brazil.

Visceral leishmaniasis (VL) is a neglected tropical disease transmitted by Lutzomyia longipalpis, a sand fly widely distributed in Brazil. Despite efforts to strengthen national control programs reduction in incidence and geographical distribution of VL in Brazil has not yet been successful; VL is in fact expanding its range in newly urbanized areas. Ecological niche models (ENM) for use in surveillance and response systems may enable more effective operational VL control by mapping risk areas and elucidation of eco-epidemiologic risk factors. ENMs for VL and Lu. longipalpis were generated using monthly WorldClim 2.0 data (30-year climate normal, 1-km spatial resolution) and monthly soil moisture active passive (SMAP) satellite L4 soil moisture data. SMAP L4 Global 3-hourly 9-km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data V004 were obtained for the first image of day 1 and day 15 (0:00-3:00 hour) of each month. ENM were developed using MaxEnt software to generate risk maps based on an algorithm for maximum entropy. The jack-knife procedure was used to identify the contribution of each variable to model performance. The three most meaningful components were used to generate ENM distribution maps by ArcGIS 10.6. Similar patterns of VL and vector distribution were observed using SMAP as compared to WorldClim 2.0 models based on temperature and precipitation data or water budget. Results indicate that direct Earth-observing satellite measurement of soil moisture by SMAP can be used in lieu of models calculated from classical temperature and precipitation climate station data to assess VL risk.

PREVALENCE OF VISCERAL LEISHMANIASIS AMONG ADULTS IN SANA’A CITY-YEMEN

Background and Aims: Visceral leishmaniasis (VL) is a zoonotic and human disease caused by species of Leishmania. Parasites are transmitted to the vertebrate host by the bite of a sand fly female (Phlebotomus longipalpis), where the infected promastigotes transform into amastigotes; and this is deadly if left untreated. The purposes of the current research were to reveal the prevalence and potential risk factors for VL in adults in Sana’a city, Yemen. Subjects and methods: This cross-sectional study was performed during the period from January 2020 to November 2020. Individuals who come for a regular medical examination at Al-Zahrawi Medical Center, Althobhani Specialist Laboratories, Police Hospital, and University of Science and Technology Hospital. A target sample size of 300 was selected, and serum samples were collected from all subjects to determine the prevalence of anti-VL antibodies in human by immune-chromatographic assay using K39 recombinant antigen. Results: The ages of the participants' ranged from 18-65 years, with a mean of 29.8±8.2 years. The positive rate of antibodies against Leishmania species by immune-chromatographic dipstick strip (rK39) was 6.0%. There was statistically important association linking male gender and contracting VL (8.8%, OR=4.1, CI=1.2-14.4, P=0.01). There was a significant association (&lt;0.001) between the presence of dogs, rats, and goats in or around live houses and positive VL antibodies with an OR equal to 8.8.7.3 and 8.4, respectively. There were significant risk factors for garbage around the living house, there was also a significant association between displacement and the incidence of VL (P&lt;0.001) (OR=8.6, CI=2.8–27.2). Conclusion: Visceral leishmaniasis was highly prevalent in Sana'a city, and potential risk factors for VL were present with displacement, dogs, rats, goats, garbage, sleeping outside enclosed rooms, and sand flies in living houses. Further studies of human VL need to be conducted to clarify this issue in Yemen, to track and confirm potential reservoirs among canines and other animals, as well as to study vectors. Keywords: adults, immune-chromatographic assay, prevalence, potential risk factors, recombinant antigen K39, Sana’a city, visceral leishmaniasis, Yemen. Peer Review History: Received: 9 March 2022; Revised: 14 April; Accepted: 29 April, Available online: 15 May 2022 Academic Editor: Dr. Sally A. El-Zahaby, Pharos University in Alexandria, Egypt, sally.elzahaby@yahoo.com UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Tamer Elhabibi, Suez Canal University, Egypt, tamer_hassan@pharm.suez.edu.eg Dr. Nicola Micale, University of Messina, Italy, nmicale@unime.it Dr. Rawaa Souhil Al-Kayali, Aleppo University, Syria, rawah67@hotmail.com Similar Articles: PREVALENCE OF HEPATITIS G VIRUS AMONG PATIENTS WITH CHRONIC LIVER DISEASE AND HEALTHY INDIVIDUALS, SANA'A CITY-YEMEN