HIV/AIDS-related visceral leishmaniasis: a clinical and epidemiological description of visceral leishmaniasis in northern Brazil

Introduction: This study aimed to describe the main features of visceral leishmaniasis (VL), both related to and independent of human immunodeficiency virus (HIV) infection, in patients who were registered in Tocantins, Brazil. Methods: Data from 1,779 new patients with VL, 33 of whom were also infected with HIV, were reviewed. Results: The incidence of VL/HIV coinfection increased from 0.32/100,000 inhabitants in 2007 to 1.08/100,000 inhabitants in 2010. VL occurred predominantly in children aged 10 years or younger, while VL/HIV was more common in patients aged between 18 and 50 years. There were more male patients in the VL/HIV group than in the VL group. Relapse rates were also considerably higher in the VL/HIV (9.1%) group than in the VL group (1.5%). Despite a similar clinical presentation, VL/HIV patients exhibited a higher proportion (24.2%) of concomitant infectious diseases and jaundice. Pentavalent antimonials were used for the initial treatment of VL and VL/HIV infections. However, amphotericin B deoxycholate and liposomal amphotericin B were also widely used in the treatment of VL/HIV coinfection. The mortality rate was higher in the VL/HIV coinfection group (19.4%) than in the VL group (5.4%). Furthermore, the mortality rate due to other causes was significantly higher in the VL/HIV group (12.9%) than in the VL group (0.7%). Conclusions: The study showed that the incidence, clinical characteristics and outcomes among the VL and VL/HIV patients in this state are similar to those from other endemic regions, indicating that both infections are emerging with increasing frequency in Brazil.

Leishmaniasis transmission: distribution and coarse-resolution ecology of two vectors and two parasites in Egypt

Introduction: In past decades, leishmaniasis burden has been low across Egypt; however, changing environment and land use has placed several parts of the country at risk. As a consequence, leishmaniasis has become a particularly difficult health problem, both for local inhabitants and for multinational military personnel. Methods: To evaluate coarse-resolution aspects of the ecology of leishmaniasis transmission, collection records for sandflies and Leishmania species were obtained from diverse sources. To characterize environmental variation across the country, we used multitemporal Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for 2005-2011. Ecological niche models were generated using MaxEnt, and results were analyzed using background similarity tests to assess whether associations among vectors and parasites (i.e., niche similarity) can be detected across broad geographic regions. Results: We found niche similarity only between one vector species and its corresponding parasite species (i.e., Phlebotomus papatasi with Leishmania major), suggesting that geographic ranges of zoonotic cutaneous leishmaniasis and its potential vector may overlap, but under distinct environmental associations. Other associations (e.g., P. sergenti with L. major) were not supported. Mapping suitable areas for each species suggested that northeastern Egypt is particularly at risk because both parasites have potential to circulate. Conclusions: Ecological niche modeling approaches can be used as a first-pass assessment of vector-parasite interactions, offering useful insights into constraints on the geography of transmission patterns of leishmaniasis.

A comparison of four DNA extraction protocols for the analysis of urine from patients with visceral leishmaniasis

Introduction Polymerase chain reaction (PCR) may offer an alternative diagnostic option when clinical signs and symptoms suggest visceral leishmaniasis (VL) but microscopic scanning and serological tests provide negative results. PCR using urine is sensitive enough to diagnose human visceral leishmaniasis (VL). However, DNA quality is a crucial factor for successful amplification. Methods A comparative performance evaluation of DNA extraction methods from the urine of patients with VL using two commercially available extraction kits and two phenol-chloroform protocols was conducted to determine which method produces the highest quality DNA suitable for PCR amplification, as well as the most sensitive, fast and inexpensive method. All commercially available kits were able to shorten the duration of DNA extraction. Results With regard to detection limits, both phenol: chloroform extraction and the QIAamp DNA Mini Kit provided good results (0.1 pg of DNA) for the extraction of DNA from a parasite smaller than Leishmania (Leishmania) infantum (< 100fg of DNA). However, among 11 urine samples from subjects with VL, better performance was achieved with the phenol:chloroform method (8/11) relative to the QIAamp DNA Mini Kit (4/11), with a greater number of positive samples detected at a lower cost using PCR. Conclusion Our results demonstrate that phenol:chloroform with an ethanol precipitation prior to extraction is the most efficient method in terms of yield and cost, using urine as a non-invasive source of DNA and providing an alternative diagnostic method at a low cost.

Cutaneous and visceral leishmaniasis co-infection in dogs from Rio de Janeiro, Brazil: evaluation by specific PCR and RFLP-PCR assays

Introduction During a diagnostic evaluation of canine visceral leishmaniasis (VL), two of seventeen dogs were found to be co-infected by Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi. Methods Specific polymerase chain reaction (PCR) and restriction fragment length polymorphism-PCR (RFLP-PCR) assays were performed. Results PCR assays for Leishmania subgenus identification followed by RFLP-PCR analysis in biopsies from cutaneous lesions and the spleen confirmed the presence of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi in those fragments. Conclusions This report reinforces the importance of using serological and molecular techniques in the epidemiological surveillance of canine populations in endemic areas in which both diseases are known to co-exist. In such cases, a reassessment of the control measures is required.

Temporal, spatial and spatiotemporal analysis of the occurrence of visceral leishmaniasis in humans in the City of Birigui, State of São Paulo, from 1999 to 2012

Introduction In 1999, Birigui and Araçatuba were the first municipalities in the State of São Paulo to present autochthonous cases of visceral leishmaniasis in humans (VLH). The aim of this study was to describe the temporal, spatial and spatiotemporal behaviors of VLH in Birigui. Methods Secondary data were obtained from the Notifiable Diseases Information System from 1999 to 2012. The incidence, mortality and case fatality rates by sex and age were calculated. The cases of VLH were geocoded and grouped according to census tracts. Local empirical Bayesian incidence rates were calculated. The existence of spatial and spatiotemporal clusters was investigated using SaTScan software. Results There were 156 confirmed cases of autochthonous VLH. The incidence rate was higher in the 0-4-year-old children, and the mortality and case fatality rates were higher in people aged 60 years and older. The peaks of incidence occurred in 2006 and 2011. The Bayesian rates identified the presence of VLH in all of the census tracts in the municipality; however, spatial and spatiotemporal clusters were found in the central area of the municipality. Conclusions Birigui, located in the Araçatuba region, has recently experienced increasing numbers of VLH cases; this increase is contrary to the behavior observed over the entire region, which has shown a decreasing trend in the number of VLH cases. The observations that the highest incidence is in children 0-4 years old and the highest mortality is in people 60 years and older are in agreement with the expected patterns of VLH.

The first canine visceral leishmaniasis outbreak in Campinas, State of São Paulo Southeastern Brazil

Introduction Early detection of American visceral leishmaniasis (AVL) outbreak in animals is crucial for controlling this disease in non-endemic areas. Methods Epidemiological surveillance (2009-2012) was performed in Campinas, State of São Paulo, Brazil. Results In 2009, Leishmania chagasi was positively identified in four dogs. Entomological research and three serological studies (2010-2012) were undertaken as monitoring measures; these approaches revealed a moderate prevalence of Leishmania present in 4% of the canine population. Nyssomyia whitmani and Lutzomyia longipalpis were the predominant species identified. Conclusions Detection of an AVL outbreak in dogs in an area with an evolving natural landscape containing sand flies is crucial for control programs.

Evaluation of parasitological examination, kDNA polymerase chain reaction and rK39-based immunochromatography for the diagnosis of visceral leishmaniasis in seropositive dogs from the screening-culling program in Brazil

Introduction Dogs play a primary role in the zoonotic cycle of visceral leishmaniasis (VL). Therefore, the accurate diagnosis of infected dogs, primarily asymptomatic dogs, is crucial to the efficiency of VL control programs. Methods We investigated the agreement of four diagnostic tests for canine visceral leishmaniasis (CVL): parasite detection, either after myeloculture or by direct microscopic examination of tissue imprints; kinetoplast-deoxyribonucleic acid-polymerase chain reaction (kDNA-PCR); and an immunochromatographic test (ICT). An enzyme-linked immunosorbent assay (ELISA) and an indirect immunofluorescence test (IFAT), both of which were adopted as part of the screening-culling program in Brazil, were used as reference tests. Our sample set consisted of 44 seropositive dogs, 25 of which were clinically asymptomatic and 19 were symptomatic for CVL according to ELISA-IFAT. Results The highest and lowest test co-positivities were observed for ICT (77.3%) and myeloculture (58.1%), respectively. When analyzed together, the overall percentage of co-positive tests was significantly higher for the symptomatic group compared to the asymptomatic group. However, only ICT was significantly different based on the results of a separate analysis per test for each group of dogs. The majority (93.8%) of animals exhibited at least one positive test result, with an average of 2.66 positive tests per dog. Half of the symptomatic dogs tested positive for all four tests administered. Conclusions The variability between test results reinforces the need for more efficient and reliable methods to accurately diagnose canine VL, particularly in asymptomatic animals.

Epidemiological and environmental aspects of visceral leishmaniasis in children under 15 years of age between 2007 and 2012 in the City of Araguaína, State of Tocantins, Brazil

Introduction Visceral leishmaniasis (VL) stands out as a zoonosis observed on four continents and also in urban expansion zones in several regions of Brazil. Methods A cross-sectional epidemiological study of VL cases in children under 15 years of age in the period from 2007 to 2012. Clinical data were gathered from medical reports; meteorological data were obtained at the Meteorological Measurement Department of UFT. Environmental variables were divided into two periods, rainy and dry. Results The study revealed no difference by gender (p=0.67) among the 821 patients. However, the most affected age group was between one and five years of age (58.6%; p<0.01); the highest prevalence of the disease (99.03%; p<0.01) occurred in urban zones; and the most affected ethnic group (85.5%; p<0.01) was mixed race. The highest incidence coefficients in this population occurred in 2007 and 2008 (578.39/100,000 inhabitants; 18.5/100,000 inhabitants, respectively), whereas the highest lethality coefficients occurred in 2008 and 2011 (0.85/100 deaths). There was no significant correlation between average rainfall and the number of VL cases. The correlation between temperature and number of VL cases was negative (r = -0.4039; p<0.01). Conclusions In Araguaína, visceral leishmaniasis in children under 15 years is an urban-based endemic disease distributed across all districts of the city wherein temperature as an environmental factor, a higher prevalence in mixed race children between one and five years of age, and a high incidence coefficient all strongly contribute to child mortality.

Effectiveness of miltefosine-pentoxifylline compared to miltefosine in the treatment of cutaneous leishmaniasis in C57Bl/6 mice

Introduction The treatment of leishmaniasis ischallenging, given the difficulties in drug administration and resistance. Therefore, we chose to test the efficacy of miltefosine combined with pentoxifylline. Methods Twenty-seven isogenic C57Bl/6 mice were infected with Leishmania (Leishmania) amazonensis, and equally divided into three groups: miltefosine (200mg/kg/day), miltefosine (200mg/kg/day) with pentoxifylline (8mg/kg/day), and untreated. Response to treatment was evaluated using paw diameter and parasitological criteria. Results The number of viable Leishmania reduced significantly within the miltefosine-pentoxifylline group (p < 0.05). Conclusions There is hope that a viable treatment exists for Leishmania infection.

High visceral leishmaniasis mortality rate in Barra Mansa, a new area of visceral leishmaniasis transmission in the State of Rio de Janeiro, Brazil

Introduction Nine cases of visceral leishmaniasis occurred recently in Barra Mansa, State of Rio de Janeiro, with a high mortality rate. Methods We reviewed the medical records of the patients. Results Eight were male; 7 were adults. Patients who died progressed to death quickly and presented with aggravating factors: systemic steroid therapy before diagnosis, bleeding, severe liver involvement, infection, and/or refusal to receive transfusion. Conclusions We warn clinicians to be aware of the emergence of visceral leishmaniasis in new areas and to keep in mind the possibility of atypical clinical pictures and aggravating factors, so timely diagnosis can be made and prompt and adequate treatment can be initiated.

The existence of only one haplotype of Leishmania major in the main and potential reservoir hosts of zoonotic cutaneous leishmaniasis using different molecular markers in a focal area in Iran

IntroductionLeishmania major is the causative agent of zoonotic cutaneous leishmaniasis (ZCL), and great gerbils are the main reservoir hosts in Iran. Abarkouh in central Iran is an emerging focal point for which the reservoir hosts of ZCL are unclear. This research project was designed to detect any Leishmania parasites in different wild rodent species.MethodsAll rodents captured in 2011 and 2012 from Abarkouh district were identified based on morphological characteristics and by amplification of the rodent cytochrome b (Cyt b) gene. To detect Leishmania infection in rodents, deoxyribonucleic acid (DNA) of each ear was extracted. Internal transcribed spacer-ribosomal deoxyribonucleic acid (ITS-rDNA), microsatellites, kinetoplast deoxyribonucleic acid (kDNA) and cytochrome b genes of Leishmania parasites were amplified by polymerase chain reaction (PCR). Restriction fragment length polymorphism (RFLP) and sequencing were employed to confirm the Leishmania identification.ResultsOf 68 captured rodents in the region, 55 Rhombomys opimus were identified and nine Leishmaniainfections (9/55) were found. In addition, eight Meriones libycus and two Tatera indicawere sampled, and one of each was confirmed to be infected. Two Meriones persicus and one Mus musculuswere sampled with no infection.ConclusionsThe results showed that all 11 unambiguously positive Leishmania infections were Leishmania major. Only one haplotype of L. major(GenBank access No. EF413075) was found and at least three rodents R. opimus, M. libycus and T. indica—appear to be the main and potential reservoir hosts in this ZCL focus. The reservoir hosts are variable and versatile in small ZCL focal locations.

Awareness of visceral leishmaniasis and its relationship to canine infection in riverside endemic areas in Northeastern Brazil

IntroductionAn awareness of visceral leishmaniasis (VL) is necessary to encourage the population to participate in prevention and control in collaboration with more efficient, centrally organized health programs. The aim of this study was to evaluate the awareness of the riverside population regarding VL and the association between awareness and the prevalence of canine visceral leishmaniasis (CVL).MethodsIn total, 71 people living in riverside areas in the City of Mossoró in State of Rio Grande do Norte participated of the study, and 71 dogs were tested for CVL by polymerase chain reaction (PCR). Association analysis of several variables related to knowledge of the riverside population regarding CVL positivity was performed, yielding odds ratios (OR) and 95% confidence intervals (CI), and significance was determined using chi-square (χ2) and Fisher's exact tests.ResultsAmong individuals whose dogs tested positive for CVL, 60% did not know the cure for CVL, and these subjects were three times more likely to have a dog test positive for CVL than those who were aware the cure for CVL. Knowledge of CVL cure was the only variable that remained in the logistic model after the successive removal of variables, with an adjusted OR of 3.11 (95%CI: 1.1-8,799; p=0.032).ConclusionsInsufficient awareness regarding VL in riverside areas with CVL-positive dogs was associated with increased rates of canine infection, which suggests that changes in habits and the adoption of attitudes and preventive practices may contribute to the control and prevention of this disease. This study reinforces the need to invest in better health education programs regarding VL.

Poor response to azithromycin in cutaneous leishmaniasis leading to a premature interruption of a multicentric phase III clinical trial in Brazil

Introduction Parenteral antimony-based compounds are still the standard of care for cutaneous leishmaniasis (CL) treatment in many countries, despite their high toxicity. Previous studies showed that oral azithromycin could be an option for CL treatment. The aim of this study was to evaluate efficacy and safety of oral azithromycin (AZ) for CL treatment compared with injectable meglumine antimoniate (MA). Methods This was a randomized, open-label, 2-arm, non-inferiority clinical trial. Treatment-naïve patients with localized CL were treated with MA (15mg/kg/day up to 1,215mg) or AZ (500mg/day) during 20 consecutive days. The primary efficacy end point was a CL cure 90 days after treatment completion. The analysis was performed with intention-to-treat (ITT) and per protocol (PP) analyses. After an anticipated interim analysis, the study was interrupted due to the high failure rate in the azithromycin group. Results Twenty-four volunteers were included in each group. The MA group had a higher cure rate than the AZ group with the ITT and PP analyses, which were 54.2% versus 20.8% [relative risk (RR) 1.97; 95% confidence intervals (95%CI) 1.13-3.42] and 72.2% versus 23.8% (RR 3.03; 95%CI 1.34-6.87), respectively. No unexpected adverse events were observed. Conclusions Azithromycin is ineffective for CL treatment and does not seem to have a role in the therapeutic arsenal for CL.

Outbreak of canine visceral leishmaniasis in Barra Mansa, State of Rio de Janeiro

Introduction In Brazil, visceral leishmaniasis (VL) has spread to various regions. This study reports canine cases of VL in Barra Mansa, where human VL cases were recently reported. Methods Using the human index case, a canine survey was performed by dual-path platform immunochromatography and enzyme-linked immunosorbent assay. Seropositive animals were euthanized. Cultures were collected to detect Leishmania parasites. Results Serological tests detected 141 canine VL cases, and Leishmania chagasi were isolated from 82.2% animals. Conclusions Leishmania chagasi is in circulation in Barra Mansa. This study broadens information on the parasite's distribution in the State of Rio de Janeiro.

Seroprevalence and risk factors associated with visceral leishmaniasis in dogs in Jaciara, State of Mato Grosso

Introduction Visceral leishmaniasis is a neglected disease. Jaciara, State of Mato Grosso has the most cases. This study aimed to determine the risk factors and seroprevalence of canine visceral leishmaniasis in urban and rural areas. Methods This cross-sectional study of domestic dogs used enzyme-linked immunosorbent assay and indirect immunofluorescence test. Results The prevalence was 54.7% among 345 analyzed samples. Short coat, age of 1-6 years, and living less than 100m from vegetation posed the highest infection risks. Conclusions Certain dog behaviors and characteristics, and their correlation with environmental conditions, were relevant in the high prevalence of canine leishmaniasis in Jaciara.