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1.
Acta Trop ; 216: 105828, 2021 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-33465353

RESUMEN

Malaria is the world's deadliest parasitic disease. Great progress has been made in the fight against malaria over the past two decades, but this has recently begun to plateau, in part due to the global development of antimalarial drug resistance. The ability to track drug resistance is necessary to achieve progress in treatment, disease surveillance and epidemiology, which has prompted the development of advanced diagnostic methods. These new methods provide unprecedented access to information that can help to guide public health policies. Development of new technologies increases the potential for high throughput and reduced costs of diagnostic tests; improving the accessibility of tools to investigate the forces driving disease dynamics and, ultimately, clinical outcomes for malaria patients and public health. This literature review provides a summary of the methods currently available for the detection of antimalarial drug resistance from the examination of patients' blood samples. While no single method is perfect for every application, many of the newly developed methods give promise for more reliable and efficient characterisation of Plasmodium resistance in a range of settings. By exploiting the strengths of the tools available, we can develop a deeper understanding of the evolutionary and spatiotemporal dynamics of this disease. This will translate into more effective disease control, better-informed policy, and more timely and successful treatment for malaria patients.

2.
Adv Parasitol ; 108: 47-131, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32291086

RESUMEN

Intestinal helminths are extremely widespread and highly prevalent infections of humans, particularly in rural and poor urban areas of low and middle-income countries. These parasites have chronic and often insidious effects on human health and child development including abdominal problems, anaemia, stunting and wasting. Certain animals play a fundamental role in the transmission of many intestinal helminths to humans. However, the contribution of zoonotic transmission to the overall burden of human intestinal helminth infection and the relative importance of different animal reservoirs remains incomplete. Moreover, control programmes and transmission models for intestinal helminths often do not consider the role of zoonotic reservoirs of infection. Such reservoirs will become increasingly important as control is scaled up and there is a move towards interruption and even elimination of parasite transmission. With a focus on southeast Asia, and the Philippines in particular, this review summarises the major zoonotic intestinal helminths, risk factors for infection and highlights knowledge gaps related to their epidemiology and transmission. Various methodologies are discussed, including parasite genomics, mathematical modelling and socio-economic analysis, that could be employed to improve understanding of intestinal helminth spread, reservoir attribution and the burden associated with infection, as well as assess effectiveness of interventions. For sustainable control and ultimately elimination of intestinal helminths, there is a need to move beyond scheduled mass deworming and to consider animal and environmental reservoirs. A One Health approach to control of intestinal helminths is proposed, integrating interventions targeting humans, animals and the environment, including improved access to water, hygiene and sanitation. This will require coordination and collaboration across different sectors to achieve best health outcomes for all.


Asunto(s)
Helmintiasis/prevención & control , Helmintiasis/transmisión , Parasitosis Intestinales/prevención & control , Parasitosis Intestinales/transmisión , Zoonosis/prevención & control , Zoonosis/transmisión , Animales , Asia Sudoriental , Helmintiasis/parasitología , Helmintos/fisiología , Humanos , Parasitosis Intestinales/parasitología , Factores de Riesgo , Zoonosis/parasitología
3.
J Infect Dis ; 217(7): 1099-1109, 2018 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-29325068

RESUMEN

As part of a longitudinal cohort investigation of intestinal schistosomiasis and malaria in Ugandan children and their mothers on the shorelines of Lakes Victoria and Albert, we documented risk factors and morbidity associated with nonfalciparum Plasmodium infections and the longitudinal dynamics of Plasmodium species in children. Host age, household location, and Plasmodium falciparum infection were strongly associated with nonfalciparum Plasmodium infections, and Plasmodium malariae infection was associated with splenomegaly. Despite regular artemisinin combination therapy treatment, there was a 3-fold rise in P. malariae prevalence, which was not accountable for by increasing age of the child. Worryingly, our findings reveal the consistent emergence of nonfalciparum infections in children, highlighting the complex dynamics underlying multispecies infections here. Given the growing body of evidence that nonfalciparum malaria infections cause significant morbidity, we encourage better surveillance for nonfalciparum Plasmodium infections, particularly in children, with more sensitive DNA detection methods and improved field-based diagnostics.


Asunto(s)
Antimaláricos/uso terapéutico , Artemisininas/uso terapéutico , Malaria/prevención & control , Malaria/parasitología , Plasmodium/clasificación , Adolescente , Adulto , Antimaláricos/administración & dosificación , Artemisininas/administración & dosificación , Niño , Preescolar , Quimioterapia Combinada , Femenino , Humanos , Lactante , Estudios Longitudinales , Malaria/epidemiología , Masculino , Persona de Mediana Edad , Plasmodium/aislamiento & purificación , Factores de Riesgo , Uganda/epidemiología , Adulto Joven
5.
J Zoo Wildl Med ; 48(1): 1-6, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28363058

RESUMEN

Between 1996 and 2013, 71 blue-crowned laughingthrush (Dryonastes courtoisi) chicks, a small passerine bird endemic to China, were born at Mulhouse Zoo in northeast France. None of them survived past 1 yr, and 82% died between 0 and 6 days old of an unidentified cause and despite an attempt to establish an artificial breeding protocol. Atoxoplasma spp., causing a disease known as systemic isosporosis, is a coccidian parasite that can infect several species of birds. Mulhouse's adult birds were suspected to be infected with Atoxoplasma spp. and to transmit this parasite to their offspring. A treatment with toltrazuril (Baycox® 2.5%) was implemented in the four adult birds. Coprologic examinations were performed before, during, and after the treatment to quantify the parasite load in feces. Polymerase chain reaction (PCR) assays were used to test blood samples from the adult and liver, lung, gizzard, and kidney samples from 10 chicks to detect Atoxoplasma spp. Five of the 10 chicks had some tissue samples positive for Atoxoplasma spp. in at least one of the three repeats of the atoxoplasmosis PCR. An average of 181 Isospora spp. oocysts per gram of feces were found in the group of adults before treatment. This number was reduced to zero 1 wk after the beginning of the toltrazuril treatment. The PCR results suggest a transovarian transmission of Atoxoplasma spp., but further investigation is needed for confirmation. The treatment with toltrazuril appears to allow a significant reduction of the parasite excretion.


Asunto(s)
Enfermedades de las Aves/parasitología , Coccidios/aislamiento & purificación , Coccidiosis/veterinaria , Passeriformes , Animales , Animales de Zoológico , Enfermedades de las Aves/prevención & control , Coccidiosis/parasitología , Coccidiosis/prevención & control , Coccidiostáticos/farmacología , Femenino , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Triazinas/farmacología
6.
Infect Genet Evol ; 48: 4-9, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27939588

RESUMEN

Ascaris lumbricoides and A. suum are two parasitic nematodes infecting humans and pigs, respectively. There has been considerable debate as to whether Ascaris in the two hosts should be considered a single or two separate species. Previous studies identified at least three major clusters (A, B and C) of human and pig Ascaris based on partial cox1 sequences. In the present study, we selected major haplotypes from these different clusters to characterize their whole mitochondrial genomes for phylogenetic analysis. We also undertook coalescent simulations to investigate the evolutionary history of the different Ascaris haplotypes. The topology of the phylogenetic tree based on complete mitochondrial genomic sequences was found to be similar to partial cox1 sequencing, but the support at internal nodes was higher in the former. Coalescent simulations suggested the presence of at least two divergence events: the first one occurring early in the Neolithic period which resulted in a differentiated population of Ascaris in pigs (cluster C), the second occurring more recently (~900 generations ago), resulting in clusters A and B which might have been spread worldwide by human activities.


Asunto(s)
Ascaris lumbricoides/genética , Genoma Mitocondrial , Animales , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/genética , Proteínas del Helminto/genética , Humanos , Tipificación de Secuencias Multilocus , Filogenia , Porcinos
7.
Parasitology ; 144(1): 26-36, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27609615

RESUMEN

The complexity and connectedness of eco-social processes have major influence on the emergence and spread of infectious diseases amongst humans and animals. The disciplinary nature of most research activity has made it difficult to improve our understanding of interactions and feedback loops within the relevant systems. Influenced by the One Health approach, increasing efforts have recently been made to address this knowledge gap. Disease emergence and spread is strongly influenced by host density and contact structures, pathogen characteristics and pathogen population and molecular evolutionary dynamics in different host species, and host response to infection. All these mechanisms are strongly influenced by eco-social processes, such as globalization and urbanization, which lead to changes in global ecosystem dynamics, including patterns of mobility, human population density and contact structures, and food production and consumption. An improved understanding of epidemiological and eco-social processes, including their interdependence, will be essential to be able to manage diseases in these circumstances. The interfaces between wild animals, domestic animals and humans need to be examined to identify the main risk pathways and put in place appropriate mitigation. Some recent examples of emerging infectious disease are described to illustrate eco-social processes that are influencing disease emergence and spread.


Asunto(s)
Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/transmisión , Ecosistema , Factores Sociológicos , Zoonosis/epidemiología , Animales , Animales Domésticos , Animales Salvajes , Evolución Biológica , Salud Global , Humanos , Internacionalidad , Urbanización , Zoonosis/transmisión
8.
Parasitology ; 144(1): 1-6, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27573469

RESUMEN

The field of parasitism is broad, encompassing relationships between organisms where one benefits at the expense of another. Traditionally the discipline focuses on eukaryotes, with the study of bacteria and viruses complementary but distinct. Nonetheless, parasites vary in size and complexity from single celled protozoa, to enormous plants like those in the genus Rafflesia. Lifecycles range from obligate intracellular to extensive exoparasitism. Examples of parasites include high-profile medical and zoonotic pathogens such as Plasmodium, veterinary pathogens of wild and captive animals and many of the agents which cause neglected tropical diseases, stretching to parasites which infect plants and other parasites (e.g. Kikuchi et al. 2011; Hotez et al. 2014; Blake et al. 2015; Hemingway, 2015; Meekums et al. 2015; Sandlund et al. 2015). The breadth of parasitology has been matched by the variety of ways in which parasites are studied, drawing upon biological, chemical, molecular, epidemiological and other expertise. Despite such breadth bridging between disciplines has commonly been problematic, regardless of extensive encouragement from government agencies, peer audiences and funding bodies promoting multidisciplinary research. Now, progress in understanding and collaboration can benefit from establishment of the One Health concept (Zinsstag et al. 2012; Stark et al. 2015). One Health draws upon biological, environmental, medical, veterinary and social science disciplines in order to improve human, animal and environmental health, although it remains tantalizingly difficult to engage many relevant parties. For infectious diseases traditional divides have been exacerbated as the importance of wildlife reservoirs, climate change, food production systems and socio-economic diversity have been recognized but often not addressed in a multidisciplinary manner. In response the 2015 Autumn Symposium organized by the British Society for Parasitology (BSP; https://www.bsp.uk.net/home/) was focused on One Health, running under the title 'One Health: parasites and beyond…'. The meeting, held at the Royal Veterinary College (RVC) in Camden, London from September 14th to 15th, drew upon a blend of specialist parasitology reinforced with additional complementary expertise. Scientists, advocates, policy makers and industry representatives were invited to present at the meeting, promoting and developing One Health understanding with relevance to parasitology. The decision to widen the scope of the meeting to non-parasitological, but informative topics, is reflected in the diversity of the articles included in this special issue. A key feature of the meeting was encouragement of early career scientists, with more than 35% of the delegates registered as students and 25 posters.


Asunto(s)
Salud Global , Parásitos/clasificación , Parásitos/patogenicidad , Enfermedades Parasitarias , Animales , Animales Salvajes/parasitología , Cambio Climático , Enfermedades Transmisibles/parasitología , Ambiente , Humanos , Parásitos/crecimiento & desarrollo , Medicina Tropical
10.
Parasit Vectors ; 9: 37, 2016 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-26800683

RESUMEN

BACKGROUND: Trichuris suis and T. trichiura are two different whipworm species that infect pigs and humans, respectively. T. suis is found in pigs worldwide while T. trichiura is responsible for nearly 460 million infections in people, mainly in areas of poor sanitation in tropical and subtropical areas. The evolutionary relationship and the historical factors responsible for this worldwide distribution are poorly understood. In this study, we aimed to reconstruct the demographic history of Trichuris in humans and pigs, the evolutionary origin of Trichuris in these hosts and factors responsible for parasite dispersal globally. METHODS: Parts of the mitochondrial nad1 and rrnL genes were sequenced followed by population genetic and phylogenetic analyses. Populations of Trichuris examined were recovered from humans (n = 31), pigs (n = 58) and non-human primates (n = 49) in different countries on different continents, namely Denmark, USA, Uganda, Ecuador, China and St. Kitts (Caribbean). Additional sequences available from GenBank were incorporated into the analyses. RESULTS: We found no differentiation between human-derived Trichuris in Uganda and the majority of the Trichuris samples from non-human primates suggesting a common African origin of the parasite, which then was transmitted to Asia and further to South America. On the other hand, there was no differentiation between pig-derived Trichuris from Europe and the New World suggesting dispersal relates to human activities by transporting pigs and their parasites through colonisation and trade. Evidence for recent pig transport from China to Ecuador and from Europe to Uganda was also observed from their parasites. In contrast, there was high genetic differentiation between the pig Trichuris in Denmark and China in concordance with the host genetics. CONCLUSIONS: We found evidence for an African origin of T. trichiura which were then transmitted with human ancestors to Asia and further to South America. A host shift to pigs may have occurred in Asia from where T. suis seems to have been transmitted globally by a combination of natural host dispersal and anthropogenic factors.


Asunto(s)
Enfermedades de los Porcinos/parasitología , Tricuriasis/parasitología , Trichuris/genética , Animales , Secuencia de Bases , Evolución Biológica , China , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Mitocondrial/química , ADN Mitocondrial/genética , Demografía , Dinamarca , Ecuador , Genética de Población , Humanos , Datos de Secuencia Molecular , Filogenia , Primates , Análisis de Secuencia de ADN , Porcinos , Trichuris/aislamiento & purificación , Uganda , Estados Unidos
11.
J Infect Dis ; 213(5): 784-7, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26433222

RESUMEN

Although asymptomatic carriage of human malaria species has been widely reported, the extent of asymptomatic, submicroscopic Plasmodium knowlesi parasitemia is unknown. In this study, samples were obtained from individuals residing in households or villages of symptomatic malaria cases with the aim of detecting submicroscopic P. knowlesi in this population. Four published molecular assays were used to confirm the presence of P. knowlesi. Latent class analysis revealed that the estimated proportion of asymptomatic individuals was 6.9% (95% confidence interval, 5.6%-8.4%). This study confirms the presence of a substantial number of asymptomatic monoinfections across all age groups; further work is needed to estimate prevalence in the wider community.


Asunto(s)
Portador Sano , Malaria/epidemiología , Malaria/parasitología , Plasmodium knowlesi , Adolescente , Adulto , Composición Familiar , Femenino , Humanos , Malasia/epidemiología , Masculino , Persona de Mediana Edad , Adulto Joven
12.
Parasit Vectors ; 8: 168, 2015 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-25889461

RESUMEN

BACKGROUND: Since the nematodes Trichuris trichiura and T. suis are morphologically indistinguishable, genetic analysis is required to assess epidemiological cross-over between people and pigs. This study aimed to clarify the transmission biology of trichuriasis in Ecuador. FINDINGS: Adult Trichuris worms were collected during a parasitological survey of 132 people and 46 pigs in Esmeraldas Province, Ecuador. Morphometric analysis of 49 pig worms and 64 human worms revealed significant variation. In discriminant analysis morphometric characteristics correctly classified male worms according to host species. In PCR-RFLP analysis of the ribosomal Internal Transcribed Spacer (ITS-2) and 18S DNA (59 pig worms and 82 human worms), nearly all Trichuris exhibited expected restriction patterns. However, two pig-derived worms showed a "heterozygous-type" ITS-2 pattern, with one also having a "heterozygous-type" 18S pattern. Phylogenetic analysis of the mitochondrial large ribosomal subunit partitioned worms by host species. Notably, some Ecuadorian T. suis clustered with porcine Trichuris from USA and Denmark and some with Chinese T. suis. CONCLUSION: This is the first study in Latin America to genetically analyse Trichuris parasites. Although T. trichiura does not appear to be zoonotic in Ecuador, there is evidence of genetic exchange between T. trichiura and T. suis warranting more detailed genetic sampling.


Asunto(s)
Tricuriasis/veterinaria , Trichuris/genética , Zoonosis , Albendazol/uso terapéutico , Animales , Antihelmínticos/uso terapéutico , Ecuador/epidemiología , Humanos , Filogenia , Pamoato de Pirantel/uso terapéutico , Población Rural , Tricuriasis/epidemiología , Tricuriasis/parasitología , Tricuriasis/transmisión
13.
Biomed Res Int ; 2015: 717261, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25705680

RESUMEN

This study documented the population dynamics of Biomphalaria and associated natural infections with digenetic trematodes, along the shores of Lake Albert and Lake Victoria, recording local physicochemical factors. Over a two-and-a-half-year study period with monthly sampling, physicochemical factors were measured at 12 survey sites and all freshwater snails were collected. Retained Biomphalaria were subsequently monitored in laboratory aquaria for shedding trematode cercariae, which were classified as either human infective (Schistosoma mansoni) or nonhuman infective. The population dynamics of Biomphalaria differed by location and by lake and had positive relationship with pH (P < 0.001) in both lakes and negative relationship with conductivity (P = 0.04) in Lake Albert. Of the Biomphalaria collected in Lake Albert (N = 6,183), 8.9% were infected with digenetic trematodes of which 15.8% were shedding S. mansoni cercariae and 84.2% with nonhuman infective cercariae. In Lake Victoria, 2.1% of collected Biomphalaria (N = 13,172) were infected with digenetic trematodes with 13.9% shedding S. mansoni cercariae, 85.7% shedding nonhuman infective cercariae, and 0.4% of infected snails shedding both types of cercariae. Upon morphological identification, species of Biomphalaria infected included B. sudanica, B. pfeifferi, and B. stanleyi in Lake Albert and B. sudanica, B. pfeifferi, and B. choanomphala in Lake Victoria. The study found the physicochemical factors that influenced Biomphalaria population and infections. The number and extent of snails shedding S. mansoni cercariae illustrate the high risk of transmission within these lake settings. For better control of this disease, greater effort should be placed on reducing environmental contamination by improvement of local water sanitation and hygiene.


Asunto(s)
Biomphalaria/genética , Dinámica Poblacional , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/epidemiología , Animales , Biomphalaria/patogenicidad , Humanos , Lagos/parasitología , Schistosoma mansoni/genética , Esquistosomiasis mansoni/genética , Esquistosomiasis mansoni/parasitología , Uganda/epidemiología
14.
Parasitology ; 141(14): 1947-61, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25158604

RESUMEN

Within the World Health Organization 2012-2020 roadmap for control and elimination of schistosomiasis, the scale-up of mass drug administration with praziquantel is set to change the epidemiological landscape across Africa and Arabia. Central in measuring progress is renewed emphasis upon diagnostics which operate at individual, community and environmental levels by assessing reductions in disease, infections and parasite transmission. However, a fundamental tension is revealed between levels for present diagnostic tools, and methods applied in control settings are not necessarily adequate for application in elimination scenarios. Indeed navigating the transition from control to elimination needs careful consideration and planning. In the present context of control, we review current options for diagnosis of schistosomiasis at different levels, highlighting several strengths and weaknesses therein. Future challenges in elimination are raised and we propose that more cost-effective diagnostics and clinical staging algorithms are needed. Using the Kingdom of Saudi Arabia as a contemporary example, embedding new diagnostic methods within the primary care health system is discussed with reference to both urogenital and intestinal schistosomiasis.


Asunto(s)
Antihelmínticos/administración & dosificación , Pruebas Diagnósticas de Rutina/métodos , Praziquantel/administración & dosificación , Schistosoma/aislamiento & purificación , Esquistosomiasis/diagnóstico , África/epidemiología , Animales , Pruebas Diagnósticas de Rutina/economía , Erradicación de la Enfermedad/economía , Erradicación de la Enfermedad/métodos , Femenino , Humanos , Masculino , Arabia Saudita/epidemiología , Schistosoma/efectos de los fármacos , Esquistosomiasis/tratamiento farmacológico , Esquistosomiasis/epidemiología , Esquistosomiasis/prevención & control , Factores de Tiempo
15.
Parasitology ; 141(14): 1880-90, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24837880

RESUMEN

During a longitudinal study investigating the dynamics of malaria in Ugandan lakeshore communities, a consistently high malaria prevalence was observed in young children despite regular treatment. To explore the short-term performance of artemether-lumefantrine (AL), a pilot investigation into parasite carriage after treatment(s) was conducted in Bukoba village. A total of 163 children (aged 2-7 years) with a positive blood film and rapid antigen test were treated with AL; only 8.7% of these had elevated axillary temperatures. On day 7 and then on day 17, 40 children (26.3%) and 33 (22.3%) were positive by microscopy, respectively. Real-time PCR analysis demonstrated that multi-species Plasmodium infections were common at baseline, with 41.1% of children positive for Plasmodium falciparum/Plasmodium malariae, 9.2% for P. falciparum/ Plasmodium ovale spp. and 8.0% for all three species. Moreover, on day 17, 39.9% of children infected with falciparum malaria at baseline were again positive for the same species, and 9.2% of those infected with P. malariae at baseline were positive for P. malariae. Here, chronic multi-species malaria infections persisted in children after AL treatment(s). Better point-of-care diagnostics for non-falciparum infections are needed, as well as further investigation of AL performance in asymptomatic individuals.


Asunto(s)
Antimaláricos/uso terapéutico , Artemisininas/uso terapéutico , Etanolaminas/uso terapéutico , Fluorenos/uso terapéutico , Malaria/diagnóstico , Plasmodium/aislamiento & purificación , Arteméter , Niño , Preescolar , Coinfección , Pruebas Diagnósticas de Rutina , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Lumefantrina , Malaria/tratamiento farmacológico , Malaria/epidemiología , Malaria/parasitología , Masculino , Plasmodium/genética , Plasmodium/inmunología , Plasmodium falciparum/genética , Plasmodium falciparum/inmunología , Plasmodium falciparum/aislamiento & purificación , Plasmodium ovale/genética , Plasmodium ovale/inmunología , Plasmodium ovale/aislamiento & purificación , Sistemas de Atención de Punto , Prevalencia , Uganda/epidemiología
16.
Parasit Vectors ; 7: 153, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24690282

RESUMEN

BACKGROUND: To complement ongoing schistosomiasis control within national control programmes (NCPs) that administer praziquantel to school-age children, assessing the risk and extent of schistosomiasis in pre-school-age children (PSAC) is important. METHODS: In June 2012, schistosomiasis in Chikhwawa district, Malawi was assessed across 12 villages examining pre-school-age children (PSAC) and their mothers by serological and parasitological diagnosis, as supplemented with urine-antigen and questionnaire-interview methods. Urinary tract morbidity was inferred by haematuria and albuminuria assays. RESULTS: In total, 49.5% (CI95 42.6-56.4) of 208 PSAC and 94.5% (CI95 90.9-98.1) of 165 mothers were seropositive for schistosomiasis, in 2 villages seroprevalence exceeded 75% in PSAC. Egg-patent urogenital and intestinal schistosomiasis was observed; 17.7% (CI95 12.4-23.2) of PSAC and 45.1% (CI95 37.4-52.8) of mothers having active schistosomiasis by parasitological and urine-antigen testing combined. PSAC often had extensive daily water contact and many (~25%) had haematuria and albuminuria. As eggs with an atypical morphology of Schistosoma haematobium were observed, a general selection of schistosome eggs was characterized by DNA barcoding, finding Group I S. haematobium and Group IV and V S. mansoni. Malacological surveys encountered several populations of Bulinus globosus but failed to find Biomphalaria. CONCLUSIONS: Both PSAC and their mothers appear to be at significant risk of schistosomiasis and should be considered for treatment within the NCP of Malawi.


Asunto(s)
Schistosoma/genética , Esquistosomiasis/epidemiología , Caracoles/clasificación , Adolescente , Adulto , Envejecimiento , Animales , Antihelmínticos/administración & dosificación , Antihelmínticos/uso terapéutico , Preescolar , Femenino , Humanos , Lactante , Malaui/epidemiología , Masculino , Persona de Mediana Edad , Praziquantel/administración & dosificación , Praziquantel/uso terapéutico , Prevalencia , Schistosoma/clasificación , Esquistosomiasis/tratamiento farmacológico , Caracoles/parasitología , Caracoles/fisiología
17.
J Infect Dis ; 210(6): 932-41, 2014 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-24688073

RESUMEN

BACKGROUND: The roundworm Ascaris lumbricoides infects 0.8 billion people worldwide, and Ascaris suum infects innumerable pigs across the globe. The extent of natural cross-transmission of Ascaris between pig and human hosts in different geographical settings is unknown, warranting investigation. METHODS: Adult Ascaris organisms were obtained from humans and pigs in Europe, Africa, Asia, and Latin America. Barcodes were assigned to 536 parasites on the basis of sequence analysis of the mitochondrial cytochrome c oxidase I gene. Genotyping of 410 worms was also conducted using a panel of microsatellite markers. Phylogenetic, population genetic, and Bayesian assignment methods were used for analysis. RESULTS: There was marked genetic segregation between worms originating from human hosts and those originating from pig hosts. However, human Ascaris infections in Europe were of pig origin, and there was evidence of cross-transmission between humans and pigs in Africa. Significant genetic differentiation exists between parasite populations from different countries, villages, and hosts. CONCLUSIONS: In conducting an analysis of variation within Ascaris populations from pig and human hosts across the globe, we demonstrate that cross-transmission takes place in developing and developed countries, contingent upon epidemiological potential and local phylogeography. Our results provide novel insights into the transmission dynamics and speciation of Ascaris worms from humans and pigs that are of importance for control programs.


Asunto(s)
Ascariasis/epidemiología , Epidemiología Molecular , Enfermedades de los Porcinos/epidemiología , Animales , Ascariasis/veterinaria , Ascaris/genética , Ciclooxigenasa 1/genética , ADN de Helmintos/genética , Haplotipos/genética , Humanos , Repeticiones de Microsatélite/genética , Porcinos , Enfermedades de los Porcinos/parasitología , Zoonosis/epidemiología , Zoonosis/genética , Zoonosis/parasitología
18.
Lancet Infect Dis ; 14(7): 640-9, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24747019

RESUMEN

HIV/AIDS and schistosomiasis both cause a substantial disease burden in sub-Saharan Africa and the two diseases often overlap in their epidemiological characteristics. Although disease-specific control interventions are continuing, potential synergies in the control efforts for these two diseases have not been investigated. With a focus on children with schistosomiasis, we assess the risk for increased HIV transmission, HIV progression, and impaired response to drugs when given alongside HIV interventions. A new research agenda tailored to children is needed to better understand the interactions of these two diseases and the potential for combined responses.


Asunto(s)
Coinfección/parasitología , Coinfección/virología , Infecciones por VIH/parasitología , Esquistosomiasis/virología , África/epidemiología , Niño , Coinfección/epidemiología , Coinfección/prevención & control , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Humanos , Factores de Riesgo , Esquistosomiasis/epidemiología , Esquistosomiasis/parasitología , Esquistosomiasis/prevención & control
19.
PLoS Negl Trop Dis ; 7(12): e2561, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24349589

RESUMEN

Significant numbers of pre-school children are infected with Schistosoma mansoni in sub-Saharan Africa and are likely to play a role in parasite transmission. However, they are currently excluded from control programmes. Molecular phylogenetic studies have provided insights into the evolutionary origins and transmission dynamics of S. mansoni, but there has been no research into schistosome molecular epidemiology in pre-school children. Here, we investigated the genetic diversity and population structure of S. mansoni in pre-school children and mothers living in lakeshore communities in Uganda and monitored for changes over time after praziquantel treatment. Parasites were sampled from children (<6 years) and mothers enrolled in the longitudinal Schistosomiasis Mothers and Infants Study at baseline and at 6-, 12- and 18-month follow-up surveys. 1347 parasites from 35 mothers and 45 children were genotyped by direct sequencing of the cytochrome c oxidase (cox1) gene. The cox1 region was highly diverse with over 230 unique sequences identified. Parasite populations were genetically differentiated between lakes and non-synonymous mutations were more diverse at Lake Victoria than Lake Albert. Surprisingly, parasite populations sampled from children showed a similar genetic diversity to those sampled from mothers, pointing towards a non-linear relationship between duration of exposure and accumulation of parasite diversity. The genetic diversity six months after praziquantel treatment was similar to pre-treatment diversity. Our results confirm the substantial genetic diversity of S. mansoni in East Africa and provide significant insights into transmission dynamics within young children and mothers, important information for schistosomiasis control programmes.


Asunto(s)
Variación Genética , Schistosoma mansoni/clasificación , Schistosoma mansoni/genética , Esquistosomiasis mansoni/epidemiología , Esquistosomiasis mansoni/parasitología , África , Animales , Antihelmínticos/uso terapéutico , Preescolar , Complejo IV de Transporte de Electrones/genética , Salud de la Familia , Femenino , Genética de Población , Genotipo , Humanos , Lactante , Estudios Longitudinales , Masculino , Epidemiología Molecular , Datos de Secuencia Molecular , Madres , Praziquantel/uso terapéutico , Schistosoma mansoni/aislamiento & purificación , Esquistosomiasis mansoni/tratamiento farmacológico , Análisis de Secuencia de ADN , Uganda/epidemiología
20.
PLoS Negl Trop Dis ; 7(11): e2542, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24244777

RESUMEN

BACKGROUND: Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB) is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ). METHODS: 216 children (ages 3-9 years old) from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH). POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression. RESULTS: Fecal calprotectin concentrations of 150-300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02). FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03) and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003). Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline. CONCLUSIONS: Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after treatment.


Asunto(s)
Heces/parasitología , Complejo de Antígeno L1 de Leucocito/sangre , Sangre Oculta , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/sangre , Animales , Niño , Preescolar , Femenino , Humanos , Intestinos/parasitología , Masculino , Esquistosomiasis mansoni/parasitología
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