Asrat Hailu

Bioinformatics, Biotechnology, Biostatistics

39.40

Publications

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    ABSTRACT: Visceral leishmaniasis (VL) or kala-azar cases in seasonal labour migrants from highland areas are addressed to travel history to the Metema-Humera lowlands, northwestern Ethiopia. Factors that affect the incidence of VL in extra-domestic habitats were not evaluated. The aim of this study was to evaluate sero-prevalence of Leishmania donovani infection in randomly selected labour migrant workers and entomological risk factors which might affect the incidence of kala-azar. Sero-prevalence of L. donovani infection in labour migrants was obtained from Direct Agglutination Test (DAT) using blood samples. Logistic regression analysis was used to correlate the possible risk factors with L. donovani infection. The season for L. donovani infection or Phlebotomus orientalis bite was estimated from the study of population dynamic of P. orientalis in areas where the blood was sampled. A total of 7, 443 P. orientalis (1,748 female and 5,695 male) were collected from agricultural fields and thickets of Acacia seyal using 461 CDC light traps. The highest mean number of P. orientalis/trap in the thickets of A. seyal and agricultural fields were 46.9 and 43.9 in March and April respectively. The mean P. orientalis/trap for November - May dry season in agricultural fields (11.39) and thickets of A. seyal (25.30) were higher compared to 0.66 in fields and 3.92 in thickets during June - August weeding season. Of the total 359 labour migrants screened using DAT, 45 (12.5%) were DAT-positive (≥1:800) for L. donovani infections. Very high titers (1:12800) were found in 3 (0.8%) individuals who had the risk of kala-azar development. Statistically significant p-values and odd ratio (OR) for staying in the areas both in the weeding and harvesting seasons (p = 0.035; OR = 2.83) and sleeping in the agricultural fields (p = 0.01; OR = 15.096) were positively correlated with L. donovani infection. Night harvest (p = 0.028; OR = 0.133) and knowledge about sign or symptoms (p = 0.042; OR = 0.383) were negatively associated with this infection. Sleeping in open agricultural fields was related with L. donovani infections in labour migrants during June-August weeding season.
    BMC Infectious Diseases 12/2015; 15(1):830. DOI:10.1186/s12879-015-0830-2 · 2.56 Impact Factor
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    ABSTRACT: Blood-feeding behavior studies are important for estimating the efficiency of pathogen transmission and assessing the relative human disease risk. However, in Ethiopia and other parts of East Africa there are large remaining gaps in identifying the feeding habits of Phlebotomus orientalis, the vector of Leishmania donovani. The aim of the study was to determine the blood feeding patterns of P. orientalis in Tahtay Adiyabo district, northern Ethiopia. For bloodmeal analysis, sandflies were collected from three different villages of Tahtay Adiyabo district using CDC light traps, sticky traps, and pyrethrum spray catches. Bloodmeal of engorged female sandflies was identified using cytochrome (cyt) b-PCR and reverse-line blotting (RLB) and enzyme linked immunosorbent assay (ELISA) assays. Most (637/641) of the females analyzed were P. orientalis. Successful identification of the host from bloodmeals was achieved in 83.03 and 92.1 % using cyt b PCR-RLB and ELISA, respectively. Bloodmeal analysis of P. orientalis females revealed that they have a range of hosts with predominant preference to bovines followed by donkey, human, goat, sheep, dog, and camel. Results obtained from bloodmeal analyses demonstrate that the feeding preference of P. orientalis is mainly zoophilic, which could vary depending on the availability of hosts.
    Parasites & Vectors 05/2015; 8(1):270. DOI:10.1186/s13071-015-0883-5 · 3.25 Impact Factor
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    ABSTRACT: In this work, we describe a two-stage sampling design to estimate the infection prevalence in a population. In the first stage, an imperfect diagnostic test was performed on a random sample of the population. In the second stage, a different imperfect test was performed in a stratified random sample of the first sample. To estimate infection prevalence, we assumed conditional independence between the diagnostic tests and develop method of moments estimators based on expectations of the proportions of people with positive and negative results on both tests that are functions of the tests' sensitivity, specificity, and the infection prevalence. A closed-form solution of the estimating equations was obtained assuming a specificity of 100% for both tests. We applied our method to estimate the infection prevalence of visceral leishmaniasis according to two quantitative polymerase chain reaction tests performed on blood samples taken from 4756 patients in northern Ethiopia. The sensitivities of the tests were also estimated, as well as the standard errors of all estimates, using a parametric bootstrap. We also examined the impact of departures from our assumptions of 100% specificity and conditional independence on the estimated prevalence. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Statistics in Medicine 05/2015; DOI:10.1002/sim.6545 · 2.04 Impact Factor
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    ABSTRACT: Diagnostic guidelines for Visceral Leishmaniasis (VL) in the East African region are complex. Patients meeting the VL clinical case definition should be tested by rK39 rapid diagnostic test (RDT) followed by the Direct Agglutination Test (DAT) or tissue aspiration if RDT-negative. Otherwise, RDT-positive patients should be started on VL treatment. We evaluated how this guideline is adhered to by assessing the routine clinical practice in a university hospital in North-West Ethiopia. Retrospective record analysis was done for all patients who had an rK39-RDT done at University of Gondar (UoG) Hospital between June 2012 and June 2013. We described the diagnostic work-up performed and the proportion initiated on VL treatment by test result. From a total of 928 patients tested, 308 (33.2%) were rK39 RDT-positive. Spleen or bone marrow aspiration was done for 237 (77.2%) RDT-positive patients. Of these, 165 were confirmed parasitologically, yielding a positive predictive value of 69.6%. Only 126 (20.3%) of the 620 patients with a negative rK39 test underwent further testing by tissue aspiration, of which 22 (17.5%) were also parasitology positive. HIV test results were available for 570 (61.4%) patients and 36 (6.3%) were HIV-infected. Of the 187 parasitologically confirmed patients, 182 (97.3%) were started on VL treatment. A negative rK39 test was often not followed by further testing and a positive rK39 test result was followed by tissue aspiration in three out of four cases. Further research is required to understand why the diagnostic work-up did not comply with the guidelines, including evaluating adherence to the VL clinical case definition and quality of rK39-RDT testing.
    PLoS Neglected Tropical Diseases 05/2015; 9(5):e0003738. DOI:10.1371/journal.pntd.0003738 · 4.49 Impact Factor
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    ABSTRACT: Human visceral (VL, also known as Kala-azar) and cutaneous (CL) leishmaniasis are important infectious diseases affecting countries in East Africa that remain endemic in several regions of Ethiopia. The transmission and epidemiology of the disease is complicated due to the complex life cycle of the parasites and the involvement of various Leishmania spp., sand fly vectors and reservoir animals besides human hosts. Particularly in East Africa, the role of animals as reservoirs for human VL remains unclear. Isolation of Leishmania donovani parasites from naturally infected rodents has been reported in several endemic countries; however, the status of rodents as reservoirs in Ethiopia remains unclear. Here, we demonstrated natural Leishmania infections in rodents. Animals were trapped in 41 localities of endemic and non-endemic areas in eight geographical regions of Ethiopia and DNA was isolated from spleens of 586 rodents belonging to 21 genera and 38 species. Leishmania infection was evaluated by real-time PCR of kinetoplast (k)DNA and confirmed by sequencing of the PCR products. Subsequently, parasite species identification was confirmed by PCR and DNA sequencing of the 18S ribosomal RNA internal transcribed spacer one (ITS1) gene. Out of fifty (8.2%) rodent specimens positive for Leishmania kDNA-PCR and sequencing, 10 were subsequently identified by sequencing of the ITS1 showing that five belonged to the L. donovani complex and five to L. tropica. Forty nine kDNA-positive rodents were found in the endemic localities of southern and eastern Ethiopia while only one was identified from north-western Ethiopia. Moreover, all the ten ITS1-positive rodents were captured in areas where human leishmaniasis cases have been reported and potential sand fly vectors occur. Our findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishmaniasis in Ethiopia, possibly as reservoir hosts. Copyright © 2015. Published by Elsevier B.V.
    Acta Tropica 02/2015; 13. DOI:10.1016/j.actatropica.2015.02.006 · 2.52 Impact Factor
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    ABSTRACT: Phlebotomus orientalis is the main sandfly vector of visceral leishmaniasis in the north and northwest of Ethiopia. CDC light traps and sticky traps are commonly used for monitoring sandfly populations. However, their trapping efficiency is greatly influenced by various environmental factors including moonlight and lunar periodicity. In view of that, the current study assessed the effect of moonlight and lunar periodicity on the performance of light traps in collecting P. orientalis. Trapping of P. orientalis and other Phlebotomus spp. was conducted for 7 months between December 2012 and June 2013 using CDC light traps and sticky traps from peri-domestic and agricultural fields. Throughout the trapping periods, collections of sandfly specimens were carried out for 4 nights per month, totaling 28 trapping nights that coincided with the four lunar phases (viz., first quarter, third quarter, new and full moon) distributed in each month. In total, 13,533 sandflies of eight Phlebotomus species (P. orientalis, P. bergeroti, P. rodhaini, P. duboscqi, P. papatasi, P. martini, P. lesleyae and P. heischi) were recorded. The predominant species was P. orientalis in both trapping sites and by both methods of collection in all lunar phases. A significant difference (P < 0.05) was observed in the mean numbers of P. orientalis and other Phlebotomus spp. caught by CDC light traps among the four lunar phases. The highest mean number (231.13 ± 36.27 flies/trap/night) of P. orientalis was collected during the new moon phases, when the moonlight is absent. Fewer sandflies were attracted to light traps during a full moon. However, the number of P. orientalis and the other Phlebotomus spp. from sticky traps did not differ in their density among the four lunar phases (P = 0.122). Results of the current study demonstrated that the attraction and trapping efficiency of CDC light traps is largely influenced by the presence moonlight, especially during a full moon. Therefore, sampling of sandflies using light traps to estimate population density and other epidemiological studies in the field should take the effect of moonlight and lunar periodicity into account on the trapping efficacy of light traps.
    Parasites & Vectors 02/2015; Gebresilassie et al. Parasites & Vectors (2015) 8:106(8:106). DOI:10.1186/s13071-015-0723-7 · 3.25 Impact Factor
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    ABSTRACT: Phlebotomus orientalis is the most likely vector of Leishmania donovani causing visceral leishmaniasis in northwest Ethiopia. Understanding of sand fly night activities is very essential to design appropriate sand fly control methods in order to reduce Leishmania infection. The aim of this study was to determine the nocturnal activity of Phlebotomus species. This study was conducted for six consecutive months from January to June 2013 in Adebay village where visceral leishmaniasis is endemic. Sandflies were collected using CDC Light traps changed at one hour interval, in periphery village (peridomestic area) and farm field. The traps were activated from 18:00 to 7:00 hours. Overall, 5,902 sandflies were collected. Eight Phlebotomus species representing four subgenera were indentified: Phlebotomus (Larroussius) orientalis, P.(Phlebotmus) papatasi, P.(Phlebotmus) bergeroti, P. (Phlebotomus)duboscqi, P. (Paraphlebotomus) alexanderi, P. (Anaphlebotomus) rodhani and other two Parvidens species(P. lesleyae and P. heischi). Among eight species of sand flies collected P.orientalis were the most predominant species followed by P. papatasi and P. lesleyae. The result indicated that female and male P.orientalis showed similar activity pattern (19:00-05:00hrs). Both sexes were active throughout the night (19:00-06:00 hours), reaching a peak between 01:00 and 03:00hrs (mean density of 16.46 females/trap/hour/night; and 33.83 males/trap/hour/night). Male P. papatasi were the dominant having two peaks, an early smaller peak between 21:00-22:00 hrs and a larger second one around midnight (24:00-02:00 hrs). Females displayed similar activity patterns, with an early peak at 21:00-22:00 and a late smaller peak at 02:00-03:00 hours. Hourly collections of P.orientalis and P. papatasi, the corresponding temperatures revealed no significant correlations. In conclusion, P.orientalis and P. papatasi remained active throughout the night. High risk of VL transmissions is likely concentrated during the peak hours and local inhabitants could reduce the risk of infection by using appropriate personal protective measures such as repellents and bed nets.
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    ABSTRACT: Background Phlebotomus orientalis feeds on a variety of wild and domestic animals and transmits Leishmania donovani from hitherto unknown reservoir hosts to humans in extra-domestic habitats in the Metema - Humera lowlands. The aim of this study was to determine the nocturnal activities of P. orientalis and its preferred blood meal hosts.Methods Collections of Phlebotomus orientalis were made by using CDC light traps to determine the density as P. orientalis/hour CDC trap and preference to rodents by using Turner¿s traps in agricultural fields, animal shelters and thickets of Acacia seyal in Baeker site-1 and Gelanzeraf site-2. The blood meal sources were detected by Reverse Line Blot (RLB) of cytochrome b polymerase chain reaction (PCR) amplification in August, 2012 from collections of sand flies in thickets of A. seyal (March 2011) and dense mixed forest (July 2011) in Baeker site 1. RLB PCR involved first amplification of animal specific sequences of cytochrome b using PCR techniques. Then the amplified sequence was hybridized with 11 species-specific probes for domestic animals adsorbed on nitrocellulose membrane for calorimetric color detection.ResultsA total of 6,083 P. orientalis (2,702 males and 3,381 females) were collected at hourly intervals using 22 CDC traps from January to May 2013. The peak activities of P. orientalis were at 1.00 a.m (134.0¿±¿7.21) near animal shelters, 3.00 a.m (66.33¿±¿46.40) in agricultural fields and 21:00 pm (40.6¿±¿30.06) in thickets of A. seyal. This species was not attracted to the different species of rodents in trials carried out in March and April 2013. RLB PCR identified 7 human (28%), 9 mixed (human and cattle) (36%) and 2 cattle (8%) blood meals while 7 were unknown (28%).Conclusion Female P. orientalis can bite humans in extra-domestic habitats of Kafta-Humera lowlands at any hour of the night with peak biting after midnight.
    Parasites & Vectors 12/2014; 7(1):594. DOI:10.1186/PREACCEPT-1609531833143638 · 3.25 Impact Factor
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    ABSTRACT: Although podoconiosis is one of the major causes of tropical lymphoedema and is endemic in Ethiopia its epidemiology and risk factors are poorly understood. Individual-level data for 129,959 individuals from 1,315 communities in 659 woreda (districts) were collected for a nationwide integrated survey of lymphatic filariasis and podoconiosis. Blood samples were tested for circulating Wuchereria bancrofti antigen using immunochromatographic card tests. A clinical algorithm was used to reach a diagnosis of podoconiosis by excluding other potential causes of lymphoedema of the lower limb. Bayesian multilevel models were used to identify individual and environmental risk factors. Overall, 8,110 of 129,959 (6.2%, 95% confidence interval [CI] 6.1–6.4%) surveyed individuals were identified with lymphoedema of the lower limb, of whom 5,253 (4.0%, 95% CI 3.9–4.1%) were confirmed to be podoconiosis cases. In multivariable analysis, being female, older, unmarried, washing the feet less frequently than daily, a
    The American journal of tropical medicine and hygiene 11/2014; 92(1). DOI:10.4269/ajtmh.14-0446 · 2.74 Impact Factor
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    ABSTRACT: Background: An important factor influencing the transmission dynamics of vector-borne diseases is the contribution of hosts with different parasitemia (no. of parasites per ml of blood) to the infected vector population. Today, estimation of this contribution is often impractical since it relies exclusively on limited-scale xenodiagnostic or artificial feeding experiments (i.e., measuring the proportion of vectors that become infected after feeding on infected blood/host). Methodology: We developed a novel mechanistic model that facilitates the quantification of the contribution of hosts with different parasitemias to the infection of the vectors from data on the distribution of these parasitemias within the host population. We applied the model to an ample data set of Leishmania donovani carriers, the causative agent of visceral leishmaniasis in Ethiopia. Results: Calculations facilitated by the model quantified the host parasitemias that are mostly responsible for the infection of vector, the sand fly Phlebotomus orientalis. Our findings indicate that a 3.2% of the most infected people were responsible for the infection of between 53% and 79% (mean – 62%) of the infected sand fly vector population. Significance: Our modeling framework can easily be extended to facilitate the calculation of the contribution of other host groups (such as different host species, hosts with different ages) to the infected vector population. Identifying the hosts that contribute most towards infection of the vectors is crucial for understanding the transmission dynamics, and planning targeted intervention policy of visceral leishmaniasis as well as other vector borne infectious diseases (e.g., West Nile Fever).
    PLoS Neglected Tropical Diseases 11/2014; 8(10):e3288. DOI:10.1371/journal.pntd.0003288 · 4.49 Impact Factor
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    ABSTRACT: Objective After the epidemics of L. donovani complex in 2004/05 in human patients, to investigate the presence of antibodies against L. donovani in domestic animals in north-west Ethiopia. Methods Two hundred and three domestic animals were screened. Serum and biopsy samples were collected. A modified direct agglutination test (DAT) for canine reservoirs was used to screen serum samples at 1:320 cut-off titre. Giemsa stain and culture on Novy macNeal Nicolae (NNN) media were used for biopsy samples. Pre-tested questionnaires were used to elicit information on potential risk factors. ResultsAntibody against L. donovani in domestic animals was detected in 30.5% of animals. The highest seropositivity rates were 41.9% in cattle, 40% in dogs, 33.3% in donkeys, 10% in goats and 4.8% in sheep. No Leishmania parasite was isolated from spleen, liver, skin snip and exudates, bone marrow or lymph node of dogs. Dogs owned by households with history of kala-azar treatment and humans sharing the house with cattle were more affected by visceral leishmaniasis (P<0.05). Conclusion This study showed a high serological prevalence of leishmaniasis in domestic animals. Their role in the epidemiology of visceral leishmaniasis remains unclear.
    Tropical Medicine & International Health 10/2014; 20(2). DOI:10.1111/tmi.12418 · 2.30 Impact Factor
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    ABSTRACT: Background Visceral leishmaniasis (VL, also called `¿kala-azar¿), is a life threatening neglected tropical infectious disease which mainly affects the poorest of the poor. VL is prevalent in Ethiopia particularly in the northwest of the country. Understanding the risk factors of VL infection helps in its prevention and control. The aim of the present study was to identify the factors associated with VL.MethodsA case¿control study was carried out during the period of January-July 2013 in northwest Ethiopia. Cases and controls were diagnosed using clinical presentation, the rk39 rapid diagnostic test and Direct Agglutination Test (DAT). A total of 283 (84.8% males versus 15.2% females) participants were interviewed. 90 cases and 193 controls were involved, matched by age, sex and geographical location with a ratio of 1:2 (case: controls). Univariate and backward multivariate conditional logistic regression were used to identify risk factors of VL.ResultsElevated odds of VL was associated with goat ownership (OR¿=¿6.4; 95%: confidence interval [Cl]: 1.5-28.4), living in houses with cracked wall (OR¿=¿6.4; 95% Cl: 1.6-25.6), increased family size (OR¿=¿1.3; 95%Cl: 1.0-1.8) and the number of days spent in the farm field (OR¿=¿1.1; 95% Cl: 1.0-1.2). However, daily individual activities around the home and farm fields, mainly sleeping on a bed (OR¿=¿0.2; 95%: Cl 0.03-0.9), sleeping outside the house under a bed net (OR¿=¿0.1; 95% Cl: 0.02-0.36)] and smoking plant parts in the house during the night time (OR¿=¿0.1; 95% Cl: 0.01-0.6) were associated with decreased odds of being VL case.Conclusion Our findings showed that use of bed net and smoke could be helpful for the prevention of VL in the area particularly among individuals who spend most of their time in the farm. VL control effort could be focused on improving housing conditions, such as sealing cracks and crevices inside and outside houses. Further research is warranted to elucidate the role of goats in the transmission of L. donovani, assess the impact of bed nets and the role of the traditional practice of smoking plants.
    Parasites & Vectors 10/2014; 7(1):470. DOI:10.1186/PREACCEPT-7749314101347455 · 3.25 Impact Factor
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    ABSTRACT: The development of rK39-based rapid diagnostic tests (RDTs) has greatly aided the diagnosis of visceral leishmaniasis, especially in the Indian subcontinent and Brazil, by offering high sensitivity and specificity. However, these tests have been less sensitive and less specific in sub-Saharan Africa. To improve upon the performance of rK39 in Africa, we engineered the fusion molecule rK28, which retained some of the rK39 repeats and combined them with repeat sequences from two additional Leishmania genes. This polyprotein was used in the development of several prototype RDTs by different commercial manufacturers with the goal of assessing relative performance in inexpensive formats. Here, we report field studies showing that the rK28 antigen could be readily adapted to a variety of RDT formats to achieve high sensitivity, generally > 90%, and adequate specificity to aid in the diagnosis of human visceral leishmaniasis in East Africa, Asia, and South America.
    The American journal of tropical medicine and hygiene 10/2014; 91(6). DOI:10.4269/ajtmh.13-0759 · 2.74 Impact Factor
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    ABSTRACT: In regions where it is endemic, visceral leishmaniasis is an important opportunistic infectious disease in people living with HIV. Typically, clinical presentation of visceral leishmaniasis includes chronic fever, hepatosplenomegaly, and weight loss. In Leishmania infantum endemic regions in Europe, atypical visceral leishmaniasis presentations have been well documented, with almost every possible organ involved. However, such reports are rare in Leishmania donovani endemic regions such as east Africa. In this Personal View, we describe the various atypical disease presentations in patients screened as part of an HIV and visceral leishmaniasis clinical trial in north Ethiopia, where up to 40% of patients with visceral leishmaniasis are co-infected with HIV. Atypical presentations such as these are not covered in clinical guidelines used in these settings. Apart from the lack of diagnostic facilities, this gap contributes to the underdiagnosis of atypical visceral leishmaniasis, with associated morbidity and mortality. Involvement of clinicians experienced with the management of HIV and visceral leishmaniasis co-infection in the development of HIV clinical guidelines in affected regions is warranted.
    The Lancet Infectious Diseases 10/2014; 15(1). DOI:10.1016/S1473-3099(14)70833-3 · 19.45 Impact Factor
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    ABSTRACT: Objective Visceral leishmaniasis (VL) in north-west Ethiopia is causing an overwhelming case load among adult migrant workers that masked the disease burden in children. This study describes the clinical profile and explores comorbidities in paediatric VL patients.MethodsA prospective study at two hospitals in this region (Gondar and Humera) was conducted in a year period, 2011–2012. The clinical manifestations and comorbidities such as malnutrition, intestinal parasitosis and vitamin D deficiency and HIV infection were assessed, and treatment outcomes noted.ResultsA total of 122 children with VL were detected during the study period with median age of 8.5 years (IQR 5–12 years); 23% were under 5 years. Eighty-five (69.7%) cases were male. The clinical manifestations were similar to the adult patients. High rates of malnutrition, intestinal parasitosis (47.5%) and hypovitaminosis D (56.4%) were detected. The proportion of stunting and wasting was 63% and 22.2% in children aged under five years, and 50.5% and 75.9% in 5-year and older children, respectively, using WHO standard growth curves. Only one child had HIV infection. In 95% of the cases, sodium stibogluconate (20 mg/kg/day for 30 days) was used for treatment. The treatment success rate at end of therapy was 98.3%, but the definitive outcome at 6 months could not be determined because of a high loss to follow-up (80.2%).Conclusion While HIV co-infection was rare, malnutrition, intestinal parasitosis and vitamin D deficiency were frequent indicating the need for further research on their role in the pathophysiology. Meanwhile, systematic assessment and management of malnutrition and intestinal parasitosis in VL programmes is recommended.
    Tropical Medicine & International Health 10/2014; DOI:10.1111/tmi.12407 · 2.30 Impact Factor
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    PLoS Neglected Tropical Diseases 09/2014; 8(9):e3132. DOI:10.1371/journal.pntd.0003132 · 4.49 Impact Factor
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    ABSTRACT: BackgroundKafta Humera lowlands are endemic for kala-azar (visceral leishmaniasis). These lowlands are characterized by black clay soil which is used for growing sesame, sorghum and cotton for commercial purposes.The aim of this study was to determine seasonal dynamics and habitat preferences of Phlebotomus orientalis, the vector of kala-azar, in extra-domestic habitats of Kafta Humera lowlands.MethodsCDC-light Trap [CDC-LT] and Sticky paper Trap [ST] were used to collect sand flies from different habitats before species identification by their morphological characteristics using appropriate keys. Data summarized and analyzed included: species, sex, density, habitats, type of trap used and date (month).ResultsA total of 389,207 sand flies using CDC-LT (n = 955) and ST (n = 5551) were collected from May 17, 2011 to June 6, 2012. The highest Mean Monthly Density (MMD) of P. orientalis trapped by CDC-LT was found in thickets of Acacia seyal in March (64.11 ± 75.87). The corresponding highest MMD of P. orientalis trapped by STs was found in April (58.69 ± 85.20) in agricultural field. No P. orientalis were caught in September using CDC traps and July-October using sticky traps. The overall MMD of P. orientalis trapped by CDC-LT was 15. 78 ± 28.93 (n = 320) in agricultural field, 19.37 ± 36.42 (n = 255) in thickets of A. seyal, and 3.81 ± 6.45 (n = 380) in dense mixed forest. Similar habitats in different localities did not show statistically significant difference for the MMD of P. orientalis trapped by CDC-LT (p = 0.117) and ST (p = 0.134).ConclusionAgricultural fields and thickets of A. seyal habitats, which exhibit extensive soil cracks and fissures, as opposed to dense mixed forests, serve as preferred breeding sites for P. orientalis.
    Parasites & Vectors 08/2014; 7(1):359. DOI:10.1186/1756-3305-7-359 · 3.25 Impact Factor
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    ABSTRACT: In the wake of the HIV epidemic, visceral leishmaniasis (VL), a disseminated protozoan infection caused by the Leishmania donovani complex, has been re-emerging, particularly in North Ethiopia where up to 40% of patients with VL are co-infected with HIV. Management of VL in HIV co-infection is complicated by increased drug toxicity, and high treatment failure and relapse rates with all currently available drugs, despite initiation of antiretroviral treatment. Tackling L. donovani infection before disease onset would thus be a logical approach. A screen-and-treat approach targeting latent or the early stage of infection has successfully been implemented in other HIV-associated opportunistic infections. While conceptually attractive in the context of VL-HIV, the basic understanding and evidence underpinning such an approach is currently lacking. Prospective cohort studies will have to be conducted to quantify the risk of VL in different risk groups and across CD4 cell count levels. This will allow developing clinical prognostic tools, integrating clinical, HIV and Leishmania infection markers. Interventional studies will be needed to evaluate prophylactic or pre-emptive treatment strategies for those at risk, ideally relying on an oral (combination) regimen. Issues like tolerability, emergence of resistance and drug interactions will require due attention. The need for maintenance therapy will have to be assessed. Based on the risk-benefit data, VL risk cut-offs will have to be identified to target treatment to those most likely to benefit. Such a strategy should be complemented with early initiation of antiretroviral treatment and other strategies to prevent HIV and Leishmania infection.
    PLoS Neglected Tropical Diseases 08/2014; 8(8):e3011. DOI:10.1371/journal.pntd.0003011 · 4.49 Impact Factor
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    PLoS Neglected Tropical Diseases 08/2014; 8(8):e3023. DOI:10.1371/journal.pntd.0003023 · 4.49 Impact Factor

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