Female Phlebotomine Sand Flies Research Articles

Visceral leishmaniasis in selected communities of Hamar and Banna-Tsamai districts in Lower Omo Valley, South West Ethiopia: Sero-epidemological and Leishmanin Skin Test Surveys.

BackgroundVisceral leishmaniasis [VL] is a debilitating parasitic disease which invariably kills untreated patients. The disease is caused by Leishmania (L.) donovani or L. infantum, and transmitted by the bite of female phlebotomine sandflies. VL often remains subclinical but can become symptomatic with an acute/subacute or chronic course. Globally, the Eastern Africa region is one of the main VL endemic areas. The disease is prevalent in numerous foci within Eritrea, Ethiopia, Kenya, Somalia, Sudan South Sudan, and Uganda. In Ethiopia, the Lower Omo plain is one of the many VL endemic regions.ObjectivesThe objective of this study was to determine the prevalence of asymptomatic visceral leishmaniasisin Hamar and Banna-Tsamai districts of the South Omo plains where VL is becoming an emerging health problem of neglected communities.MethodsA community based cross-sectional survey was conducted in 2013 between 25th of July and 14th of August. A total of 1682 individuals living in 404 households were included in the study. Socio-demographic and clinical data were collected from each of the participants and venous blood was also collected for the detection of antibodies to visceral leishmaniasis using Direct Agglutination Test. Leishmanin Skin Test was performed to detect the exposure to the parasite.ResultsThe surveys included 14 villages located in areas where VL had been reported. In a study population of 1682 individuals, the overall positive leishmanian skin test and sero-prevalence rates respectively were 8.6% and 1.8%. A statistically significant variation in the rate of positive LST response was observed in different study sites and age groups. Positive LST response showed an increasing trend with age. The sero-prevalence rate also showed a statistically significant variation among different study sites. Higher rates of sero-prevalence were observed in children and adolescents. The LST and sero-prevalence rates in Hamar District exceeded significantly that of Banna-Tsamai District (10.7% versus 5.8% for LST; and 2.6% versus 0.7% for sero-prevalence).ConclusionThe prevalence of asymptomatic VL infection in Hamar and Banna-Tsamai districts during the study period in 2013 was low compared to rates previously reported in other endemic areas of Ethiopia. This could be due to the fact that the disease is emerging in Hamar and Banna-Tsamai districts. Based on records of a nearby Hospital, increasing numbers of active VL cases have been reported in these districts through the years 2006–2012, especially in Hamar District. Both districts are important destinations of tourism, and thus the importance of surveillance should be emphasized. Detailed epidemiological and entomological studies are recommended.

Asymptomatic carriers of Leishmania infantum in patients infected with human immunodeficiency virus (HIV) in Morocco.

In Morocco, visceral leishmaniasis (VL) is a parasitic disease caused by the flagellated protozoan parasite Leishmania infantum. L. infantum is transmitted by the bite of female phlebotomine sandflies, and its main reservoir hosts are domestic dogs. Asymptomatic infection with L. infantum is more frequent than clinically apparent disease. In HIV-infected patients, the risk of clinical VL is increased due to immunosuppression that may reactivate latent infections. However, coinfected subjects do not necessarily develop VL and may remain as asymptomatic carriers depending on their immune status. The present study investigates the asymptomatic carriers of L. infantum in HIV-infected patients in central Morocco, where human cases of visceral leishmaniasis by L. infantum have been reported. A total of 200 HIV-infected patients attending the Infectious Diseases Unit of the Ibn Zohar Hospital of Marrakech participated in the study. Parasitological and serological blood analyses included a direct microscopic examination (DME), culture in Novy-McNeal-Nicolle (NNN) medium, and serology by indirect immunofluorescence (IFI). We found prevalence rates of 5% (10/200) by IFI, 3% (6/200) by DME, and 2.5% (5/200) by culture. The parasite was identified as L. infantum by PCR from positive cultures.

Leishmania proteophosphoglycans regurgitated from infected sand flies accelerate dermal wound repair and exacerbate leishmaniasis via insulin-like growth factor 1-dependent signalling.

Leishmania parasites are transmitted to vertebrate hosts by female phlebotomine sand flies as they bloodfeed by lacerating the upper capillaries of the dermis with their barbed mouthparts. In the sand fly midgut secreted proteophosphoglycans from Leishmania form a biological plug known as the promastigote secretory gel (PSG), which blocks the gut and facilitates the regurgitation of infective parasites. The interaction between the wound created by the sand fly bite and PSG is not known. Here we nanoinjected a sand fly egested dose of PSG into BALB/c mouse skin that lead to the differential expression of 7,907 transcripts. These transcripts were transiently up-regulated during the first 6 hours post-wound and enriched for pathways involved in inflammation, cell proliferation, fibrosis, epithelial cell differentiation and wound remodelling. We found that PSG significantly accelerated wound healing in vitro and in mice; which was associated with an early up-regulation of transcripts involved in inflammation (IL-1β, IL-6, IL-10, TNFα) and inflammatory cell recruitment (CCL2, CCL3, CCL4, CXCL2), followed 6 days later by enhanced expression of transcripts associated with epithelial cell proliferation, fibroplasia and fibrosis (FGFR2, EGF, EGFR, IGF1). Dermal expression of IGF1 was enhanced following an infected sand fly bite and was acutely responsive to the deposition of PSG but not the inoculation of parasites or sand fly saliva. Antibody blockade of IGF1 ablated the gel’s ability to promote wound closure in mouse ears and significantly reduced the virulence of Leishmania mexicana infection delivered by an individual sand fly bite. Dermal macrophages recruited to air-pouches on the backs of mice revealed that IGF1 was pivotal to the PSG’s ability to promote macrophage alternative activation and Leishmania infection. Our data demonstrate that through the regurgitation of PSG Leishmania exploit the wound healing response of the host to the vector bite by promoting the action of IGF1 to drive the alternative activation of macrophages.

Canine Leishmaniasis: An Overview of the Current Status and Strategies for Control.

Canine leishmaniasis (CanL) is a vector-borne disease caused by Leishmania infantum and is transmitted by female phlebotomine sand flies primarily between animals and secondarily to humans. The course of infection may be different from one individual dog to another, ranging from spontaneous cure to acute evolution that leads to death, if proper management and therapy are not adopted. A parasitological cure is rarely achieved and clinical recurrences in CanL are frequent. Vaccination associated with the use of topical insecticides is undoubtedly the most effective form of prevention and control of the disease. In order to integrate the most important scientific knowledge of the literature in one objective publication, this review proposes a short overview of the main points of CanL.

Quantitative proteomic analysis of amastigotes from Leishmania (L.) amazonensis LV79 and PH8 strains reveals molecular traits associated with the virulence phenotype.

BackgroundLeishmaniasis is an antropozoonosis caused by Leishmania parasites that affects around 12 million people in 98 different countries. The disease has different clinical forms, which depend mainly on the parasite genetics and on the immunologic status of the host. The promastigote form of the parasite is transmitted by an infected female phlebotomine sand fly, is internalized by phagocytic cells, mainly macrophages, and converts into amastigotes which replicate inside these cells. Macrophages are important cells of the immune system, capable of efficiently killing intracellular pathogens. However, Leishmania can evade these mechanisms due to expression of virulence factors. Different strains of the same Leishmania species may have different infectivity and metastatic phenotypes in vivo, and we have previously shown that analysis of amastigote proteome can give important information on parasite infectivity. Differential abundance of virulence factors probably accounts for the higher virulence of PH8 strain parasites shown in this work. In order to test this hypothesis, we have quantitatively compared the proteomes of PH8 and LV79 lesion-derived amastigotes using a label-free proteomic approach.Methodology/Principal findingsIn the present work, we have compared lesion development by L. (L.) amazonensis PH8 and LV79 strains in mice, showing that they have different virulence in vivo. Viability and numbers of lesion-derived amastigotes were accordingly significantly different. Proteome profiles can discriminate parasites from the two strains and several proteins were differentially expressed.Conclusions/SignificanceThis work shows that PH8 strain is more virulent in mice, and that lesion-derived parasites from this strain are more viable and more infective in vitro. Amastigote proteome comparison identified GP63 as highly expressed in PH8 strain, and Superoxide Dismutase, Tryparedoxin Peroxidase and Heat Shock Protein 70 as more abundant in LV79 strain. The expression profile of all proteins and of the differential ones precisely classified PH8 and LV79 samples, indicating that the two strains have proteins with different abundances and that proteome profiles correlate with their phenotypes.

Diversity and altitudinal distribution of phlebotomine sand flies (Diptera: Psychodidae) in visceral leishmaniasis endemic areas of northwest Ethiopia

BackgroundThe Leishmaniases are caused by the protozoan parasites of the genus Leishmania and are transmitted to humans by the bite of infected female phlebotomine sand flies. Both visceral and cutaneous leishmaniases are widely distributed in different parts of Ethiopia. The aim of this study was to determine the diversity and altitudinal distribution of phlebotomine sand flies from Kafta Humera to Gondar town in northwest Ethiopia. MethodsSeven localities were selected with distinct altitudinal variations between 550m above sea level (m a.s.l) and 2300m a.s.l. In each locality, sand flies were collected using standard CDC light traps and sticky traps during the active sand fly season from December 2012 to May 2013. Shannon-Weiner species diversity index and Jaccard’s coefficient were used to estimate species diversity and similarity between altitudes and localities, respectively. ResultsA total of 89,044 sand flies (41,798 males and 47, 246 females) were collected from the seven localities/towns throughout the study period. Twenty-two species belonging to 11 species in the genus Phlebotomus and 11 species in the genus Sergentomyia were documented. Of these, Sergentomyia clydei (25.87%), S. schwetzi (25.21%), S. africana (24.65%), S. bedfordi (8.89%), Phlebotomus orientalis (6.43%), and S. antennata (4.8%) were the most prevalent species. The remaining 10 Phlebotomus species and six Sergentomyia were less frequent catches. In CDC light trap and sticky trap, higher species diversity and richness for both male and female sand flies was observed at low altitude ranging from 550 to 699m a.s.l in Adebay village in Kafta Humera district whereas low species richness and high evenness of both sexes were also observed in an altitude 1950–2300m a.s.l. ConclusionThe results revealed that the presence of leishmaniasis vectors such as P. orientalis, P. longipes, P. papatasi, and P. duboscqi in different altitudes in northwest Ethiopia. P. orientalis a vector of L. donovani, occurred between altitude 500–1100m a.s.l, the area could be at high risk of VL. P. longipes a vector of L. aethiopica, was recorded in the highland area in Tikil-Dingay and Gondar town, implicating the possibility of CL transmission. Hence, further investigation into vector competence in relation to leishmaniasis (VL and CL) in the region is very vital.

First molecular detection of Leishmania infantum in Sergentomyia minuta (Diptera, Psychodidae) in Alentejo, southern Portugal

Protozoan parasites, such as Leishmania spp., are the causative agents of many insect-borne infectious diseases with medical and veterinary importance. Leishmaniasis, caused by Leishmania spp., is transmitted by female phlebotomine sand flies. In the Alentejo region of Portugal, located at the north of Algarve, cases of human and canine leishmaniasis caused by Leishmania infantum have been notified. However, no recent studies regarding the sand fly fauna in the region are available. We therefore aimed to explore the phlebotomine sand fly species found in both, Évora and Beja Districts, to gain an insight about the leishmaniasis epidemiology in these areas. After the identification of the insect species, PCR molecular tests were used to assess L. infantum infection rate in the sand fly captured females, together with the analysis of blood meal sources of the insect vectors. One Sergentomyia minuta female was positive for L. infantum infection and another for human blood as a meal source. The occurrence of this phlebotomine species infected with L. infantum may suggest that, in the Mediterranean basin, leishmaniasis epidemiology is changing. Also, if the importance of S. minuta for the zoonotic and anthroponotic cycle of leishmaniasis is later proven, the strategies to control its vector will inevitably to be rethought.

Antileishmanial and Trypanocidal Activities of Extracts and Aporphine Alkaloids Isolated from Monodora Genus (Annonaceae)

Leishmaniasis and trypanosomiasis are protozoan diseases caused respectively by the kinetoplastid protozoan Leishmania parasites transmitted by the female phlebotomine sandflies and Trypanosoma parasites transmitted by the tsetse fly. In the search for agents from tropical medicinal plants to treat these two neglected tropical diseases, serially extracted petroleum ether, dichloromethane and methanol extracts of the leaves of Monodora crispata and Monodora brevipes, and eleven aporphines alkaloids isolated from the dried powdered leaves of the two plants were evaluated against Leishmania donovani promastigotes and Trypanosoma brucei brucei trypomastigotes. The extracts of both plants and the isolated compounds displayed varied levels of antiprotozoal activities. The oxoaporphine compounds, (+)-anolobine (7) and (+)-listeferine (8), exerted the most significant activity against L. donovani (IC50: 14.59 μM) and T. brucei brucei (LC100: 50.02 μM) respectively. This is the first report on the antiprotozoal activity of the isolated compounds. The results offer potential for further studies of the oxoaporphines for enhanced antiprotozoal activity.

Evaluation of Tanacetum parthenium cytotoxicity on Leishmania infatum and L. major

Over 20 Leishmania species are transmitted by infected female phlebotomine sandflies causing visceral, cutaneous and mucocutaneous infections. The first line treatments of leishmaniasis are still pentavalent antimonials developed more than 50 years ago which are highly toxic and prone to resistance. Currently 1.5 – 2 million new cases of leishmaniasis are reported annually and lack of an effective and safe drug to cure the disease remains a concern. Recent research has focused on plant components for discovery of new medicines. Tanacetum parthenium, known as feverfew, has long been used in folk medicine and recent studies have reported it as a biologically active herb. The in vitro activity of T. parthenium against Leishmania amazonensis [1] and cancer [2] are attributed to its sesquiterpene lactones [3], particularly parthenolide. In this research, we evaluated the cytotoxic effect of the hydroalcoholic extract of T. parthenium on promastigotes of L. infatum and L. major compared to the drugs glucantime and luteolin. The content of parthenolide in the crude extract was also quantified by HPLC. The extract showed 50% inhibition of L. infatum cell growth at concentrations of 4.5, 1.9 and 1.1 mg/ml and after 24, 48 and 72h incubation, respectively. For L. major, these values were 4, 1.8 and 0.9 mg/ml, respectively. The results demonstrated that the crude extract was considerably more effective than glucantime and luteolin. Based on HPLC analysis the dry leaves contained 0.74%w/w parthenolide. Since T. parthenium is an edible and safe herb, this study indicates that it could be a potential candidate for further investigations on its antileishmanial effects.

Spatial distribution of sand fly species (Psychodidae: Phlebtominae), ecological niche, and climatic regionalization in zoonotic foci of cutaneous leishmaniasis, southwest of Iran.

Cutaneous leishmaniasis (CL) is a complex vector-borne disease caused by Leishmania parasites that are transmitted by the bite of several species of infected female phlebotomine sand flies. Monthly factor analysis of climatic variables indicated fundamental variables. Principal component-based regionalization was used for recognition of climatic zones using a clustering integrated method that identified five climatic zones based on factor analysis. To investigate spatial distribution of the sand fly species, the kriging method was used as an advanced geostatistical procedure in the ArcGIS modeling system that is beneficial to design measurement plans and to predict the transmission cycle in various regions of Khuzestan province, southwest of Iran. However, more than an 80% probability of P. papatasi was observed in rainy and temperate bio-climatic zones with a high potential of CL transmission. Finding P. sergenti revealed the probability of transmission and distribution patterns of a non-native vector of CL in related zones. These findings could be used as models indicating climatic zones and environmental variables connected to sand fly presence and vector distribution. Furthermore, this information is appropriate for future research efforts into the ecology of Phlebotomine sand flies and for the prevention of CL vector transmission as a public health priority.

Molecular identification of Lutzomyia migonei (Diptera: Psychodidae) as a potential vector for Leishmania infantum (Kinetoplastida: Trypanosomatidae)

Visceral leishmaniasis (VL) in Brazil is caused by the protozoan Leishmania infantum. This parasite is transmitted by the bite of a female sand fly. The most important sand fly species in VL transmission is Lutzomyia longipalpis. In Fortaleza, the capital of Ceará State, Brazil, the simultaneous occurrence of Lutzomyia migonei and L. longipalpis was detected in localities where VL transmission is observed. The purpose of this study was to determine conclusively if L. migonei can be found naturally infected with L. infantum in key focus in Fortaleza. Using a CDC traps we performed phlebotomine capture during one year. External morphological features and qPCR targeting species-specific gene sequences of Lutzomyia species were used to identify the female phlebotomine sand flies. The molecular identification of the Leishmania species was performed using qPCR targeting species-specific gene sequences of L. infantum and Leishmania braziliensis. The males L. migonei abundance was higher in the rainy season. Humidity and rainfall positively correlated with males L. migonei abundance, while temperature showed a negative correlation. The correlation between the density of L. migonei female with rainfall, relative air humidity, and temperature were not statistically significant. According to the molecular data produced by qPCR amplifications, three positive sand flies were identified as L. longipalpis, and one was identified as L. migonei. The infection rate was 0.35% and 0.18%, respectively. The parasite load was 32,492±2572 L. infantum in L. migonei while the L. longipalpis had parasite loads between 2,444,964.6±116,000 and 6,287,130±124,277. Our findings confirm L. migonei as a potential vector of VL in Fortaleza at a molecular level.

Leishmaniose viscérale sans splénomégalie. À propos d’un cas chez un nourrisson

Pediatric visceral leishmaniasis is caused by Leishmania infantum, a dog parasite transmitted to humans by the bite of the female phlebotomine sand fly. The well-known clinical triad is fever, pallor, and splenomegaly. A secondary macrophage activation syndrome (MAS) can complicate this infection, which is lethal when not treated. When MAS is observed without any explanation, a visceral leishmaniasis is highly recommended. We report a case of visceral leishmaniasis in a 21-month-old child complicated by a macrophage activation syndrome without splenomegaly. No immunodeficiency was diagnosed that could explain this unusual clinical condition. To our knowledge, this is the first case of visceral leishmaniasis without splenomegaly reported to date.

Exploring the Leishmania Hydrophilic Acylated Surface Protein B (HASPB) Export Pathway by Live Cell Imaging Methods.

Leishmania major is a human-infective protozoan parasite transmitted by the bite of the female phlebotomine sand fly. The L. major hydrophilic acylated surface protein B (HASPB) is only expressed in infective parasite stages suggesting a role in parasite virulence. HASPB is a "nonclassically" secreted protein that lacks a conventional signal peptide, reaching the cell surface by an alternative route to the classical ER-Golgi pathway. Instead HASPB trafficking to and exposure on the parasite plasma membrane requires dual N-terminal acylation. Here, we use live cell imaging methods to further explore this pathway allowing visualization of key events in real time at the individual cell level. These methods include live cell imaging using fluorescent reporters to determine the subcellular localization of wild type and acylation site mutation HASPB18-GFP fusion proteins, fluorescence recovery after photobleaching (FRAP) to analyze the dynamics of HASPB in live cells, and live antibody staining to detect surface exposure of HASPB by confocal microscopy.

Evaluation of clinical and laboratory findings of adult visceral leishmaniasis cases

Visceral leishmaniasis (VL, kala-azar) is a zoonotic infection caused by Leishmania species which are transmitted to humans by the bites of infected female phlebotomine sandflies. Leishmania infantum is the responsible species of VL in Aegean, Mediterranean, and Central Anatolia regions of Turkey mainly observed sporadically in pediatric age groups. The aim of this study was to evaluate the clinical and laboratory findings of adult patients with VL who were admitted to our hospital. A total of 10 patients (3 female, 7 male; age range: 18-67 years, mean age: 39.3 ± 16.51) followed in the infectious diseases clinic of the hospital between 2000 and 2013 were evaluated retrospectively. The diagnosis of VL was based on the presence of appropriate clinical and physical examination, as well as biochemical findings, positive serological test results (indirect fluorescent antibody test, and rK39 rapid antigen test) and/or detection of amastigote forms of parasite in the bone marrow aspiration samples. Of the cases three were diagnosed with both bone marrow and serology positivity, five with bone marrow positivity and one of each only with liver biopsy and positive serology result. Time interval from onset of the symptoms until the establishment of the specific clinical diagnosis was ranged from 2 to 12 weeks. The most frequent initial symptoms were fever, fatigue and abdominal distension. None of the patients had immunosupressive conditions such as HIV infection, corticosteroid use, immunosupressive treatment, or transplantation. All the patients were from Aegean region and six were living in rural areas. In all cases, hepatosplenomegaly, increased erythrocyte sedimentation rate, albumin/globulin ratio inversion, anemia, leukopenia and among nine cases trombocytopenia were detected. In one case acute renal failure has been developed before treatment and the patient was admitted to dialysis program. Bacterial superinfection occurred in two cases. Patients were treated with either meglumine antimonate (Glucantime(®), 20 mg/kg/day, intramuscularly for 28 days) or liposomal amphotericin B (3 mg/kg/day, intravenously for the first 5 days, then on 14(th) and 21(st) days) according to the availability of drugs. During one year follow-up period all of the patients improved and no recurrence was seen in any patient. In conclusion, among adult patients with fever uncontrolled within 2-week course of ampiric antibiotic treatment without any infectious focus or malignancy, VL should also be considered.

Rotation of the external genitalia in male Phlebotomine sand flies (Diptera, Psychodidae) in laboratory conditions and in captured specimens in Algarve, Portugal

Protozoal parasites are the causative agents of many insect-borne infectious diseases worldwide with impact on human and animal health. Leishmaniasis is caused by Leishmania spp. and transmitted by female Phlebotomine sand flies. In Portugal, two species of Phlebotomus (Larroussius), namely Phlebotomus perniciosus and Phlebotomus ariasi are the proven vectors of Leishmania infantum. Phlebotomine females and males rest and breed in the same sites; and these locations can be predicted according to the male external genitalia maturation. Therefore, this study aimed to determine the timing of complete rotation of the male external genitalia in laboratory conditions and to characterize the external genitalia rotation in field captured males to predict the male and female sand fly breeding and resting sites. This knowledge can be applied in the design and implementation of integrated sand fly control strategies targeting these sites.

Treatment of Leishmaniasis: A Review and Assessment of Recent Research

Leishmaniasis is a diverse group of neglected diseases caused by protozoan parasite of genus Leishmania and transmitted by the bite of a female phlebotomine sand fly. These diseases stand as a major health problem worldwide, especially in their visceral form. Despite innumerable studies on leishmaniasis, many questions are still unanswered. One of the main challenges is the presence of different Leishmania species and various clinical manifestations, complicating the therapeutic approach. There are many available antileishmanial agents, but the drug of choice is still out of reach, since almost all available drugs share several limitations and many of them are expensive with severe side effects or have a markedly reduced effectiveness. Immunosuppressed patients should also be given a special attention which represents an additional challenge. In the meantime, the combination of local and parenteral therapies with existing drugs remain a priority to improve the efficacy and to shorten the duration of the treatment. This review was undertaken to highlight the chemotherapeutic strategies, their mechanisms of action and main limitations.

Toxicity and efficacy of aqueous crude extracts from Allium sativum, Callistemon citrinus and Moringa stenopetala against L. major

Cutaneous leishmaniasis (CL) treatment involves pentavalent antimonials, amphotericin B, pentamidine, miltefosine among others. These drugs are toxic, costly, and require prolonged use. CL is a protozoan skin infection which may lead to disfiguring and stigmatization. In Kenya, CL is common in Baringo County where it is caused by Leishmania major and transmitted by infected female phlebotomine sand fly. Leishmaniases are common in poverty stricken areas where victims opt for local herbal therapies. Herbs used haven’t been tested scientifically to verify their toxicity and efficacy. The current study determines in vitro toxicity and in vivo efficacy of aqueous crude extracts of Moringa stenopetala, Callistemon citrinus, and Allium sativum against L. major. The IC50 of aqueous extracts against promastigotes ranged from 297µg/ml to 575µg/ml compared to Pentostam and liposomal amphotericin B with IC50 of 0.26µg/ml and 0.82µg/ml respectively. The viability of promastigotes upon exposure to extracts ranged from 52.55% to 60.57%. Similarly the IC50 of extracts against vero cells ranged between  467µg/ml to 2105µg/ml compared to 108µg/ml and 60µg/ml for pentostam and liposomal amphotericin B respectively. Orally administered A. sativum reduced L. major caused footpad lesions significantly (P < 0.05) when compared to control PBS. The efficacy of oral C. citrinus extracts (B) in reducing amastigotes in spleens of infected BALB/c mice was 82.99%, followed by oral M. stenopetala (A) at 66.96% and oral A. sativum (C) at 60.37% compared to pentostam and liposomal amphotericin B at 66.40% and 60.62% respectively. The difference between the mean total LDUs for aqueous oral C. citrinus extracts and control oral PBS was significant (P = 0.017). It was concluded that crude aqueous extracts of A. sativum, M. stenopetala, and C. citrinus show antileishmanial activity at low toxicity. Inclusion of garlic and moringa in the diets of people in leishmaniases foci should be emphasized.

Health & Demographic Surveillance System profile: the Muzaffarpur-TMRC Health and Demographic Surveillance System.

The Muzaffarpur-TMRC Health and Demographic Surveillance System (HDSS), established in 2007, was developed as an enlargement of the scope of a research collaboration on the project Visceral Leishmaniasis in Bihar, which had been ongoing since 2005. The HDSS is located in a visceral leishmaniasis (VL)-endemic area in the Muzaffarpur district of Bihar state in India. It is the only HDSS conducting research on VL, which is a vector-borne infectious disease transmitted by female phlebotomine sandflies and is fatal if left untreated. Currently the HDSS serves a population of over 105,000 in 66 villages. The HDSS collects data on vital events including pregnancies, births, deaths, migration and marriages, as well as other socio-economic indicators, at regular intervals. Incident VL cases are identified. The HDSS team is experienced in conducting both qualitative and quantitative studies, sample collection and rapid diagnostic tests in the field. In each village, volunteers connect the HDSS team with the community members. The Muzaffarpur-TMRC HDSS provides opportunities for studies on VL and other neglected tropical diseases (NTDs) and their interaction with demographic events such as migration. Queries related to research collaborations and data sharing can be sent to Dr Shyam Sundar at [drshyamsundar@hotmail.com].

Wild gorillas as a potential reservoir of Leishmania major.

Vector-borne parasites of the genus Leishmania are responsible for severe human diseases. Cutaneous leishmaniasis, a common form of the disease, is most often caused by the transmission of Leishmania major to humans by female phlebotomine sand flies. Apes are increasingly being seen as a source of zoonotic diseases, including malaria and rickettsiosis. To examine whether gorillas harbor Leishmania species, we screened fecal samples from wild western lowland gorillas (Gorilla gorilla gorilla) in Cameroon for the presence of these pathogens. Of 91 wild gorilla fecal samples, 12 contained Leishmania parasites, and 4 contained phlebotomine sand fly vectors. The molecular identity was determined by running 3 different polymerase chain reaction tests for detection of L. major. Next, fluorescence in situ hybridization was performed to visualize L. major parasites in fecal samples from the gorillas. Both promastigote and amastigote forms of the parasite were found. This work strongly suggests that wild gorillas carry pathogenic Leishmania parasites.

Epidemiology of visceral leishmaniasis.

Leishmania species are the causative agents of leishmaniasis, a neglected tropical disease. These parasitic protozoans are usually transmitted between vertebrate hosts by the bite of blood sucking female phlebotomine sand flies. This review focuses on the two parasites causing most human visceral leishmaniasis (VL), which leads to substantial health problems or death for up to 400,000 people per year. Except for travel cases, Leishmania donovani infections are restricted to the (sub-)tropics of Asia and Africa, where transmission is mostly anthroponotic, while Leishmania infantum occurs in the drier parts of Latin America as well as in the Mediterranean climate regions of the Old World, with the domestic dog serving as the main reservoir host. The prevalence of VL caused by L. infantum has been declining where living standards have improved. In contrast, infections of L. donovani continue to cause VL epidemics in rural areas on the Indian subcontinent and in East Africa. The current review compares and contrasts these continental differences and suggests priorities for basic and applied research that might improve VL control. Transmission cycles, pathogenesis, diagnosis, treatment and prognosis, prevention (including vector control), surveillance, transmission modeling, and international control efforts are all reviewed. Most case detection is passive, and so routine surveillance does not usually permit accurate assessments of any changes in the incidence of VL. Also, it is not usually possible to estimate the human inoculation rate of parasites by the sand fly vectors because of the limitations of survey methods. Consequently, transmission modeling rarely passes beyond the proof of principle stage, and yet it is required to help develop risk factor analysis for control programs. Anthroponotic VL should be susceptible to elimination by rapid case detection and treatment combined with local vector control, and one of the most important interventions may well be socioeconomic development.